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| author | Ard Biesheuvel <ardb@kernel.org> | 2024-02-14 15:29:17 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2024-02-16 15:42:39 +0300 |
| commit | a6bbf5d4d9d13509fd068de664238c16934962c6 (patch) | |
| tree | dd6cf839e7e166c851e1b23fdfa830951878ea6f /arch/arm64/mm | |
| parent | 925a0eb48044bf3d48531703c3b7522e1a8c87fb (diff) | |
| download | linux-a6bbf5d4d9d13509fd068de664238c16934962c6.tar.xz | |
arm64: mm: Add definitions to support 5 levels of paging
Add the required types and descriptor accessors to support 5 levels of
paging in the common code. This is one of the prerequisites for
supporting 52-bit virtual addressing with 4k pages.
Note that this does not cover the code that handles kernel mappings or
the fixmap.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240214122845.2033971-76-ardb+git@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/mm')
| -rw-r--r-- | arch/arm64/mm/mmu.c | 31 | ||||
| -rw-r--r-- | arch/arm64/mm/pgd.c | 15 |
2 files changed, 41 insertions, 5 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index ba00d0205447..d2e9dec38a15 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1025,7 +1025,7 @@ static void free_empty_pud_table(p4d_t *p4dp, unsigned long addr, if (CONFIG_PGTABLE_LEVELS <= 3) return; - if (!pgtable_range_aligned(start, end, floor, ceiling, PGDIR_MASK)) + if (!pgtable_range_aligned(start, end, floor, ceiling, P4D_MASK)) return; /* @@ -1048,8 +1048,8 @@ static void free_empty_p4d_table(pgd_t *pgdp, unsigned long addr, unsigned long end, unsigned long floor, unsigned long ceiling) { - unsigned long next; p4d_t *p4dp, p4d; + unsigned long i, next, start = addr; do { next = p4d_addr_end(addr, end); @@ -1061,6 +1061,27 @@ static void free_empty_p4d_table(pgd_t *pgdp, unsigned long addr, WARN_ON(!p4d_present(p4d)); free_empty_pud_table(p4dp, addr, next, floor, ceiling); } while (addr = next, addr < end); + + if (!pgtable_l5_enabled()) + return; + + if (!pgtable_range_aligned(start, end, floor, ceiling, PGDIR_MASK)) + return; + + /* + * Check whether we can free the p4d page if the rest of the + * entries are empty. Overlap with other regions have been + * handled by the floor/ceiling check. + */ + p4dp = p4d_offset(pgdp, 0UL); + for (i = 0; i < PTRS_PER_P4D; i++) { + if (!p4d_none(READ_ONCE(p4dp[i]))) + return; + } + + pgd_clear(pgdp); + __flush_tlb_kernel_pgtable(start); + free_hotplug_pgtable_page(virt_to_page(p4dp)); } static void free_empty_tables(unsigned long addr, unsigned long end, @@ -1145,6 +1166,12 @@ int pmd_set_huge(pmd_t *pmdp, phys_addr_t phys, pgprot_t prot) return 1; } +#ifndef __PAGETABLE_P4D_FOLDED +void p4d_clear_huge(p4d_t *p4dp) +{ +} +#endif + int pud_clear_huge(pud_t *pudp) { if (!pud_sect(READ_ONCE(*pudp))) diff --git a/arch/arm64/mm/pgd.c b/arch/arm64/mm/pgd.c index 4a64089e5771..3c4f8a279d2b 100644 --- a/arch/arm64/mm/pgd.c +++ b/arch/arm64/mm/pgd.c @@ -17,11 +17,20 @@ static struct kmem_cache *pgd_cache __ro_after_init; +static bool pgdir_is_page_size(void) +{ + if (PGD_SIZE == PAGE_SIZE) + return true; + if (CONFIG_PGTABLE_LEVELS == 5) + return !pgtable_l5_enabled(); + return false; +} + pgd_t *pgd_alloc(struct mm_struct *mm) { gfp_t gfp = GFP_PGTABLE_USER; - if (PGD_SIZE == PAGE_SIZE) + if (pgdir_is_page_size()) return (pgd_t *)__get_free_page(gfp); else return kmem_cache_alloc(pgd_cache, gfp); @@ -29,7 +38,7 @@ pgd_t *pgd_alloc(struct mm_struct *mm) void pgd_free(struct mm_struct *mm, pgd_t *pgd) { - if (PGD_SIZE == PAGE_SIZE) + if (pgdir_is_page_size()) free_page((unsigned long)pgd); else kmem_cache_free(pgd_cache, pgd); @@ -37,7 +46,7 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd) void __init pgtable_cache_init(void) { - if (PGD_SIZE == PAGE_SIZE) + if (pgdir_is_page_size()) return; #ifdef CONFIG_ARM64_PA_BITS_52 |