bnx2: Use proper handler during netpoll.
[linux-2.6.git] / mm / pagewalk.c
1 #include <linux/mm.h>
2 #include <linux/highmem.h>
3 #include <linux/sched.h>
4 #include <linux/hugetlb.h>
5
6 static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
7                           struct mm_walk *walk)
8 {
9         pte_t *pte;
10         int err = 0;
11
12         pte = pte_offset_map(pmd, addr);
13         for (;;) {
14                 err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, walk);
15                 if (err)
16                        break;
17                 addr += PAGE_SIZE;
18                 if (addr == end)
19                         break;
20                 pte++;
21         }
22
23         pte_unmap(pte);
24         return err;
25 }
26
27 static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
28                           struct mm_walk *walk)
29 {
30         pmd_t *pmd;
31         unsigned long next;
32         int err = 0;
33
34         pmd = pmd_offset(pud, addr);
35         do {
36                 next = pmd_addr_end(addr, end);
37                 if (pmd_none_or_clear_bad(pmd)) {
38                         if (walk->pte_hole)
39                                 err = walk->pte_hole(addr, next, walk);
40                         if (err)
41                                 break;
42                         continue;
43                 }
44                 if (walk->pmd_entry)
45                         err = walk->pmd_entry(pmd, addr, next, walk);
46                 if (!err && walk->pte_entry)
47                         err = walk_pte_range(pmd, addr, next, walk);
48                 if (err)
49                         break;
50         } while (pmd++, addr = next, addr != end);
51
52         return err;
53 }
54
55 static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
56                           struct mm_walk *walk)
57 {
58         pud_t *pud;
59         unsigned long next;
60         int err = 0;
61
62         pud = pud_offset(pgd, addr);
63         do {
64                 next = pud_addr_end(addr, end);
65                 if (pud_none_or_clear_bad(pud)) {
66                         if (walk->pte_hole)
67                                 err = walk->pte_hole(addr, next, walk);
68                         if (err)
69                                 break;
70                         continue;
71                 }
72                 if (walk->pud_entry)
73                         err = walk->pud_entry(pud, addr, next, walk);
74                 if (!err && (walk->pmd_entry || walk->pte_entry))
75                         err = walk_pmd_range(pud, addr, next, walk);
76                 if (err)
77                         break;
78         } while (pud++, addr = next, addr != end);
79
80         return err;
81 }
82
83 /**
84  * walk_page_range - walk a memory map's page tables with a callback
85  * @mm: memory map to walk
86  * @addr: starting address
87  * @end: ending address
88  * @walk: set of callbacks to invoke for each level of the tree
89  *
90  * Recursively walk the page table for the memory area in a VMA,
91  * calling supplied callbacks. Callbacks are called in-order (first
92  * PGD, first PUD, first PMD, first PTE, second PTE... second PMD,
93  * etc.). If lower-level callbacks are omitted, walking depth is reduced.
94  *
95  * Each callback receives an entry pointer and the start and end of the
96  * associated range, and a copy of the original mm_walk for access to
97  * the ->private or ->mm fields.
98  *
99  * No locks are taken, but the bottom level iterator will map PTE
100  * directories from highmem if necessary.
101  *
102  * If any callback returns a non-zero value, the walk is aborted and
103  * the return value is propagated back to the caller. Otherwise 0 is returned.
104  */
105 int walk_page_range(unsigned long addr, unsigned long end,
106                     struct mm_walk *walk)
107 {
108         pgd_t *pgd;
109         unsigned long next;
110         int err = 0;
111         struct vm_area_struct *vma;
112
113         if (addr >= end)
114                 return err;
115
116         if (!walk->mm)
117                 return -EINVAL;
118
119         pgd = pgd_offset(walk->mm, addr);
120         do {
121                 next = pgd_addr_end(addr, end);
122
123                 /*
124                  * handle hugetlb vma individually because pagetable walk for
125                  * the hugetlb page is dependent on the architecture and
126                  * we can't handled it in the same manner as non-huge pages.
127                  */
128                 vma = find_vma(walk->mm, addr);
129 #ifdef CONFIG_HUGETLB_PAGE
130                 if (vma && is_vm_hugetlb_page(vma)) {
131                         pte_t *pte;
132                         struct hstate *hs;
133
134                         if (vma->vm_end < next)
135                                 next = vma->vm_end;
136                         hs = hstate_vma(vma);
137                         pte = huge_pte_offset(walk->mm,
138                                               addr & huge_page_mask(hs));
139                         if (pte && !huge_pte_none(huge_ptep_get(pte))
140                             && walk->hugetlb_entry)
141                                 err = walk->hugetlb_entry(pte, addr,
142                                                           next, walk);
143                         if (err)
144                                 break;
145                         continue;
146                 }
147 #endif
148                 if (pgd_none_or_clear_bad(pgd)) {
149                         if (walk->pte_hole)
150                                 err = walk->pte_hole(addr, next, walk);
151                         if (err)
152                                 break;
153                         pgd++;
154                         continue;
155                 }
156                 if (walk->pgd_entry)
157                         err = walk->pgd_entry(pgd, addr, next, walk);
158                 if (!err &&
159                     (walk->pud_entry || walk->pmd_entry || walk->pte_entry))
160                         err = walk_pud_range(pgd, addr, next, walk);
161                 if (err)
162                         break;
163                 pgd++;
164         } while (addr = next, addr != end);
165
166         return err;
167 }