Commit 6f0e1142 authored by Baolin Wang's avatar Baolin Wang Committed by Andrew Morton
Browse files

arm64: mm: support batch clearing of the young flag for large folios 

Currently, contpte_ptep_test_and_clear_young() and
contpte_ptep_clear_flush_young() only clear the young flag and flush TLBs
for PTEs within the contiguous range.  To support batch PTE operations for
other sized large folios in the following patches, adding a new parameter
to specify the number of PTEs that map consecutive pages of the same large
folio in a single VMA and a single page table.

While we are at it, rename the functions to maintain consistency with
other contpte_*() functions.

Link: https://lkml.kernel.org/r/5644250dcc0417278c266ad37118d27f541fd052.1770645603.git.baolin.wang@linux.alibaba.com


Signed-off-by: default avatarBaolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: default avatarRyan Roberts <ryan.roberts@arm.com>
Reviewed-by: default avatarDavid Hildenbrand (Arm) <david@kernel.org>
Cc: Barry Song <baohua@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Harry Yoo <harry.yoo@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 67d59bdd

arch/arm64/include/asm/pgtable.h

+6 −6
Original line number Diff line number Diff line
@@ -1648,10 +1648,10 @@ extern void contpte_clear_full_ptes(struct mm_struct *mm, unsigned long addr, 
extern pte_t contpte_get_and_clear_full_ptes(struct mm_struct *mm,

				unsigned long addr, pte_t *ptep,

				unsigned int nr, int full);

extern int contpte_ptep_test_and_clear_young(struct vm_area_struct *vma,

				unsigned long addr, pte_t *ptep);

extern int contpte_ptep_clear_flush_young(struct vm_area_struct *vma,

				unsigned long addr, pte_t *ptep);

int contpte_test_and_clear_young_ptes(struct vm_area_struct *vma,

				unsigned long addr, pte_t *ptep, unsigned int nr);

int contpte_clear_flush_young_ptes(struct vm_area_struct *vma,

				unsigned long addr, pte_t *ptep, unsigned int nr);

extern void contpte_wrprotect_ptes(struct mm_struct *mm, unsigned long addr,

				pte_t *ptep, unsigned int nr);

extern int contpte_ptep_set_access_flags(struct vm_area_struct *vma,
@@ -1823,7 +1823,7 @@ static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, 
	if (likely(!pte_valid_cont(orig_pte)))

		return __ptep_test_and_clear_young(vma, addr, ptep);



	return contpte_ptep_test_and_clear_young(vma, addr, ptep);

	return contpte_test_and_clear_young_ptes(vma, addr, ptep, 1);

}



#define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
@@ -1835,7 +1835,7 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma, 
	if (likely(!pte_valid_cont(orig_pte)))

		return __ptep_clear_flush_young(vma, addr, ptep);



	return contpte_ptep_clear_flush_young(vma, addr, ptep);

	return contpte_clear_flush_young_ptes(vma, addr, ptep, 1);

}



#define wrprotect_ptes wrprotect_ptes

arch/arm64/mm/contpte.c

+19 −14
Original line number Diff line number Diff line
@@ -508,8 +508,9 @@ pte_t contpte_get_and_clear_full_ptes(struct mm_struct *mm, 
}

EXPORT_SYMBOL_GPL(contpte_get_and_clear_full_ptes);



int contpte_ptep_test_and_clear_young(struct vm_area_struct *vma,

					unsigned long addr, pte_t *ptep)

int contpte_test_and_clear_young_ptes(struct vm_area_struct *vma,

					unsigned long addr, pte_t *ptep,

					unsigned int nr)

{

	/*

	 * ptep_clear_flush_young() technically requires us to clear the access
@@ -518,41 +519,45 @@ int contpte_ptep_test_and_clear_young(struct vm_area_struct *vma, 
	 * contig range when the range is covered by a single folio, we can get

	 * away with clearing young for the whole contig range here, so we avoid

	 * having to unfold.

	 *

	 * The 'nr' means consecutive (present) PTEs that map consecutive pages

	 * of the same large folio in a single VMA and a single page table.

	 */



	unsigned long end = addr + nr * PAGE_SIZE;

	int young = 0;

	int i;



	ptep = contpte_align_down(ptep);

	addr = ALIGN_DOWN(addr, CONT_PTE_SIZE);



	for (i = 0; i < CONT_PTES; i++, ptep++, addr += PAGE_SIZE)

	ptep = contpte_align_addr_ptep(&addr, &end, ptep, nr);

	for (; addr != end; ptep++, addr += PAGE_SIZE)

		young |= __ptep_test_and_clear_young(vma, addr, ptep);



	return young;

}

EXPORT_SYMBOL_GPL(contpte_ptep_test_and_clear_young);

EXPORT_SYMBOL_GPL(contpte_test_and_clear_young_ptes);



int contpte_ptep_clear_flush_young(struct vm_area_struct *vma,

					unsigned long addr, pte_t *ptep)

int contpte_clear_flush_young_ptes(struct vm_area_struct *vma,

				unsigned long addr, pte_t *ptep,

				unsigned int nr)

{

	int young;



	young = contpte_ptep_test_and_clear_young(vma, addr, ptep);

	young = contpte_test_and_clear_young_ptes(vma, addr, ptep, nr);



	if (young) {

		unsigned long end = addr + nr * PAGE_SIZE;



		contpte_align_addr_ptep(&addr, &end, ptep, nr);

		/*

		 * See comment in __ptep_clear_flush_young(); same rationale for

		 * eliding the trailing DSB applies here.

		 */

		addr = ALIGN_DOWN(addr, CONT_PTE_SIZE);

		__flush_tlb_range_nosync(vma->vm_mm, addr, addr + CONT_PTE_SIZE,

		__flush_tlb_range_nosync(vma->vm_mm, addr, end,

					 PAGE_SIZE, true, 3);

	}



	return young;

}

EXPORT_SYMBOL_GPL(contpte_ptep_clear_flush_young);

EXPORT_SYMBOL_GPL(contpte_clear_flush_young_ptes);



void contpte_wrprotect_ptes(struct mm_struct *mm, unsigned long addr,

					pte_t *ptep, unsigned int nr)