From 961faac114819a01e627fe9c9c82b830bb3849d4 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 25 Jan 2016 11:45:07 +0000 Subject: [PATCH] arm64: mm: add functions to walk tables in fixmap As a preparatory step to allow us to allocate early page tables from unmapped memory using memblock_alloc, add new p??_{set,clear}_fixmap* functions which can be used to walk page tables outside of the linear mapping by using fixmap slots. Signed-off-by: Mark Rutland Reviewed-by: Catalin Marinas Tested-by: Ard Biesheuvel Reviewed-by: Ard Biesheuvel Tested-by: Jeremy Linton Cc: Laura Abbott Cc: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/fixmap.h | 10 ++++++++++ arch/arm64/include/asm/pgtable.h | 26 ++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h index 309704544d22..1a617d46fce9 100644 --- a/arch/arm64/include/asm/fixmap.h +++ b/arch/arm64/include/asm/fixmap.h @@ -62,6 +62,16 @@ enum fixed_addresses { FIX_BTMAP_END = __end_of_permanent_fixed_addresses, FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1, + + /* + * Used for kernel page table creation, so unmapped memory may be used + * for tables. + */ + FIX_PTE, + FIX_PMD, + FIX_PUD, + FIX_PGD, + __end_of_fixed_addresses }; diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 842c192a1ca1..4229f75fd145 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -57,6 +57,7 @@ #ifndef __ASSEMBLY__ +#include #include extern void __pte_error(const char *file, int line, unsigned long val); @@ -438,6 +439,10 @@ static inline phys_addr_t pmd_page_paddr(pmd_t pmd) #define pte_unmap(pte) do { } while (0) #define pte_unmap_nested(pte) do { } while (0) +#define pte_set_fixmap(addr) ((pte_t *)set_fixmap_offset(FIX_PTE, addr)) +#define pte_set_fixmap_offset(pmd, addr) pte_set_fixmap(pte_offset_phys(pmd, addr)) +#define pte_clear_fixmap() clear_fixmap(FIX_PTE) + #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK)) /* @@ -477,12 +482,21 @@ static inline phys_addr_t pud_page_paddr(pud_t pud) #define pmd_offset_phys(dir, addr) (pud_page_paddr(*(dir)) + pmd_index(addr) * sizeof(pmd_t)) #define pmd_offset(dir, addr) ((pmd_t *)__va(pmd_offset_phys((dir), (addr)))) +#define pmd_set_fixmap(addr) ((pmd_t *)set_fixmap_offset(FIX_PMD, addr)) +#define pmd_set_fixmap_offset(pud, addr) pmd_set_fixmap(pmd_offset_phys(pud, addr)) +#define pmd_clear_fixmap() clear_fixmap(FIX_PMD) + #define pud_page(pud) pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK)) #else #define pud_page_paddr(pud) ({ BUILD_BUG(); 0; }) +/* Match pmd_offset folding in */ +#define pmd_set_fixmap(addr) NULL +#define pmd_set_fixmap_offset(pudp, addr) ((pmd_t *)pudp) +#define pmd_clear_fixmap() + #endif /* CONFIG_PGTABLE_LEVELS > 2 */ #if CONFIG_PGTABLE_LEVELS > 3 @@ -515,12 +529,21 @@ static inline phys_addr_t pgd_page_paddr(pgd_t pgd) #define pud_offset_phys(dir, addr) (pgd_page_paddr(*(dir)) + pud_index(addr) * sizeof(pud_t)) #define pud_offset(dir, addr) ((pud_t *)__va(pud_offset_phys((dir), (addr)))) +#define pud_set_fixmap(addr) ((pud_t *)set_fixmap_offset(FIX_PUD, addr)) +#define pud_set_fixmap_offset(pgd, addr) pud_set_fixmap(pud_offset_phys(pgd, addr)) +#define pud_clear_fixmap() clear_fixmap(FIX_PUD) + #define pgd_page(pgd) pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK)) #else #define pgd_page_paddr(pgd) ({ BUILD_BUG(); 0;}) +/* Match pud_offset folding in */ +#define pud_set_fixmap(addr) NULL +#define pud_set_fixmap_offset(pgdp, addr) ((pud_t *)pgdp) +#define pud_clear_fixmap() + #endif /* CONFIG_PGTABLE_LEVELS > 3 */ #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd)) @@ -535,6 +558,9 @@ static inline phys_addr_t pgd_page_paddr(pgd_t pgd) /* to find an entry in a kernel page-table-directory */ #define pgd_offset_k(addr) pgd_offset(&init_mm, addr) +#define pgd_set_fixmap(addr) ((pgd_t *)set_fixmap_offset(FIX_PGD, addr)) +#define pgd_clear_fixmap() clear_fixmap(FIX_PGD) + static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY | -- 2.20.1