1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
  23  */
  24 /*
  25  * Copyright (c) 2010, Intel Corporation.
  26  * All rights reserved.
  27  */
  28 /*
  29  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  30  * Copyright (c) 2014, 2015 by Delphix. All rights reserved.
  31  * Copyright 2014 Joyent, Inc.  All rights reserved.
  32  */
  33 
  34 /*
  35  * VM - Hardware Address Translation management for i386 and amd64
  36  *
  37  * Implementation of the interfaces described in <common/vm/hat.h>
  38  *
  39  * Nearly all the details of how the hardware is managed should not be
  40  * visible outside this layer except for misc. machine specific functions
  41  * that work in conjunction with this code.
  42  *
  43  * Routines used only inside of i86pc/vm start with hati_ for HAT Internal.
  44  */
  45 
  46 #include <sys/machparam.h>
  47 #include <sys/machsystm.h>
  48 #include <sys/mman.h>
  49 #include <sys/types.h>
  50 #include <sys/systm.h>
  51 #include <sys/cpuvar.h>
  52 #include <sys/thread.h>
  53 #include <sys/proc.h>
  54 #include <sys/cpu.h>
  55 #include <sys/kmem.h>
  56 #include <sys/disp.h>
  57 #include <sys/shm.h>
  58 #include <sys/sysmacros.h>
  59 #include <sys/machparam.h>
  60 #include <sys/vmem.h>
  61 #include <sys/vmsystm.h>
  62 #include <sys/promif.h>
  63 #include <sys/var.h>
  64 #include <sys/x86_archext.h>
  65 #include <sys/atomic.h>
  66 #include <sys/bitmap.h>
  67 #include <sys/controlregs.h>
  68 #include <sys/bootconf.h>
  69 #include <sys/bootsvcs.h>
  70 #include <sys/bootinfo.h>
  71 #include <sys/archsystm.h>
  72 
  73 #include <vm/seg_kmem.h>
  74 #include <vm/hat_i86.h>
  75 #include <vm/as.h>
  76 #include <vm/seg.h>
  77 #include <vm/page.h>
  78 #include <vm/seg_kp.h>
  79 #include <vm/seg_kpm.h>
  80 #include <vm/vm_dep.h>
  81 #ifdef __xpv
  82 #include <sys/hypervisor.h>
  83 #endif
  84 #include <vm/kboot_mmu.h>
  85 #include <vm/seg_spt.h>
  86 
  87 #include <sys/cmn_err.h>
  88 
  89 /*
  90  * Basic parameters for hat operation.
  91  */
  92 struct hat_mmu_info mmu;
  93 
  94 /*
  95  * The page that is the kernel's top level pagetable.
  96  *
  97  * For 32 bit PAE support on i86pc, the kernel hat will use the 1st 4 entries
  98  * on this 4K page for its top level page table. The remaining groups of
  99  * 4 entries are used for per processor copies of user VLP pagetables for
 100  * running threads.  See hat_switch() and reload_pae32() for details.
 101  *
 102  * vlp_page[0..3] - level==2 PTEs for kernel HAT
 103  * vlp_page[4..7] - level==2 PTEs for user thread on cpu 0
 104  * vlp_page[8..11]  - level==2 PTE for user thread on cpu 1
 105  * etc...
 106  */
 107 static x86pte_t *vlp_page;
 108 
 109 /*
 110  * forward declaration of internal utility routines
 111  */
 112 static x86pte_t hati_update_pte(htable_t *ht, uint_t entry, x86pte_t expected,
 113         x86pte_t new);
 114 
 115 /*
 116  * The kernel address space exists in all HATs. To implement this the
 117  * kernel reserves a fixed number of entries in the topmost level(s) of page
 118  * tables. The values are setup during startup and then copied to every user
 119  * hat created by hat_alloc(). This means that kernelbase must be:
 120  *
 121  *        4Meg aligned for 32 bit kernels
 122  *      512Gig aligned for x86_64 64 bit kernel
 123  *
 124  * The hat_kernel_range_ts describe what needs to be copied from kernel hat
 125  * to each user hat.
 126  */
 127 typedef struct hat_kernel_range {
 128         level_t         hkr_level;
 129         uintptr_t       hkr_start_va;
 130         uintptr_t       hkr_end_va;     /* zero means to end of memory */
 131 } hat_kernel_range_t;
 132 #define NUM_KERNEL_RANGE 2
 133 static hat_kernel_range_t kernel_ranges[NUM_KERNEL_RANGE];
 134 static int num_kernel_ranges;
 135 
 136 uint_t use_boot_reserve = 1;    /* cleared after early boot process */
 137 uint_t can_steal_post_boot = 0; /* set late in boot to enable stealing */
 138 
 139 /*
 140  * enable_1gpg: controls 1g page support for user applications.
 141  * By default, 1g pages are exported to user applications. enable_1gpg can
 142  * be set to 0 to not export.
 143  */
 144 int     enable_1gpg = 1;
 145 
 146 /*
 147  * AMD shanghai processors provide better management of 1gb ptes in its tlb.
 148  * By default, 1g page support will be disabled for pre-shanghai AMD
 149  * processors that don't have optimal tlb support for the 1g page size.
 150  * chk_optimal_1gtlb can be set to 0 to force 1g page support on sub-optimal
 151  * processors.
 152  */
 153 int     chk_optimal_1gtlb = 1;
 154 
 155 
 156 #ifdef DEBUG
 157 uint_t  map1gcnt;
 158 #endif
 159 
 160 
 161 /*
 162  * A cpuset for all cpus. This is used for kernel address cross calls, since
 163  * the kernel addresses apply to all cpus.
 164  */
 165 cpuset_t khat_cpuset;
 166 
 167 /*
 168  * management stuff for hat structures
 169  */
 170 kmutex_t        hat_list_lock;
 171 kcondvar_t      hat_list_cv;
 172 kmem_cache_t    *hat_cache;
 173 kmem_cache_t    *hat_hash_cache;
 174 kmem_cache_t    *vlp_hash_cache;
 175 
 176 /*
 177  * Simple statistics
 178  */
 179 struct hatstats hatstat;
 180 
 181 /*
 182  * Some earlier hypervisor versions do not emulate cmpxchg of PTEs
 183  * correctly.  For such hypervisors we must set PT_USER for kernel
 184  * entries ourselves (normally the emulation would set PT_USER for
 185  * kernel entries and PT_USER|PT_GLOBAL for user entries).  pt_kern is
 186  * thus set appropriately.  Note that dboot/kbm is OK, as only the full
 187  * HAT uses cmpxchg() and the other paths (hypercall etc.) were never
 188  * incorrect.
 189  */
 190 int pt_kern;
 191 
 192 /*
 193  * useful stuff for atomic access/clearing/setting REF/MOD/RO bits in page_t's.
 194  */
 195 extern void atomic_orb(uchar_t *addr, uchar_t val);
 196 extern void atomic_andb(uchar_t *addr, uchar_t val);
 197 
 198 #ifndef __xpv
 199 extern pfn_t memseg_get_start(struct memseg *);
 200 #endif
 201 
 202 #define PP_GETRM(pp, rmmask)    (pp->p_nrm & rmmask)
 203 #define PP_ISMOD(pp)            PP_GETRM(pp, P_MOD)
 204 #define PP_ISREF(pp)            PP_GETRM(pp, P_REF)
 205 #define PP_ISRO(pp)             PP_GETRM(pp, P_RO)
 206 
 207 #define PP_SETRM(pp, rm)        atomic_orb(&(pp->p_nrm), rm)
 208 #define PP_SETMOD(pp)           PP_SETRM(pp, P_MOD)
 209 #define PP_SETREF(pp)           PP_SETRM(pp, P_REF)
 210 #define PP_SETRO(pp)            PP_SETRM(pp, P_RO)
 211 
 212 #define PP_CLRRM(pp, rm)        atomic_andb(&(pp->p_nrm), ~(rm))
 213 #define PP_CLRMOD(pp)           PP_CLRRM(pp, P_MOD)
 214 #define PP_CLRREF(pp)           PP_CLRRM(pp, P_REF)
 215 #define PP_CLRRO(pp)            PP_CLRRM(pp, P_RO)
 216 #define PP_CLRALL(pp)           PP_CLRRM(pp, P_MOD | P_REF | P_RO)
 217 
 218 /*
 219  * kmem cache constructor for struct hat
 220  */
 221 /*ARGSUSED*/
 222 static int
 223 hati_constructor(void *buf, void *handle, int kmflags)
 224 {
 225         hat_t   *hat = buf;
 226 
 227         mutex_init(&hat->hat_mutex, NULL, MUTEX_DEFAULT, NULL);
 228         bzero(hat->hat_pages_mapped,
 229             sizeof (pgcnt_t) * (mmu.max_page_level + 1));
 230         hat->hat_ism_pgcnt = 0;
 231         hat->hat_stats = 0;
 232         hat->hat_flags = 0;
 233         CPUSET_ZERO(hat->hat_cpus);
 234         hat->hat_htable = NULL;
 235         hat->hat_ht_hash = NULL;
 236         return (0);
 237 }
 238 
 239 /*
 240  * Allocate a hat structure for as. We also create the top level
 241  * htable and initialize it to contain the kernel hat entries.
 242  */
 243 hat_t *
 244 hat_alloc(struct as *as)
 245 {
 246         hat_t                   *hat;
 247         htable_t                *ht;    /* top level htable */
 248         uint_t                  use_vlp;
 249         uint_t                  r;
 250         hat_kernel_range_t      *rp;
 251         uintptr_t               va;
 252         uintptr_t               eva;
 253         uint_t                  start;
 254         uint_t                  cnt;
 255         htable_t                *src;
 256 
 257         /*
 258          * Once we start creating user process HATs we can enable
 259          * the htable_steal() code.
 260          */
 261         if (can_steal_post_boot == 0)
 262                 can_steal_post_boot = 1;
 263 
 264         ASSERT(AS_WRITE_HELD(as));
 265         hat = kmem_cache_alloc(hat_cache, KM_SLEEP);
 266         hat->hat_as = as;
 267         mutex_init(&hat->hat_mutex, NULL, MUTEX_DEFAULT, NULL);
 268         ASSERT(hat->hat_flags == 0);
 269 
 270 #if defined(__xpv)
 271         /*
 272          * No VLP stuff on the hypervisor due to the 64-bit split top level
 273          * page tables.  On 32-bit it's not needed as the hypervisor takes
 274          * care of copying the top level PTEs to a below 4Gig page.
 275          */
 276         use_vlp = 0;
 277 #else   /* __xpv */
 278         /* 32 bit processes uses a VLP style hat when running with PAE */
 279 #if defined(__amd64)
 280         use_vlp = (ttoproc(curthread)->p_model == DATAMODEL_ILP32);
 281 #elif defined(__i386)
 282         use_vlp = mmu.pae_hat;
 283 #endif
 284 #endif  /* __xpv */
 285         if (use_vlp) {
 286                 hat->hat_flags = HAT_VLP;
 287                 bzero(hat->hat_vlp_ptes, VLP_SIZE);
 288         }
 289 
 290         /*
 291          * Allocate the htable hash
 292          */
 293         if ((hat->hat_flags & HAT_VLP)) {
 294                 hat->hat_num_hash = mmu.vlp_hash_cnt;
 295                 hat->hat_ht_hash = kmem_cache_alloc(vlp_hash_cache, KM_SLEEP);
 296         } else {
 297                 hat->hat_num_hash = mmu.hash_cnt;
 298                 hat->hat_ht_hash = kmem_cache_alloc(hat_hash_cache, KM_SLEEP);
 299         }
 300         bzero(hat->hat_ht_hash, hat->hat_num_hash * sizeof (htable_t *));
 301 
 302         /*
 303          * Initialize Kernel HAT entries at the top of the top level page
 304          * tables for the new hat.
 305          */
 306         hat->hat_htable = NULL;
 307         hat->hat_ht_cached = NULL;
 308         XPV_DISALLOW_MIGRATE();
 309         ht = htable_create(hat, (uintptr_t)0, TOP_LEVEL(hat), NULL);
 310         hat->hat_htable = ht;
 311 
 312 #if defined(__amd64)
 313         if (hat->hat_flags & HAT_VLP)
 314                 goto init_done;
 315 #endif
 316 
 317         for (r = 0; r < num_kernel_ranges; ++r) {
 318                 rp = &kernel_ranges[r];
 319                 for (va = rp->hkr_start_va; va != rp->hkr_end_va;
 320                     va += cnt * LEVEL_SIZE(rp->hkr_level)) {
 321 
 322                         if (rp->hkr_level == TOP_LEVEL(hat))
 323                                 ht = hat->hat_htable;
 324                         else
 325                                 ht = htable_create(hat, va, rp->hkr_level,
 326                                     NULL);
 327 
 328                         start = htable_va2entry(va, ht);
 329                         cnt = HTABLE_NUM_PTES(ht) - start;
 330                         eva = va +
 331                             ((uintptr_t)cnt << LEVEL_SHIFT(rp->hkr_level));
 332                         if (rp->hkr_end_va != 0 &&
 333                             (eva > rp->hkr_end_va || eva == 0))
 334                                 cnt = htable_va2entry(rp->hkr_end_va, ht) -
 335                                     start;
 336 
 337 #if defined(__i386) && !defined(__xpv)
 338                         if (ht->ht_flags & HTABLE_VLP) {
 339                                 bcopy(&vlp_page[start],
 340                                     &hat->hat_vlp_ptes[start],
 341                                     cnt * sizeof (x86pte_t));
 342                                 continue;
 343                         }
 344 #endif
 345                         src = htable_lookup(kas.a_hat, va, rp->hkr_level);
 346                         ASSERT(src != NULL);
 347                         x86pte_copy(src, ht, start, cnt);
 348                         htable_release(src);
 349                 }
 350         }
 351 
 352 init_done:
 353 
 354 #if defined(__xpv)
 355         /*
 356          * Pin top level page tables after initializing them
 357          */
 358         xen_pin(hat->hat_htable->ht_pfn, mmu.max_level);
 359 #if defined(__amd64)
 360         xen_pin(hat->hat_user_ptable, mmu.max_level);
 361 #endif
 362 #endif
 363         XPV_ALLOW_MIGRATE();
 364 
 365         /*
 366          * Put it at the start of the global list of all hats (used by stealing)
 367          *
 368          * kas.a_hat is not in the list but is instead used to find the
 369          * first and last items in the list.
 370          *
 371          * - kas.a_hat->hat_next points to the start of the user hats.
 372          *   The list ends where hat->hat_next == NULL
 373          *
 374          * - kas.a_hat->hat_prev points to the last of the user hats.
 375          *   The list begins where hat->hat_prev == NULL
 376          */
 377         mutex_enter(&hat_list_lock);
 378         hat->hat_prev = NULL;
 379         hat->hat_next = kas.a_hat->hat_next;
 380         if (hat->hat_next)
 381                 hat->hat_next->hat_prev = hat;
 382         else
 383                 kas.a_hat->hat_prev = hat;
 384         kas.a_hat->hat_next = hat;
 385         mutex_exit(&hat_list_lock);
 386 
 387         return (hat);
 388 }
 389 
 390 /*
 391  * process has finished executing but as has not been cleaned up yet.
 392  */
 393 /*ARGSUSED*/
 394 void
 395 hat_free_start(hat_t *hat)
 396 {
 397         ASSERT(AS_WRITE_HELD(hat->hat_as));
 398 
 399         /*
 400          * If the hat is currently a stealing victim, wait for the stealing
 401          * to finish.  Once we mark it as HAT_FREEING, htable_steal()
 402          * won't look at its pagetables anymore.
 403          */
 404         mutex_enter(&hat_list_lock);
 405         while (hat->hat_flags & HAT_VICTIM)
 406                 cv_wait(&hat_list_cv, &hat_list_lock);
 407         hat->hat_flags |= HAT_FREEING;
 408         mutex_exit(&hat_list_lock);
 409 }
 410 
 411 /*
 412  * An address space is being destroyed, so we destroy the associated hat.
 413  */
 414 void
 415 hat_free_end(hat_t *hat)
 416 {
 417         kmem_cache_t *cache;
 418 
 419         ASSERT(hat->hat_flags & HAT_FREEING);
 420 
 421         /*
 422          * must not be running on the given hat
 423          */
 424         ASSERT(CPU->cpu_current_hat != hat);
 425 
 426         /*
 427          * Remove it from the list of HATs
 428          */
 429         mutex_enter(&hat_list_lock);
 430         if (hat->hat_prev)
 431                 hat->hat_prev->hat_next = hat->hat_next;
 432         else
 433                 kas.a_hat->hat_next = hat->hat_next;
 434         if (hat->hat_next)
 435                 hat->hat_next->hat_prev = hat->hat_prev;
 436         else
 437                 kas.a_hat->hat_prev = hat->hat_prev;
 438         mutex_exit(&hat_list_lock);
 439         hat->hat_next = hat->hat_prev = NULL;
 440 
 441 #if defined(__xpv)
 442         /*
 443          * On the hypervisor, unpin top level page table(s)
 444          */
 445         xen_unpin(hat->hat_htable->ht_pfn);
 446 #if defined(__amd64)
 447         xen_unpin(hat->hat_user_ptable);
 448 #endif
 449 #endif
 450 
 451         /*
 452          * Make a pass through the htables freeing them all up.
 453          */
 454         htable_purge_hat(hat);
 455 
 456         /*
 457          * Decide which kmem cache the hash table came from, then free it.
 458          */
 459         if (hat->hat_flags & HAT_VLP)
 460                 cache = vlp_hash_cache;
 461         else
 462                 cache = hat_hash_cache;
 463         kmem_cache_free(cache, hat->hat_ht_hash);
 464         hat->hat_ht_hash = NULL;
 465 
 466         hat->hat_flags = 0;
 467         kmem_cache_free(hat_cache, hat);
 468 }
 469 
 470 /*
 471  * round kernelbase down to a supported value to use for _userlimit
 472  *
 473  * userlimit must be aligned down to an entry in the top level htable.
 474  * The one exception is for 32 bit HAT's running PAE.
 475  */
 476 uintptr_t
 477 hat_kernelbase(uintptr_t va)
 478 {
 479 #if defined(__i386)
 480         va &= LEVEL_MASK(1);
 481 #endif
 482         if (IN_VA_HOLE(va))
 483                 panic("_userlimit %p will fall in VA hole\n", (void *)va);
 484         return (va);
 485 }
 486 
 487 /*
 488  *
 489  */
 490 static void
 491 set_max_page_level()
 492 {
 493         level_t lvl;
 494 
 495         if (!kbm_largepage_support) {
 496                 lvl = 0;
 497         } else {
 498                 if (is_x86_feature(x86_featureset, X86FSET_1GPG)) {
 499                         lvl = 2;
 500                         if (chk_optimal_1gtlb &&
 501                             cpuid_opteron_erratum(CPU, 6671130)) {
 502                                 lvl = 1;
 503                         }
 504                         if (plat_mnode_xcheck(LEVEL_SIZE(2) >>
 505                             LEVEL_SHIFT(0))) {
 506                                 lvl = 1;
 507                         }
 508                 } else {
 509                         lvl = 1;
 510                 }
 511         }
 512         mmu.max_page_level = lvl;
 513 
 514         if ((lvl == 2) && (enable_1gpg == 0))
 515                 mmu.umax_page_level = 1;
 516         else
 517                 mmu.umax_page_level = lvl;
 518 }
 519 
 520 /*
 521  * Initialize hat data structures based on processor MMU information.
 522  */
 523 void
 524 mmu_init(void)
 525 {
 526         uint_t max_htables;
 527         uint_t pa_bits;
 528         uint_t va_bits;
 529         int i;
 530 
 531         /*
 532          * If CPU enabled the page table global bit, use it for the kernel
 533          * This is bit 7 in CR4 (PGE - Page Global Enable).
 534          */
 535         if (is_x86_feature(x86_featureset, X86FSET_PGE) &&
 536             (getcr4() & CR4_PGE) != 0)
 537                 mmu.pt_global = PT_GLOBAL;
 538 
 539         /*
 540          * Detect NX and PAE usage.
 541          */
 542         mmu.pae_hat = kbm_pae_support;
 543         if (kbm_nx_support)
 544                 mmu.pt_nx = PT_NX;
 545         else
 546                 mmu.pt_nx = 0;
 547 
 548         /*
 549          * Use CPU info to set various MMU parameters
 550          */
 551         cpuid_get_addrsize(CPU, &pa_bits, &va_bits);
 552 
 553         if (va_bits < sizeof (void *) * NBBY) {
 554                 mmu.hole_start = (1ul << (va_bits - 1));
 555                 mmu.hole_end = 0ul - mmu.hole_start - 1;
 556         } else {
 557                 mmu.hole_end = 0;
 558                 mmu.hole_start = mmu.hole_end - 1;
 559         }
 560 #if defined(OPTERON_ERRATUM_121)
 561         /*
 562          * If erratum 121 has already been detected at this time, hole_start
 563          * contains the value to be subtracted from mmu.hole_start.
 564          */
 565         ASSERT(hole_start == 0 || opteron_erratum_121 != 0);
 566         hole_start = mmu.hole_start - hole_start;
 567 #else
 568         hole_start = mmu.hole_start;
 569 #endif
 570         hole_end = mmu.hole_end;
 571 
 572         mmu.highest_pfn = mmu_btop((1ull << pa_bits) - 1);
 573         if (mmu.pae_hat == 0 && pa_bits > 32)
 574                 mmu.highest_pfn = PFN_4G - 1;
 575 
 576         if (mmu.pae_hat) {
 577                 mmu.pte_size = 8;       /* 8 byte PTEs */
 578                 mmu.pte_size_shift = 3;
 579         } else {
 580                 mmu.pte_size = 4;       /* 4 byte PTEs */
 581                 mmu.pte_size_shift = 2;
 582         }
 583 
 584         if (mmu.pae_hat && !is_x86_feature(x86_featureset, X86FSET_PAE))
 585                 panic("Processor does not support PAE");
 586 
 587         if (!is_x86_feature(x86_featureset, X86FSET_CX8))
 588                 panic("Processor does not support cmpxchg8b instruction");
 589 
 590 #if defined(__amd64)
 591 
 592         mmu.num_level = 4;
 593         mmu.max_level = 3;
 594         mmu.ptes_per_table = 512;
 595         mmu.top_level_count = 512;
 596 
 597         mmu.level_shift[0] = 12;
 598         mmu.level_shift[1] = 21;
 599         mmu.level_shift[2] = 30;
 600         mmu.level_shift[3] = 39;
 601 
 602 #elif defined(__i386)
 603 
 604         if (mmu.pae_hat) {
 605                 mmu.num_level = 3;
 606                 mmu.max_level = 2;
 607                 mmu.ptes_per_table = 512;
 608                 mmu.top_level_count = 4;
 609 
 610                 mmu.level_shift[0] = 12;
 611                 mmu.level_shift[1] = 21;
 612                 mmu.level_shift[2] = 30;
 613 
 614         } else {
 615                 mmu.num_level = 2;
 616                 mmu.max_level = 1;
 617                 mmu.ptes_per_table = 1024;
 618                 mmu.top_level_count = 1024;
 619 
 620                 mmu.level_shift[0] = 12;
 621                 mmu.level_shift[1] = 22;
 622         }
 623 
 624 #endif  /* __i386 */
 625 
 626         for (i = 0; i < mmu.num_level; ++i) {
 627                 mmu.level_size[i] = 1UL << mmu.level_shift[i];
 628                 mmu.level_offset[i] = mmu.level_size[i] - 1;
 629                 mmu.level_mask[i] = ~mmu.level_offset[i];
 630         }
 631 
 632         set_max_page_level();
 633 
 634         mmu_page_sizes = mmu.max_page_level + 1;
 635         mmu_exported_page_sizes = mmu.umax_page_level + 1;
 636 
 637         /* restrict legacy applications from using pagesizes 1g and above */
 638         mmu_legacy_page_sizes =
 639             (mmu_exported_page_sizes > 2) ? 2 : mmu_exported_page_sizes;
 640 
 641 
 642         for (i = 0; i <= mmu.max_page_level; ++i) {
 643                 mmu.pte_bits[i] = PT_VALID | pt_kern;
 644                 if (i > 0)
 645                         mmu.pte_bits[i] |= PT_PAGESIZE;
 646         }
 647 
 648         /*
 649          * NOTE Legacy 32 bit PAE mode only has the P_VALID bit at top level.
 650          */
 651         for (i = 1; i < mmu.num_level; ++i)
 652                 mmu.ptp_bits[i] = PT_PTPBITS;
 653 
 654 #if defined(__i386)
 655         mmu.ptp_bits[2] = PT_VALID;
 656 #endif
 657 
 658         /*
 659          * Compute how many hash table entries to have per process for htables.
 660          * We start with 1 page's worth of entries.
 661          *
 662          * If physical memory is small, reduce the amount need to cover it.
 663          */
 664         max_htables = physmax / mmu.ptes_per_table;
 665         mmu.hash_cnt = MMU_PAGESIZE / sizeof (htable_t *);
 666         while (mmu.hash_cnt > 16 && mmu.hash_cnt >= max_htables)
 667                 mmu.hash_cnt >>= 1;
 668         mmu.vlp_hash_cnt = mmu.hash_cnt;
 669 
 670 #if defined(__amd64)
 671         /*
 672          * If running in 64 bits and physical memory is large,
 673          * increase the size of the cache to cover all of memory for
 674          * a 64 bit process.
 675          */
 676 #define HASH_MAX_LENGTH 4
 677         while (mmu.hash_cnt * HASH_MAX_LENGTH < max_htables)
 678                 mmu.hash_cnt <<= 1;
 679 #endif
 680 }
 681 
 682 
 683 /*
 684  * initialize hat data structures
 685  */
 686 void
 687 hat_init()
 688 {
 689 #if defined(__i386)
 690         /*
 691          * _userlimit must be aligned correctly
 692          */
 693         if ((_userlimit & LEVEL_MASK(1)) != _userlimit) {
 694                 prom_printf("hat_init(): _userlimit=%p, not aligned at %p\n",
 695                     (void *)_userlimit, (void *)LEVEL_SIZE(1));
 696                 halt("hat_init(): Unable to continue");
 697         }
 698 #endif
 699 
 700         cv_init(&hat_list_cv, NULL, CV_DEFAULT, NULL);
 701 
 702         /*
 703          * initialize kmem caches
 704          */
 705         htable_init();
 706         hment_init();
 707 
 708         hat_cache = kmem_cache_create("hat_t",
 709             sizeof (hat_t), 0, hati_constructor, NULL, NULL,
 710             NULL, 0, 0);
 711 
 712         hat_hash_cache = kmem_cache_create("HatHash",
 713             mmu.hash_cnt * sizeof (htable_t *), 0, NULL, NULL, NULL,
 714             NULL, 0, 0);
 715 
 716         /*
 717          * VLP hats can use a smaller hash table size on large memroy machines
 718          */
 719         if (mmu.hash_cnt == mmu.vlp_hash_cnt) {
 720                 vlp_hash_cache = hat_hash_cache;
 721         } else {
 722                 vlp_hash_cache = kmem_cache_create("HatVlpHash",
 723                     mmu.vlp_hash_cnt * sizeof (htable_t *), 0, NULL, NULL, NULL,
 724                     NULL, 0, 0);
 725         }
 726 
 727         /*
 728          * Set up the kernel's hat
 729          */
 730         AS_LOCK_ENTER(&kas, RW_WRITER);
 731         kas.a_hat = kmem_cache_alloc(hat_cache, KM_NOSLEEP);
 732         mutex_init(&kas.a_hat->hat_mutex, NULL, MUTEX_DEFAULT, NULL);
 733         kas.a_hat->hat_as = &kas;
 734         kas.a_hat->hat_flags = 0;
 735         AS_LOCK_EXIT(&kas);
 736 
 737         CPUSET_ZERO(khat_cpuset);
 738         CPUSET_ADD(khat_cpuset, CPU->cpu_id);
 739 
 740         /*
 741          * The kernel hat's next pointer serves as the head of the hat list .
 742          * The kernel hat's prev pointer tracks the last hat on the list for
 743          * htable_steal() to use.
 744          */
 745         kas.a_hat->hat_next = NULL;
 746         kas.a_hat->hat_prev = NULL;
 747 
 748         /*
 749          * Allocate an htable hash bucket for the kernel
 750          * XX64 - tune for 64 bit procs
 751          */
 752         kas.a_hat->hat_num_hash = mmu.hash_cnt;
 753         kas.a_hat->hat_ht_hash = kmem_cache_alloc(hat_hash_cache, KM_NOSLEEP);
 754         bzero(kas.a_hat->hat_ht_hash, mmu.hash_cnt * sizeof (htable_t *));
 755 
 756         /*
 757          * zero out the top level and cached htable pointers
 758          */
 759         kas.a_hat->hat_ht_cached = NULL;
 760         kas.a_hat->hat_htable = NULL;
 761 
 762         /*
 763          * Pre-allocate hrm_hashtab before enabling the collection of
 764          * refmod statistics.  Allocating on the fly would mean us
 765          * running the risk of suffering recursive mutex enters or
 766          * deadlocks.
 767          */
 768         hrm_hashtab = kmem_zalloc(HRM_HASHSIZE * sizeof (struct hrmstat *),
 769             KM_SLEEP);
 770 }
 771 
 772 /*
 773  * Prepare CPU specific pagetables for VLP processes on 64 bit kernels.
 774  *
 775  * Each CPU has a set of 2 pagetables that are reused for any 32 bit
 776  * process it runs. They are the top level pagetable, hci_vlp_l3ptes, and
 777  * the next to top level table for the bottom 512 Gig, hci_vlp_l2ptes.
 778  */
 779 /*ARGSUSED*/
 780 static void
 781 hat_vlp_setup(struct cpu *cpu)
 782 {
 783 #if defined(__amd64) && !defined(__xpv)
 784         struct hat_cpu_info *hci = cpu->cpu_hat_info;
 785         pfn_t pfn;
 786 
 787         /*
 788          * allocate the level==2 page table for the bottom most
 789          * 512Gig of address space (this is where 32 bit apps live)
 790          */
 791         ASSERT(hci != NULL);
 792         hci->hci_vlp_l2ptes = kmem_zalloc(MMU_PAGESIZE, KM_SLEEP);
 793 
 794         /*
 795          * Allocate a top level pagetable and copy the kernel's
 796          * entries into it. Then link in hci_vlp_l2ptes in the 1st entry.
 797          */
 798         hci->hci_vlp_l3ptes = kmem_zalloc(MMU_PAGESIZE, KM_SLEEP);
 799         hci->hci_vlp_pfn =
 800             hat_getpfnum(kas.a_hat, (caddr_t)hci->hci_vlp_l3ptes);
 801         ASSERT(hci->hci_vlp_pfn != PFN_INVALID);
 802         bcopy(vlp_page, hci->hci_vlp_l3ptes, MMU_PAGESIZE);
 803 
 804         pfn = hat_getpfnum(kas.a_hat, (caddr_t)hci->hci_vlp_l2ptes);
 805         ASSERT(pfn != PFN_INVALID);
 806         hci->hci_vlp_l3ptes[0] = MAKEPTP(pfn, 2);
 807 #endif /* __amd64 && !__xpv */
 808 }
 809 
 810 /*ARGSUSED*/
 811 static void
 812 hat_vlp_teardown(cpu_t *cpu)
 813 {
 814 #if defined(__amd64) && !defined(__xpv)
 815         struct hat_cpu_info *hci;
 816 
 817         if ((hci = cpu->cpu_hat_info) == NULL)
 818                 return;
 819         if (hci->hci_vlp_l2ptes)
 820                 kmem_free(hci->hci_vlp_l2ptes, MMU_PAGESIZE);
 821         if (hci->hci_vlp_l3ptes)
 822                 kmem_free(hci->hci_vlp_l3ptes, MMU_PAGESIZE);
 823 #endif
 824 }
 825 
 826 #define NEXT_HKR(r, l, s, e) {                  \
 827         kernel_ranges[r].hkr_level = l;         \
 828         kernel_ranges[r].hkr_start_va = s;      \
 829         kernel_ranges[r].hkr_end_va = e;        \
 830         ++r;                                    \
 831 }
 832 
 833 /*
 834  * Finish filling in the kernel hat.
 835  * Pre fill in all top level kernel page table entries for the kernel's
 836  * part of the address range.  From this point on we can't use any new
 837  * kernel large pages if they need PTE's at max_level
 838  *
 839  * create the kmap mappings.
 840  */
 841 void
 842 hat_init_finish(void)
 843 {
 844         size_t          size;
 845         uint_t          r = 0;
 846         uintptr_t       va;
 847         hat_kernel_range_t *rp;
 848 
 849 
 850         /*
 851          * We are now effectively running on the kernel hat.
 852          * Clearing use_boot_reserve shuts off using the pre-allocated boot
 853          * reserve for all HAT allocations.  From here on, the reserves are
 854          * only used when avoiding recursion in kmem_alloc().
 855          */
 856         use_boot_reserve = 0;
 857         htable_adjust_reserve();
 858 
 859         /*
 860          * User HATs are initialized with copies of all kernel mappings in
 861          * higher level page tables. Ensure that those entries exist.
 862          */
 863 #if defined(__amd64)
 864 
 865         NEXT_HKR(r, 3, kernelbase, 0);
 866 #if defined(__xpv)
 867         NEXT_HKR(r, 3, HYPERVISOR_VIRT_START, HYPERVISOR_VIRT_END);
 868 #endif
 869 
 870 #elif defined(__i386)
 871 
 872 #if !defined(__xpv)
 873         if (mmu.pae_hat) {
 874                 va = kernelbase;
 875                 if ((va & LEVEL_MASK(2)) != va) {
 876                         va = P2ROUNDUP(va, LEVEL_SIZE(2));
 877                         NEXT_HKR(r, 1, kernelbase, va);
 878                 }
 879                 if (va != 0)
 880                         NEXT_HKR(r, 2, va, 0);
 881         } else
 882 #endif /* __xpv */
 883                 NEXT_HKR(r, 1, kernelbase, 0);
 884 
 885 #endif /* __i386 */
 886 
 887         num_kernel_ranges = r;
 888 
 889         /*
 890          * Create all the kernel pagetables that will have entries
 891          * shared to user HATs.
 892          */
 893         for (r = 0; r < num_kernel_ranges; ++r) {
 894                 rp = &kernel_ranges[r];
 895                 for (va = rp->hkr_start_va; va != rp->hkr_end_va;
 896                     va += LEVEL_SIZE(rp->hkr_level)) {
 897                         htable_t *ht;
 898 
 899                         if (IN_HYPERVISOR_VA(va))
 900                                 continue;
 901 
 902                         /* can/must skip if a page mapping already exists */
 903                         if (rp->hkr_level <= mmu.max_page_level &&
 904                             (ht = htable_getpage(kas.a_hat, va, NULL)) !=
 905                             NULL) {
 906                                 htable_release(ht);
 907                                 continue;
 908                         }
 909 
 910                         (void) htable_create(kas.a_hat, va, rp->hkr_level - 1,
 911                             NULL);
 912                 }
 913         }
 914 
 915         /*
 916          * 32 bit PAE metal kernels use only 4 of the 512 entries in the
 917          * page holding the top level pagetable. We use the remainder for
 918          * the "per CPU" page tables for VLP processes.
 919          * Map the top level kernel pagetable into the kernel to make
 920          * it easy to use bcopy access these tables.
 921          */
 922         if (mmu.pae_hat) {
 923                 vlp_page = vmem_alloc(heap_arena, MMU_PAGESIZE, VM_SLEEP);
 924                 hat_devload(kas.a_hat, (caddr_t)vlp_page, MMU_PAGESIZE,
 925                     kas.a_hat->hat_htable->ht_pfn,
 926 #if !defined(__xpv)
 927                     PROT_WRITE |
 928 #endif
 929                     PROT_READ | HAT_NOSYNC | HAT_UNORDERED_OK,
 930                     HAT_LOAD | HAT_LOAD_NOCONSIST);
 931         }
 932         hat_vlp_setup(CPU);
 933 
 934         /*
 935          * Create kmap (cached mappings of kernel PTEs)
 936          * for 32 bit we map from segmap_start .. ekernelheap
 937          * for 64 bit we map from segmap_start .. segmap_start + segmapsize;
 938          */
 939 #if defined(__i386)
 940         size = (uintptr_t)ekernelheap - segmap_start;
 941 #elif defined(__amd64)
 942         size = segmapsize;
 943 #endif
 944         hat_kmap_init((uintptr_t)segmap_start, size);
 945 }
 946 
 947 /*
 948  * On 32 bit PAE mode, PTE's are 64 bits, but ordinary atomic memory references
 949  * are 32 bit, so for safety we must use atomic_cas_64() to install these.
 950  */
 951 #ifdef __i386
 952 static void
 953 reload_pae32(hat_t *hat, cpu_t *cpu)
 954 {
 955         x86pte_t *src;
 956         x86pte_t *dest;
 957         x86pte_t pte;
 958         int i;
 959 
 960         /*
 961          * Load the 4 entries of the level 2 page table into this
 962          * cpu's range of the vlp_page and point cr3 at them.
 963          */
 964         ASSERT(mmu.pae_hat);
 965         src = hat->hat_vlp_ptes;
 966         dest = vlp_page + (cpu->cpu_id + 1) * VLP_NUM_PTES;
 967         for (i = 0; i < VLP_NUM_PTES; ++i) {
 968                 for (;;) {
 969                         pte = dest[i];
 970                         if (pte == src[i])
 971                                 break;
 972                         if (atomic_cas_64(dest + i, pte, src[i]) != src[i])
 973                                 break;
 974                 }
 975         }
 976 }
 977 #endif
 978 
 979 /*
 980  * Switch to a new active hat, maintaining bit masks to track active CPUs.
 981  *
 982  * On the 32-bit PAE hypervisor, %cr3 is a 64-bit value, on metal it
 983  * remains a 32-bit value.
 984  */
 985 void
 986 hat_switch(hat_t *hat)
 987 {
 988         uint64_t        newcr3;
 989         cpu_t           *cpu = CPU;
 990         hat_t           *old = cpu->cpu_current_hat;
 991 
 992         /*
 993          * set up this information first, so we don't miss any cross calls
 994          */
 995         if (old != NULL) {
 996                 if (old == hat)
 997                         return;
 998                 if (old != kas.a_hat)
 999                         CPUSET_ATOMIC_DEL(old->hat_cpus, cpu->cpu_id);
1000         }
1001 
1002         /*
1003          * Add this CPU to the active set for this HAT.
1004          */
1005         if (hat != kas.a_hat) {
1006                 CPUSET_ATOMIC_ADD(hat->hat_cpus, cpu->cpu_id);
1007         }
1008         cpu->cpu_current_hat = hat;
1009 
1010         /*
1011          * now go ahead and load cr3
1012          */
1013         if (hat->hat_flags & HAT_VLP) {
1014 #if defined(__amd64)
1015                 x86pte_t *vlpptep = cpu->cpu_hat_info->hci_vlp_l2ptes;
1016 
1017                 VLP_COPY(hat->hat_vlp_ptes, vlpptep);
1018                 newcr3 = MAKECR3(cpu->cpu_hat_info->hci_vlp_pfn);
1019 #elif defined(__i386)
1020                 reload_pae32(hat, cpu);
1021                 newcr3 = MAKECR3(kas.a_hat->hat_htable->ht_pfn) +
1022                     (cpu->cpu_id + 1) * VLP_SIZE;
1023 #endif
1024         } else {
1025                 newcr3 = MAKECR3((uint64_t)hat->hat_htable->ht_pfn);
1026         }
1027 #ifdef __xpv
1028         {
1029                 struct mmuext_op t[2];
1030                 uint_t retcnt;
1031                 uint_t opcnt = 1;
1032 
1033                 t[0].cmd = MMUEXT_NEW_BASEPTR;
1034                 t[0].arg1.mfn = mmu_btop(pa_to_ma(newcr3));
1035 #if defined(__amd64)
1036                 /*
1037                  * There's an interesting problem here, as to what to
1038                  * actually specify when switching to the kernel hat.
1039                  * For now we'll reuse the kernel hat again.
1040                  */
1041                 t[1].cmd = MMUEXT_NEW_USER_BASEPTR;
1042                 if (hat == kas.a_hat)
1043                         t[1].arg1.mfn = mmu_btop(pa_to_ma(newcr3));
1044                 else
1045                         t[1].arg1.mfn = pfn_to_mfn(hat->hat_user_ptable);
1046                 ++opcnt;
1047 #endif  /* __amd64 */
1048                 if (HYPERVISOR_mmuext_op(t, opcnt, &retcnt, DOMID_SELF) < 0)
1049                         panic("HYPERVISOR_mmu_update() failed");
1050                 ASSERT(retcnt == opcnt);
1051 
1052         }
1053 #else
1054         setcr3(newcr3);
1055 #endif
1056         ASSERT(cpu == CPU);
1057 }
1058 
1059 /*
1060  * Utility to return a valid x86pte_t from protections, pfn, and level number
1061  */
1062 static x86pte_t
1063 hati_mkpte(pfn_t pfn, uint_t attr, level_t level, uint_t flags)
1064 {
1065         x86pte_t        pte;
1066         uint_t          cache_attr = attr & HAT_ORDER_MASK;
1067 
1068         pte = MAKEPTE(pfn, level);
1069 
1070         if (attr & PROT_WRITE)
1071                 PTE_SET(pte, PT_WRITABLE);
1072 
1073         if (attr & PROT_USER)
1074                 PTE_SET(pte, PT_USER);
1075 
1076         if (!(attr & PROT_EXEC))
1077                 PTE_SET(pte, mmu.pt_nx);
1078 
1079         /*
1080          * Set the software bits used track ref/mod sync's and hments.
1081          * If not using REF/MOD, set them to avoid h/w rewriting PTEs.
1082          */
1083         if (flags & HAT_LOAD_NOCONSIST)
1084                 PTE_SET(pte, PT_NOCONSIST | PT_REF | PT_MOD);
1085         else if (attr & HAT_NOSYNC)
1086                 PTE_SET(pte, PT_NOSYNC | PT_REF | PT_MOD);
1087 
1088         /*
1089          * Set the caching attributes in the PTE. The combination
1090          * of attributes are poorly defined, so we pay attention
1091          * to them in the given order.
1092          *
1093          * The test for HAT_STRICTORDER is different because it's defined
1094          * as "0" - which was a stupid thing to do, but is too late to change!
1095          */
1096         if (cache_attr == HAT_STRICTORDER) {
1097                 PTE_SET(pte, PT_NOCACHE);
1098         /*LINTED [Lint hates empty ifs, but it's the obvious way to do this] */
1099         } else if (cache_attr & (HAT_UNORDERED_OK | HAT_STORECACHING_OK)) {
1100                 /* nothing to set */;
1101         } else if (cache_attr & (HAT_MERGING_OK | HAT_LOADCACHING_OK)) {
1102                 PTE_SET(pte, PT_NOCACHE);
1103                 if (is_x86_feature(x86_featureset, X86FSET_PAT))
1104                         PTE_SET(pte, (level == 0) ? PT_PAT_4K : PT_PAT_LARGE);
1105                 else
1106                         PTE_SET(pte, PT_WRITETHRU);
1107         } else {
1108                 panic("hati_mkpte(): bad caching attributes: %x\n", cache_attr);
1109         }
1110 
1111         return (pte);
1112 }
1113 
1114 /*
1115  * Duplicate address translations of the parent to the child.
1116  * This function really isn't used anymore.
1117  */
1118 /*ARGSUSED*/
1119 int
1120 hat_dup(hat_t *old, hat_t *new, caddr_t addr, size_t len, uint_t flag)
1121 {
1122         ASSERT((uintptr_t)addr < kernelbase);
1123         ASSERT(new != kas.a_hat);
1124         ASSERT(old != kas.a_hat);
1125         return (0);
1126 }
1127 
1128 /*
1129  * Allocate any hat resources required for a process being swapped in.
1130  */
1131 /*ARGSUSED*/
1132 void
1133 hat_swapin(hat_t *hat)
1134 {
1135         /* do nothing - we let everything fault back in */
1136 }
1137 
1138 /*
1139  * Unload all translations associated with an address space of a process
1140  * that is being swapped out.
1141  */
1142 void
1143 hat_swapout(hat_t *hat)
1144 {
1145         uintptr_t       vaddr = (uintptr_t)0;
1146         uintptr_t       eaddr = _userlimit;
1147         htable_t        *ht = NULL;
1148         level_t         l;
1149 
1150         XPV_DISALLOW_MIGRATE();
1151         /*
1152          * We can't just call hat_unload(hat, 0, _userlimit...)  here, because
1153          * seg_spt and shared pagetables can't be swapped out.
1154          * Take a look at segspt_shmswapout() - it's a big no-op.
1155          *
1156          * Instead we'll walk through all the address space and unload
1157          * any mappings which we are sure are not shared, not locked.
1158          */
1159         ASSERT(IS_PAGEALIGNED(vaddr));
1160         ASSERT(IS_PAGEALIGNED(eaddr));
1161         ASSERT(AS_LOCK_HELD(hat->hat_as));
1162         if ((uintptr_t)hat->hat_as->a_userlimit < eaddr)
1163                 eaddr = (uintptr_t)hat->hat_as->a_userlimit;
1164 
1165         while (vaddr < eaddr) {
1166                 (void) htable_walk(hat, &ht, &vaddr, eaddr);
1167                 if (ht == NULL)
1168                         break;
1169 
1170                 ASSERT(!IN_VA_HOLE(vaddr));
1171 
1172                 /*
1173                  * If the page table is shared skip its entire range.
1174                  */
1175                 l = ht->ht_level;
1176                 if (ht->ht_flags & HTABLE_SHARED_PFN) {
1177                         vaddr = ht->ht_vaddr + LEVEL_SIZE(l + 1);
1178                         htable_release(ht);
1179                         ht = NULL;
1180                         continue;
1181                 }
1182 
1183                 /*
1184                  * If the page table has no locked entries, unload this one.
1185                  */
1186                 if (ht->ht_lock_cnt == 0)
1187                         hat_unload(hat, (caddr_t)vaddr, LEVEL_SIZE(l),
1188                             HAT_UNLOAD_UNMAP);
1189 
1190                 /*
1191                  * If we have a level 0 page table with locked entries,
1192                  * skip the entire page table, otherwise skip just one entry.
1193                  */
1194                 if (ht->ht_lock_cnt > 0 && l == 0)
1195                         vaddr = ht->ht_vaddr + LEVEL_SIZE(1);
1196                 else
1197                         vaddr += LEVEL_SIZE(l);
1198         }
1199         if (ht)
1200                 htable_release(ht);
1201 
1202         /*
1203          * We're in swapout because the system is low on memory, so
1204          * go back and flush all the htables off the cached list.
1205          */
1206         htable_purge_hat(hat);
1207         XPV_ALLOW_MIGRATE();
1208 }
1209 
1210 /*
1211  * returns number of bytes that have valid mappings in hat.
1212  */
1213 size_t
1214 hat_get_mapped_size(hat_t *hat)
1215 {
1216         size_t total = 0;
1217         int l;
1218 
1219         for (l = 0; l <= mmu.max_page_level; l++)
1220                 total += (hat->hat_pages_mapped[l] << LEVEL_SHIFT(l));
1221         total += hat->hat_ism_pgcnt;
1222 
1223         return (total);
1224 }
1225 
1226 /*
1227  * enable/disable collection of stats for hat.
1228  */
1229 int
1230 hat_stats_enable(hat_t *hat)
1231 {
1232         atomic_inc_32(&hat->hat_stats);
1233         return (1);
1234 }
1235 
1236 void
1237 hat_stats_disable(hat_t *hat)
1238 {
1239         atomic_dec_32(&hat->hat_stats);
1240 }
1241 
1242 /*
1243  * Utility to sync the ref/mod bits from a page table entry to the page_t
1244  * We must be holding the mapping list lock when this is called.
1245  */
1246 static void
1247 hati_sync_pte_to_page(page_t *pp, x86pte_t pte, level_t level)
1248 {
1249         uint_t  rm = 0;
1250         pgcnt_t pgcnt;
1251 
1252         if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC)
1253                 return;
1254 
1255         if (PTE_GET(pte, PT_REF))
1256                 rm |= P_REF;
1257 
1258         if (PTE_GET(pte, PT_MOD))
1259                 rm |= P_MOD;
1260 
1261         if (rm == 0)
1262                 return;
1263 
1264         /*
1265          * sync to all constituent pages of a large page
1266          */
1267         ASSERT(x86_hm_held(pp));
1268         pgcnt = page_get_pagecnt(level);
1269         ASSERT(IS_P2ALIGNED(pp->p_pagenum, pgcnt));
1270         for (; pgcnt > 0; --pgcnt) {
1271                 /*
1272                  * hat_page_demote() can't decrease
1273                  * pszc below this mapping size
1274                  * since this large mapping existed after we
1275                  * took mlist lock.
1276                  */
1277                 ASSERT(pp->p_szc >= level);
1278                 hat_page_setattr(pp, rm);
1279                 ++pp;
1280         }
1281 }
1282 
1283 /*
1284  * This the set of PTE bits for PFN, permissions and caching
1285  * that are allowed to change on a HAT_LOAD_REMAP
1286  */
1287 #define PT_REMAP_BITS                                                   \
1288         (PT_PADDR | PT_NX | PT_WRITABLE | PT_WRITETHRU |                \
1289         PT_NOCACHE | PT_PAT_4K | PT_PAT_LARGE | PT_IGNORE | PT_REF | PT_MOD)
1290 
1291 #define REMAPASSERT(EX) if (!(EX)) panic("hati_pte_map: " #EX)
1292 /*
1293  * Do the low-level work to get a mapping entered into a HAT's pagetables
1294  * and in the mapping list of the associated page_t.
1295  */
1296 static int
1297 hati_pte_map(
1298         htable_t        *ht,
1299         uint_t          entry,
1300         page_t          *pp,
1301         x86pte_t        pte,
1302         int             flags,
1303         void            *pte_ptr)
1304 {
1305         hat_t           *hat = ht->ht_hat;
1306         x86pte_t        old_pte;
1307         level_t         l = ht->ht_level;
1308         hment_t         *hm;
1309         uint_t          is_consist;
1310         uint_t          is_locked;
1311         int             rv = 0;
1312 
1313         /*
1314          * Is this a consistent (ie. need mapping list lock) mapping?
1315          */
1316         is_consist = (pp != NULL && (flags & HAT_LOAD_NOCONSIST) == 0);
1317 
1318         /*
1319          * Track locked mapping count in the htable.  Do this first,
1320          * as we track locking even if there already is a mapping present.
1321          */
1322         is_locked = (flags & HAT_LOAD_LOCK) != 0 && hat != kas.a_hat;
1323         if (is_locked)
1324                 HTABLE_LOCK_INC(ht);
1325 
1326         /*
1327          * Acquire the page's mapping list lock and get an hment to use.
1328          * Note that hment_prepare() might return NULL.
1329          */
1330         if (is_consist) {
1331                 x86_hm_enter(pp);
1332                 hm = hment_prepare(ht, entry, pp);
1333         }
1334 
1335         /*
1336          * Set the new pte, retrieving the old one at the same time.
1337          */
1338         old_pte = x86pte_set(ht, entry, pte, pte_ptr);
1339 
1340         /*
1341          * Did we get a large page / page table collision?
1342          */
1343         if (old_pte == LPAGE_ERROR) {
1344                 if (is_locked)
1345                         HTABLE_LOCK_DEC(ht);
1346                 rv = -1;
1347                 goto done;
1348         }
1349 
1350         /*
1351          * If the mapping didn't change there is nothing more to do.
1352          */
1353         if (PTE_EQUIV(pte, old_pte))
1354                 goto done;
1355 
1356         /*
1357          * Install a new mapping in the page's mapping list
1358          */
1359         if (!PTE_ISVALID(old_pte)) {
1360                 if (is_consist) {
1361                         hment_assign(ht, entry, pp, hm);
1362                         x86_hm_exit(pp);
1363                 } else {
1364                         ASSERT(flags & HAT_LOAD_NOCONSIST);
1365                 }
1366 #if defined(__amd64)
1367                 if (ht->ht_flags & HTABLE_VLP) {
1368                         cpu_t *cpu = CPU;
1369                         x86pte_t *vlpptep = cpu->cpu_hat_info->hci_vlp_l2ptes;
1370                         VLP_COPY(hat->hat_vlp_ptes, vlpptep);
1371                 }
1372 #endif
1373                 HTABLE_INC(ht->ht_valid_cnt);
1374                 PGCNT_INC(hat, l);
1375                 return (rv);
1376         }
1377 
1378         /*
1379          * Remap's are more complicated:
1380          *  - HAT_LOAD_REMAP must be specified if changing the pfn.
1381          *    We also require that NOCONSIST be specified.
1382          *  - Otherwise only permission or caching bits may change.
1383          */
1384         if (!PTE_ISPAGE(old_pte, l))
1385                 panic("non-null/page mapping pte=" FMT_PTE, old_pte);
1386 
1387         if (PTE2PFN(old_pte, l) != PTE2PFN(pte, l)) {
1388                 REMAPASSERT(flags & HAT_LOAD_REMAP);
1389                 REMAPASSERT(flags & HAT_LOAD_NOCONSIST);
1390                 REMAPASSERT(PTE_GET(old_pte, PT_SOFTWARE) >= PT_NOCONSIST);
1391                 REMAPASSERT(pf_is_memory(PTE2PFN(old_pte, l)) ==
1392                     pf_is_memory(PTE2PFN(pte, l)));
1393                 REMAPASSERT(!is_consist);
1394         }
1395 
1396         /*
1397          * We only let remaps change the certain bits in the PTE.
1398          */
1399         if (PTE_GET(old_pte, ~PT_REMAP_BITS) != PTE_GET(pte, ~PT_REMAP_BITS))
1400                 panic("remap bits changed: old_pte="FMT_PTE", pte="FMT_PTE"\n",
1401                     old_pte, pte);
1402 
1403         /*
1404          * We don't create any mapping list entries on a remap, so release
1405          * any allocated hment after we drop the mapping list lock.
1406          */
1407 done:
1408         if (is_consist) {
1409                 x86_hm_exit(pp);
1410                 if (hm != NULL)
1411                         hment_free(hm);
1412         }
1413         return (rv);
1414 }
1415 
1416 /*
1417  * Internal routine to load a single page table entry. This only fails if
1418  * we attempt to overwrite a page table link with a large page.
1419  */
1420 static int
1421 hati_load_common(
1422         hat_t           *hat,
1423         uintptr_t       va,
1424         page_t          *pp,
1425         uint_t          attr,
1426         uint_t          flags,
1427         level_t         level,
1428         pfn_t           pfn)
1429 {
1430         htable_t        *ht;
1431         uint_t          entry;
1432         x86pte_t        pte;
1433         int             rv = 0;
1434 
1435         /*
1436          * The number 16 is arbitrary and here to catch a recursion problem
1437          * early before we blow out the kernel stack.
1438          */
1439         ++curthread->t_hatdepth;
1440         ASSERT(curthread->t_hatdepth < 16);
1441 
1442         ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
1443 
1444         if (flags & HAT_LOAD_SHARE)
1445                 hat->hat_flags |= HAT_SHARED;
1446 
1447         /*
1448          * Find the page table that maps this page if it already exists.
1449          */
1450         ht = htable_lookup(hat, va, level);
1451 
1452         /*
1453          * We must have HAT_LOAD_NOCONSIST if page_t is NULL.
1454          */
1455         if (pp == NULL)
1456                 flags |= HAT_LOAD_NOCONSIST;
1457 
1458         if (ht == NULL) {
1459                 ht = htable_create(hat, va, level, NULL);
1460                 ASSERT(ht != NULL);
1461         }
1462         entry = htable_va2entry(va, ht);
1463 
1464         /*
1465          * a bunch of paranoid error checking
1466          */
1467         ASSERT(ht->ht_busy > 0);
1468         if (ht->ht_vaddr > va || va > HTABLE_LAST_PAGE(ht))
1469                 panic("hati_load_common: bad htable %p, va %p",
1470                     (void *)ht, (void *)va);
1471         ASSERT(ht->ht_level == level);
1472 
1473         /*
1474          * construct the new PTE
1475          */
1476         if (hat == kas.a_hat)
1477                 attr &= ~PROT_USER;
1478         pte = hati_mkpte(pfn, attr, level, flags);
1479         if (hat == kas.a_hat && va >= kernelbase)
1480                 PTE_SET(pte, mmu.pt_global);
1481 
1482         /*
1483          * establish the mapping
1484          */
1485         rv = hati_pte_map(ht, entry, pp, pte, flags, NULL);
1486 
1487         /*
1488          * release the htable and any reserves
1489          */
1490         htable_release(ht);
1491         --curthread->t_hatdepth;
1492         return (rv);
1493 }
1494 
1495 /*
1496  * special case of hat_memload to deal with some kernel addrs for performance
1497  */
1498 static void
1499 hat_kmap_load(
1500         caddr_t         addr,
1501         page_t          *pp,
1502         uint_t          attr,
1503         uint_t          flags)
1504 {
1505         uintptr_t       va = (uintptr_t)addr;
1506         x86pte_t        pte;
1507         pfn_t           pfn = page_pptonum(pp);
1508         pgcnt_t         pg_off = mmu_btop(va - mmu.kmap_addr);
1509         htable_t        *ht;
1510         uint_t          entry;
1511         void            *pte_ptr;
1512 
1513         /*
1514          * construct the requested PTE
1515          */
1516         attr &= ~PROT_USER;
1517         attr |= HAT_STORECACHING_OK;
1518         pte = hati_mkpte(pfn, attr, 0, flags);
1519         PTE_SET(pte, mmu.pt_global);
1520 
1521         /*
1522          * Figure out the pte_ptr and htable and use common code to finish up
1523          */
1524         if (mmu.pae_hat)
1525                 pte_ptr = mmu.kmap_ptes + pg_off;
1526         else
1527                 pte_ptr = (x86pte32_t *)mmu.kmap_ptes + pg_off;
1528         ht = mmu.kmap_htables[(va - mmu.kmap_htables[0]->ht_vaddr) >>
1529             LEVEL_SHIFT(1)];
1530         entry = htable_va2entry(va, ht);
1531         ++curthread->t_hatdepth;
1532         ASSERT(curthread->t_hatdepth < 16);
1533         (void) hati_pte_map(ht, entry, pp, pte, flags, pte_ptr);
1534         --curthread->t_hatdepth;
1535 }
1536 
1537 /*
1538  * hat_memload() - load a translation to the given page struct
1539  *
1540  * Flags for hat_memload/hat_devload/hat_*attr.
1541  *
1542  *      HAT_LOAD        Default flags to load a translation to the page.
1543  *
1544  *      HAT_LOAD_LOCK   Lock down mapping resources; hat_map(), hat_memload(),
1545  *                      and hat_devload().
1546  *
1547  *      HAT_LOAD_NOCONSIST Do not add mapping to page_t mapping list.
1548  *                      sets PT_NOCONSIST
1549  *
1550  *      HAT_LOAD_SHARE  A flag to hat_memload() to indicate h/w page tables
1551  *                      that map some user pages (not kas) is shared by more
1552  *                      than one process (eg. ISM).
1553  *
1554  *      HAT_LOAD_REMAP  Reload a valid pte with a different page frame.
1555  *
1556  *      HAT_NO_KALLOC   Do not kmem_alloc while creating the mapping; at this
1557  *                      point, it's setting up mapping to allocate internal
1558  *                      hat layer data structures.  This flag forces hat layer
1559  *                      to tap its reserves in order to prevent infinite
1560  *                      recursion.
1561  *
1562  * The following is a protection attribute (like PROT_READ, etc.)
1563  *
1564  *      HAT_NOSYNC      set PT_NOSYNC - this mapping's ref/mod bits
1565  *                      are never cleared.
1566  *
1567  * Installing new valid PTE's and creation of the mapping list
1568  * entry are controlled under the same lock. It's derived from the
1569  * page_t being mapped.
1570  */
1571 static uint_t supported_memload_flags =
1572         HAT_LOAD | HAT_LOAD_LOCK | HAT_LOAD_ADV | HAT_LOAD_NOCONSIST |
1573         HAT_LOAD_SHARE | HAT_NO_KALLOC | HAT_LOAD_REMAP | HAT_LOAD_TEXT;
1574 
1575 void
1576 hat_memload(
1577         hat_t           *hat,
1578         caddr_t         addr,
1579         page_t          *pp,
1580         uint_t          attr,
1581         uint_t          flags)
1582 {
1583         uintptr_t       va = (uintptr_t)addr;
1584         level_t         level = 0;
1585         pfn_t           pfn = page_pptonum(pp);
1586 
1587         XPV_DISALLOW_MIGRATE();
1588         ASSERT(IS_PAGEALIGNED(va));
1589         ASSERT(hat == kas.a_hat || va < _userlimit);
1590         ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
1591         ASSERT((flags & supported_memload_flags) == flags);
1592 
1593         ASSERT(!IN_VA_HOLE(va));
1594         ASSERT(!PP_ISFREE(pp));
1595 
1596         /*
1597          * kernel address special case for performance.
1598          */
1599         if (mmu.kmap_addr <= va && va < mmu.kmap_eaddr) {
1600                 ASSERT(hat == kas.a_hat);
1601                 hat_kmap_load(addr, pp, attr, flags);
1602                 XPV_ALLOW_MIGRATE();
1603                 return;
1604         }
1605 
1606         /*
1607          * This is used for memory with normal caching enabled, so
1608          * always set HAT_STORECACHING_OK.
1609          */
1610         attr |= HAT_STORECACHING_OK;
1611         if (hati_load_common(hat, va, pp, attr, flags, level, pfn) != 0)
1612                 panic("unexpected hati_load_common() failure");
1613         XPV_ALLOW_MIGRATE();
1614 }
1615 
1616 /* ARGSUSED */
1617 void
1618 hat_memload_region(struct hat *hat, caddr_t addr, struct page *pp,
1619     uint_t attr, uint_t flags, hat_region_cookie_t rcookie)
1620 {
1621         hat_memload(hat, addr, pp, attr, flags);
1622 }
1623 
1624 /*
1625  * Load the given array of page structs using large pages when possible
1626  */
1627 void
1628 hat_memload_array(
1629         hat_t           *hat,
1630         caddr_t         addr,
1631         size_t          len,
1632         page_t          **pages,
1633         uint_t          attr,
1634         uint_t          flags)
1635 {
1636         uintptr_t       va = (uintptr_t)addr;
1637         uintptr_t       eaddr = va + len;
1638         level_t         level;
1639         size_t          pgsize;
1640         pgcnt_t         pgindx = 0;
1641         pfn_t           pfn;
1642         pgcnt_t         i;
1643 
1644         XPV_DISALLOW_MIGRATE();
1645         ASSERT(IS_PAGEALIGNED(va));
1646         ASSERT(hat == kas.a_hat || va + len <= _userlimit);
1647         ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
1648         ASSERT((flags & supported_memload_flags) == flags);
1649 
1650         /*
1651          * memload is used for memory with full caching enabled, so
1652          * set HAT_STORECACHING_OK.
1653          */
1654         attr |= HAT_STORECACHING_OK;
1655 
1656         /*
1657          * handle all pages using largest possible pagesize
1658          */
1659         while (va < eaddr) {
1660                 /*
1661                  * decide what level mapping to use (ie. pagesize)
1662                  */
1663                 pfn = page_pptonum(pages[pgindx]);
1664                 for (level = mmu.max_page_level; ; --level) {
1665                         pgsize = LEVEL_SIZE(level);
1666                         if (level == 0)
1667                                 break;
1668 
1669                         if (!IS_P2ALIGNED(va, pgsize) ||
1670                             (eaddr - va) < pgsize ||
1671                             !IS_P2ALIGNED(pfn_to_pa(pfn), pgsize))
1672                                 continue;
1673 
1674                         /*
1675                          * To use a large mapping of this size, all the
1676                          * pages we are passed must be sequential subpages
1677                          * of the large page.
1678                          * hat_page_demote() can't change p_szc because
1679                          * all pages are locked.
1680                          */
1681                         if (pages[pgindx]->p_szc >= level) {
1682                                 for (i = 0; i < mmu_btop(pgsize); ++i) {
1683                                         if (pfn + i !=
1684                                             page_pptonum(pages[pgindx + i]))
1685                                                 break;
1686                                         ASSERT(pages[pgindx + i]->p_szc >=
1687                                             level);
1688                                         ASSERT(pages[pgindx] + i ==
1689                                             pages[pgindx + i]);
1690                                 }
1691                                 if (i == mmu_btop(pgsize)) {
1692 #ifdef DEBUG
1693                                         if (level == 2)
1694                                                 map1gcnt++;
1695 #endif
1696                                         break;
1697                                 }
1698                         }
1699                 }
1700 
1701                 /*
1702                  * Load this page mapping. If the load fails, try a smaller
1703                  * pagesize.
1704                  */
1705                 ASSERT(!IN_VA_HOLE(va));
1706                 while (hati_load_common(hat, va, pages[pgindx], attr,
1707                     flags, level, pfn) != 0) {
1708                         if (level == 0)
1709                                 panic("unexpected hati_load_common() failure");
1710                         --level;
1711                         pgsize = LEVEL_SIZE(level);
1712                 }
1713 
1714                 /*
1715                  * move to next page
1716                  */
1717                 va += pgsize;
1718                 pgindx += mmu_btop(pgsize);
1719         }
1720         XPV_ALLOW_MIGRATE();
1721 }
1722 
1723 /* ARGSUSED */
1724 void
1725 hat_memload_array_region(struct hat *hat, caddr_t addr, size_t len,
1726     struct page **pps, uint_t attr, uint_t flags,
1727     hat_region_cookie_t rcookie)
1728 {
1729         hat_memload_array(hat, addr, len, pps, attr, flags);
1730 }
1731 
1732 /*
1733  * void hat_devload(hat, addr, len, pf, attr, flags)
1734  *      load/lock the given page frame number
1735  *
1736  * Advisory ordering attributes. Apply only to device mappings.
1737  *
1738  * HAT_STRICTORDER: the CPU must issue the references in order, as the
1739  *      programmer specified.  This is the default.
1740  * HAT_UNORDERED_OK: the CPU may reorder the references (this is all kinds
1741  *      of reordering; store or load with store or load).
1742  * HAT_MERGING_OK: merging and batching: the CPU may merge individual stores
1743  *      to consecutive locations (for example, turn two consecutive byte
1744  *      stores into one halfword store), and it may batch individual loads
1745  *      (for example, turn two consecutive byte loads into one halfword load).
1746  *      This also implies re-ordering.
1747  * HAT_LOADCACHING_OK: the CPU may cache the data it fetches and reuse it
1748  *      until another store occurs.  The default is to fetch new data
1749  *      on every load.  This also implies merging.
1750  * HAT_STORECACHING_OK: the CPU may keep the data in the cache and push it to
1751  *      the device (perhaps with other data) at a later time.  The default is
1752  *      to push the data right away.  This also implies load caching.
1753  *
1754  * Equivalent of hat_memload(), but can be used for device memory where
1755  * there are no page_t's and we support additional flags (write merging, etc).
1756  * Note that we can have large page mappings with this interface.
1757  */
1758 int supported_devload_flags = HAT_LOAD | HAT_LOAD_LOCK |
1759         HAT_LOAD_NOCONSIST | HAT_STRICTORDER | HAT_UNORDERED_OK |
1760         HAT_MERGING_OK | HAT_LOADCACHING_OK | HAT_STORECACHING_OK;
1761 
1762 void
1763 hat_devload(
1764         hat_t           *hat,
1765         caddr_t         addr,
1766         size_t          len,
1767         pfn_t           pfn,
1768         uint_t          attr,
1769         int             flags)
1770 {
1771         uintptr_t       va = ALIGN2PAGE(addr);
1772         uintptr_t       eva = va + len;
1773         level_t         level;
1774         size_t          pgsize;
1775         page_t          *pp;
1776         int             f;      /* per PTE copy of flags  - maybe modified */
1777         uint_t          a;      /* per PTE copy of attr */
1778 
1779         XPV_DISALLOW_MIGRATE();
1780         ASSERT(IS_PAGEALIGNED(va));
1781         ASSERT(hat == kas.a_hat || eva <= _userlimit);
1782         ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
1783         ASSERT((flags & supported_devload_flags) == flags);
1784 
1785         /*
1786          * handle all pages
1787          */
1788         while (va < eva) {
1789 
1790                 /*
1791                  * decide what level mapping to use (ie. pagesize)
1792                  */
1793                 for (level = mmu.max_page_level; ; --level) {
1794                         pgsize = LEVEL_SIZE(level);
1795                         if (level == 0)
1796                                 break;
1797                         if (IS_P2ALIGNED(va, pgsize) &&
1798                             (eva - va) >= pgsize &&
1799                             IS_P2ALIGNED(pfn, mmu_btop(pgsize))) {
1800 #ifdef DEBUG
1801                                 if (level == 2)
1802                                         map1gcnt++;
1803 #endif
1804                                 break;
1805                         }
1806                 }
1807 
1808                 /*
1809                  * If this is just memory then allow caching (this happens
1810                  * for the nucleus pages) - though HAT_PLAT_NOCACHE can be used
1811                  * to override that. If we don't have a page_t then make sure
1812                  * NOCONSIST is set.
1813                  */
1814                 a = attr;
1815                 f = flags;
1816                 if (!pf_is_memory(pfn))
1817                         f |= HAT_LOAD_NOCONSIST;
1818                 else if (!(a & HAT_PLAT_NOCACHE))
1819                         a |= HAT_STORECACHING_OK;
1820 
1821                 if (f & HAT_LOAD_NOCONSIST)
1822                         pp = NULL;
1823                 else
1824                         pp = page_numtopp_nolock(pfn);
1825 
1826                 /*
1827                  * Check to make sure we are really trying to map a valid
1828                  * memory page. The caller wishing to intentionally map
1829                  * free memory pages will have passed the HAT_LOAD_NOCONSIST
1830                  * flag, then pp will be NULL.
1831                  */
1832                 if (pp != NULL) {
1833                         if (PP_ISFREE(pp)) {
1834                                 panic("hat_devload: loading "
1835                                     "a mapping to free page %p", (void *)pp);
1836                         }
1837 
1838                         if (!PAGE_LOCKED(pp) && !PP_ISNORELOC(pp)) {
1839                                 panic("hat_devload: loading a mapping "
1840                                     "to an unlocked page %p",
1841                                     (void *)pp);
1842                         }
1843                 }
1844 
1845                 /*
1846                  * load this page mapping
1847                  */
1848                 ASSERT(!IN_VA_HOLE(va));
1849                 while (hati_load_common(hat, va, pp, a, f, level, pfn) != 0) {
1850                         if (level == 0)
1851                                 panic("unexpected hati_load_common() failure");
1852                         --level;
1853                         pgsize = LEVEL_SIZE(level);
1854                 }
1855 
1856                 /*
1857                  * move to next page
1858                  */
1859                 va += pgsize;
1860                 pfn += mmu_btop(pgsize);
1861         }
1862         XPV_ALLOW_MIGRATE();
1863 }
1864 
1865 /*
1866  * void hat_unlock(hat, addr, len)
1867  *      unlock the mappings to a given range of addresses
1868  *
1869  * Locks are tracked by ht_lock_cnt in the htable.
1870  */
1871 void
1872 hat_unlock(hat_t *hat, caddr_t addr, size_t len)
1873 {
1874         uintptr_t       vaddr = (uintptr_t)addr;
1875         uintptr_t       eaddr = vaddr + len;
1876         htable_t        *ht = NULL;
1877 
1878         /*
1879          * kernel entries are always locked, we don't track lock counts
1880          */
1881         ASSERT(hat == kas.a_hat || eaddr <= _userlimit);
1882         ASSERT(IS_PAGEALIGNED(vaddr));
1883         ASSERT(IS_PAGEALIGNED(eaddr));
1884         if (hat == kas.a_hat)
1885                 return;
1886         if (eaddr > _userlimit)
1887                 panic("hat_unlock() address out of range - above _userlimit");
1888 
1889         XPV_DISALLOW_MIGRATE();
1890         ASSERT(AS_LOCK_HELD(hat->hat_as));
1891         while (vaddr < eaddr) {
1892                 (void) htable_walk(hat, &ht, &vaddr, eaddr);
1893                 if (ht == NULL)
1894                         break;
1895 
1896                 ASSERT(!IN_VA_HOLE(vaddr));
1897 
1898                 if (ht->ht_lock_cnt < 1)
1899                         panic("hat_unlock(): lock_cnt < 1, "
1900                             "htable=%p, vaddr=%p\n", (void *)ht, (void *)vaddr);
1901                 HTABLE_LOCK_DEC(ht);
1902 
1903                 vaddr += LEVEL_SIZE(ht->ht_level);
1904         }
1905         if (ht)
1906                 htable_release(ht);
1907         XPV_ALLOW_MIGRATE();
1908 }
1909 
1910 /* ARGSUSED */
1911 void
1912 hat_unlock_region(struct hat *hat, caddr_t addr, size_t len,
1913     hat_region_cookie_t rcookie)
1914 {
1915         panic("No shared region support on x86");
1916 }
1917 
1918 #if !defined(__xpv)
1919 /*
1920  * Cross call service routine to demap a virtual page on
1921  * the current CPU or flush all mappings in TLB.
1922  */
1923 /*ARGSUSED*/
1924 static int
1925 hati_demap_func(xc_arg_t a1, xc_arg_t a2, xc_arg_t a3)
1926 {
1927         hat_t   *hat = (hat_t *)a1;
1928         caddr_t addr = (caddr_t)a2;
1929         size_t len = (size_t)a3;
1930 
1931         /*
1932          * If the target hat isn't the kernel and this CPU isn't operating
1933          * in the target hat, we can ignore the cross call.
1934          */
1935         if (hat != kas.a_hat && hat != CPU->cpu_current_hat)
1936                 return (0);
1937 
1938         /*
1939          * For a normal address, we flush a range of contiguous mappings
1940          */
1941         if ((uintptr_t)addr != DEMAP_ALL_ADDR) {
1942                 for (size_t i = 0; i < len; i += MMU_PAGESIZE)
1943                         mmu_tlbflush_entry(addr + i);
1944                 return (0);
1945         }
1946 
1947         /*
1948          * Otherwise we reload cr3 to effect a complete TLB flush.
1949          *
1950          * A reload of cr3 on a VLP process also means we must also recopy in
1951          * the pte values from the struct hat
1952          */
1953         if (hat->hat_flags & HAT_VLP) {
1954 #if defined(__amd64)
1955                 x86pte_t *vlpptep = CPU->cpu_hat_info->hci_vlp_l2ptes;
1956 
1957                 VLP_COPY(hat->hat_vlp_ptes, vlpptep);
1958 #elif defined(__i386)
1959                 reload_pae32(hat, CPU);
1960 #endif
1961         }
1962         reload_cr3();
1963         return (0);
1964 }
1965 
1966 /*
1967  * Flush all TLB entries, including global (ie. kernel) ones.
1968  */
1969 static void
1970 flush_all_tlb_entries(void)
1971 {
1972         ulong_t cr4 = getcr4();
1973 
1974         if (cr4 & CR4_PGE) {
1975                 setcr4(cr4 & ~(ulong_t)CR4_PGE);
1976                 setcr4(cr4);
1977 
1978                 /*
1979                  * 32 bit PAE also needs to always reload_cr3()
1980                  */
1981                 if (mmu.max_level == 2)
1982                         reload_cr3();
1983         } else {
1984                 reload_cr3();
1985         }
1986 }
1987 
1988 #define TLB_CPU_HALTED  (01ul)
1989 #define TLB_INVAL_ALL   (02ul)
1990 #define CAS_TLB_INFO(cpu, old, new)     \
1991         atomic_cas_ulong((ulong_t *)&(cpu)->cpu_m.mcpu_tlb_info, (old), (new))
1992 
1993 /*
1994  * Record that a CPU is going idle
1995  */
1996 void
1997 tlb_going_idle(void)
1998 {
1999         atomic_or_ulong((ulong_t *)&CPU->cpu_m.mcpu_tlb_info, TLB_CPU_HALTED);
2000 }
2001 
2002 /*
2003  * Service a delayed TLB flush if coming out of being idle.
2004  * It will be called from cpu idle notification with interrupt disabled.
2005  */
2006 void
2007 tlb_service(void)
2008 {
2009         ulong_t tlb_info;
2010         ulong_t found;
2011 
2012         /*
2013          * We only have to do something if coming out of being idle.
2014          */
2015         tlb_info = CPU->cpu_m.mcpu_tlb_info;
2016         if (tlb_info & TLB_CPU_HALTED) {
2017                 ASSERT(CPU->cpu_current_hat == kas.a_hat);
2018 
2019                 /*
2020                  * Atomic clear and fetch of old state.
2021                  */
2022                 while ((found = CAS_TLB_INFO(CPU, tlb_info, 0)) != tlb_info) {
2023                         ASSERT(found & TLB_CPU_HALTED);
2024                         tlb_info = found;
2025                         SMT_PAUSE();
2026                 }
2027                 if (tlb_info & TLB_INVAL_ALL)
2028                         flush_all_tlb_entries();
2029         }
2030 }
2031 #endif /* !__xpv */
2032 
2033 /*
2034  * Internal routine to do cross calls to invalidate a range of pages on
2035  * all CPUs using a given hat.
2036  */
2037 void
2038 hat_tlb_inval_range(hat_t *hat, uintptr_t va, size_t len)
2039 {
2040         extern int      flushes_require_xcalls; /* from mp_startup.c */
2041         cpuset_t        justme;
2042         cpuset_t        cpus_to_shootdown;
2043 #ifndef __xpv
2044         cpuset_t        check_cpus;
2045         cpu_t           *cpup;
2046         int             c;
2047 #endif
2048 
2049         /*
2050          * If the hat is being destroyed, there are no more users, so
2051          * demap need not do anything.
2052          */
2053         if (hat->hat_flags & HAT_FREEING)
2054                 return;
2055 
2056         /*
2057          * If demapping from a shared pagetable, we best demap the
2058          * entire set of user TLBs, since we don't know what addresses
2059          * these were shared at.
2060          */
2061         if (hat->hat_flags & HAT_SHARED) {
2062                 hat = kas.a_hat;
2063                 va = DEMAP_ALL_ADDR;
2064         }
2065 
2066         /*
2067          * if not running with multiple CPUs, don't use cross calls
2068          */
2069         if (panicstr || !flushes_require_xcalls) {
2070 #ifdef __xpv
2071                 if (va == DEMAP_ALL_ADDR) {
2072                         xen_flush_tlb();
2073                 } else {
2074                         for (size_t i = 0; i < len; i += MMU_PAGESIZE)
2075                                 xen_flush_va((caddr_t)(va + i));
2076                 }
2077 #else
2078                 (void) hati_demap_func((xc_arg_t)hat,
2079                     (xc_arg_t)va, (xc_arg_t)len);
2080 #endif
2081                 return;
2082         }
2083 
2084 
2085         /*
2086          * Determine CPUs to shootdown. Kernel changes always do all CPUs.
2087          * Otherwise it's just CPUs currently executing in this hat.
2088          */
2089         kpreempt_disable();
2090         CPUSET_ONLY(justme, CPU->cpu_id);
2091         if (hat == kas.a_hat)
2092                 cpus_to_shootdown = khat_cpuset;
2093         else
2094                 cpus_to_shootdown = hat->hat_cpus;
2095 
2096 #ifndef __xpv
2097         /*
2098          * If any CPUs in the set are idle, just request a delayed flush
2099          * and avoid waking them up.
2100          */
2101         check_cpus = cpus_to_shootdown;
2102         for (c = 0; c < NCPU && !CPUSET_ISNULL(check_cpus); ++c) {
2103                 ulong_t tlb_info;
2104 
2105                 if (!CPU_IN_SET(check_cpus, c))
2106                         continue;
2107                 CPUSET_DEL(check_cpus, c);
2108                 cpup = cpu[c];
2109                 if (cpup == NULL)
2110                         continue;
2111 
2112                 tlb_info = cpup->cpu_m.mcpu_tlb_info;
2113                 while (tlb_info == TLB_CPU_HALTED) {
2114                         (void) CAS_TLB_INFO(cpup, TLB_CPU_HALTED,
2115                             TLB_CPU_HALTED | TLB_INVAL_ALL);
2116                         SMT_PAUSE();
2117                         tlb_info = cpup->cpu_m.mcpu_tlb_info;
2118                 }
2119                 if (tlb_info == (TLB_CPU_HALTED | TLB_INVAL_ALL)) {
2120                         HATSTAT_INC(hs_tlb_inval_delayed);
2121                         CPUSET_DEL(cpus_to_shootdown, c);
2122                 }
2123         }
2124 #endif
2125 
2126         if (CPUSET_ISNULL(cpus_to_shootdown) ||
2127             CPUSET_ISEQUAL(cpus_to_shootdown, justme)) {
2128 
2129 #ifdef __xpv
2130                 if (va == DEMAP_ALL_ADDR) {
2131                         xen_flush_tlb();
2132                 } else {
2133                         for (size_t i = 0; i < len; i += MMU_PAGESIZE)
2134                                 xen_flush_va((caddr_t)(va + i));
2135                 }
2136 #else
2137                 (void) hati_demap_func((xc_arg_t)hat,
2138                     (xc_arg_t)va, (xc_arg_t)len);
2139 #endif
2140 
2141         } else {
2142 
2143                 CPUSET_ADD(cpus_to_shootdown, CPU->cpu_id);
2144 #ifdef __xpv
2145                 if (va == DEMAP_ALL_ADDR) {
2146                         xen_gflush_tlb(cpus_to_shootdown);
2147                 } else {
2148                         for (size_t i = 0; i < len; i += MMU_PAGESIZE) {
2149                                 xen_gflush_va((caddr_t)(va + i),
2150                                     cpus_to_shootdown);
2151                         }
2152                 }
2153 #else
2154                 xc_call((xc_arg_t)hat, (xc_arg_t)va, (xc_arg_t)len,
2155                     CPUSET2BV(cpus_to_shootdown), hati_demap_func);
2156 #endif
2157 
2158         }
2159         kpreempt_enable();
2160 }
2161 
2162 void
2163 hat_tlb_inval(hat_t *hat, uintptr_t va)
2164 {
2165         hat_tlb_inval_range(hat, va, MMU_PAGESIZE);
2166 }
2167 
2168 /*
2169  * Interior routine for HAT_UNLOADs from hat_unload_callback(),
2170  * hat_kmap_unload() OR from hat_steal() code.  This routine doesn't
2171  * handle releasing of the htables.
2172  */
2173 void
2174 hat_pte_unmap(
2175         htable_t        *ht,
2176         uint_t          entry,
2177         uint_t          flags,
2178         x86pte_t        old_pte,
2179         void            *pte_ptr,
2180         boolean_t       tlb)
2181 {
2182         hat_t           *hat = ht->ht_hat;
2183         hment_t         *hm = NULL;
2184         page_t          *pp = NULL;
2185         level_t         l = ht->ht_level;
2186         pfn_t           pfn;
2187 
2188         /*
2189          * We always track the locking counts, even if nothing is unmapped
2190          */
2191         if ((flags & HAT_UNLOAD_UNLOCK) != 0 && hat != kas.a_hat) {
2192                 ASSERT(ht->ht_lock_cnt > 0);
2193                 HTABLE_LOCK_DEC(ht);
2194         }
2195 
2196         /*
2197          * Figure out which page's mapping list lock to acquire using the PFN
2198          * passed in "old" PTE. We then attempt to invalidate the PTE.
2199          * If another thread, probably a hat_pageunload, has asynchronously
2200          * unmapped/remapped this address we'll loop here.
2201          */
2202         ASSERT(ht->ht_busy > 0);
2203         while (PTE_ISVALID(old_pte)) {
2204                 pfn = PTE2PFN(old_pte, l);
2205                 if (PTE_GET(old_pte, PT_SOFTWARE) >= PT_NOCONSIST) {
2206                         pp = NULL;
2207                 } else {
2208 #ifdef __xpv
2209                         if (pfn == PFN_INVALID)
2210                                 panic("Invalid PFN, but not PT_NOCONSIST");
2211 #endif
2212                         pp = page_numtopp_nolock(pfn);
2213                         if (pp == NULL) {
2214                                 panic("no page_t, not NOCONSIST: old_pte="
2215                                     FMT_PTE " ht=%lx entry=0x%x pte_ptr=%lx",
2216                                     old_pte, (uintptr_t)ht, entry,
2217                                     (uintptr_t)pte_ptr);
2218                         }
2219                         x86_hm_enter(pp);
2220                 }
2221 
2222                 old_pte = x86pte_inval(ht, entry, old_pte, pte_ptr, tlb);
2223 
2224                 /*
2225                  * If the page hadn't changed we've unmapped it and can proceed
2226                  */
2227                 if (PTE_ISVALID(old_pte) && PTE2PFN(old_pte, l) == pfn)
2228                         break;
2229 
2230                 /*
2231                  * Otherwise, we'll have to retry with the current old_pte.
2232                  * Drop the hment lock, since the pfn may have changed.
2233                  */
2234                 if (pp != NULL) {
2235                         x86_hm_exit(pp);
2236                         pp = NULL;
2237                 } else {
2238                         ASSERT(PTE_GET(old_pte, PT_SOFTWARE) >= PT_NOCONSIST);
2239                 }
2240         }
2241 
2242         /*
2243          * If the old mapping wasn't valid, there's nothing more to do
2244          */
2245         if (!PTE_ISVALID(old_pte)) {
2246                 if (pp != NULL)
2247                         x86_hm_exit(pp);
2248                 return;
2249         }
2250 
2251         /*
2252          * Take care of syncing any MOD/REF bits and removing the hment.
2253          */
2254         if (pp != NULL) {
2255                 if (!(flags & HAT_UNLOAD_NOSYNC))
2256                         hati_sync_pte_to_page(pp, old_pte, l);
2257                 hm = hment_remove(pp, ht, entry);
2258                 x86_hm_exit(pp);
2259                 if (hm != NULL)
2260                         hment_free(hm);
2261         }
2262 
2263         /*
2264          * Handle book keeping in the htable and hat
2265          */
2266         ASSERT(ht->ht_valid_cnt > 0);
2267         HTABLE_DEC(ht->ht_valid_cnt);
2268         PGCNT_DEC(hat, l);
2269 }
2270 
2271 /*
2272  * very cheap unload implementation to special case some kernel addresses
2273  */
2274 static void
2275 hat_kmap_unload(caddr_t addr, size_t len, uint_t flags)
2276 {
2277         uintptr_t       va = (uintptr_t)addr;
2278         uintptr_t       eva = va + len;
2279         pgcnt_t         pg_index;
2280         htable_t        *ht;
2281         uint_t          entry;
2282         x86pte_t        *pte_ptr;
2283         x86pte_t        old_pte;
2284 
2285         for (; va < eva; va += MMU_PAGESIZE) {
2286                 /*
2287                  * Get the PTE
2288                  */
2289                 pg_index = mmu_btop(va - mmu.kmap_addr);
2290                 pte_ptr = PT_INDEX_PTR(mmu.kmap_ptes, pg_index);
2291                 old_pte = GET_PTE(pte_ptr);
2292 
2293                 /*
2294                  * get the htable / entry
2295                  */
2296                 ht = mmu.kmap_htables[(va - mmu.kmap_htables[0]->ht_vaddr)
2297                     >> LEVEL_SHIFT(1)];
2298                 entry = htable_va2entry(va, ht);
2299 
2300                 /*
2301                  * use mostly common code to unmap it.
2302                  */
2303                 hat_pte_unmap(ht, entry, flags, old_pte, pte_ptr, B_TRUE);
2304         }
2305 }
2306 
2307 
2308 /*
2309  * unload a range of virtual address space (no callback)
2310  */
2311 void
2312 hat_unload(hat_t *hat, caddr_t addr, size_t len, uint_t flags)
2313 {
2314         uintptr_t va = (uintptr_t)addr;
2315 
2316         XPV_DISALLOW_MIGRATE();
2317         ASSERT(hat == kas.a_hat || va + len <= _userlimit);
2318 
2319         /*
2320          * special case for performance.
2321          */
2322         if (mmu.kmap_addr <= va && va < mmu.kmap_eaddr) {
2323                 ASSERT(hat == kas.a_hat);
2324                 hat_kmap_unload(addr, len, flags);
2325         } else {
2326                 hat_unload_callback(hat, addr, len, flags, NULL);
2327         }
2328         XPV_ALLOW_MIGRATE();
2329 }
2330 
2331 /*
2332  * Do the callbacks for ranges being unloaded.
2333  */
2334 typedef struct range_info {
2335         uintptr_t       rng_va;
2336         ulong_t         rng_cnt;
2337         level_t         rng_level;
2338 } range_info_t;
2339 
2340 /*
2341  * Invalidate the TLB, and perform the callback to the upper level VM system,
2342  * for the specified ranges of contiguous pages.
2343  */
2344 static void
2345 handle_ranges(hat_t *hat, hat_callback_t *cb, uint_t cnt, range_info_t *range)
2346 {
2347         while (cnt > 0) {
2348                 size_t len;
2349 
2350                 --cnt;
2351                 len = range[cnt].rng_cnt << LEVEL_SHIFT(range[cnt].rng_level);
2352                 hat_tlb_inval_range(hat, (uintptr_t)range[cnt].rng_va, len);
2353 
2354                 if (cb != NULL) {
2355                         cb->hcb_start_addr = (caddr_t)range[cnt].rng_va;
2356                         cb->hcb_end_addr = cb->hcb_start_addr;
2357                         cb->hcb_end_addr += len;
2358                         cb->hcb_function(cb);
2359                 }
2360         }
2361 }
2362 
2363 /*
2364  * Unload a given range of addresses (has optional callback)
2365  *
2366  * Flags:
2367  * define       HAT_UNLOAD              0x00
2368  * define       HAT_UNLOAD_NOSYNC       0x02
2369  * define       HAT_UNLOAD_UNLOCK       0x04
2370  * define       HAT_UNLOAD_OTHER        0x08 - not used
2371  * define       HAT_UNLOAD_UNMAP        0x10 - same as HAT_UNLOAD
2372  */
2373 #define MAX_UNLOAD_CNT (8)
2374 void
2375 hat_unload_callback(
2376         hat_t           *hat,
2377         caddr_t         addr,
2378         size_t          len,
2379         uint_t          flags,
2380         hat_callback_t  *cb)
2381 {
2382         uintptr_t       vaddr = (uintptr_t)addr;
2383         uintptr_t       eaddr = vaddr + len;
2384         htable_t        *ht = NULL;
2385         uint_t          entry;
2386         uintptr_t       contig_va = (uintptr_t)-1L;
2387         range_info_t    r[MAX_UNLOAD_CNT];
2388         uint_t          r_cnt = 0;
2389         x86pte_t        old_pte;
2390 
2391         XPV_DISALLOW_MIGRATE();
2392         ASSERT(hat == kas.a_hat || eaddr <= _userlimit);
2393         ASSERT(IS_PAGEALIGNED(vaddr));
2394         ASSERT(IS_PAGEALIGNED(eaddr));
2395 
2396         /*
2397          * Special case a single page being unloaded for speed. This happens
2398          * quite frequently, COW faults after a fork() for example.
2399          */
2400         if (cb == NULL && len == MMU_PAGESIZE) {
2401                 ht = htable_getpte(hat, vaddr, &entry, &old_pte, 0);
2402                 if (ht != NULL) {
2403                         if (PTE_ISVALID(old_pte)) {
2404                                 hat_pte_unmap(ht, entry, flags, old_pte,
2405                                     NULL, B_TRUE);
2406                         }
2407                         htable_release(ht);
2408                 }
2409                 XPV_ALLOW_MIGRATE();
2410                 return;
2411         }
2412 
2413         while (vaddr < eaddr) {
2414                 old_pte = htable_walk(hat, &ht, &vaddr, eaddr);
2415                 if (ht == NULL)
2416                         break;
2417 
2418                 ASSERT(!IN_VA_HOLE(vaddr));
2419 
2420                 if (vaddr < (uintptr_t)addr)
2421                         panic("hat_unload_callback(): unmap inside large page");
2422 
2423                 /*
2424                  * We'll do the call backs for contiguous ranges
2425                  */
2426                 if (vaddr != contig_va ||
2427                     (r_cnt > 0 && r[r_cnt - 1].rng_level != ht->ht_level)) {
2428                         if (r_cnt == MAX_UNLOAD_CNT) {
2429                                 handle_ranges(hat, cb, r_cnt, r);
2430                                 r_cnt = 0;
2431                         }
2432                         r[r_cnt].rng_va = vaddr;
2433                         r[r_cnt].rng_cnt = 0;
2434                         r[r_cnt].rng_level = ht->ht_level;
2435                         ++r_cnt;
2436                 }
2437 
2438                 /*
2439                  * Unload one mapping (for a single page) from the page tables.
2440                  * Note that we do not remove the mapping from the TLB yet,
2441                  * as indicated by the tlb=FALSE argument to hat_pte_unmap().
2442                  * handle_ranges() will clear the TLB entries with one call to
2443                  * hat_tlb_inval_range() per contiguous range.  This is
2444                  * safe because the page can not be reused until the
2445                  * callback is made (or we return).
2446                  */
2447                 entry = htable_va2entry(vaddr, ht);
2448                 hat_pte_unmap(ht, entry, flags, old_pte, NULL, B_FALSE);
2449                 ASSERT(ht->ht_level <= mmu.max_page_level);
2450                 vaddr += LEVEL_SIZE(ht->ht_level);
2451                 contig_va = vaddr;
2452                 ++r[r_cnt - 1].rng_cnt;
2453         }
2454         if (ht)
2455                 htable_release(ht);
2456 
2457         /*
2458          * handle last range for callbacks
2459          */
2460         if (r_cnt > 0)
2461                 handle_ranges(hat, cb, r_cnt, r);
2462         XPV_ALLOW_MIGRATE();
2463 }
2464 
2465 /*
2466  * Invalidate a virtual address translation on a slave CPU during
2467  * panic() dumps.
2468  */
2469 void
2470 hat_flush_range(hat_t *hat, caddr_t va, size_t size)
2471 {
2472         ssize_t sz;
2473         caddr_t endva = va + size;
2474 
2475         while (va < endva) {
2476                 sz = hat_getpagesize(hat, va);
2477                 if (sz < 0) {
2478 #ifdef __xpv
2479                         xen_flush_tlb();
2480 #else
2481                         flush_all_tlb_entries();
2482 #endif
2483                         break;
2484                 }
2485 #ifdef __xpv
2486                 xen_flush_va(va);
2487 #else
2488                 mmu_tlbflush_entry(va);
2489 #endif
2490                 va += sz;
2491         }
2492 }
2493 
2494 /*
2495  * synchronize mapping with software data structures
2496  *
2497  * This interface is currently only used by the working set monitor
2498  * driver.
2499  */
2500 /*ARGSUSED*/
2501 void
2502 hat_sync(hat_t *hat, caddr_t addr, size_t len, uint_t flags)
2503 {
2504         uintptr_t       vaddr = (uintptr_t)addr;
2505         uintptr_t       eaddr = vaddr + len;
2506         htable_t        *ht = NULL;
2507         uint_t          entry;
2508         x86pte_t        pte;
2509         x86pte_t        save_pte;
2510         x86pte_t        new;
2511         page_t          *pp;
2512 
2513         ASSERT(!IN_VA_HOLE(vaddr));
2514         ASSERT(IS_PAGEALIGNED(vaddr));
2515         ASSERT(IS_PAGEALIGNED(eaddr));
2516         ASSERT(hat == kas.a_hat || eaddr <= _userlimit);
2517 
2518         XPV_DISALLOW_MIGRATE();
2519         for (; vaddr < eaddr; vaddr += LEVEL_SIZE(ht->ht_level)) {
2520 try_again:
2521                 pte = htable_walk(hat, &ht, &vaddr, eaddr);
2522                 if (ht == NULL)
2523                         break;
2524                 entry = htable_va2entry(vaddr, ht);
2525 
2526                 if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC ||
2527                     PTE_GET(pte, PT_REF | PT_MOD) == 0)
2528                         continue;
2529 
2530                 /*
2531                  * We need to acquire the mapping list lock to protect
2532                  * against hat_pageunload(), hat_unload(), etc.
2533                  */
2534                 pp = page_numtopp_nolock(PTE2PFN(pte, ht->ht_level));
2535                 if (pp == NULL)
2536                         break;
2537                 x86_hm_enter(pp);
2538                 save_pte = pte;
2539                 pte = x86pte_get(ht, entry);
2540                 if (pte != save_pte) {
2541                         x86_hm_exit(pp);
2542                         goto try_again;
2543                 }
2544                 if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC ||
2545                     PTE_GET(pte, PT_REF | PT_MOD) == 0) {
2546                         x86_hm_exit(pp);
2547                         continue;
2548                 }
2549 
2550                 /*
2551                  * Need to clear ref or mod bits. We may compete with
2552                  * hardware updating the R/M bits and have to try again.
2553                  */
2554                 if (flags == HAT_SYNC_ZERORM) {
2555                         new = pte;
2556                         PTE_CLR(new, PT_REF | PT_MOD);
2557                         pte = hati_update_pte(ht, entry, pte, new);
2558                         if (pte != 0) {
2559                                 x86_hm_exit(pp);
2560                                 goto try_again;
2561                         }
2562                 } else {
2563                         /*
2564                          * sync the PTE to the page_t
2565                          */
2566                         hati_sync_pte_to_page(pp, save_pte, ht->ht_level);
2567                 }
2568                 x86_hm_exit(pp);
2569         }
2570         if (ht)
2571                 htable_release(ht);
2572         XPV_ALLOW_MIGRATE();
2573 }
2574 
2575 /*
2576  * void hat_map(hat, addr, len, flags)
2577  */
2578 /*ARGSUSED*/
2579 void
2580 hat_map(hat_t *hat, caddr_t addr, size_t len, uint_t flags)
2581 {
2582         /* does nothing */
2583 }
2584 
2585 /*
2586  * uint_t hat_getattr(hat, addr, *attr)
2587  *      returns attr for <hat,addr> in *attr.  returns 0 if there was a
2588  *      mapping and *attr is valid, nonzero if there was no mapping and
2589  *      *attr is not valid.
2590  */
2591 uint_t
2592 hat_getattr(hat_t *hat, caddr_t addr, uint_t *attr)
2593 {
2594         uintptr_t       vaddr = ALIGN2PAGE(addr);
2595         htable_t        *ht = NULL;
2596         x86pte_t        pte;
2597 
2598         ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
2599 
2600         if (IN_VA_HOLE(vaddr))
2601                 return ((uint_t)-1);
2602 
2603         ht = htable_getpte(hat, vaddr, NULL, &pte, mmu.max_page_level);
2604         if (ht == NULL)
2605                 return ((uint_t)-1);
2606 
2607         if (!PTE_ISVALID(pte) || !PTE_ISPAGE(pte, ht->ht_level)) {
2608                 htable_release(ht);
2609                 return ((uint_t)-1);
2610         }
2611 
2612         *attr = PROT_READ;
2613         if (PTE_GET(pte, PT_WRITABLE))
2614                 *attr |= PROT_WRITE;
2615         if (PTE_GET(pte, PT_USER))
2616                 *attr |= PROT_USER;
2617         if (!PTE_GET(pte, mmu.pt_nx))
2618                 *attr |= PROT_EXEC;
2619         if (PTE_GET(pte, PT_SOFTWARE) >= PT_NOSYNC)
2620                 *attr |= HAT_NOSYNC;
2621         htable_release(ht);
2622         return (0);
2623 }
2624 
2625 /*
2626  * hat_updateattr() applies the given attribute change to an existing mapping
2627  */
2628 #define HAT_LOAD_ATTR           1
2629 #define HAT_SET_ATTR            2
2630 #define HAT_CLR_ATTR            3
2631 
2632 static void
2633 hat_updateattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr, int what)
2634 {
2635         uintptr_t       vaddr = (uintptr_t)addr;
2636         uintptr_t       eaddr = (uintptr_t)addr + len;
2637         htable_t        *ht = NULL;
2638         uint_t          entry;
2639         x86pte_t        oldpte, newpte;
2640         page_t          *pp;
2641 
2642         XPV_DISALLOW_MIGRATE();
2643         ASSERT(IS_PAGEALIGNED(vaddr));
2644         ASSERT(IS_PAGEALIGNED(eaddr));
2645         ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
2646         for (; vaddr < eaddr; vaddr += LEVEL_SIZE(ht->ht_level)) {
2647 try_again:
2648                 oldpte = htable_walk(hat, &ht, &vaddr, eaddr);
2649                 if (ht == NULL)
2650                         break;
2651                 if (PTE_GET(oldpte, PT_SOFTWARE) >= PT_NOCONSIST)
2652                         continue;
2653 
2654                 pp = page_numtopp_nolock(PTE2PFN(oldpte, ht->ht_level));
2655                 if (pp == NULL)
2656                         continue;
2657                 x86_hm_enter(pp);
2658 
2659                 newpte = oldpte;
2660                 /*
2661                  * We found a page table entry in the desired range,
2662                  * figure out the new attributes.
2663                  */
2664                 if (what == HAT_SET_ATTR || what == HAT_LOAD_ATTR) {
2665                         if ((attr & PROT_WRITE) &&
2666                             !PTE_GET(oldpte, PT_WRITABLE))
2667                                 newpte |= PT_WRITABLE;
2668 
2669                         if ((attr & HAT_NOSYNC) &&
2670                             PTE_GET(oldpte, PT_SOFTWARE) < PT_NOSYNC)
2671                                 newpte |= PT_NOSYNC;
2672 
2673                         if ((attr & PROT_EXEC) && PTE_GET(oldpte, mmu.pt_nx))
2674                                 newpte &= ~mmu.pt_nx;
2675                 }
2676 
2677                 if (what == HAT_LOAD_ATTR) {
2678                         if (!(attr & PROT_WRITE) &&
2679                             PTE_GET(oldpte, PT_WRITABLE))
2680                                 newpte &= ~PT_WRITABLE;
2681 
2682                         if (!(attr & HAT_NOSYNC) &&
2683                             PTE_GET(oldpte, PT_SOFTWARE) >= PT_NOSYNC)
2684                                 newpte &= ~PT_SOFTWARE;
2685 
2686                         if (!(attr & PROT_EXEC) && !PTE_GET(oldpte, mmu.pt_nx))
2687                                 newpte |= mmu.pt_nx;
2688                 }
2689 
2690                 if (what == HAT_CLR_ATTR) {
2691                         if ((attr & PROT_WRITE) && PTE_GET(oldpte, PT_WRITABLE))
2692                                 newpte &= ~PT_WRITABLE;
2693 
2694                         if ((attr & HAT_NOSYNC) &&
2695                             PTE_GET(oldpte, PT_SOFTWARE) >= PT_NOSYNC)
2696                                 newpte &= ~PT_SOFTWARE;
2697 
2698                         if ((attr & PROT_EXEC) && !PTE_GET(oldpte, mmu.pt_nx))
2699                                 newpte |= mmu.pt_nx;
2700                 }
2701 
2702                 /*
2703                  * Ensure NOSYNC/NOCONSIST mappings have REF and MOD set.
2704                  * x86pte_set() depends on this.
2705                  */
2706                 if (PTE_GET(newpte, PT_SOFTWARE) >= PT_NOSYNC)
2707                         newpte |= PT_REF | PT_MOD;
2708 
2709                 /*
2710                  * what about PROT_READ or others? this code only handles:
2711                  * EXEC, WRITE, NOSYNC
2712                  */
2713 
2714                 /*
2715                  * If new PTE really changed, update the table.
2716                  */
2717                 if (newpte != oldpte) {
2718                         entry = htable_va2entry(vaddr, ht);
2719                         oldpte = hati_update_pte(ht, entry, oldpte, newpte);
2720                         if (oldpte != 0) {
2721                                 x86_hm_exit(pp);
2722                                 goto try_again;
2723                         }
2724                 }
2725                 x86_hm_exit(pp);
2726         }
2727         if (ht)
2728                 htable_release(ht);
2729         XPV_ALLOW_MIGRATE();
2730 }
2731 
2732 /*
2733  * Various wrappers for hat_updateattr()
2734  */
2735 void
2736 hat_setattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr)
2737 {
2738         ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
2739         hat_updateattr(hat, addr, len, attr, HAT_SET_ATTR);
2740 }
2741 
2742 void
2743 hat_clrattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr)
2744 {
2745         ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
2746         hat_updateattr(hat, addr, len, attr, HAT_CLR_ATTR);
2747 }
2748 
2749 void
2750 hat_chgattr(hat_t *hat, caddr_t addr, size_t len, uint_t attr)
2751 {
2752         ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
2753         hat_updateattr(hat, addr, len, attr, HAT_LOAD_ATTR);
2754 }
2755 
2756 void
2757 hat_chgprot(hat_t *hat, caddr_t addr, size_t len, uint_t vprot)
2758 {
2759         ASSERT(hat == kas.a_hat || (uintptr_t)addr + len <= _userlimit);
2760         hat_updateattr(hat, addr, len, vprot & HAT_PROT_MASK, HAT_LOAD_ATTR);
2761 }
2762 
2763 /*
2764  * size_t hat_getpagesize(hat, addr)
2765  *      returns pagesize in bytes for <hat, addr>. returns -1 of there is
2766  *      no mapping. This is an advisory call.
2767  */
2768 ssize_t
2769 hat_getpagesize(hat_t *hat, caddr_t addr)
2770 {
2771         uintptr_t       vaddr = ALIGN2PAGE(addr);
2772         htable_t        *ht;
2773         size_t          pagesize;
2774 
2775         ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
2776         if (IN_VA_HOLE(vaddr))
2777                 return (-1);
2778         ht = htable_getpage(hat, vaddr, NULL);
2779         if (ht == NULL)
2780                 return (-1);
2781         pagesize = LEVEL_SIZE(ht->ht_level);
2782         htable_release(ht);
2783         return (pagesize);
2784 }
2785 
2786 
2787 
2788 /*
2789  * pfn_t hat_getpfnum(hat, addr)
2790  *      returns pfn for <hat, addr> or PFN_INVALID if mapping is invalid.
2791  */
2792 pfn_t
2793 hat_getpfnum(hat_t *hat, caddr_t addr)
2794 {
2795         uintptr_t       vaddr = ALIGN2PAGE(addr);
2796         htable_t        *ht;
2797         uint_t          entry;
2798         pfn_t           pfn = PFN_INVALID;
2799 
2800         ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
2801         if (khat_running == 0)
2802                 return (PFN_INVALID);
2803 
2804         if (IN_VA_HOLE(vaddr))
2805                 return (PFN_INVALID);
2806 
2807         XPV_DISALLOW_MIGRATE();
2808         /*
2809          * A very common use of hat_getpfnum() is from the DDI for kernel pages.
2810          * Use the kmap_ptes (which also covers the 32 bit heap) to speed
2811          * this up.
2812          */
2813         if (mmu.kmap_addr <= vaddr && vaddr < mmu.kmap_eaddr) {
2814                 x86pte_t pte;
2815                 pgcnt_t pg_index;
2816 
2817                 pg_index = mmu_btop(vaddr - mmu.kmap_addr);
2818                 pte = GET_PTE(PT_INDEX_PTR(mmu.kmap_ptes, pg_index));
2819                 if (PTE_ISVALID(pte))
2820                         /*LINTED [use of constant 0 causes a lint warning] */
2821                         pfn = PTE2PFN(pte, 0);
2822                 XPV_ALLOW_MIGRATE();
2823                 return (pfn);
2824         }
2825 
2826         ht = htable_getpage(hat, vaddr, &entry);
2827         if (ht == NULL) {
2828                 XPV_ALLOW_MIGRATE();
2829                 return (PFN_INVALID);
2830         }
2831         ASSERT(vaddr >= ht->ht_vaddr);
2832         ASSERT(vaddr <= HTABLE_LAST_PAGE(ht));
2833         pfn = PTE2PFN(x86pte_get(ht, entry), ht->ht_level);
2834         if (ht->ht_level > 0)
2835                 pfn += mmu_btop(vaddr & LEVEL_OFFSET(ht->ht_level));
2836         htable_release(ht);
2837         XPV_ALLOW_MIGRATE();
2838         return (pfn);
2839 }
2840 
2841 /*
2842  * int hat_probe(hat, addr)
2843  *      return 0 if no valid mapping is present.  Faster version
2844  *      of hat_getattr in certain architectures.
2845  */
2846 int
2847 hat_probe(hat_t *hat, caddr_t addr)
2848 {
2849         uintptr_t       vaddr = ALIGN2PAGE(addr);
2850         uint_t          entry;
2851         htable_t        *ht;
2852         pgcnt_t         pg_off;
2853 
2854         ASSERT(hat == kas.a_hat || vaddr <= _userlimit);
2855         ASSERT(hat == kas.a_hat || AS_LOCK_HELD(hat->hat_as));
2856         if (IN_VA_HOLE(vaddr))
2857                 return (0);
2858 
2859         /*
2860          * Most common use of hat_probe is from segmap. We special case it
2861          * for performance.
2862          */
2863         if (mmu.kmap_addr <= vaddr && vaddr < mmu.kmap_eaddr) {
2864                 pg_off = mmu_btop(vaddr - mmu.kmap_addr);
2865                 if (mmu.pae_hat)
2866                         return (PTE_ISVALID(mmu.kmap_ptes[pg_off]));
2867                 else
2868                         return (PTE_ISVALID(
2869                             ((x86pte32_t *)mmu.kmap_ptes)[pg_off]));
2870         }
2871 
2872         ht = htable_getpage(hat, vaddr, &entry);
2873         htable_release(ht);
2874         return (ht != NULL);
2875 }
2876 
2877 /*
2878  * Find out if the segment for hat_share()/hat_unshare() is DISM or locked ISM.
2879  */
2880 static int
2881 is_it_dism(hat_t *hat, caddr_t va)
2882 {
2883         struct seg *seg;
2884         struct shm_data *shmd;
2885         struct spt_data *sptd;
2886 
2887         seg = as_findseg(hat->hat_as, va, 0);
2888         ASSERT(seg != NULL);
2889         ASSERT(seg->s_base <= va);
2890         shmd = (struct shm_data *)seg->s_data;
2891         ASSERT(shmd != NULL);
2892         sptd = (struct spt_data *)shmd->shm_sptseg->s_data;
2893         ASSERT(sptd != NULL);
2894         if (sptd->spt_flags & SHM_PAGEABLE)
2895                 return (1);
2896         return (0);
2897 }
2898 
2899 /*
2900  * Simple implementation of ISM. hat_share() is similar to hat_memload_array(),
2901  * except that we use the ism_hat's existing mappings to determine the pages
2902  * and protections to use for this hat. If we find a full properly aligned
2903  * and sized pagetable, we will attempt to share the pagetable itself.
2904  */
2905 /*ARGSUSED*/
2906 int
2907 hat_share(
2908         hat_t           *hat,
2909         caddr_t         addr,
2910         hat_t           *ism_hat,
2911         caddr_t         src_addr,
2912         size_t          len,    /* almost useless value, see below.. */
2913         uint_t          ismszc)
2914 {
2915         uintptr_t       vaddr_start = (uintptr_t)addr;
2916         uintptr_t       vaddr;
2917         uintptr_t       eaddr = vaddr_start + len;
2918         uintptr_t       ism_addr_start = (uintptr_t)src_addr;
2919         uintptr_t       ism_addr = ism_addr_start;
2920         uintptr_t       e_ism_addr = ism_addr + len;
2921         htable_t        *ism_ht = NULL;
2922         htable_t        *ht;
2923         x86pte_t        pte;
2924         page_t          *pp;
2925         pfn_t           pfn;
2926         level_t         l;
2927         pgcnt_t         pgcnt;
2928         uint_t          prot;
2929         int             is_dism;
2930         int             flags;
2931 
2932         /*
2933          * We might be asked to share an empty DISM hat by as_dup()
2934          */
2935         ASSERT(hat != kas.a_hat);
2936         ASSERT(eaddr <= _userlimit);
2937         if (!(ism_hat->hat_flags & HAT_SHARED)) {
2938                 ASSERT(hat_get_mapped_size(ism_hat) == 0);
2939                 return (0);
2940         }
2941         XPV_DISALLOW_MIGRATE();
2942 
2943         /*
2944          * The SPT segment driver often passes us a size larger than there are
2945          * valid mappings. That's because it rounds the segment size up to a
2946          * large pagesize, even if the actual memory mapped by ism_hat is less.
2947          */
2948         ASSERT(IS_PAGEALIGNED(vaddr_start));
2949         ASSERT(IS_PAGEALIGNED(ism_addr_start));
2950         ASSERT(ism_hat->hat_flags & HAT_SHARED);
2951         is_dism = is_it_dism(hat, addr);
2952         while (ism_addr < e_ism_addr) {
2953                 /*
2954                  * use htable_walk to get the next valid ISM mapping
2955                  */
2956                 pte = htable_walk(ism_hat, &ism_ht, &ism_addr, e_ism_addr);
2957                 if (ism_ht == NULL)
2958                         break;
2959 
2960                 /*
2961                  * First check to see if we already share the page table.
2962                  */
2963                 l = ism_ht->ht_level;
2964                 vaddr = vaddr_start + (ism_addr - ism_addr_start);
2965                 ht = htable_lookup(hat, vaddr, l);
2966                 if (ht != NULL) {
2967                         if (ht->ht_flags & HTABLE_SHARED_PFN)
2968                                 goto shared;
2969                         htable_release(ht);
2970                         goto not_shared;
2971                 }
2972 
2973                 /*
2974                  * Can't ever share top table.
2975                  */
2976                 if (l == mmu.max_level)
2977                         goto not_shared;
2978 
2979                 /*
2980                  * Avoid level mismatches later due to DISM faults.
2981                  */
2982                 if (is_dism && l > 0)
2983                         goto not_shared;
2984 
2985                 /*
2986                  * addresses and lengths must align
2987                  * table must be fully populated
2988                  * no lower level page tables
2989                  */
2990                 if (ism_addr != ism_ht->ht_vaddr ||
2991                     (vaddr & LEVEL_OFFSET(l + 1)) != 0)
2992                         goto not_shared;
2993 
2994                 /*
2995                  * The range of address space must cover a full table.
2996                  */
2997                 if (e_ism_addr - ism_addr < LEVEL_SIZE(l + 1))
2998                         goto not_shared;
2999 
3000                 /*
3001                  * All entries in the ISM page table must be leaf PTEs.
3002                  */
3003                 if (l > 0) {
3004                         int e;
3005 
3006                         /*
3007                          * We know the 0th is from htable_walk() above.
3008                          */
3009                         for (e = 1; e < HTABLE_NUM_PTES(ism_ht); ++e) {
3010                                 x86pte_t pte;
3011                                 pte = x86pte_get(ism_ht, e);
3012                                 if (!PTE_ISPAGE(pte, l))
3013                                         goto not_shared;
3014                         }
3015                 }
3016 
3017                 /*
3018                  * share the page table
3019                  */
3020                 ht = htable_create(hat, vaddr, l, ism_ht);
3021 shared:
3022                 ASSERT(ht->ht_flags & HTABLE_SHARED_PFN);
3023                 ASSERT(ht->ht_shares == ism_ht);
3024                 hat->hat_ism_pgcnt +=
3025                     (ism_ht->ht_valid_cnt - ht->ht_valid_cnt) <<
3026                     (LEVEL_SHIFT(ht->ht_level) - MMU_PAGESHIFT);
3027                 ht->ht_valid_cnt = ism_ht->ht_valid_cnt;
3028                 htable_release(ht);
3029                 ism_addr = ism_ht->ht_vaddr + LEVEL_SIZE(l + 1);
3030                 htable_release(ism_ht);
3031                 ism_ht = NULL;
3032                 continue;
3033 
3034 not_shared:
3035                 /*
3036                  * Unable to share the page table. Instead we will
3037                  * create new mappings from the values in the ISM mappings.
3038                  * Figure out what level size mappings to use;
3039                  */
3040                 for (l = ism_ht->ht_level; l > 0; --l) {
3041                         if (LEVEL_SIZE(l) <= eaddr - vaddr &&
3042                             (vaddr & LEVEL_OFFSET(l)) == 0)
3043                                 break;
3044                 }
3045 
3046                 /*
3047                  * The ISM mapping might be larger than the share area,
3048                  * be careful to truncate it if needed.
3049                  */
3050                 if (eaddr - vaddr >= LEVEL_SIZE(ism_ht->ht_level)) {
3051                         pgcnt = mmu_btop(LEVEL_SIZE(ism_ht->ht_level));
3052                 } else {
3053                         pgcnt = mmu_btop(eaddr - vaddr);
3054                         l = 0;
3055                 }
3056 
3057                 pfn = PTE2PFN(pte, ism_ht->ht_level);
3058                 ASSERT(pfn != PFN_INVALID);
3059                 while (pgcnt > 0) {
3060                         /*
3061                          * Make a new pte for the PFN for this level.
3062                          * Copy protections for the pte from the ISM pte.
3063                          */
3064                         pp = page_numtopp_nolock(pfn);
3065                         ASSERT(pp != NULL);
3066 
3067                         prot = PROT_USER | PROT_READ | HAT_UNORDERED_OK;
3068                         if (PTE_GET(pte, PT_WRITABLE))
3069                                 prot |= PROT_WRITE;
3070                         if (!PTE_GET(pte, PT_NX))
3071                                 prot |= PROT_EXEC;
3072 
3073                         flags = HAT_LOAD;
3074                         if (!is_dism)
3075                                 flags |= HAT_LOAD_LOCK | HAT_LOAD_NOCONSIST;
3076                         while (hati_load_common(hat, vaddr, pp, prot, flags,
3077                             l, pfn) != 0) {
3078                                 if (l == 0)
3079                                         panic("hati_load_common() failure");
3080                                 --l;
3081                         }
3082 
3083                         vaddr += LEVEL_SIZE(l);
3084                         ism_addr += LEVEL_SIZE(l);
3085                         pfn += mmu_btop(LEVEL_SIZE(l));
3086                         pgcnt -= mmu_btop(LEVEL_SIZE(l));
3087                 }
3088         }
3089         if (ism_ht != NULL)
3090                 htable_release(ism_ht);
3091         XPV_ALLOW_MIGRATE();
3092         return (0);
3093 }
3094 
3095 
3096 /*
3097  * hat_unshare() is similar to hat_unload_callback(), but
3098  * we have to look for empty shared pagetables. Note that
3099  * hat_unshare() is always invoked against an entire segment.
3100  */
3101 /*ARGSUSED*/
3102 void
3103 hat_unshare(hat_t *hat, caddr_t addr, size_t len, uint_t ismszc)
3104 {
3105         uint64_t        vaddr = (uintptr_t)addr;
3106         uintptr_t       eaddr = vaddr + len;
3107         htable_t        *ht = NULL;
3108         uint_t          need_demaps = 0;
3109         int             flags = HAT_UNLOAD_UNMAP;
3110         level_t         l;
3111 
3112         ASSERT(hat != kas.a_hat);
3113         ASSERT(eaddr <= _userlimit);
3114         ASSERT(IS_PAGEALIGNED(vaddr));
3115         ASSERT(IS_PAGEALIGNED(eaddr));
3116         XPV_DISALLOW_MIGRATE();
3117 
3118         /*
3119          * First go through and remove any shared pagetables.
3120          *
3121          * Note that it's ok to delay the TLB shootdown till the entire range is
3122          * finished, because if hat_pageunload() were to unload a shared
3123          * pagetable page, its hat_tlb_inval() will do a global TLB invalidate.
3124          */
3125         l = mmu.max_page_level;
3126         if (l == mmu.max_level)
3127                 --l;
3128         for (; l >= 0; --l) {
3129                 for (vaddr = (uintptr_t)addr; vaddr < eaddr;
3130                     vaddr = (vaddr & LEVEL_MASK(l + 1)) + LEVEL_SIZE(l + 1)) {
3131                         ASSERT(!IN_VA_HOLE(vaddr));
3132                         /*
3133                          * find a pagetable that maps the current address
3134                          */
3135                         ht = htable_lookup(hat, vaddr, l);
3136                         if (ht == NULL)
3137                                 continue;
3138                         if (ht->ht_flags & HTABLE_SHARED_PFN) {
3139                                 /*
3140                                  * clear page count, set valid_cnt to 0,
3141                                  * let htable_release() finish the job
3142                                  */
3143                                 hat->hat_ism_pgcnt -= ht->ht_valid_cnt <<
3144                                     (LEVEL_SHIFT(ht->ht_level) - MMU_PAGESHIFT);
3145                                 ht->ht_valid_cnt = 0;
3146                                 need_demaps = 1;
3147                         }
3148                         htable_release(ht);
3149                 }
3150         }
3151 
3152         /*
3153          * flush the TLBs - since we're probably dealing with MANY mappings
3154          * we do just one CR3 reload.
3155          */
3156         if (!(hat->hat_flags & HAT_FREEING) && need_demaps)
3157                 hat_tlb_inval(hat, DEMAP_ALL_ADDR);
3158 
3159         /*
3160          * Now go back and clean up any unaligned mappings that
3161          * couldn't share pagetables.
3162          */
3163         if (!is_it_dism(hat, addr))
3164                 flags |= HAT_UNLOAD_UNLOCK;
3165         hat_unload(hat, addr, len, flags);
3166         XPV_ALLOW_MIGRATE();
3167 }
3168 
3169 
3170 /*
3171  * hat_reserve() does nothing
3172  */
3173 /*ARGSUSED*/
3174 void
3175 hat_reserve(struct as *as, caddr_t addr, size_t len)
3176 {
3177 }
3178 
3179 
3180 /*
3181  * Called when all mappings to a page should have write permission removed.
3182  * Mostly stolen from hat_pagesync()
3183  */
3184 static void
3185 hati_page_clrwrt(struct page *pp)
3186 {
3187         hment_t         *hm = NULL;
3188         htable_t        *ht;
3189         uint_t          entry;
3190         x86pte_t        old;
3191         x86pte_t        new;
3192         uint_t          pszc = 0;
3193 
3194         XPV_DISALLOW_MIGRATE();
3195 next_size:
3196         /*
3197          * walk thru the mapping list clearing write permission
3198          */
3199         x86_hm_enter(pp);
3200         while ((hm = hment_walk(pp, &ht, &entry, hm)) != NULL) {
3201                 if (ht->ht_level < pszc)
3202                         continue;
3203                 old = x86pte_get(ht, entry);
3204 
3205                 for (;;) {
3206                         /*
3207                          * Is this mapping of interest?
3208                          */
3209                         if (PTE2PFN(old, ht->ht_level) != pp->p_pagenum ||
3210                             PTE_GET(old, PT_WRITABLE) == 0)
3211                                 break;
3212 
3213                         /*
3214                          * Clear ref/mod writable bits. This requires cross
3215                          * calls to ensure any executing TLBs see cleared bits.
3216                          */
3217                         new = old;
3218                         PTE_CLR(new, PT_REF | PT_MOD | PT_WRITABLE);
3219                         old = hati_update_pte(ht, entry, old, new);
3220                         if (old != 0)
3221                                 continue;
3222 
3223                         break;
3224                 }
3225         }
3226         x86_hm_exit(pp);
3227         while (pszc < pp->p_szc) {
3228                 page_t *tpp;
3229                 pszc++;
3230                 tpp = PP_GROUPLEADER(pp, pszc);
3231                 if (pp != tpp) {
3232                         pp = tpp;
3233                         goto next_size;
3234                 }
3235         }
3236         XPV_ALLOW_MIGRATE();
3237 }
3238 
3239 /*
3240  * void hat_page_setattr(pp, flag)
3241  * void hat_page_clrattr(pp, flag)
3242  *      used to set/clr ref/mod bits.
3243  */
3244 void
3245 hat_page_setattr(struct page *pp, uint_t flag)
3246 {
3247         vnode_t         *vp = pp->p_vnode;
3248         kmutex_t        *vphm = NULL;
3249         page_t          **listp;
3250         int             noshuffle;
3251 
3252         noshuffle = flag & P_NSH;
3253         flag &= ~P_NSH;
3254 
3255         if (PP_GETRM(pp, flag) == flag)
3256                 return;
3257 
3258         if ((flag & P_MOD) != 0 && vp != NULL && IS_VMODSORT(vp) &&
3259             !noshuffle) {
3260                 vphm = page_vnode_mutex(vp);
3261                 mutex_enter(vphm);
3262         }
3263 
3264         PP_SETRM(pp, flag);
3265 
3266         if (vphm != NULL) {
3267 
3268                 /*
3269                  * Some File Systems examine v_pages for NULL w/o
3270                  * grabbing the vphm mutex. Must not let it become NULL when
3271                  * pp is the only page on the list.
3272                  */
3273                 if (pp->p_vpnext != pp) {
3274                         page_vpsub(&vp->v_pages, pp);
3275                         if (vp->v_pages != NULL)
3276                                 listp = &vp->v_pages->p_vpprev->p_vpnext;
3277                         else
3278                                 listp = &vp->v_pages;
3279                         page_vpadd(listp, pp);
3280                 }
3281                 mutex_exit(vphm);
3282         }
3283 }
3284 
3285 void
3286 hat_page_clrattr(struct page *pp, uint_t flag)
3287 {
3288         vnode_t         *vp = pp->p_vnode;
3289         ASSERT(!(flag & ~(P_MOD | P_REF | P_RO)));
3290 
3291         /*
3292          * Caller is expected to hold page's io lock for VMODSORT to work
3293          * correctly with pvn_vplist_dirty() and pvn_getdirty() when mod
3294          * bit is cleared.
3295          * We don't have assert to avoid tripping some existing third party
3296          * code. The dirty page is moved back to top of the v_page list
3297          * after IO is done in pvn_write_done().
3298          */
3299         PP_CLRRM(pp, flag);
3300 
3301         if ((flag & P_MOD) != 0 && vp != NULL && IS_VMODSORT(vp)) {
3302 
3303                 /*
3304                  * VMODSORT works by removing write permissions and getting
3305                  * a fault when a page is made dirty. At this point
3306                  * we need to remove write permission from all mappings
3307                  * to this page.
3308                  */
3309                 hati_page_clrwrt(pp);
3310         }
3311 }
3312 
3313 /*
3314  *      If flag is specified, returns 0 if attribute is disabled
3315  *      and non zero if enabled.  If flag specifes multiple attributes
3316  *      then returns 0 if ALL attributes are disabled.  This is an advisory
3317  *      call.
3318  */
3319 uint_t
3320 hat_page_getattr(struct page *pp, uint_t flag)
3321 {
3322         return (PP_GETRM(pp, flag));
3323 }
3324 
3325 
3326 /*
3327  * common code used by hat_page_inval() and hment_steal()
3328  */
3329 hment_t *
3330 hati_page_unmap(page_t *pp, htable_t *ht, uint_t entry)
3331 {
3332         x86pte_t old_pte;
3333         pfn_t pfn = pp->p_pagenum;
3334         hment_t *hm;
3335 
3336         /*
3337          * We need to acquire a hold on the htable in order to
3338          * do the invalidate. We know the htable must exist, since
3339          * unmap's don't release the htable until after removing any
3340          * hment. Having x86_hm_enter() keeps that from proceeding.
3341          */
3342         htable_acquire(ht);
3343 
3344         /*
3345          * Invalidate the PTE and remove the hment.
3346          */
3347         old_pte = x86pte_inval(ht, entry, 0, NULL, B_TRUE);
3348         if (PTE2PFN(old_pte, ht->ht_level) != pfn) {
3349                 panic("x86pte_inval() failure found PTE = " FMT_PTE
3350                     " pfn being unmapped is %lx ht=0x%lx entry=0x%x",
3351                     old_pte, pfn, (uintptr_t)ht, entry);
3352         }
3353 
3354         /*
3355          * Clean up all the htable information for this mapping
3356          */
3357         ASSERT(ht->ht_valid_cnt > 0);
3358         HTABLE_DEC(ht->ht_valid_cnt);
3359         PGCNT_DEC(ht->ht_hat, ht->ht_level);
3360 
3361         /*
3362          * sync ref/mod bits to the page_t
3363          */
3364         if (PTE_GET(old_pte, PT_SOFTWARE) < PT_NOSYNC)
3365                 hati_sync_pte_to_page(pp, old_pte, ht->ht_level);
3366 
3367         /*
3368          * Remove the mapping list entry for this page.
3369          */
3370         hm = hment_remove(pp, ht, entry);
3371 
3372         /*
3373          * drop the mapping list lock so that we might free the
3374          * hment and htable.
3375          */
3376         x86_hm_exit(pp);
3377         htable_release(ht);
3378         return (hm);
3379 }
3380 
3381 extern int      vpm_enable;
3382 /*
3383  * Unload translations to a page. If the page is a subpage of a large
3384  * page, the large page mappings are also removed.
3385  * If curhat is not NULL, then we only unload the translation
3386  * for the given process, otherwise all translations are unloaded.
3387  */
3388 void
3389 hat_page_inval(struct page *pp, uint_t pg_szcd, struct hat *curhat)
3390 {
3391         page_t          *cur_pp = pp;
3392         hment_t         *hm;
3393         hment_t         *prev;
3394         htable_t        *ht;
3395         uint_t          entry;
3396         level_t         level;
3397         ulong_t         cnt;
3398 
3399         XPV_DISALLOW_MIGRATE();
3400 
3401 #if defined(__amd64)
3402         /*
3403          * clear the vpm ref.
3404          */
3405         if (vpm_enable) {
3406                 pp->p_vpmref = 0;
3407         }
3408 #endif
3409         /*
3410          * The loop with next_size handles pages with multiple pagesize mappings
3411          */
3412 next_size:
3413         if (curhat != NULL)
3414                 cnt = hat_page_getshare(cur_pp);
3415         for (;;) {
3416 
3417                 /*
3418                  * Get a mapping list entry
3419                  */
3420                 x86_hm_enter(cur_pp);
3421                 for (prev = NULL; ; prev = hm) {
3422                         hm = hment_walk(cur_pp, &ht, &entry, prev);
3423                         if (hm == NULL) {
3424                                 x86_hm_exit(cur_pp);
3425 
3426 curproc_done:
3427                                 /*
3428                                  * If not part of a larger page, we're done.
3429                                  */
3430                                 if (cur_pp->p_szc <= pg_szcd) {
3431                                         XPV_ALLOW_MIGRATE();
3432                                         return;
3433                                 }
3434 
3435                                 /*
3436                                  * Else check the next larger page size.
3437                                  * hat_page_demote() may decrease p_szc
3438                                  * but that's ok we'll just take an extra
3439                                  * trip discover there're no larger mappings
3440                                  * and return.
3441                                  */
3442                                 ++pg_szcd;
3443                                 cur_pp = PP_GROUPLEADER(cur_pp, pg_szcd);
3444                                 goto next_size;
3445                         }
3446 
3447                         /*
3448                          * If this mapping size matches, remove it.
3449                          */
3450                         level = ht->ht_level;
3451                         if (level == pg_szcd) {
3452                                 if (curhat == NULL || ht->ht_hat == curhat)
3453                                         break;
3454                                 /*
3455                                  * Unloading only the given process but it's
3456                                  * not the hat for the current process. Leave
3457                                  * entry in place. Also do a safety check to
3458                                  * ensure we don't get in an infinite loop
3459                                  */
3460                                 if (cnt-- == 0) {
3461                                         x86_hm_exit(cur_pp);
3462                                         goto curproc_done;
3463                                 }
3464                         }
3465                 }
3466 
3467                 /*
3468                  * Remove the mapping list entry for this page.
3469                  * Note this does the x86_hm_exit() for us.
3470                  */
3471                 hm = hati_page_unmap(cur_pp, ht, entry);
3472                 if (hm != NULL)
3473                         hment_free(hm);
3474 
3475                 /* Perform check above for being part of a larger page. */
3476                 if (curhat != NULL)
3477                         goto curproc_done;
3478         }
3479 }
3480 
3481 /*
3482  * Unload translations to a page. If unloadflag is HAT_CURPROC_PGUNLOAD, then
3483  * we only unload the translation for the current process, otherwise all
3484  * translations are unloaded.
3485  */
3486 static int
3487 hati_pageunload(struct page *pp, uint_t pg_szcd, uint_t unloadflag)
3488 {
3489         struct hat      *curhat = NULL;
3490 
3491         /*
3492          * prevent recursion due to kmem_free()
3493          */
3494         ++curthread->t_hatdepth;
3495         ASSERT(curthread->t_hatdepth < 16);
3496 
3497         if (unloadflag == HAT_CURPROC_PGUNLOAD)
3498                 curhat = curthread->t_procp->p_as->a_hat;
3499 
3500         hat_page_inval(pp, pg_szcd, curhat);
3501 
3502         ASSERT(curthread->t_hatdepth > 0);
3503         --curthread->t_hatdepth;
3504         return (0);
3505 }
3506 
3507 int
3508 hat_pageunload(struct page *pp, uint_t unloadflag)
3509 {
3510         ASSERT(PAGE_EXCL(pp));
3511         return (hati_pageunload(pp, 0, unloadflag));
3512 }
3513 
3514 /*
3515  * Unload all large mappings to pp and reduce by 1 p_szc field of every large
3516  * page level that included pp.
3517  *
3518  * pp must be locked EXCL. Even though no other constituent pages are locked
3519  * it's legal to unload large mappings to pp because all constituent pages of
3520  * large locked mappings have to be locked SHARED.  therefore if we have EXCL
3521  * lock on one of constituent pages none of the large mappings to pp are
3522  * locked.
3523  *
3524  * Change (always decrease) p_szc field starting from the last constituent
3525  * page and ending with root constituent page so that root's pszc always shows
3526  * the area where hat_page_demote() may be active.
3527  *
3528  * This mechanism is only used for file system pages where it's not always
3529  * possible to get EXCL locks on all constituent pages to demote the size code
3530  * (as is done for anonymous or kernel large pages).
3531  */
3532 void
3533 hat_page_demote(page_t *pp)
3534 {
3535         uint_t          pszc;
3536         uint_t          rszc;
3537         uint_t          szc;
3538         page_t          *rootpp;
3539         page_t          *firstpp;
3540         page_t          *lastpp;
3541         pgcnt_t         pgcnt;
3542 
3543         ASSERT(PAGE_EXCL(pp));
3544         ASSERT(!PP_ISFREE(pp));
3545         ASSERT(page_szc_lock_assert(pp));
3546 
3547         if (pp->p_szc == 0)
3548                 return;
3549 
3550         rootpp = PP_GROUPLEADER(pp, 1);
3551         (void) hati_pageunload(rootpp, 1, HAT_FORCE_PGUNLOAD);
3552 
3553         /*
3554          * all large mappings to pp are gone
3555          * and no new can be setup since pp is locked exclusively.
3556          *
3557          * Lock the root to make sure there's only one hat_page_demote()
3558          * outstanding within the area of this root's pszc.
3559          *
3560          * Second potential hat_page_demote() is already eliminated by upper
3561          * VM layer via page_szc_lock() but we don't rely on it and use our
3562          * own locking (so that upper layer locking can be changed without
3563          * assumptions that hat depends on upper layer VM to prevent multiple
3564          * hat_page_demote() to be issued simultaneously to the same large
3565          * page).
3566          */
3567 again:
3568         pszc = pp->p_szc;
3569         if (pszc == 0)
3570                 return;
3571         rootpp = PP_GROUPLEADER(pp, pszc);
3572         x86_hm_enter(rootpp);
3573         /*
3574          * If root's p_szc is different from pszc we raced with another
3575          * hat_page_demote().  Drop the lock and try to find the root again.
3576          * If root's p_szc is greater than pszc previous hat_page_demote() is
3577          * not done yet.  Take and release mlist lock of root's root to wait
3578          * for previous hat_page_demote() to complete.
3579          */
3580         if ((rszc = rootpp->p_szc) != pszc) {
3581                 x86_hm_exit(rootpp);
3582                 if (rszc > pszc) {
3583                         /* p_szc of a locked non free page can't increase */
3584                         ASSERT(pp != rootpp);
3585 
3586                         rootpp = PP_GROUPLEADER(rootpp, rszc);
3587                         x86_hm_enter(rootpp);
3588                         x86_hm_exit(rootpp);
3589                 }
3590                 goto again;
3591         }
3592         ASSERT(pp->p_szc == pszc);
3593 
3594         /*
3595          * Decrement by 1 p_szc of every constituent page of a region that
3596          * covered pp. For example if original szc is 3 it gets changed to 2
3597          * everywhere except in region 2 that covered pp. Region 2 that
3598          * covered pp gets demoted to 1 everywhere except in region 1 that
3599          * covered pp. The region 1 that covered pp is demoted to region
3600          * 0. It's done this way because from region 3 we removed level 3
3601          * mappings, from region 2 that covered pp we removed level 2 mappings
3602          * and from region 1 that covered pp we removed level 1 mappings.  All
3603          * changes are done from from high pfn's to low pfn's so that roots
3604          * are changed last allowing one to know the largest region where
3605          * hat_page_demote() is stil active by only looking at the root page.
3606          *
3607          * This algorithm is implemented in 2 while loops. First loop changes
3608          * p_szc of pages to the right of pp's level 1 region and second
3609          * loop changes p_szc of pages of level 1 region that covers pp
3610          * and all pages to the left of level 1 region that covers pp.
3611          * In the first loop p_szc keeps dropping with every iteration
3612          * and in the second loop it keeps increasing with every iteration.
3613          *
3614          * First loop description: Demote pages to the right of pp outside of
3615          * level 1 region that covers pp.  In every iteration of the while
3616          * loop below find the last page of szc region and the first page of
3617          * (szc - 1) region that is immediately to the right of (szc - 1)
3618          * region that covers pp.  From last such page to first such page
3619          * change every page's szc to szc - 1. Decrement szc and continue
3620          * looping until szc is 1. If pp belongs to the last (szc - 1) region
3621          * of szc region skip to the next iteration.
3622          */
3623         szc = pszc;
3624         while (szc > 1) {
3625                 lastpp = PP_GROUPLEADER(pp, szc);
3626                 pgcnt = page_get_pagecnt(szc);
3627                 lastpp += pgcnt - 1;
3628                 firstpp = PP_GROUPLEADER(pp, (szc - 1));
3629                 pgcnt = page_get_pagecnt(szc - 1);
3630                 if (lastpp - firstpp < pgcnt) {
3631                         szc--;
3632                         continue;
3633                 }
3634                 firstpp += pgcnt;
3635                 while (lastpp != firstpp) {
3636                         ASSERT(lastpp->p_szc == pszc);
3637                         lastpp->p_szc = szc - 1;
3638                         lastpp--;
3639                 }
3640                 firstpp->p_szc = szc - 1;
3641                 szc--;
3642         }
3643 
3644         /*
3645          * Second loop description:
3646          * First iteration changes p_szc to 0 of every
3647          * page of level 1 region that covers pp.
3648          * Subsequent iterations find last page of szc region
3649          * immediately to the left of szc region that covered pp
3650          * and first page of (szc + 1) region that covers pp.
3651          * From last to first page change p_szc of every page to szc.
3652          * Increment szc and continue looping until szc is pszc.
3653          * If pp belongs to the fist szc region of (szc + 1) region
3654          * skip to the next iteration.
3655          *
3656          */
3657         szc = 0;
3658         while (szc < pszc) {
3659                 firstpp = PP_GROUPLEADER(pp, (szc + 1));
3660                 if (szc == 0) {
3661                         pgcnt = page_get_pagecnt(1);
3662                         lastpp = firstpp + (pgcnt - 1);
3663                 } else {
3664                         lastpp = PP_GROUPLEADER(pp, szc);
3665                         if (firstpp == lastpp) {
3666                                 szc++;
3667                                 continue;
3668                         }
3669                         lastpp--;
3670                         pgcnt = page_get_pagecnt(szc);
3671                 }
3672                 while (lastpp != firstpp) {
3673                         ASSERT(lastpp->p_szc == pszc);
3674                         lastpp->p_szc = szc;
3675                         lastpp--;
3676                 }
3677                 firstpp->p_szc = szc;
3678                 if (firstpp == rootpp)
3679                         break;
3680                 szc++;
3681         }
3682         x86_hm_exit(rootpp);
3683 }
3684 
3685 /*
3686  * get hw stats from hardware into page struct and reset hw stats
3687  * returns attributes of page
3688  * Flags for hat_pagesync, hat_getstat, hat_sync
3689  *
3690  * define       HAT_SYNC_ZERORM         0x01
3691  *
3692  * Additional flags for hat_pagesync
3693  *
3694  * define       HAT_SYNC_STOPON_REF     0x02
3695  * define       HAT_SYNC_STOPON_MOD     0x04
3696  * define       HAT_SYNC_STOPON_RM      0x06
3697  * define       HAT_SYNC_STOPON_SHARED  0x08
3698  */
3699 uint_t
3700 hat_pagesync(struct page *pp, uint_t flags)
3701 {
3702         hment_t         *hm = NULL;
3703         htable_t        *ht;
3704         uint_t          entry;
3705         x86pte_t        old, save_old;
3706         x86pte_t        new;
3707         uchar_t         nrmbits = P_REF|P_MOD|P_RO;
3708         extern ulong_t  po_share;
3709         page_t          *save_pp = pp;
3710         uint_t          pszc = 0;
3711 
3712         ASSERT(PAGE_LOCKED(pp) || panicstr);
3713 
3714         if (PP_ISRO(pp) && (flags & HAT_SYNC_STOPON_MOD))
3715                 return (pp->p_nrm & nrmbits);
3716 
3717         if ((flags & HAT_SYNC_ZERORM) == 0) {
3718 
3719                 if ((flags & HAT_SYNC_STOPON_REF) != 0 && PP_ISREF(pp))
3720                         return (pp->p_nrm & nrmbits);
3721 
3722                 if ((flags & HAT_SYNC_STOPON_MOD) != 0 && PP_ISMOD(pp))
3723                         return (pp->p_nrm & nrmbits);
3724 
3725                 if ((flags & HAT_SYNC_STOPON_SHARED) != 0 &&
3726                     hat_page_getshare(pp) > po_share) {
3727                         if (PP_ISRO(pp))
3728                                 PP_SETREF(pp);
3729                         return (pp->p_nrm & nrmbits);
3730                 }
3731         }
3732 
3733         XPV_DISALLOW_MIGRATE();
3734 next_size:
3735         /*
3736          * walk thru the mapping list syncing (and clearing) ref/mod bits.
3737          */
3738         x86_hm_enter(pp);
3739         while ((hm = hment_walk(pp, &ht, &entry, hm)) != NULL) {
3740                 if (ht->ht_level < pszc)
3741                         continue;
3742                 old = x86pte_get(ht, entry);
3743 try_again:
3744 
3745                 ASSERT(PTE2PFN(old, ht->ht_level) == pp->p_pagenum);
3746 
3747                 if (PTE_GET(old, PT_REF | PT_MOD) == 0)
3748                         continue;
3749 
3750                 save_old = old;
3751                 if ((flags & HAT_SYNC_ZERORM) != 0) {
3752 
3753                         /*
3754                          * Need to clear ref or mod bits. Need to demap
3755                          * to make sure any executing TLBs see cleared bits.
3756                          */
3757                         new = old;
3758                         PTE_CLR(new, PT_REF | PT_MOD);
3759                         old = hati_update_pte(ht, entry, old, new);
3760                         if (old != 0)
3761                                 goto try_again;
3762 
3763                         old = save_old;
3764                 }
3765 
3766                 /*
3767                  * Sync the PTE
3768                  */
3769                 if (!(flags & HAT_SYNC_ZERORM) &&
3770                     PTE_GET(old, PT_SOFTWARE) <= PT_NOSYNC)
3771                         hati_sync_pte_to_page(pp, old, ht->ht_level);
3772 
3773                 /*
3774                  * can stop short if we found a ref'd or mod'd page
3775                  */
3776                 if ((flags & HAT_SYNC_STOPON_MOD) && PP_ISMOD(save_pp) ||
3777                     (flags & HAT_SYNC_STOPON_REF) && PP_ISREF(save_pp)) {
3778                         x86_hm_exit(pp);
3779                         goto done;
3780                 }
3781         }
3782         x86_hm_exit(pp);
3783         while (pszc < pp->p_szc) {
3784                 page_t *tpp;
3785                 pszc++;
3786                 tpp = PP_GROUPLEADER(pp, pszc);
3787                 if (pp != tpp) {
3788                         pp = tpp;
3789                         goto next_size;
3790                 }
3791         }
3792 done:
3793         XPV_ALLOW_MIGRATE();
3794         return (save_pp->p_nrm & nrmbits);
3795 }
3796 
3797 /*
3798  * returns approx number of mappings to this pp.  A return of 0 implies
3799  * there are no mappings to the page.
3800  */
3801 ulong_t
3802 hat_page_getshare(page_t *pp)
3803 {
3804         uint_t cnt;
3805         cnt = hment_mapcnt(pp);
3806 #if defined(__amd64)
3807         if (vpm_enable && pp->p_vpmref) {
3808                 cnt += 1;
3809         }
3810 #endif
3811         return (cnt);
3812 }
3813 
3814 /*
3815  * Return 1 the number of mappings exceeds sh_thresh. Return 0
3816  * otherwise.
3817  */
3818 int
3819 hat_page_checkshare(page_t *pp, ulong_t sh_thresh)
3820 {
3821         return (hat_page_getshare(pp) > sh_thresh);
3822 }
3823 
3824 /*
3825  * hat_softlock isn't supported anymore
3826  */
3827 /*ARGSUSED*/
3828 faultcode_t
3829 hat_softlock(
3830         hat_t *hat,
3831         caddr_t addr,
3832         size_t *len,
3833         struct page **page_array,
3834         uint_t flags)
3835 {
3836         return (FC_NOSUPPORT);
3837 }
3838 
3839 
3840 
3841 /*
3842  * Routine to expose supported HAT features to platform independent code.
3843  */
3844 /*ARGSUSED*/
3845 int
3846 hat_supported(enum hat_features feature, void *arg)
3847 {
3848         switch (feature) {
3849 
3850         case HAT_SHARED_PT:     /* this is really ISM */
3851                 return (1);
3852 
3853         case HAT_DYNAMIC_ISM_UNMAP:
3854                 return (0);
3855 
3856         case HAT_VMODSORT:
3857                 return (1);
3858 
3859         case HAT_SHARED_REGIONS:
3860                 return (0);
3861 
3862         default:
3863                 panic("hat_supported() - unknown feature");
3864         }
3865         return (0);
3866 }
3867 
3868 /*
3869  * Called when a thread is exiting and has been switched to the kernel AS
3870  */
3871 void
3872 hat_thread_exit(kthread_t *thd)
3873 {
3874         ASSERT(thd->t_procp->p_as == &kas);
3875         XPV_DISALLOW_MIGRATE();
3876         hat_switch(thd->t_procp->p_as->a_hat);
3877         XPV_ALLOW_MIGRATE();
3878 }
3879 
3880 /*
3881  * Setup the given brand new hat structure as the new HAT on this cpu's mmu.
3882  */
3883 /*ARGSUSED*/
3884 void
3885 hat_setup(hat_t *hat, int flags)
3886 {
3887         XPV_DISALLOW_MIGRATE();
3888         kpreempt_disable();
3889 
3890         hat_switch(hat);
3891 
3892         kpreempt_enable();
3893         XPV_ALLOW_MIGRATE();
3894 }
3895 
3896 /*
3897  * Prepare for a CPU private mapping for the given address.
3898  *
3899  * The address can only be used from a single CPU and can be remapped
3900  * using hat_mempte_remap().  Return the address of the PTE.
3901  *
3902  * We do the htable_create() if necessary and increment the valid count so
3903  * the htable can't disappear.  We also hat_devload() the page table into
3904  * kernel so that the PTE is quickly accessed.
3905  */
3906 hat_mempte_t
3907 hat_mempte_setup(caddr_t addr)
3908 {
3909         uintptr_t       va = (uintptr_t)addr;
3910         htable_t        *ht;
3911         uint_t          entry;
3912         x86pte_t        oldpte;
3913         hat_mempte_t    p;
3914 
3915         ASSERT(IS_PAGEALIGNED(va));
3916         ASSERT(!IN_VA_HOLE(va));
3917         ++curthread->t_hatdepth;
3918         XPV_DISALLOW_MIGRATE();
3919         ht = htable_getpte(kas.a_hat, va, &entry, &oldpte, 0);
3920         if (ht == NULL) {
3921                 ht = htable_create(kas.a_hat, va, 0, NULL);
3922                 entry = htable_va2entry(va, ht);
3923                 ASSERT(ht->ht_level == 0);
3924                 oldpte = x86pte_get(ht, entry);
3925         }
3926         if (PTE_ISVALID(oldpte))
3927                 panic("hat_mempte_setup(): address already mapped"
3928                     "ht=%p, entry=%d, pte=" FMT_PTE, (void *)ht, entry, oldpte);
3929 
3930         /*
3931          * increment ht_valid_cnt so that the pagetable can't disappear
3932          */
3933         HTABLE_INC(ht->ht_valid_cnt);
3934 
3935         /*
3936          * return the PTE physical address to the caller.
3937          */
3938         htable_release(ht);
3939         XPV_ALLOW_MIGRATE();
3940         p = PT_INDEX_PHYSADDR(pfn_to_pa(ht->ht_pfn), entry);
3941         --curthread->t_hatdepth;
3942         return (p);
3943 }
3944 
3945 /*
3946  * Release a CPU private mapping for the given address.
3947  * We decrement the htable valid count so it might be destroyed.
3948  */
3949 /*ARGSUSED1*/
3950 void
3951 hat_mempte_release(caddr_t addr, hat_mempte_t pte_pa)
3952 {
3953         htable_t        *ht;
3954 
3955         XPV_DISALLOW_MIGRATE();
3956         /*
3957          * invalidate any left over mapping and decrement the htable valid count
3958          */
3959 #ifdef __xpv
3960         if (HYPERVISOR_update_va_mapping((uintptr_t)addr, 0,
3961             UVMF_INVLPG | UVMF_LOCAL))
3962                 panic("HYPERVISOR_update_va_mapping() failed");
3963 #else
3964         {
3965                 x86pte_t *pteptr;
3966 
3967                 pteptr = x86pte_mapin(mmu_btop(pte_pa),
3968                     (pte_pa & MMU_PAGEOFFSET) >> mmu.pte_size_shift, NULL);
3969                 if (mmu.pae_hat)
3970                         *pteptr = 0;
3971                 else
3972                         *(x86pte32_t *)pteptr = 0;
3973                 mmu_tlbflush_entry(addr);
3974                 x86pte_mapout();
3975         }
3976 #endif
3977 
3978         ht = htable_getpte(kas.a_hat, ALIGN2PAGE(addr), NULL, NULL, 0);
3979         if (ht == NULL)
3980                 panic("hat_mempte_release(): invalid address");
3981         ASSERT(ht->ht_level == 0);
3982         HTABLE_DEC(ht->ht_valid_cnt);
3983         htable_release(ht);
3984         XPV_ALLOW_MIGRATE();
3985 }
3986 
3987 /*
3988  * Apply a temporary CPU private mapping to a page. We flush the TLB only
3989  * on this CPU, so this ought to have been called with preemption disabled.
3990  */
3991 void
3992 hat_mempte_remap(
3993         pfn_t           pfn,
3994         caddr_t         addr,
3995         hat_mempte_t    pte_pa,
3996         uint_t          attr,
3997         uint_t          flags)
3998 {
3999         uintptr_t       va = (uintptr_t)addr;
4000         x86pte_t        pte;
4001 
4002         /*
4003          * Remap the given PTE to the new page's PFN. Invalidate only
4004          * on this CPU.
4005          */
4006 #ifdef DEBUG
4007         htable_t        *ht;
4008         uint_t          entry;
4009 
4010         ASSERT(IS_PAGEALIGNED(va));
4011         ASSERT(!IN_VA_HOLE(va));
4012         ht = htable_getpte(kas.a_hat, va, &entry, NULL, 0);
4013         ASSERT(ht != NULL);
4014         ASSERT(ht->ht_level == 0);
4015         ASSERT(ht->ht_valid_cnt > 0);
4016         ASSERT(ht->ht_pfn == mmu_btop(pte_pa));
4017         htable_release(ht);
4018 #endif
4019         XPV_DISALLOW_MIGRATE();
4020         pte = hati_mkpte(pfn, attr, 0, flags);
4021 #ifdef __xpv
4022         if (HYPERVISOR_update_va_mapping(va, pte, UVMF_INVLPG | UVMF_LOCAL))
4023                 panic("HYPERVISOR_update_va_mapping() failed");
4024 #else
4025         {
4026                 x86pte_t *pteptr;
4027 
4028                 pteptr = x86pte_mapin(mmu_btop(pte_pa),
4029                     (pte_pa & MMU_PAGEOFFSET) >> mmu.pte_size_shift, NULL);
4030                 if (mmu.pae_hat)
4031                         *(x86pte_t *)pteptr = pte;
4032                 else
4033                         *(x86pte32_t *)pteptr = (x86pte32_t)pte;
4034                 mmu_tlbflush_entry(addr);
4035                 x86pte_mapout();
4036         }
4037 #endif
4038         XPV_ALLOW_MIGRATE();
4039 }
4040 
4041 
4042 
4043 /*
4044  * Hat locking functions
4045  * XXX - these two functions are currently being used by hatstats
4046  *      they can be removed by using a per-as mutex for hatstats.
4047  */
4048 void
4049 hat_enter(hat_t *hat)
4050 {
4051         mutex_enter(&hat->hat_mutex);
4052 }
4053 
4054 void
4055 hat_exit(hat_t *hat)
4056 {
4057         mutex_exit(&hat->hat_mutex);
4058 }
4059 
4060 /*
4061  * HAT part of cpu initialization.
4062  */
4063 void
4064 hat_cpu_online(struct cpu *cpup)
4065 {
4066         if (cpup != CPU) {
4067                 x86pte_cpu_init(cpup);
4068                 hat_vlp_setup(cpup);
4069         }
4070         CPUSET_ATOMIC_ADD(khat_cpuset, cpup->cpu_id);
4071 }
4072 
4073 /*
4074  * HAT part of cpu deletion.
4075  * (currently, we only call this after the cpu is safely passivated.)
4076  */
4077 void
4078 hat_cpu_offline(struct cpu *cpup)
4079 {
4080         ASSERT(cpup != CPU);
4081 
4082         CPUSET_ATOMIC_DEL(khat_cpuset, cpup->cpu_id);
4083         hat_vlp_teardown(cpup);
4084         x86pte_cpu_fini(cpup);
4085 }
4086 
4087 /*
4088  * Function called after all CPUs are brought online.
4089  * Used to remove low address boot mappings.
4090  */
4091 void
4092 clear_boot_mappings(uintptr_t low, uintptr_t high)
4093 {
4094         uintptr_t vaddr = low;
4095         htable_t *ht = NULL;
4096         level_t level;
4097         uint_t entry;
4098         x86pte_t pte;
4099 
4100         /*
4101          * On 1st CPU we can unload the prom mappings, basically we blow away
4102          * all virtual mappings under _userlimit.
4103          */
4104         while (vaddr < high) {
4105                 pte = htable_walk(kas.a_hat, &ht, &vaddr, high);
4106                 if (ht == NULL)
4107                         break;
4108 
4109                 level = ht->ht_level;
4110                 entry = htable_va2entry(vaddr, ht);
4111                 ASSERT(level <= mmu.max_page_level);
4112                 ASSERT(PTE_ISPAGE(pte, level));
4113 
4114                 /*
4115                  * Unload the mapping from the page tables.
4116                  */
4117                 (void) x86pte_inval(ht, entry, 0, NULL, B_TRUE);
4118                 ASSERT(ht->ht_valid_cnt > 0);
4119                 HTABLE_DEC(ht->ht_valid_cnt);
4120                 PGCNT_DEC(ht->ht_hat, ht->ht_level);
4121 
4122                 vaddr += LEVEL_SIZE(ht->ht_level);
4123         }
4124         if (ht)
4125                 htable_release(ht);
4126 }
4127 
4128 /*
4129  * Atomically update a new translation for a single page.  If the
4130  * currently installed PTE doesn't match the value we expect to find,
4131  * it's not updated and we return the PTE we found.
4132  *
4133  * If activating nosync or NOWRITE and the page was modified we need to sync
4134  * with the page_t. Also sync with page_t if clearing ref/mod bits.
4135  */
4136 static x86pte_t
4137 hati_update_pte(htable_t *ht, uint_t entry, x86pte_t expected, x86pte_t new)
4138 {
4139         page_t          *pp;
4140         uint_t          rm = 0;
4141         x86pte_t        replaced;
4142 
4143         if (PTE_GET(expected, PT_SOFTWARE) < PT_NOSYNC &&
4144             PTE_GET(expected, PT_MOD | PT_REF) &&
4145             (PTE_GET(new, PT_NOSYNC) || !PTE_GET(new, PT_WRITABLE) ||
4146             !PTE_GET(new, PT_MOD | PT_REF))) {
4147 
4148                 ASSERT(!pfn_is_foreign(PTE2PFN(expected, ht->ht_level)));
4149                 pp = page_numtopp_nolock(PTE2PFN(expected, ht->ht_level));
4150                 ASSERT(pp != NULL);
4151                 if (PTE_GET(expected, PT_MOD))
4152                         rm |= P_MOD;
4153                 if (PTE_GET(expected, PT_REF))
4154                         rm |= P_REF;
4155                 PTE_CLR(new, PT_MOD | PT_REF);
4156         }
4157 
4158         replaced = x86pte_update(ht, entry, expected, new);
4159         if (replaced != expected)
4160                 return (replaced);
4161 
4162         if (rm) {
4163                 /*
4164                  * sync to all constituent pages of a large page
4165                  */
4166                 pgcnt_t pgcnt = page_get_pagecnt(ht->ht_level);
4167                 ASSERT(IS_P2ALIGNED(pp->p_pagenum, pgcnt));
4168                 while (pgcnt-- > 0) {
4169                         /*
4170                          * hat_page_demote() can't decrease
4171                          * pszc below this mapping size
4172                          * since large mapping existed after we
4173                          * took mlist lock.
4174                          */
4175                         ASSERT(pp->p_szc >= ht->ht_level);
4176                         hat_page_setattr(pp, rm);
4177                         ++pp;
4178                 }
4179         }
4180 
4181         return (0);
4182 }
4183 
4184 /* ARGSUSED */
4185 void
4186 hat_join_srd(struct hat *hat, vnode_t *evp)
4187 {
4188 }
4189 
4190 /* ARGSUSED */
4191 hat_region_cookie_t
4192 hat_join_region(struct hat *hat,
4193     caddr_t r_saddr,
4194     size_t r_size,
4195     void *r_obj,
4196     u_offset_t r_objoff,
4197     uchar_t r_perm,
4198     uchar_t r_pgszc,
4199     hat_rgn_cb_func_t r_cb_function,
4200     uint_t flags)
4201 {
4202         panic("No shared region support on x86");
4203         return (HAT_INVALID_REGION_COOKIE);
4204 }
4205 
4206 /* ARGSUSED */
4207 void
4208 hat_leave_region(struct hat *hat, hat_region_cookie_t rcookie, uint_t flags)
4209 {
4210         panic("No shared region support on x86");
4211 }
4212 
4213 /* ARGSUSED */
4214 void
4215 hat_dup_region(struct hat *hat, hat_region_cookie_t rcookie)
4216 {
4217         panic("No shared region support on x86");
4218 }
4219 
4220 
4221 /*
4222  * Kernel Physical Mapping (kpm) facility
4223  *
4224  * Most of the routines needed to support segkpm are almost no-ops on the
4225  * x86 platform.  We map in the entire segment when it is created and leave
4226  * it mapped in, so there is no additional work required to set up and tear
4227  * down individual mappings.  All of these routines were created to support
4228  * SPARC platforms that have to avoid aliasing in their virtually indexed
4229  * caches.
4230  *
4231  * Most of the routines have sanity checks in them (e.g. verifying that the
4232  * passed-in page is locked).  We don't actually care about most of these
4233  * checks on x86, but we leave them in place to identify problems in the
4234  * upper levels.
4235  */
4236 
4237 /*
4238  * Map in a locked page and return the vaddr.
4239  */
4240 /*ARGSUSED*/
4241 caddr_t
4242 hat_kpm_mapin(struct page *pp, struct kpme *kpme)
4243 {
4244         caddr_t         vaddr;
4245 
4246 #ifdef DEBUG
4247         if (kpm_enable == 0) {
4248                 cmn_err(CE_WARN, "hat_kpm_mapin: kpm_enable not set\n");
4249                 return ((caddr_t)NULL);
4250         }
4251 
4252         if (pp == NULL || PAGE_LOCKED(pp) == 0) {
4253                 cmn_err(CE_WARN, "hat_kpm_mapin: pp zero or not locked\n");
4254                 return ((caddr_t)NULL);
4255         }
4256 #endif
4257 
4258         vaddr = hat_kpm_page2va(pp, 1);
4259 
4260         return (vaddr);
4261 }
4262 
4263 /*
4264  * Mapout a locked page.
4265  */
4266 /*ARGSUSED*/
4267 void
4268 hat_kpm_mapout(struct page *pp, struct kpme *kpme, caddr_t vaddr)
4269 {
4270 #ifdef DEBUG
4271         if (kpm_enable == 0) {
4272                 cmn_err(CE_WARN, "hat_kpm_mapout: kpm_enable not set\n");
4273                 return;
4274         }
4275 
4276         if (IS_KPM_ADDR(vaddr) == 0) {
4277                 cmn_err(CE_WARN, "hat_kpm_mapout: no kpm address\n");
4278                 return;
4279         }
4280 
4281         if (pp == NULL || PAGE_LOCKED(pp) == 0) {
4282                 cmn_err(CE_WARN, "hat_kpm_mapout: page zero or not locked\n");
4283                 return;
4284         }
4285 #endif
4286 }
4287 
4288 /*
4289  * hat_kpm_mapin_pfn is used to obtain a kpm mapping for physical
4290  * memory addresses that are not described by a page_t.  It can
4291  * also be used for normal pages that are not locked, but beware
4292  * this is dangerous - no locking is performed, so the identity of
4293  * the page could change.  hat_kpm_mapin_pfn is not supported when
4294  * vac_colors > 1, because the chosen va depends on the page identity,
4295  * which could change.
4296  * The caller must only pass pfn's for valid physical addresses; violation
4297  * of this rule will cause panic.
4298  */
4299 caddr_t
4300 hat_kpm_mapin_pfn(pfn_t pfn)
4301 {
4302         caddr_t paddr, vaddr;
4303 
4304         if (kpm_enable == 0)
4305                 return ((caddr_t)NULL);
4306 
4307         paddr = (caddr_t)ptob(pfn);
4308         vaddr = (uintptr_t)kpm_vbase + paddr;
4309 
4310         return ((caddr_t)vaddr);
4311 }
4312 
4313 /*ARGSUSED*/
4314 void
4315 hat_kpm_mapout_pfn(pfn_t pfn)
4316 {
4317         /* empty */
4318 }
4319 
4320 /*
4321  * Return the kpm virtual address for a specific pfn
4322  */
4323 caddr_t
4324 hat_kpm_pfn2va(pfn_t pfn)
4325 {
4326         uintptr_t vaddr = (uintptr_t)kpm_vbase + mmu_ptob(pfn);
4327 
4328         ASSERT(!pfn_is_foreign(pfn));
4329         return ((caddr_t)vaddr);
4330 }
4331 
4332 /*
4333  * Return the kpm virtual address for the page at pp.
4334  */
4335 /*ARGSUSED*/
4336 caddr_t
4337 hat_kpm_page2va(struct page *pp, int checkswap)
4338 {
4339         return (hat_kpm_pfn2va(pp->p_pagenum));
4340 }
4341 
4342 /*
4343  * Return the page frame number for the kpm virtual address vaddr.
4344  */
4345 pfn_t
4346 hat_kpm_va2pfn(caddr_t vaddr)
4347 {
4348         pfn_t           pfn;
4349 
4350         ASSERT(IS_KPM_ADDR(vaddr));
4351 
4352         pfn = (pfn_t)btop(vaddr - kpm_vbase);
4353 
4354         return (pfn);
4355 }
4356 
4357 
4358 /*
4359  * Return the page for the kpm virtual address vaddr.
4360  */
4361 page_t *
4362 hat_kpm_vaddr2page(caddr_t vaddr)
4363 {
4364         pfn_t           pfn;
4365 
4366         ASSERT(IS_KPM_ADDR(vaddr));
4367 
4368         pfn = hat_kpm_va2pfn(vaddr);
4369 
4370         return (page_numtopp_nolock(pfn));
4371 }
4372 
4373 /*
4374  * hat_kpm_fault is called from segkpm_fault when we take a page fault on a
4375  * KPM page.  This should never happen on x86
4376  */
4377 int
4378 hat_kpm_fault(hat_t *hat, caddr_t vaddr)
4379 {
4380         panic("pagefault in seg_kpm.  hat: 0x%p  vaddr: 0x%p",
4381             (void *)hat, (void *)vaddr);
4382 
4383         return (0);
4384 }
4385 
4386 /*ARGSUSED*/
4387 void
4388 hat_kpm_mseghash_clear(int nentries)
4389 {}
4390 
4391 /*ARGSUSED*/
4392 void
4393 hat_kpm_mseghash_update(pgcnt_t inx, struct memseg *msp)
4394 {}
4395 
4396 #ifndef __xpv
4397 void
4398 hat_kpm_addmem_mseg_update(struct memseg *msp, pgcnt_t nkpmpgs,
4399         offset_t kpm_pages_off)
4400 {
4401         _NOTE(ARGUNUSED(nkpmpgs, kpm_pages_off));
4402         pfn_t base, end;
4403 
4404         /*
4405          * kphysm_add_memory_dynamic() does not set nkpmpgs
4406          * when page_t memory is externally allocated.  That
4407          * code must properly calculate nkpmpgs in all cases
4408          * if nkpmpgs needs to be used at some point.
4409          */
4410 
4411         /*
4412          * The meta (page_t) pages for dynamically added memory are allocated
4413          * either from the incoming memory itself or from existing memory.
4414          * In the former case the base of the incoming pages will be different
4415          * than the base of the dynamic segment so call memseg_get_start() to
4416          * get the actual base of the incoming memory for each case.
4417          */
4418 
4419         base = memseg_get_start(msp);
4420         end = msp->pages_end;
4421 
4422         hat_devload(kas.a_hat, kpm_vbase + mmu_ptob(base),
4423             mmu_ptob(end - base), base, PROT_READ | PROT_WRITE,
4424             HAT_LOAD | HAT_LOAD_LOCK | HAT_LOAD_NOCONSIST);
4425 }
4426 
4427 void
4428 hat_kpm_addmem_mseg_insert(struct memseg *msp)
4429 {
4430         _NOTE(ARGUNUSED(msp));
4431 }
4432 
4433 void
4434 hat_kpm_addmem_memsegs_update(struct memseg *msp)
4435 {
4436         _NOTE(ARGUNUSED(msp));
4437 }
4438 
4439 /*
4440  * Return end of metadata for an already setup memseg.
4441  * X86 platforms don't need per-page meta data to support kpm.
4442  */
4443 caddr_t
4444 hat_kpm_mseg_reuse(struct memseg *msp)
4445 {
4446         return ((caddr_t)msp->epages);
4447 }
4448 
4449 void
4450 hat_kpm_delmem_mseg_update(struct memseg *msp, struct memseg **mspp)
4451 {
4452         _NOTE(ARGUNUSED(msp, mspp));
4453         ASSERT(0);
4454 }
4455 
4456 void
4457 hat_kpm_split_mseg_update(struct memseg *msp, struct memseg **mspp,
4458         struct memseg *lo, struct memseg *mid, struct memseg *hi)
4459 {
4460         _NOTE(ARGUNUSED(msp, mspp, lo, mid, hi));
4461         ASSERT(0);
4462 }
4463 
4464 /*
4465  * Walk the memsegs chain, applying func to each memseg span.
4466  */
4467 void
4468 hat_kpm_walk(void (*func)(void *, void *, size_t), void *arg)
4469 {
4470         pfn_t   pbase, pend;
4471         void    *base;
4472         size_t  size;
4473         struct memseg *msp;
4474 
4475         for (msp = memsegs; msp; msp = msp->next) {
4476                 pbase = msp->pages_base;
4477                 pend = msp->pages_end;
4478                 base = ptob(pbase) + kpm_vbase;
4479                 size = ptob(pend - pbase);
4480                 func(arg, base, size);
4481         }
4482 }
4483 
4484 #else   /* __xpv */
4485 
4486 /*
4487  * There are specific Hypervisor calls to establish and remove mappings
4488  * to grant table references and the privcmd driver. We have to ensure
4489  * that a page table actually exists.
4490  */
4491 void
4492 hat_prepare_mapping(hat_t *hat, caddr_t addr, uint64_t *pte_ma)
4493 {
4494         maddr_t base_ma;
4495         htable_t *ht;
4496         uint_t entry;
4497 
4498         ASSERT(IS_P2ALIGNED((uintptr_t)addr, MMU_PAGESIZE));
4499         XPV_DISALLOW_MIGRATE();
4500         ht = htable_create(hat, (uintptr_t)addr, 0, NULL);
4501 
4502         /*
4503          * if an address for pte_ma is passed in, return the MA of the pte
4504          * for this specific address.  This address is only valid as long
4505          * as the htable stays locked.
4506          */
4507         if (pte_ma != NULL) {
4508                 entry = htable_va2entry((uintptr_t)addr, ht);
4509                 base_ma = pa_to_ma(ptob(ht->ht_pfn));
4510                 *pte_ma = base_ma + (entry << mmu.pte_size_shift);
4511         }
4512         XPV_ALLOW_MIGRATE();
4513 }
4514 
4515 void
4516 hat_release_mapping(hat_t *hat, caddr_t addr)
4517 {
4518         htable_t *ht;
4519 
4520         ASSERT(IS_P2ALIGNED((uintptr_t)addr, MMU_PAGESIZE));
4521         XPV_DISALLOW_MIGRATE();
4522         ht = htable_lookup(hat, (uintptr_t)addr, 0);
4523         ASSERT(ht != NULL);
4524         ASSERT(ht->ht_busy >= 2);
4525         htable_release(ht);
4526         htable_release(ht);
4527         XPV_ALLOW_MIGRATE();
4528 }
4529 #endif  /* __xpv */