From ff5c19ed4b087073cea38ff0edc80c23d7256943 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 15 Dec 2020 20:47:23 -0800 Subject: [PATCH] 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: Christoph Hellwig Reviewed-by: Matthew Wilcox (Oracle) Cc: Daniel Vetter Cc: Dan Williams Cc: Nick Desaulniers Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/s390/pci/pci_mmio.c | 4 ++-- fs/dax.c | 9 ++++----- include/linux/mm.h | 6 +++--- mm/memory.c | 35 +++++------------------------------ 4 files changed, 14 insertions(+), 40 deletions(-) diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c index de3bdbed8881..18f2d10c3176 100644 --- a/arch/s390/pci/pci_mmio.c +++ b/arch/s390/pci/pci_mmio.c @@ -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; diff --git a/fs/dax.c b/fs/dax.c index 5b47834f2e1b..26d5dcd2d69e 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -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; /* diff --git a/include/linux/mm.h b/include/linux/mm.h index abc7b3154298..855161080f18 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -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, diff --git a/mm/memory.c b/mm/memory.c index 126e140baf73..7d608765932b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -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 @@ static int __follow_pte_pmd(struct mm_struct *mm, unsigned long address, 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;