From 97f99fedf27f337e2d3d95ca01e321beb26edc3d Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 30 Jan 2008 13:33:55 +0100 Subject: [PATCH] x86: simplify 32-bit cpa largepage splitting simplify 32-bit cpa largepage splitting: do a pure split and repeat the pte lookup to get the new pte modified. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/mm/pageattr_32.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/arch/x86/mm/pageattr_32.c b/arch/x86/mm/pageattr_32.c index 570a37bf14..1011b21f8d 100644 --- a/arch/x86/mm/pageattr_32.c +++ b/arch/x86/mm/pageattr_32.c @@ -38,7 +38,7 @@ pte_t *lookup_address(unsigned long address, int *level) } static struct page * -split_large_page(unsigned long address, pgprot_t prot, pgprot_t ref_prot) +split_large_page(unsigned long address, pgprot_t ref_prot) { unsigned long addr; struct page *base; @@ -58,10 +58,9 @@ split_large_page(unsigned long address, pgprot_t prot, pgprot_t ref_prot) pbase = (pte_t *)page_address(base); paravirt_alloc_pt(&init_mm, page_to_pfn(base)); - for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) { - set_pte(&pbase[i], pfn_pte(addr >> PAGE_SHIFT, - addr == address ? prot : ref_prot)); - } + for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) + set_pte(&pbase[i], pfn_pte(addr >> PAGE_SHIFT, ref_prot)); + return base; } @@ -101,6 +100,7 @@ static int __change_page_attr(struct page *page, pgprot_t prot) BUG_ON(PageHighMem(page)); address = (unsigned long)page_address(page); +repeat: kpte = lookup_address(address, &level); if (!kpte) return -EINVAL; @@ -128,7 +128,8 @@ static int __change_page_attr(struct page *page, pgprot_t prot) set_pte_atomic(kpte, mk_pte(page, prot)); } else { struct page *split; - split = split_large_page(address, prot, ref_prot); + + split = split_large_page(address, ref_prot); if (!split) return -ENOMEM; @@ -136,6 +137,7 @@ static int __change_page_attr(struct page *page, pgprot_t prot) * There's a small window here to waste a bit of RAM: */ set_pmd_pte(kpte, address, mk_pte(split, ref_prot)); + goto repeat; } return 0; } -- 2.39.5