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mm: simplify follow_pte{,pmd}

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commit ff5c19ed4b087073cea38ff0edc80c23d7256943 upstream.

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 <hch@lst.de>
Reviewed-by: Matthew 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Christoph Hellwig 2020-12-15 20:47:23 -08:00 committed by Greg Kroah-Hartman
parent 8aeef9c9ac
commit 78c7b24257
3 changed files with 12 additions and 38 deletions
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9
fs/dax.c
View File

@ -794,12 +794,11 @@ 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;
/*

6
include/linux/mm.h
View File

@ -1466,9 +1466,9 @@ 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 mm_struct *dst, struct mm_struct *src,
struct vm_area_struct *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,

35
mm/memory.c
View File

@ -4222,9 +4222,9 @@ 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;
@ -4289,31 +4289,6 @@ 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
@ -4334,7 +4309,7 @@ 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);
@ -4355,7 +4330,7 @@ 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;