From 83863f25e4b8214e994ef8b5647aad614d74b45d Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Fri, 5 Feb 2016 16:24:47 -0800 Subject: arm64: Add support for ARCH_SUPPORTS_DEBUG_PAGEALLOC ARCH_SUPPORTS_DEBUG_PAGEALLOC provides a hook to map and unmap pages for debugging purposes. This requires memory be mapped with PAGE_SIZE mappings since breaking down larger mappings at runtime will lead to TLB conflicts. Check if debug_pagealloc is enabled at runtime and if so, map everyting with PAGE_SIZE pages. Implement the functions to actually map/unmap the pages at runtime. Reviewed-by: Ard Biesheuvel Reviewed-by: Mark Rutland Tested-by: Mark Rutland Signed-off-by: Laura Abbott [catalin.marinas@arm.com: static annotation block_mappings_allowed() and #ifdef] Signed-off-by: Catalin Marinas --- arch/arm64/mm/mmu.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) (limited to 'arch/arm64/mm/mmu.c') diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index ef0d66cf5535..a6f28e5b9585 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -149,6 +149,26 @@ static void split_pud(pud_t *old_pud, pmd_t *pmd) } while (pmd++, i++, i < PTRS_PER_PMD); } +#ifdef CONFIG_DEBUG_PAGEALLOC +static bool block_mappings_allowed(phys_addr_t (*pgtable_alloc)(void)) +{ + + /* + * If debug_page_alloc is enabled we must map the linear map + * using pages. However, other mappings created by + * create_mapping_noalloc must use sections in some cases. Allow + * sections to be used in those cases, where no pgtable_alloc + * function is provided. + */ + return !pgtable_alloc || !debug_pagealloc_enabled(); +} +#else +static bool block_mappings_allowed(phys_addr_t (*pgtable_alloc)(void)) +{ + return true; +} +#endif + static void alloc_init_pmd(pud_t *pud, unsigned long addr, unsigned long end, phys_addr_t phys, pgprot_t prot, phys_addr_t (*pgtable_alloc)(void)) @@ -181,7 +201,8 @@ static void alloc_init_pmd(pud_t *pud, unsigned long addr, unsigned long end, do { next = pmd_addr_end(addr, end); /* try section mapping first */ - if (((addr | next | phys) & ~SECTION_MASK) == 0) { + if (((addr | next | phys) & ~SECTION_MASK) == 0 && + block_mappings_allowed(pgtable_alloc)) { pmd_t old_pmd =*pmd; set_pmd(pmd, __pmd(phys | pgprot_val(mk_sect_prot(prot)))); @@ -241,7 +262,8 @@ static void alloc_init_pud(pgd_t *pgd, unsigned long addr, unsigned long end, /* * For 4K granule only, attempt to put down a 1GB block */ - if (use_1G_block(addr, next, phys)) { + if (use_1G_block(addr, next, phys) && + block_mappings_allowed(pgtable_alloc)) { pud_t old_pud = *pud; set_pud(pud, __pud(phys | pgprot_val(mk_sect_prot(prot)))); -- cgit v1.2.3-55-g7522