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mm: remove nopfn 

There are no users of nopfn in the tree. Remove it.

[hugh@veritas.com: fix build error]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Nick Piggin 2008-07-23 21:27:05 -07:00 committed by Linus Torvalds
parent a969e903a9
commit 0d71d10a42
2 changed files with 7 additions and 69 deletions
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9
include/linux/mm.h
View File

@ -166,8 +166,6 @@ struct vm_operations_struct {
void (*open)(struct vm_area_struct * area);
void (*close)(struct vm_area_struct * area);
int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
unsigned long (*nopfn)(struct vm_area_struct *area,
unsigned long address);
/* notification that a previously read-only page is about to become
* writable, if an error is returned it will cause a SIGBUS */
@ -674,13 +672,6 @@ static inline int page_mapped(struct page *page)
return atomic_read(&(page)->_mapcount) >= 0;
}
/*
* Error return values for the *_nopfn functions
*/
#define NOPFN_SIGBUS ((unsigned long) -1)
#define NOPFN_OOM ((unsigned long) -2)
#define NOPFN_REFAULT ((unsigned long) -3)
/*
* Different kinds of faults, as returned by handle_mm_fault().
* Used to decide whether a process gets delivered SIGBUS or

67
mm/memory.c
View File

@ -1058,11 +1058,9 @@ static inline int use_zero_page(struct vm_area_struct *vma)
if (vma->vm_flags & (VM_LOCKED | VM_SHARED))
return 0;
/*
* And if we have a fault or a nopfn routine, it's not an
* anonymous region.
* And if we have a fault routine, it's not an anonymous region.
*/
return !vma->vm_ops ||
(!vma->vm_ops->fault && !vma->vm_ops->nopfn);
return !vma->vm_ops || !vma->vm_ops->fault;
}
int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
@ -1338,6 +1336,11 @@ static int insert_pfn(struct vm_area_struct *vma, unsigned long addr,
*
* This function should only be called from a vm_ops->fault handler, and
* in that case the handler should return NULL.
*
* vma cannot be a COW mapping.
*
* As this is called only for pages that do not currently exist, we
* do not need to flush old virtual caches or the TLB.
*/
int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn)
@ -2501,59 +2504,6 @@ static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
}
/*
* do_no_pfn() tries to create a new page mapping for a page without
* a struct_page backing it
*
* As this is called only for pages that do not currently exist, we
* do not need to flush old virtual caches or the TLB.
*
* We enter with non-exclusive mmap_sem (to exclude vma changes,
* but allow concurrent faults), and pte mapped but not yet locked.
* We return with mmap_sem still held, but pte unmapped and unlocked.
*
* It is expected that the ->nopfn handler always returns the same pfn
* for a given virtual mapping.
*
* Mark this `noinline' to prevent it from bloating the main pagefault code.
*/
static noinline int do_no_pfn(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, pte_t *page_table, pmd_t *pmd,
int write_access)
{
spinlock_t *ptl;
pte_t entry;
unsigned long pfn;
pte_unmap(page_table);
BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
pfn = vma->vm_ops->nopfn(vma, address & PAGE_MASK);
BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn));
if (unlikely(pfn == NOPFN_OOM))
return VM_FAULT_OOM;
else if (unlikely(pfn == NOPFN_SIGBUS))
return VM_FAULT_SIGBUS;
else if (unlikely(pfn == NOPFN_REFAULT))
return 0;
page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
/* Only go through if we didn't race with anybody else... */
if (pte_none(*page_table)) {
entry = pfn_pte(pfn, vma->vm_page_prot);
if (write_access)
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
set_pte_at(mm, address, page_table, entry);
}
pte_unmap_unlock(page_table, ptl);
return 0;
}
/*
* Fault of a previously existing named mapping. Repopulate the pte
* from the encoded file_pte if possible. This enables swappable
@ -2614,9 +2564,6 @@ static inline int handle_pte_fault(struct mm_struct *mm,
if (likely(vma->vm_ops->fault))
return do_linear_fault(mm, vma, address,
pte, pmd, write_access, entry);
if (unlikely(vma->vm_ops->nopfn))
return do_no_pfn(mm, vma, address, pte,
pmd, write_access);
}
return do_anonymous_page(mm, vma, address,
pte, pmd, write_access);