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| author | Dan Williams <dan.j.williams@intel.com> | 2018-04-05 16:24:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-05 21:36:26 -0700 |
| commit | 09135cc594d141cd279c32a18b91cb3bd3fe8cc5 (patch) | |
| tree | c42d4d5b500e79f625f6dd2b873c3bcb7000b586 /mm | |
| parent | 2923117b7162946042e49cd363846c498293230c (diff) | |
| download | linux-09135cc594d141cd279c32a18b91cb3bd3fe8cc5.tar.gz | |
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.c | 8 |
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 |