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authorNick Piggin <npiggin@suse.de>2008-07-24 00:27:05 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-24 13:47:15 -0400
commit0d71d10a4252a3938e6b70189bc776171c02e076 (patch)
tree2bdaddc5eb5de1543368508e63d8859a94354073
parenta969e903a944f69309ee5cc9e7c7b08310d1151e (diff)
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>
-rw-r--r--include/linux/mm.h9
-rw-r--r--mm/memory.c67
2 files changed, 7 insertions, 69 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 2128ef7780c6..eb815cfc1b35 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -166,8 +166,6 @@ struct vm_operations_struct {
166 void (*open)(struct vm_area_struct * area); 166 void (*open)(struct vm_area_struct * area);
167 void (*close)(struct vm_area_struct * area); 167 void (*close)(struct vm_area_struct * area);
168 int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf); 168 int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
169 unsigned long (*nopfn)(struct vm_area_struct *area,
170 unsigned long address);
171 169
172 /* notification that a previously read-only page is about to become 170 /* notification that a previously read-only page is about to become
173 * writable, if an error is returned it will cause a SIGBUS */ 171 * writable, if an error is returned it will cause a SIGBUS */
@@ -675,13 +673,6 @@ static inline int page_mapped(struct page *page)
675} 673}
676 674
677/* 675/*
678 * Error return values for the *_nopfn functions
679 */
680#define NOPFN_SIGBUS ((unsigned long) -1)
681#define NOPFN_OOM ((unsigned long) -2)
682#define NOPFN_REFAULT ((unsigned long) -3)
683
684/*
685 * Different kinds of faults, as returned by handle_mm_fault(). 676 * Different kinds of faults, as returned by handle_mm_fault().
686 * Used to decide whether a process gets delivered SIGBUS or 677 * Used to decide whether a process gets delivered SIGBUS or
687 * just gets major/minor fault counters bumped up. 678 * just gets major/minor fault counters bumped up.
diff --git a/mm/memory.c b/mm/memory.c
index 2302d228fe04..46dbed4b7446 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1058,11 +1058,9 @@ static inline int use_zero_page(struct vm_area_struct *vma)
1058 if (vma->vm_flags & (VM_LOCKED | VM_SHARED)) 1058 if (vma->vm_flags & (VM_LOCKED | VM_SHARED))
1059 return 0; 1059 return 0;
1060 /* 1060 /*
1061 * And if we have a fault or a nopfn routine, it's not an 1061 * And if we have a fault routine, it's not an anonymous region.
1062 * anonymous region.
1063 */ 1062 */
1064 return !vma->vm_ops || 1063 return !vma->vm_ops || !vma->vm_ops->fault;
1065 (!vma->vm_ops->fault && !vma->vm_ops->nopfn);
1066} 1064}
1067 1065
1068int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 1066int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
@@ -1338,6 +1336,11 @@ out:
1338 * 1336 *
1339 * This function should only be called from a vm_ops->fault handler, and 1337 * This function should only be called from a vm_ops->fault handler, and
1340 * in that case the handler should return NULL. 1338 * in that case the handler should return NULL.
1339 *
1340 * vma cannot be a COW mapping.
1341 *
1342 * As this is called only for pages that do not currently exist, we
1343 * do not need to flush old virtual caches or the TLB.
1341 */ 1344 */
1342int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr, 1345int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
1343 unsigned long pfn) 1346 unsigned long pfn)
@@ -2501,59 +2504,6 @@ static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
2501 return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte); 2504 return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
2502} 2505}
2503 2506
2504
2505/*
2506 * do_no_pfn() tries to create a new page mapping for a page without
2507 * a struct_page backing it
2508 *
2509 * As this is called only for pages that do not currently exist, we
2510 * do not need to flush old virtual caches or the TLB.
2511 *
2512 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2513 * but allow concurrent faults), and pte mapped but not yet locked.
2514 * We return with mmap_sem still held, but pte unmapped and unlocked.
2515 *
2516 * It is expected that the ->nopfn handler always returns the same pfn
2517 * for a given virtual mapping.
2518 *
2519 * Mark this `noinline' to prevent it from bloating the main pagefault code.
2520 */
2521static noinline int do_no_pfn(struct mm_struct *mm, struct vm_area_struct *vma,
2522 unsigned long address, pte_t *page_table, pmd_t *pmd,
2523 int write_access)
2524{
2525 spinlock_t *ptl;
2526 pte_t entry;
2527 unsigned long pfn;
2528
2529 pte_unmap(page_table);
2530 BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
2531 BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
2532
2533 pfn = vma->vm_ops->nopfn(vma, address & PAGE_MASK);
2534
2535 BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn));
2536
2537 if (unlikely(pfn == NOPFN_OOM))
2538 return VM_FAULT_OOM;
2539 else if (unlikely(pfn == NOPFN_SIGBUS))
2540 return VM_FAULT_SIGBUS;
2541 else if (unlikely(pfn == NOPFN_REFAULT))
2542 return 0;
2543
2544 page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
2545
2546 /* Only go through if we didn't race with anybody else... */
2547 if (pte_none(*page_table)) {
2548 entry = pfn_pte(pfn, vma->vm_page_prot);
2549 if (write_access)
2550 entry = maybe_mkwrite(pte_mkdirty(entry), vma);
2551 set_pte_at(mm, address, page_table, entry);
2552 }
2553 pte_unmap_unlock(page_table, ptl);
2554 return 0;
2555}
2556
2557/* 2507/*
2558 * Fault of a previously existing named mapping. Repopulate the pte 2508 * Fault of a previously existing named mapping. Repopulate the pte
2559 * from the encoded file_pte if possible. This enables swappable 2509 * from the encoded file_pte if possible. This enables swappable
@@ -2614,9 +2564,6 @@ static inline int handle_pte_fault(struct mm_struct *mm,
2614 if (likely(vma->vm_ops->fault)) 2564 if (likely(vma->vm_ops->fault))
2615 return do_linear_fault(mm, vma, address, 2565 return do_linear_fault(mm, vma, address,
2616 pte, pmd, write_access, entry); 2566 pte, pmd, write_access, entry);
2617 if (unlikely(vma->vm_ops->nopfn))
2618 return do_no_pfn(mm, vma, address, pte,
2619 pmd, write_access);
2620 } 2567 }
2621 return do_anonymous_page(mm, vma, address, 2568 return do_anonymous_page(mm, vma, address,
2622 pte, pmd, write_access); 2569 pte, pmd, write_access);