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Commit 94ad9338 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Linus Torvalds
Browse files

mm: introduce page_shift() 

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: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarIra Weiny <ira.weiny@intel.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a50b854e

arch/powerpc/mm/book3s64/iommu_api.c

+2 −5
Original line number Diff line number Diff line
@@ -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

drivers/vfio/vfio_iommu_spapr_tce.c

+4 −4
Original line number Diff line number Diff line
@@ -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)

include/linux/mm.h

+6 −0
Original line number Diff line number Diff line
@@ -811,6 +811,12 @@ 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