The patch titled
Subject: mm: Introduce page_shift()
has been added to the -mm tree. Its filename is
mm-introduce-page_shift.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-introduce-page_shift.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-introduce-page_shift.patch
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm: Introduce page_shift()
Replace PAGE_SHIFT + compound_order(page) with the new page_shift()
function. Minor improvements in readability.
Link: http://lkml.kernel.org/r/20190721104612.19120-3-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/mm/book3s64/iommu_api.c | 7 ++-----
drivers/vfio/vfio_iommu_spapr_tce.c | 2 +-
include/linux/mm.h | 6 ++++++
3 files changed, 9 insertions(+), 6 deletions(-)
--- a/arch/powerpc/mm/book3s64/iommu_api.c~mm-introduce-page_shift
+++ a/arch/powerpc/mm/book3s64/iommu_api.c
@@ -129,11 +129,8 @@ static long mm_iommu_do_alloc(struct mm_
* Allow to use larger than 64k IOMMU pages. Only do that
* if we are backed by hugetlb.
*/
- if ((mem->pageshift > PAGE_SHIFT) && PageHuge(page)) {
- struct page *head = compound_head(page);
-
- pageshift = compound_order(head) + PAGE_SHIFT;
- }
+ if ((mem->pageshift > PAGE_SHIFT) && PageHuge(page))
+ pageshift = page_shift(compound_head(page));
mem->pageshift = min(mem->pageshift, pageshift);
/*
* We don't need struct page reference any more, switch
--- a/drivers/vfio/vfio_iommu_spapr_tce.c~mm-introduce-page_shift
+++ a/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -190,7 +190,7 @@ static bool tce_page_is_contained(struct
* a page we just found. Otherwise the hardware can get access to
* a bigger memory chunk that it should.
*/
- return (PAGE_SHIFT + compound_order(compound_head(page))) >= page_shift;
+ return page_shift(compound_head(page)) >= page_shift;
}
static inline bool tce_groups_attached(struct tce_container *container)
--- a/include/linux/mm.h~mm-introduce-page_shift
+++ a/include/linux/mm.h
@@ -811,6 +811,12 @@ static inline unsigned long page_size(st
return PAGE_SIZE << compound_order(page);
}
+/* Returns the number of bits needed for the number of bytes in a page */
+static inline unsigned int page_shift(struct page *page)
+{
+ return PAGE_SHIFT + compound_order(page);
+}
+
void free_compound_page(struct page *page);
#ifdef CONFIG_MMU
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-introduce-page_size.patch
mm-introduce-page_shift.patch
mm-introduce-compound_nr.patch
