Commit ff5c19ed authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Linus Torvalds
Browse files

mm: simplify follow_pte{,pmd} 

Merge __follow_pte_pmd, follow_pte_pmd and follow_pte into a single
follow_pte function and just pass two additional NULL arguments for the
two previous follow_pte callers.

[sfr@canb.auug.org.au: merge fix for "s390/pci: remove races against pte updates"]
  Link: https://lkml.kernel.org/r/20201111221254.7f6a3658@canb.auug.org.au

Link: https://lkml.kernel.org/r/20201029101432.47011-3-hch@lst.de


Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 73363757

arch/s390/pci/pci_mmio.c

+2 −2
Original line number Diff line number Diff line
@@ -170,7 +170,7 @@ SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr, 
	if (!(vma->vm_flags & VM_WRITE))

		goto out_unlock_mmap;



	ret = follow_pte_pmd(vma->vm_mm, mmio_addr, NULL, &ptep, NULL, &ptl);

	ret = follow_pte(vma->vm_mm, mmio_addr, NULL, &ptep, NULL, &ptl);

	if (ret)

		goto out_unlock_mmap;
@@ -311,7 +311,7 @@ SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr, 
	if (!(vma->vm_flags & VM_WRITE))

		goto out_unlock_mmap;



	ret = follow_pte_pmd(vma->vm_mm, mmio_addr, NULL, &ptep, NULL, &ptl);

	ret = follow_pte(vma->vm_mm, mmio_addr, NULL, &ptep, NULL, &ptl);

	if (ret)

		goto out_unlock_mmap;

fs/dax.c

+4 −5
Original line number Diff line number Diff line
@@ -810,12 +810,11 @@ static void dax_entry_mkclean(struct address_space *mapping, pgoff_t index, 
		address = pgoff_address(index, vma);



		/*

		 * Note because we provide range to follow_pte_pmd it will

		 * call mmu_notifier_invalidate_range_start() on our behalf

		 * before taking any lock.

		 * Note because we provide range to follow_pte it will call

		 * mmu_notifier_invalidate_range_start() on our behalf before

		 * taking any lock.

		 */

		if (follow_pte_pmd(vma->vm_mm, address, &range,

				   &ptep, &pmdp, &ptl))

		if (follow_pte(vma->vm_mm, address, &range, &ptep, &pmdp, &ptl))

			continue;



		/*

include/linux/mm.h

+3 −3
Original line number Diff line number Diff line
@@ -1641,9 +1641,9 @@ void free_pgd_range(struct mmu_gather *tlb, unsigned long addr, 
		unsigned long end, unsigned long floor, unsigned long ceiling);

int

copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma);

int follow_pte_pmd(struct mm_struct *mm, unsigned long address,

		   struct mmu_notifier_range *range,

		   pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp);

int follow_pte(struct mm_struct *mm, unsigned long address,

		struct mmu_notifier_range *range, pte_t **ptepp, pmd_t **pmdpp,

		spinlock_t **ptlp);

int follow_pfn(struct vm_area_struct *vma, unsigned long address,

	unsigned long *pfn);

int follow_phys(struct vm_area_struct *vma, unsigned long address,

mm/memory.c

+5 −30
Original line number Diff line number Diff line
@@ -4707,9 +4707,9 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) 
}

#endif /* __PAGETABLE_PMD_FOLDED */



static int __follow_pte_pmd(struct mm_struct *mm, unsigned long address,

			    struct mmu_notifier_range *range,

			    pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp)

int follow_pte(struct mm_struct *mm, unsigned long address,

	       struct mmu_notifier_range *range, pte_t **ptepp, pmd_t **pmdpp,

	       spinlock_t **ptlp)

{

	pgd_t *pgd;

	p4d_t *p4d;
@@ -4774,31 +4774,6 @@ out: 
	return -EINVAL;

}



static inline int follow_pte(struct mm_struct *mm, unsigned long address,

			     pte_t **ptepp, spinlock_t **ptlp)

{

	int res;



	/* (void) is needed to make gcc happy */

	(void) __cond_lock(*ptlp,

			   !(res = __follow_pte_pmd(mm, address, NULL,

						    ptepp, NULL, ptlp)));

	return res;

}



int follow_pte_pmd(struct mm_struct *mm, unsigned long address,

		   struct mmu_notifier_range *range,

		   pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp)

{

	int res;



	/* (void) is needed to make gcc happy */

	(void) __cond_lock(*ptlp,

			   !(res = __follow_pte_pmd(mm, address, range,

						    ptepp, pmdpp, ptlp)));

	return res;

}



/**

 * follow_pfn - look up PFN at a user virtual address

 * @vma: memory mapping
@@ -4819,7 +4794,7 @@ int follow_pfn(struct vm_area_struct *vma, unsigned long address, 
	if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))

		return ret;



	ret = follow_pte(vma->vm_mm, address, &ptep, &ptl);

	ret = follow_pte(vma->vm_mm, address, NULL, &ptep, NULL, &ptl);

	if (ret)

		return ret;

	*pfn = pte_pfn(*ptep);
@@ -4840,7 +4815,7 @@ int follow_phys(struct vm_area_struct *vma, 
	if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))

		goto out;



	if (follow_pte(vma->vm_mm, address, &ptep, &ptl))

	if (follow_pte(vma->vm_mm, address, NULL, &ptep, NULL, &ptl))

		goto out;

	pte = *ptep;

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