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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-08-07 13:18:06 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-08-07 13:18:06 +0000 |
commit | 638a9e433ecd61e64761352dbec1fa4f5874c941 (patch) | |
tree | fdbff74a238d7a5a7d1cef071b7230bc064b9f25 /arch/arm64/mm/mmu.c | |
parent | Releasing progress-linux version 6.9.12-1~progress7.99u1. (diff) | |
download | linux-638a9e433ecd61e64761352dbec1fa4f5874c941.tar.xz linux-638a9e433ecd61e64761352dbec1fa4f5874c941.zip |
Merging upstream version 6.10.3.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/mm/mmu.c')
-rw-r--r-- | arch/arm64/mm/mmu.c | 104 |
1 files changed, 59 insertions, 45 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 495b732d5a..353ea5dc32 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -109,28 +109,12 @@ EXPORT_SYMBOL(phys_mem_access_prot); static phys_addr_t __init early_pgtable_alloc(int shift) { phys_addr_t phys; - void *ptr; phys = memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE, 0, MEMBLOCK_ALLOC_NOLEAKTRACE); if (!phys) panic("Failed to allocate page table page\n"); - /* - * The FIX_{PGD,PUD,PMD} slots may be in active use, but the FIX_PTE - * slot will be free, so we can (ab)use the FIX_PTE slot to initialise - * any level of table. - */ - ptr = pte_set_fixmap(phys); - - memset(ptr, 0, PAGE_SIZE); - - /* - * Implicit barriers also ensure the zeroed page is visible to the page - * table walker - */ - pte_clear_fixmap(); - return phys; } @@ -140,7 +124,8 @@ bool pgattr_change_is_safe(u64 old, u64 new) * The following mapping attributes may be updated in live * kernel mappings without the need for break-before-make. */ - pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE | PTE_NG; + pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE | PTE_NG | + PTE_SWBITS_MASK; /* creating or taking down mappings is always safe */ if (!pte_valid(__pte(old)) || !pte_valid(__pte(new))) @@ -172,16 +157,25 @@ bool pgattr_change_is_safe(u64 old, u64 new) return ((old ^ new) & ~mask) == 0; } -static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end, - phys_addr_t phys, pgprot_t prot) +static void init_clear_pgtable(void *table) { - pte_t *ptep; + clear_page(table); - ptep = pte_set_fixmap_offset(pmdp, addr); + /* Ensure the zeroing is observed by page table walks. */ + dsb(ishst); +} + +static void init_pte(pte_t *ptep, unsigned long addr, unsigned long end, + phys_addr_t phys, pgprot_t prot) +{ do { pte_t old_pte = __ptep_get(ptep); - __set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot)); + /* + * Required barriers to make this visible to the table walker + * are deferred to the end of alloc_init_cont_pte(). + */ + __set_pte_nosync(ptep, pfn_pte(__phys_to_pfn(phys), prot)); /* * After the PTE entry has been populated once, we @@ -192,8 +186,6 @@ static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end, phys += PAGE_SIZE; } while (ptep++, addr += PAGE_SIZE, addr != end); - - pte_clear_fixmap(); } static void alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr, @@ -204,6 +196,7 @@ static void alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr, { unsigned long next; pmd_t pmd = READ_ONCE(*pmdp); + pte_t *ptep; BUG_ON(pmd_sect(pmd)); if (pmd_none(pmd)) { @@ -214,10 +207,14 @@ static void alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr, pmdval |= PMD_TABLE_PXN; BUG_ON(!pgtable_alloc); pte_phys = pgtable_alloc(PAGE_SHIFT); + ptep = pte_set_fixmap(pte_phys); + init_clear_pgtable(ptep); + ptep += pte_index(addr); __pmd_populate(pmdp, pte_phys, pmdval); - pmd = READ_ONCE(*pmdp); + } else { + BUG_ON(pmd_bad(pmd)); + ptep = pte_set_fixmap_offset(pmdp, addr); } - BUG_ON(pmd_bad(pmd)); do { pgprot_t __prot = prot; @@ -229,20 +226,26 @@ static void alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr, (flags & NO_CONT_MAPPINGS) == 0) __prot = __pgprot(pgprot_val(prot) | PTE_CONT); - init_pte(pmdp, addr, next, phys, __prot); + init_pte(ptep, addr, next, phys, __prot); + ptep += pte_index(next) - pte_index(addr); phys += next - addr; } while (addr = next, addr != end); + + /* + * Note: barriers and maintenance necessary to clear the fixmap slot + * ensure that all previous pgtable writes are visible to the table + * walker. + */ + pte_clear_fixmap(); } -static void init_pmd(pud_t *pudp, unsigned long addr, unsigned long end, +static void init_pmd(pmd_t *pmdp, unsigned long addr, unsigned long end, phys_addr_t phys, pgprot_t prot, phys_addr_t (*pgtable_alloc)(int), int flags) { unsigned long next; - pmd_t *pmdp; - pmdp = pmd_set_fixmap_offset(pudp, addr); do { pmd_t old_pmd = READ_ONCE(*pmdp); @@ -268,8 +271,6 @@ static void init_pmd(pud_t *pudp, unsigned long addr, unsigned long end, } phys += next - addr; } while (pmdp++, addr = next, addr != end); - - pmd_clear_fixmap(); } static void alloc_init_cont_pmd(pud_t *pudp, unsigned long addr, @@ -279,6 +280,7 @@ static void alloc_init_cont_pmd(pud_t *pudp, unsigned long addr, { unsigned long next; pud_t pud = READ_ONCE(*pudp); + pmd_t *pmdp; /* * Check for initial section mappings in the pgd/pud. @@ -292,10 +294,14 @@ static void alloc_init_cont_pmd(pud_t *pudp, unsigned long addr, pudval |= PUD_TABLE_PXN; BUG_ON(!pgtable_alloc); pmd_phys = pgtable_alloc(PMD_SHIFT); + pmdp = pmd_set_fixmap(pmd_phys); + init_clear_pgtable(pmdp); + pmdp += pmd_index(addr); __pud_populate(pudp, pmd_phys, pudval); - pud = READ_ONCE(*pudp); + } else { + BUG_ON(pud_bad(pud)); + pmdp = pmd_set_fixmap_offset(pudp, addr); } - BUG_ON(pud_bad(pud)); do { pgprot_t __prot = prot; @@ -307,10 +313,13 @@ static void alloc_init_cont_pmd(pud_t *pudp, unsigned long addr, (flags & NO_CONT_MAPPINGS) == 0) __prot = __pgprot(pgprot_val(prot) | PTE_CONT); - init_pmd(pudp, addr, next, phys, __prot, pgtable_alloc, flags); + init_pmd(pmdp, addr, next, phys, __prot, pgtable_alloc, flags); + pmdp += pmd_index(next) - pmd_index(addr); phys += next - addr; } while (addr = next, addr != end); + + pmd_clear_fixmap(); } static void alloc_init_pud(p4d_t *p4dp, unsigned long addr, unsigned long end, @@ -330,12 +339,15 @@ static void alloc_init_pud(p4d_t *p4dp, unsigned long addr, unsigned long end, p4dval |= P4D_TABLE_PXN; BUG_ON(!pgtable_alloc); pud_phys = pgtable_alloc(PUD_SHIFT); + pudp = pud_set_fixmap(pud_phys); + init_clear_pgtable(pudp); + pudp += pud_index(addr); __p4d_populate(p4dp, pud_phys, p4dval); - p4d = READ_ONCE(*p4dp); + } else { + BUG_ON(p4d_bad(p4d)); + pudp = pud_set_fixmap_offset(p4dp, addr); } - BUG_ON(p4d_bad(p4d)); - pudp = pud_set_fixmap_offset(p4dp, addr); do { pud_t old_pud = READ_ONCE(*pudp); @@ -385,12 +397,15 @@ static void alloc_init_p4d(pgd_t *pgdp, unsigned long addr, unsigned long end, pgdval |= PGD_TABLE_PXN; BUG_ON(!pgtable_alloc); p4d_phys = pgtable_alloc(P4D_SHIFT); + p4dp = p4d_set_fixmap(p4d_phys); + init_clear_pgtable(p4dp); + p4dp += p4d_index(addr); __pgd_populate(pgdp, p4d_phys, pgdval); - pgd = READ_ONCE(*pgdp); + } else { + BUG_ON(pgd_bad(pgd)); + p4dp = p4d_set_fixmap_offset(pgdp, addr); } - BUG_ON(pgd_bad(pgd)); - p4dp = p4d_set_fixmap_offset(pgdp, addr); do { p4d_t old_p4d = READ_ONCE(*p4dp); @@ -457,11 +472,10 @@ void create_kpti_ng_temp_pgd(pgd_t *pgdir, phys_addr_t phys, unsigned long virt, static phys_addr_t __pgd_pgtable_alloc(int shift) { - void *ptr = (void *)__get_free_page(GFP_PGTABLE_KERNEL); - BUG_ON(!ptr); + /* Page is zeroed by init_clear_pgtable() so don't duplicate effort. */ + void *ptr = (void *)__get_free_page(GFP_PGTABLE_KERNEL & ~__GFP_ZERO); - /* Ensure the zeroed page is visible to the page table walker */ - dsb(ishst); + BUG_ON(!ptr); return __pa(ptr); } |