Date: Sun, 5 Feb 2017 00:42:15 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r313256 - in stable/10/sys: amd64/amd64 i386/i386 Message-ID: <201702050042.v150gFjr070007@repo.freebsd.org>
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Author: kib Date: Sun Feb 5 00:42:15 2017 New Revision: 313256 URL: https://svnweb.freebsd.org/changeset/base/313256 Log: MFC r312954: Do not leave stale 4K TLB entries on pde (superpage) removal or protection change. Modified: stable/10/sys/amd64/amd64/pmap.c stable/10/sys/i386/i386/pmap.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/amd64/amd64/pmap.c ============================================================================== --- stable/10/sys/amd64/amd64/pmap.c Sun Feb 5 00:39:44 2017 (r313255) +++ stable/10/sys/amd64/amd64/pmap.c Sun Feb 5 00:42:15 2017 (r313256) @@ -912,7 +912,12 @@ pmap_bootstrap(vm_paddr_t *firstaddr) virtual_avail = va; - /* Initialize the PAT MSR. */ + /* + * Initialize the PAT MSR. + * pmap_init_pat() clears and sets CR4_PGE, which, as a + * side-effect, invalidates stale PG_G TLB entries that might + * have been created in our pre-boot environment. + */ pmap_init_pat(); /* Initialize TLB Context Id. */ @@ -3372,6 +3377,7 @@ pmap_demote_pde_locked(pmap_t pmap, pd_e vm_paddr_t mptepa; vm_page_t mpte; struct spglist free; + vm_offset_t sva; int PG_PTE_CACHE; PG_G = pmap_global_bit(pmap); @@ -3410,9 +3416,9 @@ pmap_demote_pde_locked(pmap_t pmap, pd_e DMAP_MAX_ADDRESS ? VM_ALLOC_INTERRUPT : VM_ALLOC_NORMAL) | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED)) == NULL) { SLIST_INIT(&free); - pmap_remove_pde(pmap, pde, trunc_2mpage(va), &free, - lockp); - pmap_invalidate_page(pmap, trunc_2mpage(va)); + sva = trunc_2mpage(va); + pmap_remove_pde(pmap, pde, sva, &free, lockp); + pmap_invalidate_range(pmap, sva, sva + NBPDR - 1); pmap_free_zero_pages(&free); CTR2(KTR_PMAP, "pmap_demote_pde: failure for va %#lx" " in pmap %p", va, pmap); @@ -3555,11 +3561,23 @@ pmap_remove_pde(pmap_t pmap, pd_entry_t pmap->pm_stats.wired_count -= NBPDR / PAGE_SIZE; /* - * Machines that don't support invlpg, also don't support - * PG_G. - */ - if (oldpde & PG_G) - pmap_invalidate_page(kernel_pmap, sva); + * When workaround_erratum383 is false, a promotion to a 2M + * page mapping does not invalidate the 512 4K page mappings + * from the TLB. Consequently, at this point, the TLB may + * hold both 4K and 2M page mappings. Therefore, the entire + * range of addresses must be invalidated here. In contrast, + * when workaround_erratum383 is true, a promotion does + * invalidate the 512 4K page mappings, and so a single INVLPG + * suffices to invalidate the 2M page mapping. + */ + if ((oldpde & PG_G) != 0) { + if (workaround_erratum383) + pmap_invalidate_page(kernel_pmap, sva); + else + pmap_invalidate_range(kernel_pmap, sva, + sva + NBPDR - 1); + } + pmap_resident_count_dec(pmap, NBPDR / PAGE_SIZE); if (oldpde & PG_MANAGED) { CHANGE_PV_LIST_LOCK_TO_PHYS(lockp, oldpde & PG_PS_FRAME); @@ -3914,9 +3932,14 @@ retry: if (newpde != oldpde) { if (!atomic_cmpset_long(pde, oldpde, newpde)) goto retry; - if (oldpde & PG_G) - pmap_invalidate_page(pmap, sva); - else + if (oldpde & PG_G) { + /* See pmap_remove_pde() for explanation. */ + if (workaround_erratum383) + pmap_invalidate_page(kernel_pmap, sva); + else + pmap_invalidate_range(kernel_pmap, sva, + sva + NBPDR - 1); + } else anychanged = TRUE; } return (anychanged); Modified: stable/10/sys/i386/i386/pmap.c ============================================================================== --- stable/10/sys/i386/i386/pmap.c Sun Feb 5 00:39:44 2017 (r313255) +++ stable/10/sys/i386/i386/pmap.c Sun Feb 5 00:42:15 2017 (r313256) @@ -517,7 +517,14 @@ pmap_bootstrap(vm_paddr_t firstaddr) for (i = 1; i < NKPT; i++) PTD[i] = 0; - /* Initialize the PAT MSR if present. */ + /* + * Initialize the PAT MSR if present. + * pmap_init_pat() clears and sets CR4_PGE, which, as a + * side-effect, invalidates stale PG_G TLB entries that might + * have been created in our pre-boot environment. We assume + * that PAT support implies PGE and in reverse, PGE presence + * comes with PAT. Both features were added for Pentium Pro. + */ pmap_init_pat(); /* Turn on PG_G on kernel page(s) */ @@ -545,7 +552,10 @@ pmap_init_pat(void) pat_table[PAT_WRITE_PROTECTED] = 3; pat_table[PAT_UNCACHED] = 3; - /* Bail if this CPU doesn't implement PAT. */ + /* + * Bail if this CPU doesn't implement PAT. + * We assume that PAT support implies PGE. + */ if ((cpu_feature & CPUID_PAT) == 0) { for (i = 0; i < PAT_INDEX_SIZE; i++) pat_index[i] = pat_table[i]; @@ -2687,6 +2697,7 @@ pmap_demote_pde(pmap_t pmap, pd_entry_t vm_paddr_t mptepa; vm_page_t mpte; struct spglist free; + vm_offset_t sva; PMAP_LOCK_ASSERT(pmap, MA_OWNED); oldpde = *pde; @@ -2709,8 +2720,9 @@ pmap_demote_pde(pmap_t pmap, pd_entry_t va >> PDRSHIFT, VM_ALLOC_NOOBJ | VM_ALLOC_NORMAL | VM_ALLOC_WIRED)) == NULL) { SLIST_INIT(&free); - pmap_remove_pde(pmap, pde, trunc_4mpage(va), &free); - pmap_invalidate_page(pmap, trunc_4mpage(va)); + sva = trunc_4mpage(va); + pmap_remove_pde(pmap, pde, sva, &free); + pmap_invalidate_range(pmap, sva, sva + NBPDR - 1); pmap_free_zero_pages(&free); CTR2(KTR_PMAP, "pmap_demote_pde: failure for va %#x" " in pmap %p", va, pmap); @@ -2881,9 +2893,24 @@ pmap_remove_pde(pmap_t pmap, pd_entry_t /* * Machines that don't support invlpg, also don't support * PG_G. - */ - if (oldpde & PG_G) - pmap_invalidate_page(kernel_pmap, sva); + * + * When workaround_erratum383 is false, a promotion to a 2M/4M + * page mapping does not invalidate the 512/1024 4K page mappings + * from the TLB. Consequently, at this point, the TLB may + * hold both 4K and 2M/4M page mappings. Therefore, the entire + * range of addresses must be invalidated here. In contrast, + * when workaround_erratum383 is true, a promotion does + * invalidate the 512/1024 4K page mappings, and so a single INVLPG + * suffices to invalidate the 2M/4M page mapping. + */ + if ((oldpde & PG_G) != 0) { + if (workaround_erratum383) + pmap_invalidate_page(kernel_pmap, sva); + else + pmap_invalidate_range(kernel_pmap, sva, + sva + NBPDR - 1); + } + pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE; if (oldpde & PG_MANAGED) { pvh = pa_to_pvh(oldpde & PG_PS_FRAME); @@ -3193,9 +3220,14 @@ retry: if (newpde != oldpde) { if (!pde_cmpset(pde, oldpde, newpde)) goto retry; - if (oldpde & PG_G) - pmap_invalidate_page(pmap, sva); - else + if (oldpde & PG_G) { + /* See pmap_remove_pde() for explanation. */ + if (workaround_erratum383) + pmap_invalidate_page(kernel_pmap, sva); + else + pmap_invalidate_range(kernel_pmap, sva, + sva + NBPDR - 1); + } else anychanged = TRUE; } return (anychanged);
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