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authorLaura Abbott <labbott@fedoraproject.org>2016-02-05 16:24:47 -0800
committerCatalin Marinas <catalin.marinas@arm.com>2016-02-16 15:40:30 +0000
commit83863f25e4b8214e994ef8b5647aad614d74b45d (patch)
treedef928e193b847e4035a6d895efafc9f9b881896 /arch/arm64/mm/mmu.c
parent132233a759580f5ce9b1bfaac9073e47d03c460d (diff)
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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 <ard.biesheuvel@linaro.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Laura Abbott <labbott@fedoraproject.org> [catalin.marinas@arm.com: static annotation block_mappings_allowed() and #ifdef] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/mm/mmu.c')
-rw-r--r--arch/arm64/mm/mmu.c26
1 files changed, 24 insertions, 2 deletions
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))));