The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/x86/iommu/intel_idpgtbl.c

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    1 /*-
    2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
    3  *
    4  * Copyright (c) 2013 The FreeBSD Foundation
    5  * All rights reserved.
    6  *
    7  * This software was developed by Konstantin Belousov <kib@FreeBSD.org>
    8  * under sponsorship from the FreeBSD Foundation.
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Redistributions in binary form must reproduce the above copyright
   16  *    notice, this list of conditions and the following disclaimer in the
   17  *    documentation and/or other materials provided with the distribution.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  */
   31 
   32 #include <sys/cdefs.h>
   33 __FBSDID("$FreeBSD: releng/12.0/sys/x86/iommu/intel_idpgtbl.c 326263 2017-11-27 15:11:47Z pfg $");
   34 
   35 #include <sys/param.h>
   36 #include <sys/systm.h>
   37 #include <sys/malloc.h>
   38 #include <sys/bus.h>
   39 #include <sys/interrupt.h>
   40 #include <sys/kernel.h>
   41 #include <sys/ktr.h>
   42 #include <sys/lock.h>
   43 #include <sys/memdesc.h>
   44 #include <sys/mutex.h>
   45 #include <sys/proc.h>
   46 #include <sys/rwlock.h>
   47 #include <sys/rman.h>
   48 #include <sys/sf_buf.h>
   49 #include <sys/sysctl.h>
   50 #include <sys/taskqueue.h>
   51 #include <sys/tree.h>
   52 #include <sys/uio.h>
   53 #include <sys/vmem.h>
   54 #include <vm/vm.h>
   55 #include <vm/vm_extern.h>
   56 #include <vm/vm_kern.h>
   57 #include <vm/vm_object.h>
   58 #include <vm/vm_page.h>
   59 #include <vm/vm_pager.h>
   60 #include <vm/vm_map.h>
   61 #include <machine/atomic.h>
   62 #include <machine/bus.h>
   63 #include <machine/cpu.h>
   64 #include <machine/md_var.h>
   65 #include <machine/specialreg.h>
   66 #include <x86/include/busdma_impl.h>
   67 #include <x86/iommu/intel_reg.h>
   68 #include <x86/iommu/busdma_dmar.h>
   69 #include <x86/iommu/intel_dmar.h>
   70 
   71 static int domain_unmap_buf_locked(struct dmar_domain *domain,
   72     dmar_gaddr_t base, dmar_gaddr_t size, int flags);
   73 
   74 /*
   75  * The cache of the identity mapping page tables for the DMARs.  Using
   76  * the cache saves significant amount of memory for page tables by
   77  * reusing the page tables, since usually DMARs are identical and have
   78  * the same capabilities.  Still, cache records the information needed
   79  * to match DMAR capabilities and page table format, to correctly
   80  * handle different DMARs.
   81  */
   82 
   83 struct idpgtbl {
   84         dmar_gaddr_t maxaddr;   /* Page table covers the guest address
   85                                    range [0..maxaddr) */
   86         int pglvl;              /* Total page table levels ignoring
   87                                    superpages */
   88         int leaf;               /* The last materialized page table
   89                                    level, it is non-zero if superpages
   90                                    are supported */
   91         vm_object_t pgtbl_obj;  /* The page table pages */
   92         LIST_ENTRY(idpgtbl) link;
   93 };
   94 
   95 static struct sx idpgtbl_lock;
   96 SX_SYSINIT(idpgtbl, &idpgtbl_lock, "idpgtbl");
   97 static LIST_HEAD(, idpgtbl) idpgtbls = LIST_HEAD_INITIALIZER(idpgtbls);
   98 static MALLOC_DEFINE(M_DMAR_IDPGTBL, "dmar_idpgtbl",
   99     "Intel DMAR Identity mappings cache elements");
  100 
  101 /*
  102  * Build the next level of the page tables for the identity mapping.
  103  * - lvl is the level to build;
  104  * - idx is the index of the page table page in the pgtbl_obj, which is
  105  *   being allocated filled now;
  106  * - addr is the starting address in the bus address space which is
  107  *   mapped by the page table page.
  108  */
  109 static void
  110 domain_idmap_nextlvl(struct idpgtbl *tbl, int lvl, vm_pindex_t idx,
  111     dmar_gaddr_t addr)
  112 {
  113         vm_page_t m1;
  114         dmar_pte_t *pte;
  115         struct sf_buf *sf;
  116         dmar_gaddr_t f, pg_sz;
  117         vm_pindex_t base;
  118         int i;
  119 
  120         VM_OBJECT_ASSERT_LOCKED(tbl->pgtbl_obj);
  121         if (addr >= tbl->maxaddr)
  122                 return;
  123         (void)dmar_pgalloc(tbl->pgtbl_obj, idx, DMAR_PGF_OBJL | DMAR_PGF_WAITOK |
  124             DMAR_PGF_ZERO);
  125         base = idx * DMAR_NPTEPG + 1; /* Index of the first child page of idx */
  126         pg_sz = pglvl_page_size(tbl->pglvl, lvl);
  127         if (lvl != tbl->leaf) {
  128                 for (i = 0, f = addr; i < DMAR_NPTEPG; i++, f += pg_sz)
  129                         domain_idmap_nextlvl(tbl, lvl + 1, base + i, f);
  130         }
  131         VM_OBJECT_WUNLOCK(tbl->pgtbl_obj);
  132         pte = dmar_map_pgtbl(tbl->pgtbl_obj, idx, DMAR_PGF_WAITOK, &sf);
  133         if (lvl == tbl->leaf) {
  134                 for (i = 0, f = addr; i < DMAR_NPTEPG; i++, f += pg_sz) {
  135                         if (f >= tbl->maxaddr)
  136                                 break;
  137                         pte[i].pte = (DMAR_PTE_ADDR_MASK & f) |
  138                             DMAR_PTE_R | DMAR_PTE_W;
  139                 }
  140         } else {
  141                 for (i = 0, f = addr; i < DMAR_NPTEPG; i++, f += pg_sz) {
  142                         if (f >= tbl->maxaddr)
  143                                 break;
  144                         m1 = dmar_pgalloc(tbl->pgtbl_obj, base + i,
  145                             DMAR_PGF_NOALLOC);
  146                         KASSERT(m1 != NULL, ("lost page table page"));
  147                         pte[i].pte = (DMAR_PTE_ADDR_MASK &
  148                             VM_PAGE_TO_PHYS(m1)) | DMAR_PTE_R | DMAR_PTE_W;
  149                 }
  150         }
  151         /* domain_get_idmap_pgtbl flushes CPU cache if needed. */
  152         dmar_unmap_pgtbl(sf);
  153         VM_OBJECT_WLOCK(tbl->pgtbl_obj);
  154 }
  155 
  156 /*
  157  * Find a ready and compatible identity-mapping page table in the
  158  * cache. If not found, populate the identity-mapping page table for
  159  * the context, up to the maxaddr. The maxaddr byte is allowed to be
  160  * not mapped, which is aligned with the definition of Maxmem as the
  161  * highest usable physical address + 1.  If superpages are used, the
  162  * maxaddr is typically mapped.
  163  */
  164 vm_object_t
  165 domain_get_idmap_pgtbl(struct dmar_domain *domain, dmar_gaddr_t maxaddr)
  166 {
  167         struct dmar_unit *unit;
  168         struct idpgtbl *tbl;
  169         vm_object_t res;
  170         vm_page_t m;
  171         int leaf, i;
  172 
  173         leaf = 0; /* silence gcc */
  174 
  175         /*
  176          * First, determine where to stop the paging structures.
  177          */
  178         for (i = 0; i < domain->pglvl; i++) {
  179                 if (i == domain->pglvl - 1 || domain_is_sp_lvl(domain, i)) {
  180                         leaf = i;
  181                         break;
  182                 }
  183         }
  184 
  185         /*
  186          * Search the cache for a compatible page table.  Qualified
  187          * page table must map up to maxaddr, its level must be
  188          * supported by the DMAR and leaf should be equal to the
  189          * calculated value.  The later restriction could be lifted
  190          * but I believe it is currently impossible to have any
  191          * deviations for existing hardware.
  192          */
  193         sx_slock(&idpgtbl_lock);
  194         LIST_FOREACH(tbl, &idpgtbls, link) {
  195                 if (tbl->maxaddr >= maxaddr &&
  196                     dmar_pglvl_supported(domain->dmar, tbl->pglvl) &&
  197                     tbl->leaf == leaf) {
  198                         res = tbl->pgtbl_obj;
  199                         vm_object_reference(res);
  200                         sx_sunlock(&idpgtbl_lock);
  201                         domain->pglvl = tbl->pglvl; /* XXXKIB ? */
  202                         goto end;
  203                 }
  204         }
  205 
  206         /*
  207          * Not found in cache, relock the cache into exclusive mode to
  208          * be able to add element, and recheck cache again after the
  209          * relock.
  210          */
  211         sx_sunlock(&idpgtbl_lock);
  212         sx_xlock(&idpgtbl_lock);
  213         LIST_FOREACH(tbl, &idpgtbls, link) {
  214                 if (tbl->maxaddr >= maxaddr &&
  215                     dmar_pglvl_supported(domain->dmar, tbl->pglvl) &&
  216                     tbl->leaf == leaf) {
  217                         res = tbl->pgtbl_obj;
  218                         vm_object_reference(res);
  219                         sx_xunlock(&idpgtbl_lock);
  220                         domain->pglvl = tbl->pglvl; /* XXXKIB ? */
  221                         return (res);
  222                 }
  223         }
  224 
  225         /*
  226          * Still not found, create new page table.
  227          */
  228         tbl = malloc(sizeof(*tbl), M_DMAR_IDPGTBL, M_WAITOK);
  229         tbl->pglvl = domain->pglvl;
  230         tbl->leaf = leaf;
  231         tbl->maxaddr = maxaddr;
  232         tbl->pgtbl_obj = vm_pager_allocate(OBJT_PHYS, NULL,
  233             IDX_TO_OFF(pglvl_max_pages(tbl->pglvl)), 0, 0, NULL);
  234         VM_OBJECT_WLOCK(tbl->pgtbl_obj);
  235         domain_idmap_nextlvl(tbl, 0, 0, 0);
  236         VM_OBJECT_WUNLOCK(tbl->pgtbl_obj);
  237         LIST_INSERT_HEAD(&idpgtbls, tbl, link);
  238         res = tbl->pgtbl_obj;
  239         vm_object_reference(res);
  240         sx_xunlock(&idpgtbl_lock);
  241 
  242 end:
  243         /*
  244          * Table was found or created.
  245          *
  246          * If DMAR does not snoop paging structures accesses, flush
  247          * CPU cache to memory.  Note that dmar_unmap_pgtbl() coherent
  248          * argument was possibly invalid at the time of the identity
  249          * page table creation, since DMAR which was passed at the
  250          * time of creation could be coherent, while current DMAR is
  251          * not.
  252          *
  253          * If DMAR cannot look into the chipset write buffer, flush it
  254          * as well.
  255          */
  256         unit = domain->dmar;
  257         if (!DMAR_IS_COHERENT(unit)) {
  258                 VM_OBJECT_WLOCK(res);
  259                 for (m = vm_page_lookup(res, 0); m != NULL;
  260                      m = vm_page_next(m))
  261                         pmap_invalidate_cache_pages(&m, 1);
  262                 VM_OBJECT_WUNLOCK(res);
  263         }
  264         if ((unit->hw_cap & DMAR_CAP_RWBF) != 0) {
  265                 DMAR_LOCK(unit);
  266                 dmar_flush_write_bufs(unit);
  267                 DMAR_UNLOCK(unit);
  268         }
  269         
  270         return (res);
  271 }
  272 
  273 /*
  274  * Return a reference to the identity mapping page table to the cache.
  275  */
  276 void
  277 put_idmap_pgtbl(vm_object_t obj)
  278 {
  279         struct idpgtbl *tbl, *tbl1;
  280         vm_object_t rmobj;
  281 
  282         sx_slock(&idpgtbl_lock);
  283         KASSERT(obj->ref_count >= 2, ("lost cache reference"));
  284         vm_object_deallocate(obj);
  285 
  286         /*
  287          * Cache always owns one last reference on the page table object.
  288          * If there is an additional reference, object must stay.
  289          */
  290         if (obj->ref_count > 1) {
  291                 sx_sunlock(&idpgtbl_lock);
  292                 return;
  293         }
  294 
  295         /*
  296          * Cache reference is the last, remove cache element and free
  297          * page table object, returning the page table pages to the
  298          * system.
  299          */
  300         sx_sunlock(&idpgtbl_lock);
  301         sx_xlock(&idpgtbl_lock);
  302         LIST_FOREACH_SAFE(tbl, &idpgtbls, link, tbl1) {
  303                 rmobj = tbl->pgtbl_obj;
  304                 if (rmobj->ref_count == 1) {
  305                         LIST_REMOVE(tbl, link);
  306                         atomic_subtract_int(&dmar_tbl_pagecnt,
  307                             rmobj->resident_page_count);
  308                         vm_object_deallocate(rmobj);
  309                         free(tbl, M_DMAR_IDPGTBL);
  310                 }
  311         }
  312         sx_xunlock(&idpgtbl_lock);
  313 }
  314 
  315 /*
  316  * The core routines to map and unmap host pages at the given guest
  317  * address.  Support superpages.
  318  */
  319 
  320 /*
  321  * Index of the pte for the guest address base in the page table at
  322  * the level lvl.
  323  */
  324 static int
  325 domain_pgtbl_pte_off(struct dmar_domain *domain, dmar_gaddr_t base, int lvl)
  326 {
  327 
  328         base >>= DMAR_PAGE_SHIFT + (domain->pglvl - lvl - 1) *
  329             DMAR_NPTEPGSHIFT;
  330         return (base & DMAR_PTEMASK);
  331 }
  332 
  333 /*
  334  * Returns the page index of the page table page in the page table
  335  * object, which maps the given address base at the page table level
  336  * lvl.
  337  */
  338 static vm_pindex_t
  339 domain_pgtbl_get_pindex(struct dmar_domain *domain, dmar_gaddr_t base, int lvl)
  340 {
  341         vm_pindex_t idx, pidx;
  342         int i;
  343 
  344         KASSERT(lvl >= 0 && lvl < domain->pglvl,
  345             ("wrong lvl %p %d", domain, lvl));
  346 
  347         for (pidx = idx = 0, i = 0; i < lvl; i++, pidx = idx) {
  348                 idx = domain_pgtbl_pte_off(domain, base, i) +
  349                     pidx * DMAR_NPTEPG + 1;
  350         }
  351         return (idx);
  352 }
  353 
  354 static dmar_pte_t *
  355 domain_pgtbl_map_pte(struct dmar_domain *domain, dmar_gaddr_t base, int lvl,
  356     int flags, vm_pindex_t *idxp, struct sf_buf **sf)
  357 {
  358         vm_page_t m;
  359         struct sf_buf *sfp;
  360         dmar_pte_t *pte, *ptep;
  361         vm_pindex_t idx, idx1;
  362 
  363         DMAR_DOMAIN_ASSERT_PGLOCKED(domain);
  364         KASSERT((flags & DMAR_PGF_OBJL) != 0, ("lost PGF_OBJL"));
  365 
  366         idx = domain_pgtbl_get_pindex(domain, base, lvl);
  367         if (*sf != NULL && idx == *idxp) {
  368                 pte = (dmar_pte_t *)sf_buf_kva(*sf);
  369         } else {
  370                 if (*sf != NULL)
  371                         dmar_unmap_pgtbl(*sf);
  372                 *idxp = idx;
  373 retry:
  374                 pte = dmar_map_pgtbl(domain->pgtbl_obj, idx, flags, sf);
  375                 if (pte == NULL) {
  376                         KASSERT(lvl > 0,
  377                             ("lost root page table page %p", domain));
  378                         /*
  379                          * Page table page does not exist, allocate
  380                          * it and create a pte in the preceeding page level
  381                          * to reference the allocated page table page.
  382                          */
  383                         m = dmar_pgalloc(domain->pgtbl_obj, idx, flags |
  384                             DMAR_PGF_ZERO);
  385                         if (m == NULL)
  386                                 return (NULL);
  387 
  388                         /*
  389                          * Prevent potential free while pgtbl_obj is
  390                          * unlocked in the recursive call to
  391                          * domain_pgtbl_map_pte(), if other thread did
  392                          * pte write and clean while the lock is
  393                          * dropped.
  394                          */
  395                         m->wire_count++;
  396 
  397                         sfp = NULL;
  398                         ptep = domain_pgtbl_map_pte(domain, base, lvl - 1,
  399                             flags, &idx1, &sfp);
  400                         if (ptep == NULL) {
  401                                 KASSERT(m->pindex != 0,
  402                                     ("loosing root page %p", domain));
  403                                 m->wire_count--;
  404                                 dmar_pgfree(domain->pgtbl_obj, m->pindex,
  405                                     flags);
  406                                 return (NULL);
  407                         }
  408                         dmar_pte_store(&ptep->pte, DMAR_PTE_R | DMAR_PTE_W |
  409                             VM_PAGE_TO_PHYS(m));
  410                         dmar_flush_pte_to_ram(domain->dmar, ptep);
  411                         sf_buf_page(sfp)->wire_count += 1;
  412                         m->wire_count--;
  413                         dmar_unmap_pgtbl(sfp);
  414                         /* Only executed once. */
  415                         goto retry;
  416                 }
  417         }
  418         pte += domain_pgtbl_pte_off(domain, base, lvl);
  419         return (pte);
  420 }
  421 
  422 static int
  423 domain_map_buf_locked(struct dmar_domain *domain, dmar_gaddr_t base,
  424     dmar_gaddr_t size, vm_page_t *ma, uint64_t pflags, int flags)
  425 {
  426         dmar_pte_t *pte;
  427         struct sf_buf *sf;
  428         dmar_gaddr_t pg_sz, base1, size1;
  429         vm_pindex_t pi, c, idx, run_sz;
  430         int lvl;
  431         bool superpage;
  432 
  433         DMAR_DOMAIN_ASSERT_PGLOCKED(domain);
  434 
  435         base1 = base;
  436         size1 = size;
  437         flags |= DMAR_PGF_OBJL;
  438         TD_PREP_PINNED_ASSERT;
  439 
  440         for (sf = NULL, pi = 0; size > 0; base += pg_sz, size -= pg_sz,
  441             pi += run_sz) {
  442                 for (lvl = 0, c = 0, superpage = false;; lvl++) {
  443                         pg_sz = domain_page_size(domain, lvl);
  444                         run_sz = pg_sz >> DMAR_PAGE_SHIFT;
  445                         if (lvl == domain->pglvl - 1)
  446                                 break;
  447                         /*
  448                          * Check if the current base suitable for the
  449                          * superpage mapping.  First, verify the level.
  450                          */
  451                         if (!domain_is_sp_lvl(domain, lvl))
  452                                 continue;
  453                         /*
  454                          * Next, look at the size of the mapping and
  455                          * alignment of both guest and host addresses.
  456                          */
  457                         if (size < pg_sz || (base & (pg_sz - 1)) != 0 ||
  458                             (VM_PAGE_TO_PHYS(ma[pi]) & (pg_sz - 1)) != 0)
  459                                 continue;
  460                         /* All passed, check host pages contiguouty. */
  461                         if (c == 0) {
  462                                 for (c = 1; c < run_sz; c++) {
  463                                         if (VM_PAGE_TO_PHYS(ma[pi + c]) !=
  464                                             VM_PAGE_TO_PHYS(ma[pi + c - 1]) +
  465                                             PAGE_SIZE)
  466                                                 break;
  467                                 }
  468                         }
  469                         if (c >= run_sz) {
  470                                 superpage = true;
  471                                 break;
  472                         }
  473                 }
  474                 KASSERT(size >= pg_sz,
  475                     ("mapping loop overflow %p %jx %jx %jx", domain,
  476                     (uintmax_t)base, (uintmax_t)size, (uintmax_t)pg_sz));
  477                 KASSERT(pg_sz > 0, ("pg_sz 0 lvl %d", lvl));
  478                 pte = domain_pgtbl_map_pte(domain, base, lvl, flags, &idx, &sf);
  479                 if (pte == NULL) {
  480                         KASSERT((flags & DMAR_PGF_WAITOK) == 0,
  481                             ("failed waitable pte alloc %p", domain));
  482                         if (sf != NULL)
  483                                 dmar_unmap_pgtbl(sf);
  484                         domain_unmap_buf_locked(domain, base1, base - base1,
  485                             flags);
  486                         TD_PINNED_ASSERT;
  487                         return (ENOMEM);
  488                 }
  489                 dmar_pte_store(&pte->pte, VM_PAGE_TO_PHYS(ma[pi]) | pflags |
  490                     (superpage ? DMAR_PTE_SP : 0));
  491                 dmar_flush_pte_to_ram(domain->dmar, pte);
  492                 sf_buf_page(sf)->wire_count += 1;
  493         }
  494         if (sf != NULL)
  495                 dmar_unmap_pgtbl(sf);
  496         TD_PINNED_ASSERT;
  497         return (0);
  498 }
  499 
  500 int
  501 domain_map_buf(struct dmar_domain *domain, dmar_gaddr_t base, dmar_gaddr_t size,
  502     vm_page_t *ma, uint64_t pflags, int flags)
  503 {
  504         struct dmar_unit *unit;
  505         int error;
  506 
  507         unit = domain->dmar;
  508 
  509         KASSERT((domain->flags & DMAR_DOMAIN_IDMAP) == 0,
  510             ("modifying idmap pagetable domain %p", domain));
  511         KASSERT((base & DMAR_PAGE_MASK) == 0,
  512             ("non-aligned base %p %jx %jx", domain, (uintmax_t)base,
  513             (uintmax_t)size));
  514         KASSERT((size & DMAR_PAGE_MASK) == 0,
  515             ("non-aligned size %p %jx %jx", domain, (uintmax_t)base,
  516             (uintmax_t)size));
  517         KASSERT(size > 0, ("zero size %p %jx %jx", domain, (uintmax_t)base,
  518             (uintmax_t)size));
  519         KASSERT(base < (1ULL << domain->agaw),
  520             ("base too high %p %jx %jx agaw %d", domain, (uintmax_t)base,
  521             (uintmax_t)size, domain->agaw));
  522         KASSERT(base + size < (1ULL << domain->agaw),
  523             ("end too high %p %jx %jx agaw %d", domain, (uintmax_t)base,
  524             (uintmax_t)size, domain->agaw));
  525         KASSERT(base + size > base,
  526             ("size overflow %p %jx %jx", domain, (uintmax_t)base,
  527             (uintmax_t)size));
  528         KASSERT((pflags & (DMAR_PTE_R | DMAR_PTE_W)) != 0,
  529             ("neither read nor write %jx", (uintmax_t)pflags));
  530         KASSERT((pflags & ~(DMAR_PTE_R | DMAR_PTE_W | DMAR_PTE_SNP |
  531             DMAR_PTE_TM)) == 0,
  532             ("invalid pte flags %jx", (uintmax_t)pflags));
  533         KASSERT((pflags & DMAR_PTE_SNP) == 0 ||
  534             (unit->hw_ecap & DMAR_ECAP_SC) != 0,
  535             ("PTE_SNP for dmar without snoop control %p %jx",
  536             domain, (uintmax_t)pflags));
  537         KASSERT((pflags & DMAR_PTE_TM) == 0 ||
  538             (unit->hw_ecap & DMAR_ECAP_DI) != 0,
  539             ("PTE_TM for dmar without DIOTLB %p %jx",
  540             domain, (uintmax_t)pflags));
  541         KASSERT((flags & ~DMAR_PGF_WAITOK) == 0, ("invalid flags %x", flags));
  542 
  543         DMAR_DOMAIN_PGLOCK(domain);
  544         error = domain_map_buf_locked(domain, base, size, ma, pflags, flags);
  545         DMAR_DOMAIN_PGUNLOCK(domain);
  546         if (error != 0)
  547                 return (error);
  548 
  549         if ((unit->hw_cap & DMAR_CAP_CM) != 0)
  550                 domain_flush_iotlb_sync(domain, base, size);
  551         else if ((unit->hw_cap & DMAR_CAP_RWBF) != 0) {
  552                 /* See 11.1 Write Buffer Flushing. */
  553                 DMAR_LOCK(unit);
  554                 dmar_flush_write_bufs(unit);
  555                 DMAR_UNLOCK(unit);
  556         }
  557         return (0);
  558 }
  559 
  560 static void domain_unmap_clear_pte(struct dmar_domain *domain,
  561     dmar_gaddr_t base, int lvl, int flags, dmar_pte_t *pte,
  562     struct sf_buf **sf, bool free_fs);
  563 
  564 static void
  565 domain_free_pgtbl_pde(struct dmar_domain *domain, dmar_gaddr_t base,
  566     int lvl, int flags)
  567 {
  568         struct sf_buf *sf;
  569         dmar_pte_t *pde;
  570         vm_pindex_t idx;
  571 
  572         sf = NULL;
  573         pde = domain_pgtbl_map_pte(domain, base, lvl, flags, &idx, &sf);
  574         domain_unmap_clear_pte(domain, base, lvl, flags, pde, &sf, true);
  575 }
  576 
  577 static void
  578 domain_unmap_clear_pte(struct dmar_domain *domain, dmar_gaddr_t base, int lvl,
  579     int flags, dmar_pte_t *pte, struct sf_buf **sf, bool free_sf)
  580 {
  581         vm_page_t m;
  582 
  583         dmar_pte_clear(&pte->pte);
  584         dmar_flush_pte_to_ram(domain->dmar, pte);
  585         m = sf_buf_page(*sf);
  586         if (free_sf) {
  587                 dmar_unmap_pgtbl(*sf);
  588                 *sf = NULL;
  589         }
  590         m->wire_count--;
  591         if (m->wire_count != 0)
  592                 return;
  593         KASSERT(lvl != 0,
  594             ("lost reference (lvl) on root pg domain %p base %jx lvl %d",
  595             domain, (uintmax_t)base, lvl));
  596         KASSERT(m->pindex != 0,
  597             ("lost reference (idx) on root pg domain %p base %jx lvl %d",
  598             domain, (uintmax_t)base, lvl));
  599         dmar_pgfree(domain->pgtbl_obj, m->pindex, flags);
  600         domain_free_pgtbl_pde(domain, base, lvl - 1, flags);
  601 }
  602 
  603 /*
  604  * Assumes that the unmap is never partial.
  605  */
  606 static int
  607 domain_unmap_buf_locked(struct dmar_domain *domain, dmar_gaddr_t base,
  608     dmar_gaddr_t size, int flags)
  609 {
  610         dmar_pte_t *pte;
  611         struct sf_buf *sf;
  612         vm_pindex_t idx;
  613         dmar_gaddr_t pg_sz;
  614         int lvl;
  615 
  616         DMAR_DOMAIN_ASSERT_PGLOCKED(domain);
  617         if (size == 0)
  618                 return (0);
  619 
  620         KASSERT((domain->flags & DMAR_DOMAIN_IDMAP) == 0,
  621             ("modifying idmap pagetable domain %p", domain));
  622         KASSERT((base & DMAR_PAGE_MASK) == 0,
  623             ("non-aligned base %p %jx %jx", domain, (uintmax_t)base,
  624             (uintmax_t)size));
  625         KASSERT((size & DMAR_PAGE_MASK) == 0,
  626             ("non-aligned size %p %jx %jx", domain, (uintmax_t)base,
  627             (uintmax_t)size));
  628         KASSERT(base < (1ULL << domain->agaw),
  629             ("base too high %p %jx %jx agaw %d", domain, (uintmax_t)base,
  630             (uintmax_t)size, domain->agaw));
  631         KASSERT(base + size < (1ULL << domain->agaw),
  632             ("end too high %p %jx %jx agaw %d", domain, (uintmax_t)base,
  633             (uintmax_t)size, domain->agaw));
  634         KASSERT(base + size > base,
  635             ("size overflow %p %jx %jx", domain, (uintmax_t)base,
  636             (uintmax_t)size));
  637         KASSERT((flags & ~DMAR_PGF_WAITOK) == 0, ("invalid flags %x", flags));
  638 
  639         pg_sz = 0; /* silence gcc */
  640         flags |= DMAR_PGF_OBJL;
  641         TD_PREP_PINNED_ASSERT;
  642 
  643         for (sf = NULL; size > 0; base += pg_sz, size -= pg_sz) {
  644                 for (lvl = 0; lvl < domain->pglvl; lvl++) {
  645                         if (lvl != domain->pglvl - 1 &&
  646                             !domain_is_sp_lvl(domain, lvl))
  647                                 continue;
  648                         pg_sz = domain_page_size(domain, lvl);
  649                         if (pg_sz > size)
  650                                 continue;
  651                         pte = domain_pgtbl_map_pte(domain, base, lvl, flags,
  652                             &idx, &sf);
  653                         KASSERT(pte != NULL,
  654                             ("sleeping or page missed %p %jx %d 0x%x",
  655                             domain, (uintmax_t)base, lvl, flags));
  656                         if ((pte->pte & DMAR_PTE_SP) != 0 ||
  657                             lvl == domain->pglvl - 1) {
  658                                 domain_unmap_clear_pte(domain, base, lvl,
  659                                     flags, pte, &sf, false);
  660                                 break;
  661                         }
  662                 }
  663                 KASSERT(size >= pg_sz,
  664                     ("unmapping loop overflow %p %jx %jx %jx", domain,
  665                     (uintmax_t)base, (uintmax_t)size, (uintmax_t)pg_sz));
  666         }
  667         if (sf != NULL)
  668                 dmar_unmap_pgtbl(sf);
  669         /*
  670          * See 11.1 Write Buffer Flushing for an explanation why RWBF
  671          * can be ignored there.
  672          */
  673 
  674         TD_PINNED_ASSERT;
  675         return (0);
  676 }
  677 
  678 int
  679 domain_unmap_buf(struct dmar_domain *domain, dmar_gaddr_t base,
  680     dmar_gaddr_t size, int flags)
  681 {
  682         int error;
  683 
  684         DMAR_DOMAIN_PGLOCK(domain);
  685         error = domain_unmap_buf_locked(domain, base, size, flags);
  686         DMAR_DOMAIN_PGUNLOCK(domain);
  687         return (error);
  688 }
  689 
  690 int
  691 domain_alloc_pgtbl(struct dmar_domain *domain)
  692 {
  693         vm_page_t m;
  694 
  695         KASSERT(domain->pgtbl_obj == NULL,
  696             ("already initialized %p", domain));
  697 
  698         domain->pgtbl_obj = vm_pager_allocate(OBJT_PHYS, NULL,
  699             IDX_TO_OFF(pglvl_max_pages(domain->pglvl)), 0, 0, NULL);
  700         DMAR_DOMAIN_PGLOCK(domain);
  701         m = dmar_pgalloc(domain->pgtbl_obj, 0, DMAR_PGF_WAITOK |
  702             DMAR_PGF_ZERO | DMAR_PGF_OBJL);
  703         /* No implicit free of the top level page table page. */
  704         m->wire_count = 1;
  705         DMAR_DOMAIN_PGUNLOCK(domain);
  706         DMAR_LOCK(domain->dmar);
  707         domain->flags |= DMAR_DOMAIN_PGTBL_INITED;
  708         DMAR_UNLOCK(domain->dmar);
  709         return (0);
  710 }
  711 
  712 void
  713 domain_free_pgtbl(struct dmar_domain *domain)
  714 {
  715         vm_object_t obj;
  716         vm_page_t m;
  717 
  718         obj = domain->pgtbl_obj;
  719         if (obj == NULL) {
  720                 KASSERT((domain->dmar->hw_ecap & DMAR_ECAP_PT) != 0 &&
  721                     (domain->flags & DMAR_DOMAIN_IDMAP) != 0,
  722                     ("lost pagetable object domain %p", domain));
  723                 return;
  724         }
  725         DMAR_DOMAIN_ASSERT_PGLOCKED(domain);
  726         domain->pgtbl_obj = NULL;
  727 
  728         if ((domain->flags & DMAR_DOMAIN_IDMAP) != 0) {
  729                 put_idmap_pgtbl(obj);
  730                 domain->flags &= ~DMAR_DOMAIN_IDMAP;
  731                 return;
  732         }
  733 
  734         /* Obliterate wire_counts */
  735         VM_OBJECT_ASSERT_WLOCKED(obj);
  736         for (m = vm_page_lookup(obj, 0); m != NULL; m = vm_page_next(m))
  737                 m->wire_count = 0;
  738         VM_OBJECT_WUNLOCK(obj);
  739         vm_object_deallocate(obj);
  740 }
  741 
  742 static inline uint64_t
  743 domain_wait_iotlb_flush(struct dmar_unit *unit, uint64_t wt, int iro)
  744 {
  745         uint64_t iotlbr;
  746 
  747         dmar_write8(unit, iro + DMAR_IOTLB_REG_OFF, DMAR_IOTLB_IVT |
  748             DMAR_IOTLB_DR | DMAR_IOTLB_DW | wt);
  749         for (;;) {
  750                 iotlbr = dmar_read8(unit, iro + DMAR_IOTLB_REG_OFF);
  751                 if ((iotlbr & DMAR_IOTLB_IVT) == 0)
  752                         break;
  753                 cpu_spinwait();
  754         }
  755         return (iotlbr);
  756 }
  757 
  758 void
  759 domain_flush_iotlb_sync(struct dmar_domain *domain, dmar_gaddr_t base,
  760     dmar_gaddr_t size)
  761 {
  762         struct dmar_unit *unit;
  763         dmar_gaddr_t isize;
  764         uint64_t iotlbr;
  765         int am, iro;
  766 
  767         unit = domain->dmar;
  768         KASSERT(!unit->qi_enabled, ("dmar%d: sync iotlb flush call",
  769             unit->unit));
  770         iro = DMAR_ECAP_IRO(unit->hw_ecap) * 16;
  771         DMAR_LOCK(unit);
  772         if ((unit->hw_cap & DMAR_CAP_PSI) == 0 || size > 2 * 1024 * 1024) {
  773                 iotlbr = domain_wait_iotlb_flush(unit, DMAR_IOTLB_IIRG_DOM |
  774                     DMAR_IOTLB_DID(domain->domain), iro);
  775                 KASSERT((iotlbr & DMAR_IOTLB_IAIG_MASK) !=
  776                     DMAR_IOTLB_IAIG_INVLD,
  777                     ("dmar%d: invalidation failed %jx", unit->unit,
  778                     (uintmax_t)iotlbr));
  779         } else {
  780                 for (; size > 0; base += isize, size -= isize) {
  781                         am = calc_am(unit, base, size, &isize);
  782                         dmar_write8(unit, iro, base | am);
  783                         iotlbr = domain_wait_iotlb_flush(unit,
  784                             DMAR_IOTLB_IIRG_PAGE |
  785                             DMAR_IOTLB_DID(domain->domain), iro);
  786                         KASSERT((iotlbr & DMAR_IOTLB_IAIG_MASK) !=
  787                             DMAR_IOTLB_IAIG_INVLD,
  788                             ("dmar%d: PSI invalidation failed "
  789                             "iotlbr 0x%jx base 0x%jx size 0x%jx am %d",
  790                             unit->unit, (uintmax_t)iotlbr,
  791                             (uintmax_t)base, (uintmax_t)size, am));
  792                         /*
  793                          * Any non-page granularity covers whole guest
  794                          * address space for the domain.
  795                          */
  796                         if ((iotlbr & DMAR_IOTLB_IAIG_MASK) !=
  797                             DMAR_IOTLB_IAIG_PAGE)
  798                                 break;
  799                 }
  800         }
  801         DMAR_UNLOCK(unit);
  802 }

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