diff options
author | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-28 17:34:23 -0500 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-28 17:34:23 -0500 |
commit | 6aab341e0a28aff100a09831c5300a2994b8b986 (patch) | |
tree | 1af3908275aa5e1b16e80efee554a9a7504c56d4 /mm/fremap.c | |
parent | 458af5439fe7ae7d95ca14106844e61f0795166c (diff) |
mm: re-architect the VM_UNPAGED logic
This replaces the (in my opinion horrible) VM_UNMAPPED logic with very
explicit support for a "remapped page range" aka VM_PFNMAP. It allows a
VM area to contain an arbitrary range of page table entries that the VM
never touches, and never considers to be normal pages.
Any user of "remap_pfn_range()" automatically gets this new
functionality, and doesn't even have to mark the pages reserved or
indeed mark them any other way. It just works. As a side effect, doing
mmap() on /dev/mem works for arbitrary ranges.
Sparc update from David in the next commit.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/fremap.c')
-rw-r--r-- | mm/fremap.c | 22 |
1 files changed, 7 insertions, 15 deletions
diff --git a/mm/fremap.c b/mm/fremap.c index 007cbad9331..f851775e09c 100644 --- a/mm/fremap.c +++ b/mm/fremap.c | |||
@@ -27,24 +27,20 @@ static int zap_pte(struct mm_struct *mm, struct vm_area_struct *vma, | |||
27 | struct page *page = NULL; | 27 | struct page *page = NULL; |
28 | 28 | ||
29 | if (pte_present(pte)) { | 29 | if (pte_present(pte)) { |
30 | unsigned long pfn = pte_pfn(pte); | 30 | flush_cache_page(vma, addr, pte_pfn(pte)); |
31 | flush_cache_page(vma, addr, pfn); | ||
32 | pte = ptep_clear_flush(vma, addr, ptep); | 31 | pte = ptep_clear_flush(vma, addr, ptep); |
33 | if (unlikely(!pfn_valid(pfn))) { | 32 | page = vm_normal_page(vma, addr, pte); |
34 | print_bad_pte(vma, pte, addr); | 33 | if (page) { |
35 | goto out; | 34 | if (pte_dirty(pte)) |
35 | set_page_dirty(page); | ||
36 | page_remove_rmap(page); | ||
37 | page_cache_release(page); | ||
36 | } | 38 | } |
37 | page = pfn_to_page(pfn); | ||
38 | if (pte_dirty(pte)) | ||
39 | set_page_dirty(page); | ||
40 | page_remove_rmap(page); | ||
41 | page_cache_release(page); | ||
42 | } else { | 39 | } else { |
43 | if (!pte_file(pte)) | 40 | if (!pte_file(pte)) |
44 | free_swap_and_cache(pte_to_swp_entry(pte)); | 41 | free_swap_and_cache(pte_to_swp_entry(pte)); |
45 | pte_clear(mm, addr, ptep); | 42 | pte_clear(mm, addr, ptep); |
46 | } | 43 | } |
47 | out: | ||
48 | return !!page; | 44 | return !!page; |
49 | } | 45 | } |
50 | 46 | ||
@@ -65,8 +61,6 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma, | |||
65 | pte_t pte_val; | 61 | pte_t pte_val; |
66 | spinlock_t *ptl; | 62 | spinlock_t *ptl; |
67 | 63 | ||
68 | BUG_ON(vma->vm_flags & VM_UNPAGED); | ||
69 | |||
70 | pgd = pgd_offset(mm, addr); | 64 | pgd = pgd_offset(mm, addr); |
71 | pud = pud_alloc(mm, pgd, addr); | 65 | pud = pud_alloc(mm, pgd, addr); |
72 | if (!pud) | 66 | if (!pud) |
@@ -122,8 +116,6 @@ int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, | |||
122 | pte_t pte_val; | 116 | pte_t pte_val; |
123 | spinlock_t *ptl; | 117 | spinlock_t *ptl; |
124 | 118 | ||
125 | BUG_ON(vma->vm_flags & VM_UNPAGED); | ||
126 | |||
127 | pgd = pgd_offset(mm, addr); | 119 | pgd = pgd_offset(mm, addr); |
128 | pud = pud_alloc(mm, pgd, addr); | 120 | pud = pud_alloc(mm, pgd, addr); |
129 | if (!pud) | 121 | if (!pud) |