x86, mm: Align start address to correct big page size (960ddb4f) · Commits · 戴 / test

We are going to use buffer in BRK to map small range just under memory top, and use those new mapped ram to map ram range under it. The ram range that will be mapped at first could be only page aligned, but ranges around it are ram too, we could use bigger page to map it to avoid small page size. We will adjust page_size_mask in following patch: x86, mm: Use big page size for small memory range to use big page size for small ram range. Before that patch, this patch will make sure start address to be aligned down according to bigger page size, otherwise entry in page page will not have correct value. Signed-off-by:

Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1353123563-3103-18-git-send-email-yinghai@kernel.org Signed-off-by:

H. Peter Anvin <hpa@linux.intel.com>

arch/x86/mm/init_32.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -310,6 +310,7 @@ repeat:
		__pgprot(PTE_IDENT_ATTR \|
		_PAGE_PSE);

		pfn &= PMD_MASK >> PAGE_SHIFT;
		addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE +
		PAGE_OFFSET + PAGE_SIZE-1;

arch/x86/mm/init_64.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -464,7 +464,7 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end,
		pages++;
		spin_lock(&init_mm.page_table_lock);
		set_pte((pte_t *)pmd,
		pfn_pte(address >> PAGE_SHIFT,
		pfn_pte((address & PMD_MASK) >> PAGE_SHIFT,
		__pgprot(pgprot_val(prot) \| _PAGE_PSE)));
		spin_unlock(&init_mm.page_table_lock);
		last_map_addr = next;
		@@ -541,7 +541,8 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end,
		pages++;
		spin_lock(&init_mm.page_table_lock);
		set_pte((pte_t *)pud,
		pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
		pfn_pte((addr & PUD_MASK) >> PAGE_SHIFT,
		PAGE_KERNEL_LARGE));
		spin_unlock(&init_mm.page_table_lock);
		last_map_addr = next;
		continue;

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