From: Naoya Horiguchi <[email protected]> 3.12-stable review patch. If anyone has any objections, please let me know.
=============== commit 61f77eda9bbf0d2e922197ed2dcf88638a639ce5 upstream. Currently we have many duplicates in definitions around follow_huge_addr(), follow_huge_pmd(), and follow_huge_pud(), so this patch tries to remove the m. The basic idea is to put the default implementation for these functions in mm/hugetlb.c as weak symbols (regardless of CONFIG_ARCH_WANT_GENERAL_HUGETL B), and to implement arch-specific code only when the arch needs it. For follow_huge_addr(), only powerpc and ia64 have their own implementation, and in all other architectures this function just returns ERR_PTR(-EINVAL). So this patch sets returning ERR_PTR(-EINVAL) as default. As for follow_huge_(pmd|pud)(), if (pmd|pud)_huge() is implemented to always return 0 in your architecture (like in ia64 or sparc,) it's never called (the callsite is optimized away) no matter how implemented it is. So in such architectures, we don't need arch-specific implementation. In some architecture (like mips, s390 and tile,) their current arch-specific follow_huge_(pmd|pud)() are effectively identical with the common code, so this patch lets these architecture use the common code. One exception is metag, where pmd_huge() could return non-zero but it expects follow_huge_pmd() to always return NULL. This means that we need arch-specific implementation which returns NULL. This behavior looks strange to me (because non-zero pmd_huge() implies that the architecture supports PMD-based hugepage, so follow_huge_pmd() can/should return some relevant value,) but that's beyond this cleanup patch, so let's keep it. Justification of non-trivial changes: - in s390, follow_huge_pmd() checks !MACHINE_HAS_HPAGE at first, and this patch removes the check. This is OK because we can assume MACHINE_HAS_HPAGE is true when follow_huge_pmd() can be called (note that pmd_huge() has the same check and always returns 0 for !MACHINE_HAS_HPAGE.) - in s390 and mips, we use HPAGE_MASK instead of PMD_MASK as done in common code. This patch forces these archs use PMD_MASK, but it's OK because they are identical in both archs. In s390, both of HPAGE_SHIFT and PMD_SHIFT are 20. In mips, HPAGE_SHIFT is defined as (PAGE_SHIFT + PAGE_SHIFT - 3) and PMD_SHIFT is define as (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3), but PTE_ORDER is always 0, so these are identical. Signed-off-by: Naoya Horiguchi <[email protected]> Acked-by: Hugh Dickins <[email protected]> Cc: James Hogan <[email protected]> Cc: David Rientjes <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Luiz Capitulino <[email protected]> Cc: Nishanth Aravamudan <[email protected]> Cc: Lee Schermerhorn <[email protected]> Cc: Steve Capper <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> --- arch/arm/mm/hugetlbpage.c | 6 ------ arch/arm64/mm/hugetlbpage.c | 6 ------ arch/ia64/mm/hugetlbpage.c | 6 ------ arch/metag/mm/hugetlbpage.c | 6 ------ arch/mips/mm/hugetlbpage.c | 18 ------------------ arch/powerpc/mm/hugetlbpage.c | 8 ++++++++ arch/s390/mm/hugetlbpage.c | 20 -------------------- arch/sh/mm/hugetlbpage.c | 12 ------------ arch/sparc/mm/hugetlbpage.c | 12 ------------ arch/tile/mm/hugetlbpage.c | 28 ---------------------------- arch/x86/mm/hugetlbpage.c | 12 ------------ mm/hugetlb.c | 30 +++++++++++++++--------------- 12 files changed, 23 insertions(+), 141 deletions(-) diff --git a/arch/arm/mm/hugetlbpage.c b/arch/arm/mm/hugetlbpage.c index 66781bf34077..c72412415093 100644 --- a/arch/arm/mm/hugetlbpage.c +++ b/arch/arm/mm/hugetlbpage.c @@ -36,12 +36,6 @@ * of type casting from pmd_t * to pte_t *. */ -struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address, - int write) -{ - return ERR_PTR(-EINVAL); -} - int pud_huge(pud_t pud) { return 0; diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 023747bf4dd7..2de9d2e59d96 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -38,12 +38,6 @@ int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) } #endif -struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address, - int write) -{ - return ERR_PTR(-EINVAL); -} - int pmd_huge(pmd_t pmd) { return !(pmd_val(pmd) & PMD_TABLE_BIT); diff --git a/arch/ia64/mm/hugetlbpage.c b/arch/ia64/mm/hugetlbpage.c index 76069c18ee42..52b7604b5215 100644 --- a/arch/ia64/mm/hugetlbpage.c +++ b/arch/ia64/mm/hugetlbpage.c @@ -114,12 +114,6 @@ int pud_huge(pud_t pud) return 0; } -struct page * -follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write) -{ - return NULL; -} - void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr, unsigned long end, unsigned long floor, unsigned long ceiling) diff --git a/arch/metag/mm/hugetlbpage.c b/arch/metag/mm/hugetlbpage.c index 3c52fa6d0f8e..745081427659 100644 --- a/arch/metag/mm/hugetlbpage.c +++ b/arch/metag/mm/hugetlbpage.c @@ -94,12 +94,6 @@ int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) return 0; } -struct page *follow_huge_addr(struct mm_struct *mm, - unsigned long address, int write) -{ - return ERR_PTR(-EINVAL); -} - int pmd_huge(pmd_t pmd) { return pmd_page_shift(pmd) > PAGE_SHIFT; diff --git a/arch/mips/mm/hugetlbpage.c b/arch/mips/mm/hugetlbpage.c index a7fee0dfb7a9..e656e7f61e65 100644 --- a/arch/mips/mm/hugetlbpage.c +++ b/arch/mips/mm/hugetlbpage.c @@ -69,12 +69,6 @@ int is_aligned_hugepage_range(unsigned long addr, unsigned long len) return 0; } -struct page * -follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) -{ - return ERR_PTR(-EINVAL); -} - int pmd_huge(pmd_t pmd) { return (pmd_val(pmd) & _PAGE_HUGE) != 0; @@ -84,15 +78,3 @@ int pud_huge(pud_t pud) { return (pud_val(pud) & _PAGE_HUGE) != 0; } - -struct page * -follow_huge_pmd(struct mm_struct *mm, unsigned long address, - pmd_t *pmd, int write) -{ - struct page *page; - - page = pte_page(*(pte_t *)pmd); - if (page) - page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT); - return page; -} diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index 834ca8eb38f2..fc2427323414 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -706,6 +706,14 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address, return NULL; } +struct page * +follow_huge_pud(struct mm_struct *mm, unsigned long address, + pud_t *pud, int write) +{ + BUG(); + return NULL; +} + static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end, unsigned long sz) { diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c index 248445f92604..99a68d579828 100644 --- a/arch/s390/mm/hugetlbpage.c +++ b/arch/s390/mm/hugetlbpage.c @@ -204,12 +204,6 @@ int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) return 0; } -struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address, - int write) -{ - return ERR_PTR(-EINVAL); -} - int pmd_huge(pmd_t pmd) { if (!MACHINE_HAS_HPAGE) @@ -222,17 +216,3 @@ int pud_huge(pud_t pud) { return 0; } - -struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, - pmd_t *pmdp, int write) -{ - struct page *page; - - if (!MACHINE_HAS_HPAGE) - return NULL; - - page = pmd_page(*pmdp); - if (page) - page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT); - return page; -} diff --git a/arch/sh/mm/hugetlbpage.c b/arch/sh/mm/hugetlbpage.c index d7762349ea48..534bc978af8a 100644 --- a/arch/sh/mm/hugetlbpage.c +++ b/arch/sh/mm/hugetlbpage.c @@ -67,12 +67,6 @@ int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) return 0; } -struct page *follow_huge_addr(struct mm_struct *mm, - unsigned long address, int write) -{ - return ERR_PTR(-EINVAL); -} - int pmd_huge(pmd_t pmd) { return 0; @@ -82,9 +76,3 @@ int pud_huge(pud_t pud) { return 0; } - -struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, - pmd_t *pmd, int write) -{ - return NULL; -} diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c index 8545f62fa62c..d941cd024f22 100644 --- a/arch/sparc/mm/hugetlbpage.c +++ b/arch/sparc/mm/hugetlbpage.c @@ -216,12 +216,6 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, return entry; } -struct page *follow_huge_addr(struct mm_struct *mm, - unsigned long address, int write) -{ - return ERR_PTR(-EINVAL); -} - int pmd_huge(pmd_t pmd) { return 0; @@ -231,9 +225,3 @@ int pud_huge(pud_t pud) { return 0; } - -struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, - pmd_t *pmd, int write) -{ - return NULL; -} diff --git a/arch/tile/mm/hugetlbpage.c b/arch/tile/mm/hugetlbpage.c index e514899e1100..8a00c7b7b862 100644 --- a/arch/tile/mm/hugetlbpage.c +++ b/arch/tile/mm/hugetlbpage.c @@ -150,12 +150,6 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) return NULL; } -struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address, - int write) -{ - return ERR_PTR(-EINVAL); -} - int pmd_huge(pmd_t pmd) { return !!(pmd_val(pmd) & _PAGE_HUGE_PAGE); @@ -166,28 +160,6 @@ int pud_huge(pud_t pud) return !!(pud_val(pud) & _PAGE_HUGE_PAGE); } -struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, - pmd_t *pmd, int write) -{ - struct page *page; - - page = pte_page(*(pte_t *)pmd); - if (page) - page += ((address & ~PMD_MASK) >> PAGE_SHIFT); - return page; -} - -struct page *follow_huge_pud(struct mm_struct *mm, unsigned long address, - pud_t *pud, int write) -{ - struct page *page; - - page = pte_page(*(pte_t *)pud); - if (page) - page += ((address & ~PUD_MASK) >> PAGE_SHIFT); - return page; -} - int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) { return 0; diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c index e473dbe45c0f..9d80a1b5dc86 100644 --- a/arch/x86/mm/hugetlbpage.c +++ b/arch/x86/mm/hugetlbpage.c @@ -52,20 +52,8 @@ int pud_huge(pud_t pud) return 0; } -struct page * -follow_huge_pmd(struct mm_struct *mm, unsigned long address, - pmd_t *pmd, int write) -{ - return NULL; -} #else -struct page * -follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) -{ - return ERR_PTR(-EINVAL); -} - /* * pmd_huge() returns 1 if @pmd is hugetlb related entry, that is normal * hugetlb entry or non-present (migration or hwpoisoned) hugetlb entry. diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 33193ab3dbd3..ef1fbe317213 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3478,7 +3478,20 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) return (pte_t *) pmd; } -struct page * +#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ + +/* + * These functions are overwritable if your architecture needs its own + * behavior. + */ +struct page * __weak +follow_huge_addr(struct mm_struct *mm, unsigned long address, + int write) +{ + return ERR_PTR(-EINVAL); +} + +struct page * __weak follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write) { @@ -3492,7 +3505,7 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address, return page; } -struct page * +struct page * __weak follow_huge_pud(struct mm_struct *mm, unsigned long address, pud_t *pud, int write) { @@ -3504,19 +3517,6 @@ follow_huge_pud(struct mm_struct *mm, unsigned long address, return page; } -#else /* !CONFIG_ARCH_WANT_GENERAL_HUGETLB */ - -/* Can be overriden by architectures */ -__attribute__((weak)) struct page * -follow_huge_pud(struct mm_struct *mm, unsigned long address, - pud_t *pud, int write) -{ - BUG(); - return NULL; -} - -#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ - #ifdef CONFIG_MEMORY_FAILURE /* Should be called in hugetlb_lock */ -- 2.3.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
