From b538d51f14b28f890271c1b623bdd3ab418a7fa1 Mon Sep 17 00:00:00 2001
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: Mon, 23 Sep 2019 15:34:28 -0700
Subject: [PATCH] mm: introduce page_shift()
References: bnc#1155780 (VM/FS functional and performance backports)
Patch-mainline: v5.4-rc1
Git-commit: 94ad9338109fe9d0b8a4a16828719dd6dcaee4c2
Replace PAGE_SHIFT + compound_order(page) with the new page_shift()
function. Minor improvements in readability.
[akpm@linux-foundation.org: fix build in tce_page_is_contained()]
Link: http://lkml.kernel.org/r/201907241853.yNQTrJWd%25lkp@intel.com
Link: http://lkml.kernel.org/r/20190721104612.19120-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
arch/powerpc/mm/book3s64/iommu_api.c | 7 ++-----
drivers/vfio/vfio_iommu_spapr_tce.c | 8 ++++----
include/linux/mm.h | 6 ++++++
3 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/mm/book3s64/iommu_api.c b/arch/powerpc/mm/book3s64/iommu_api.c
index b056cae3388b..56cc84520577 100644
--- a/arch/powerpc/mm/book3s64/iommu_api.c
+++ b/arch/powerpc/mm/book3s64/iommu_api.c
@@ -129,11 +129,8 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua,
* 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
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index babef8b00daf..646dfdc46958 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -176,13 +176,13 @@ static long tce_iommu_register_pages(struct tce_container *container,
}
static bool tce_page_is_contained(struct mm_struct *mm, unsigned long hpa,
- unsigned int page_shift)
+ unsigned int it_page_shift)
{
struct page *page;
unsigned long size = 0;
- if (mm_iommu_is_devmem(mm, hpa, page_shift, &size))
- return size == (1UL << page_shift);
+ if (mm_iommu_is_devmem(mm, hpa, it_page_shift, &size))
+ return size == (1UL << it_page_shift);
page = pfn_to_page(hpa >> PAGE_SHIFT);
/*
@@ -190,7 +190,7 @@ static bool tce_page_is_contained(struct mm_struct *mm, unsigned long hpa,
* 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)) >= it_page_shift;
}
static inline bool tce_groups_attached(struct tce_container *container)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index cf35ee54d0f4..4644094e5b7a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -806,6 +806,12 @@ static inline unsigned long page_size(struct page *page)
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