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authorDan Williams <dan.j.williams@intel.com>2018-04-05 16:24:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-05 21:36:26 -0700
commit09135cc594d141cd279c32a18b91cb3bd3fe8cc5 (patch)
treec42d4d5b500e79f625f6dd2b873c3bcb7000b586 /mm
parent2923117b7162946042e49cd363846c498293230c (diff)
downloadlinux-09135cc594d141cd279c32a18b91cb3bd3fe8cc5.tar.bz2
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 <linux/hugetlb.h>. 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 <dan.j.williams@intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Jane Chu <jane.chu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/hugetlb.c8
1 files changed, 3 insertions, 5 deletions
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