[PATCH V2] arm64/mm: Add pud_sect_supported()
From: Anshuman Khandual <hidden>
Date: 2021-09-20 09:28:44
Section mapping at PUD level is supported only on 4K pages and currently it gets verified with explicit #ifdef or IS_ENABLED() constructs. This adds a new helper pud_sect_supported() for this purpose, which particularly cleans up the HugeTLB code path. It updates relevant switch statements with checks for __PAGETABLE_PMD_FOLDED in order to avoid build failures caused with two identical switch case values in those code blocks. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Anshuman Khandual <redacted> --- This applies on v5.15-rc2 Changes in V2: - Replaced __PAGETABLE_PUD_FOLDED with __PAGETABLE_PMD_FOLDED per Catalin Changes in V1: https://lore.kernel.org/all/1631677459-28383-1-git-send-email-anshuman.khandual@arm.com/ arch/arm64/include/asm/pgtable.h | 5 +++++ arch/arm64/include/asm/vmalloc.h | 4 ++-- arch/arm64/mm/hugetlbpage.c | 26 +++++++++++++++----------- 3 files changed, 22 insertions(+), 13 deletions(-)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index dfa76afa0ccf..84fbb52b4224 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h@@ -1022,6 +1022,11 @@ static inline pgprot_t arch_filter_pgprot(pgprot_t prot) return PAGE_READONLY_EXEC; } +static inline bool pud_sect_supported(void) +{ + return PAGE_SIZE == SZ_4K; +} + #endif /* !__ASSEMBLY__ */
diff --git a/arch/arm64/include/asm/vmalloc.h b/arch/arm64/include/asm/vmalloc.h
index 7a22aeea9bb5..b9185503feae 100644
--- a/arch/arm64/include/asm/vmalloc.h
+++ b/arch/arm64/include/asm/vmalloc.h@@ -2,6 +2,7 @@ #define _ASM_ARM64_VMALLOC_H #include <asm/page.h> +#include <asm/pgtable.h> #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
@@ -9,10 +10,9 @@ static inline bool arch_vmap_pud_supported(pgprot_t prot) { /* - * Only 4k granule supports level 1 block mappings. * SW table walks can't handle removal of intermediate entries. */ - return IS_ENABLED(CONFIG_ARM64_4K_PAGES) && + return pud_sect_supported() && !IS_ENABLED(CONFIG_PTDUMP_DEBUGFS); }
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 23505fc35324..029cf5e42c4c 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c@@ -40,11 +40,10 @@ void __init arm64_hugetlb_cma_reserve(void) { int order; -#ifdef CONFIG_ARM64_4K_PAGES - order = PUD_SHIFT - PAGE_SHIFT; -#else - order = CONT_PMD_SHIFT + PMD_SHIFT - PAGE_SHIFT; -#endif + if (pud_sect_supported()) + order = PUD_SHIFT - PAGE_SHIFT; + else + order = CONT_PMD_SHIFT + PMD_SHIFT - PAGE_SHIFT; /* * HugeTLB CMA reservation is required for gigantic * huge pages which could not be allocated via the
@@ -62,8 +61,9 @@ bool arch_hugetlb_migration_supported(struct hstate *h) size_t pagesize = huge_page_size(h); switch (pagesize) { -#ifdef CONFIG_ARM64_4K_PAGES +#ifndef __PAGETABLE_PMD_FOLDED case PUD_SIZE: + return pud_sect_supported(); #endif case PMD_SIZE: case CONT_PMD_SIZE:
@@ -126,8 +126,11 @@ static inline int num_contig_ptes(unsigned long size, size_t *pgsize) *pgsize = size; switch (size) { -#ifdef CONFIG_ARM64_4K_PAGES +#ifndef __PAGETABLE_PMD_FOLDED case PUD_SIZE: + if (pud_sect_supported()) + contig_ptes = 1; + break; #endif case PMD_SIZE: contig_ptes = 1;
@@ -489,9 +492,9 @@ void huge_ptep_clear_flush(struct vm_area_struct *vma, static int __init hugetlbpage_init(void) { -#ifdef CONFIG_ARM64_4K_PAGES - hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT); -#endif + if (pud_sect_supported()) + hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT); + hugetlb_add_hstate(CONT_PMD_SHIFT - PAGE_SHIFT); hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT); hugetlb_add_hstate(CONT_PTE_SHIFT - PAGE_SHIFT);
@@ -503,8 +506,9 @@ arch_initcall(hugetlbpage_init); bool __init arch_hugetlb_valid_size(unsigned long size) { switch (size) { -#ifdef CONFIG_ARM64_4K_PAGES +#ifndef __PAGETABLE_PMD_FOLDED case PUD_SIZE: + return pud_sect_supported(); #endif case CONT_PMD_SIZE: case PMD_SIZE:
--
2.20.1
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