From 09bc6ac3a1288d10d9cae30f2301b0ac8e90b166 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 13 Feb 2013 12:21:06 -0800 Subject: [PATCH] sparc64: Fix get_user_pages_fast() wrt. THP. Mostly mirrors the s390 logic, as unlike x86 we don't need the SetPageReferenced() bits. On sparc64 we also lack a user/privileged bit in the huge PMDs. In order to make this work for THP and non-THP builds, some header file adjustments were necessary. Namely, provide the PMD_HUGE_* bit defines and the pmd_large() inline unconditionally rather than protected by TRANSPARENT_HUGEPAGE. Reported-by: Aneesh Kumar K.V Signed-off-by: David S. Miller --- arch/sparc/include/asm/pgtable_64.h | 14 +++---- arch/sparc/mm/gup.c | 59 ++++++++++++++++++++++++++++- 2 files changed, 63 insertions(+), 10 deletions(-) diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h index 7870be0f5adc4..08fcce90316b3 100644 --- a/arch/sparc/include/asm/pgtable_64.h +++ b/arch/sparc/include/asm/pgtable_64.h @@ -71,7 +71,6 @@ #define PMD_PADDR _AC(0xfffffffe,UL) #define PMD_PADDR_SHIFT _AC(11,UL) -#ifdef CONFIG_TRANSPARENT_HUGEPAGE #define PMD_ISHUGE _AC(0x00000001,UL) /* This is the PMD layout when PMD_ISHUGE is set. With 4MB huge @@ -86,7 +85,6 @@ #define PMD_HUGE_ACCESSED _AC(0x00000080,UL) #define PMD_HUGE_EXEC _AC(0x00000040,UL) #define PMD_HUGE_SPLITTING _AC(0x00000020,UL) -#endif /* PGDs point to PMD tables which are 8K aligned. */ #define PGD_PADDR _AC(0xfffffffc,UL) @@ -628,6 +626,12 @@ static inline unsigned long pte_special(pte_t pte) return pte_val(pte) & _PAGE_SPECIAL; } +static inline int pmd_large(pmd_t pmd) +{ + return (pmd_val(pmd) & (PMD_ISHUGE | PMD_HUGE_PRESENT)) == + (PMD_ISHUGE | PMD_HUGE_PRESENT); +} + #ifdef CONFIG_TRANSPARENT_HUGEPAGE static inline int pmd_young(pmd_t pmd) { @@ -646,12 +650,6 @@ static inline unsigned long pmd_pfn(pmd_t pmd) return val >> (PAGE_SHIFT - PMD_PADDR_SHIFT); } -static inline int pmd_large(pmd_t pmd) -{ - return (pmd_val(pmd) & (PMD_ISHUGE | PMD_HUGE_PRESENT)) == - (PMD_ISHUGE | PMD_HUGE_PRESENT); -} - static inline int pmd_trans_splitting(pmd_t pmd) { return (pmd_val(pmd) & (PMD_ISHUGE|PMD_HUGE_SPLITTING)) == diff --git a/arch/sparc/mm/gup.c b/arch/sparc/mm/gup.c index 42c55df3aec30..01ee23dd724d5 100644 --- a/arch/sparc/mm/gup.c +++ b/arch/sparc/mm/gup.c @@ -66,6 +66,56 @@ static noinline int gup_pte_range(pmd_t pmd, unsigned long addr, return 1; } +static int gup_huge_pmd(pmd_t *pmdp, pmd_t pmd, unsigned long addr, + unsigned long end, int write, struct page **pages, + int *nr) +{ + struct page *head, *page, *tail; + u32 mask; + int refs; + + mask = PMD_HUGE_PRESENT; + if (write) + mask |= PMD_HUGE_WRITE; + if ((pmd_val(pmd) & mask) != mask) + return 0; + + refs = 0; + head = pmd_page(pmd); + page = head + ((addr & ~PMD_MASK) >> PAGE_SHIFT); + tail = page; + do { + VM_BUG_ON(compound_head(page) != head); + pages[*nr] = page; + (*nr)++; + page++; + refs++; + } while (addr += PAGE_SIZE, addr != end); + + if (!page_cache_add_speculative(head, refs)) { + *nr -= refs; + return 0; + } + + if (unlikely(pmd_val(pmd) != pmd_val(*pmdp))) { + *nr -= refs; + while (refs--) + put_page(head); + return 0; + } + + /* Any tail page need their mapcount reference taken before we + * return. + */ + while (refs--) { + if (PageTail(tail)) + get_huge_page_tail(tail); + tail++; + } + + return 1; +} + static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end, int write, struct page **pages, int *nr) { @@ -77,9 +127,14 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end, pmd_t pmd = *pmdp; next = pmd_addr_end(addr, end); - if (pmd_none(pmd)) + if (pmd_none(pmd) || pmd_trans_splitting(pmd)) return 0; - if (!gup_pte_range(pmd, addr, next, write, pages, nr)) + if (unlikely(pmd_large(pmd))) { + if (!gup_huge_pmd(pmdp, pmd, addr, next, + write, pages, nr)) + return 0; + } else if (!gup_pte_range(pmd, addr, next, write, + pages, nr)) return 0; } while (pmdp++, addr = next, addr != end); -- 2.39.5