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authorzhichang.yuan <zhichang.yuan@linaro.org>2014-12-09 07:26:47 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2015-01-28 12:07:28 +0000
commit523d6e9fae9333a0e2a7baf4d11c8bcca544790e (patch)
tree3c0d9fc243f9e00ce49985e078a8c641029f0833 /arch/arm64
parent62fa5e20bd73385253d2b8d3a51f80d1e6d2e1c6 (diff)
downloadlinux-523d6e9fae9333a0e2a7baf4d11c8bcca544790e.tar.bz2
arm64:mm: free the useless initial page table
For 64K page system, after mapping a PMD section, the corresponding initial page table is not needed any more. That page can be freed. Signed-off-by: Zhichang Yuan <zhichang.yuan@linaro.org> [catalin.marinas@arm.com: added BUG_ON() to catch late memblock freeing] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/include/asm/pgtable.h3
-rw-r--r--arch/arm64/mm/mmu.c15
2 files changed, 15 insertions, 3 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 59079248529d..67f6ede39474 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -342,9 +342,12 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
#ifdef CONFIG_ARM64_64K_PAGES
#define pud_sect(pud) (0)
+#define pud_table(pud) (1)
#else
#define pud_sect(pud) ((pud_val(pud) & PUD_TYPE_MASK) == \
PUD_TYPE_SECT)
+#define pud_table(pud) ((pud_val(pud) & PUD_TYPE_MASK) == \
+ PUD_TYPE_TABLE)
#endif
static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 155cbb0a74b6..eb293febfb56 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -153,8 +153,14 @@ static void alloc_init_pmd(struct mm_struct *mm, pud_t *pud,
* Check for previous table entries created during
* boot (__create_page_tables) and flush them.
*/
- if (!pmd_none(old_pmd))
+ if (!pmd_none(old_pmd)) {
flush_tlb_all();
+ if (pmd_table(old_pmd)) {
+ phys_addr_t table = __pa(pte_offset_map(&old_pmd, 0));
+ BUG_ON(alloc != early_alloc);
+ memblock_free(table, PAGE_SIZE);
+ }
+ }
} else {
alloc_init_pte(pmd, addr, next, __phys_to_pfn(phys),
prot, alloc);
@@ -209,9 +215,12 @@ static void alloc_init_pud(struct mm_struct *mm, pgd_t *pgd,
* Look up the old pmd table and free it.
*/
if (!pud_none(old_pud)) {
- phys_addr_t table = __pa(pmd_offset(&old_pud, 0));
- memblock_free(table, PAGE_SIZE);
flush_tlb_all();
+ if (pud_table(old_pud)) {
+ phys_addr_t table = __pa(pmd_offset(&old_pud, 0));
+ BUG_ON(alloc != early_alloc);
+ memblock_free(table, PAGE_SIZE);
+ }
}
} else {
alloc_init_pmd(mm, pud, addr, next, phys, prot, alloc);