From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Mon, 4 Jan 2016 17:56:46 +0000 Subject: [PATCHv2 13/18] arm64: mm: add functions to walk tables in fixmap In-Reply-To: <1451930211-22460-1-git-send-email-mark.rutland@arm.com> References: <1451930211-22460-1-git-send-email-mark.rutland@arm.com> Message-ID: <1451930211-22460-14-git-send-email-mark.rutland@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org As a prepratory step to allow us to allocate early page tables from unmapped memory using memblock_alloc, add new p??_fixmap* functions that can be used to walk page tables outside of the linear mapping by using fixmap slots. Signed-off-by: Mark Rutland Cc: Ard Biesheuvel Cc: Catalin Marinas Cc: Jeremy Linton Cc: Laura Abbott Cc: Will Deacon --- 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 3097045..1a617d4 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 f5742db..824e7f0 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); @@ -442,6 +443,10 @@ 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_fixmap(addr) ((pte_t *)set_fixmap_offset(FIX_PTE, addr)) +#define pte_fixmap_offset(pmd, addr) pte_fixmap(pte_offset_phys(pmd, addr)) +#define pte_fixmap_unmap() clear_fixmap(FIX_PTE) + #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK)) /* @@ -481,12 +486,21 @@ 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_fixmap(addr) ((pmd_t *)set_fixmap_offset(FIX_PMD, addr)) +#define pmd_fixmap_offset(pud, addr) pmd_fixmap(pmd_offset_phys(pud, addr)) +#define pmd_fixmap_unmap() 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_fixmap(addr) NULL +#define pmd_fixmap_offset(pudp, addr) ((pmd_t *)pudp) +#define pmd_fixmap_unmap() + #endif /* CONFIG_PGTABLE_LEVELS > 2 */ #if CONFIG_PGTABLE_LEVELS > 3 @@ -519,12 +533,21 @@ 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_fixmap(addr) ((pud_t *)set_fixmap_offset(FIX_PUD, addr)) +#define pud_fixmap_offset(pgd, addr) pud_fixmap(pmd_offset_phys(pgd, addr)) +#define pud_fixmap_unmap() 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_fixmap(addr) NULL +#define pud_fixmap_offset(pgdp, addr) ((pud_t *)pgdp) +#define pud_fixmap_unmap() + #endif /* CONFIG_PGTABLE_LEVELS > 3 */ #define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd_val(pgd)) @@ -539,6 +562,9 @@ 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_fixmap(addr) ((pgd_t *)set_fixmap_offset(FIX_PGD, addr)) +#define pgd_fixmap_unmap() 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 | -- 1.9.1