From 09135cc594d141cd279c32a18b91cb3bd3fe8cc5 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 5 Apr 2018 16:24:21 -0700 Subject: [PATCH] mm, powerpc: use vma_kernel_pagesize() in vma_mmu_pagesize() Patch series "mm, smaps: MMUPageSize for device-dax", v3. Similar to commit 31383c6865a5 ("mm, hugetlbfs: introduce ->split() to vm_operations_struct") here is another occasion where we want special-case hugetlbfs/hstate enabling to also apply to device-dax. This prompts the question what other hstate conversions we might do beyond ->split() and ->pagesize(), but this appears to be the last of the usages of hstate_vma() in generic/non-hugetlbfs specific code paths. This patch (of 3): The current powerpc definition of vma_mmu_pagesize() open codes looking up the page size via hstate. It is identical to the generic vma_kernel_pagesize() implementation. Now, vma_kernel_pagesize() is growing support for determining the page size of Device-DAX vmas in addition to the existing Hugetlbfs page size determination. Ideally, if the powerpc vma_mmu_pagesize() used vma_kernel_pagesize() it would automatically benefit from any new vma-type support that is added to vma_kernel_pagesize(). However, the powerpc vma_mmu_pagesize() is prevented from calling vma_kernel_pagesize() due to a circular header dependency that requires vma_mmu_pagesize() to be defined before including . Break this circular dependency by defining the default vma_mmu_pagesize() as a __weak symbol to be overridden by the powerpc version. Link: http://lkml.kernel.org/r/151996254179.27922.2213728278535578744.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Reviewed-by: Andrew Morton Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Jane Chu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/powerpc/include/asm/hugetlb.h | 6 ------ arch/powerpc/mm/hugetlbpage.c | 5 +---- mm/hugetlb.c | 8 +++----- 3 files changed, 4 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h index 1a4847f67ea8..6f6751d3eba9 100644 --- a/arch/powerpc/include/asm/hugetlb.h +++ b/arch/powerpc/include/asm/hugetlb.h @@ -118,12 +118,6 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr, unsigned long ceiling); /* - * The version of vma_mmu_pagesize() in arch/powerpc/mm/hugetlbpage.c needs - * to override the version in mm/hugetlb.c - */ -#define vma_mmu_pagesize vma_mmu_pagesize - -/* * If the arch doesn't supply something else, assume that hugepage * size aligned regions are ok without further preparation. */ diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index 876da2bc1796..3a08d211d2ee 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -568,10 +568,7 @@ unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) if (!radix_enabled()) return 1UL << mmu_psize_to_shift(psize); #endif - if (!is_vm_hugetlb_page(vma)) - return PAGE_SIZE; - - return huge_page_size(hstate_vma(vma)); + return vma_kernel_pagesize(vma); } static inline bool is_power_of_4(unsigned long x) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 976bbc5646fe..92c49b9d7cbb 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -651,15 +651,13 @@ EXPORT_SYMBOL_GPL(vma_kernel_pagesize); /* * Return the page size being used by the MMU to back a VMA. In the majority * of cases, the page size used by the kernel matches the MMU size. On - * architectures where it differs, an architecture-specific version of this - * function is required. + * architectures where it differs, an architecture-specific 'strong' + * version of this symbol is required. */ -#ifndef vma_mmu_pagesize -unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) +__weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma) { return vma_kernel_pagesize(vma); } -#endif /* * Flags for MAP_PRIVATE reservations. These are stored in the bottom -- 2.11.0