Date: Mon, 25 Oct 2021 13:54:52 GMT From: Andrew Turner <andrew@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 39dbb494404f - stable/13 - Only demote when needed in the arm64 pmap_change_props_locked Message-ID: <202110251354.19PDsqVj000562@gitrepo.freebsd.org>
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The branch stable/13 has been updated by andrew: URL: https://cgit.FreeBSD.org/src/commit/?id=39dbb494404f511422a97274d5b55fae6ef4a6e2 commit 39dbb494404f511422a97274d5b55fae6ef4a6e2 Author: Andrew Turner <andrew@FreeBSD.org> AuthorDate: 2021-10-06 16:38:22 +0000 Commit: Andrew Turner <andrew@FreeBSD.org> CommitDate: 2021-10-25 13:46:44 +0000 Only demote when needed in the arm64 pmap_change_props_locked When changing page table properties there is no need to demote a level 1 or level 2 block if we are changing the entire memory range the block is mapping. In this case just change the block directly. Reported by: alc, kib, markj Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D32339 (cherry picked from commit 806a88e742002b0e82a4ea06f8e147f627947c2c) --- sys/arm64/arm64/pmap.c | 76 ++++++++++++++++++++++++++++++-------------------- 1 file changed, 45 insertions(+), 31 deletions(-) diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c index 3fa3a4b62711..176762b9bfff 100644 --- a/sys/arm64/arm64/pmap.c +++ b/sys/arm64/arm64/pmap.c @@ -6160,7 +6160,8 @@ pmap_change_props_locked(vm_offset_t va, vm_size_t size, vm_prot_t prot, int mode) { vm_offset_t base, offset, tmpva; - pt_entry_t l3, *pte, *newpte; + vm_size_t pte_size; + pt_entry_t pte, *ptep, *newpte; pt_entry_t bits, mask; int lvl, rv; @@ -6206,11 +6207,11 @@ pmap_change_props_locked(vm_offset_t va, vm_size_t size, vm_prot_t prot, } for (tmpva = base; tmpva < base + size; ) { - pte = pmap_pte(kernel_pmap, tmpva, &lvl); - if (pte == NULL) + ptep = pmap_pte(kernel_pmap, tmpva, &lvl); + if (ptep == NULL) return (EINVAL); - if ((pmap_load(pte) & mask) == bits) { + if ((pmap_load(ptep) & mask) == bits) { /* * We already have the correct attribute, * ignore this entry. @@ -6237,47 +6238,60 @@ pmap_change_props_locked(vm_offset_t va, vm_size_t size, vm_prot_t prot, default: panic("Invalid DMAP table level: %d\n", lvl); case 1: - newpte = pmap_demote_l1(kernel_pmap, pte, + if ((tmpva & L1_OFFSET) == 0 && + (base + size - tmpva) >= L1_SIZE) { + pte_size = L1_SIZE; + break; + } + newpte = pmap_demote_l1(kernel_pmap, ptep, tmpva & ~L1_OFFSET); if (newpte == NULL) return (EINVAL); - pte = pmap_l1_to_l2(pte, tmpva); + ptep = pmap_l1_to_l2(ptep, tmpva); + /* FALLTHROUGH */ case 2: - newpte = pmap_demote_l2(kernel_pmap, pte, + if ((tmpva & L2_OFFSET) == 0 && + (base + size - tmpva) >= L2_SIZE) { + pte_size = L2_SIZE; + break; + } + newpte = pmap_demote_l2(kernel_pmap, ptep, tmpva); if (newpte == NULL) return (EINVAL); - pte = pmap_l2_to_l3(pte, tmpva); + ptep = pmap_l2_to_l3(ptep, tmpva); + /* FALLTHROUGH */ case 3: - /* Update the entry */ - l3 = pmap_load(pte); - l3 &= ~mask; - l3 |= bits; + pte_size = PAGE_SIZE; + break; + } - pmap_update_entry(kernel_pmap, pte, l3, tmpva, - PAGE_SIZE); + /* Update the entry */ + pte = pmap_load(ptep); + pte &= ~mask; + pte |= bits; - if (!VIRT_IN_DMAP(tmpva)) { - /* - * Keep the DMAP memory in sync. - */ - rv = pmap_change_props_locked( - PHYS_TO_DMAP(l3 & ~ATTR_MASK), - L3_SIZE, prot, mode); - if (rv != 0) - return (rv); - } + pmap_update_entry(kernel_pmap, ptep, pte, tmpva, + pte_size); + if (!VIRT_IN_DMAP(tmpva)) { /* - * If moving to a non-cacheable entry flush - * the cache. + * Keep the DMAP memory in sync. */ - if (mode == VM_MEMATTR_UNCACHEABLE) - cpu_dcache_wbinv_range(tmpva, L3_SIZE); - - break; + rv = pmap_change_props_locked( + PHYS_TO_DMAP(pte & ~ATTR_MASK), pte_size, + prot, mode); + if (rv != 0) + return (rv); } - tmpva += PAGE_SIZE; + + /* + * If moving to a non-cacheable entry flush + * the cache. + */ + if (mode == VM_MEMATTR_UNCACHEABLE) + cpu_dcache_wbinv_range(tmpva, pte_size); + tmpva += pte_size; } }
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