bootmem: print request details before BUG_ON(them)
[linux-2.6.git] / mm / pagewalk.c
1 #include <linux/mm.h>
2 #include <linux/highmem.h>
3 #include <linux/sched.h>
4
5 static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
6                           struct mm_walk *walk)
7 {
8         pte_t *pte;
9         int err = 0;
10
11         pte = pte_offset_map(pmd, addr);
12         for (;;) {
13                 err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, walk);
14                 if (err)
15                        break;
16                 addr += PAGE_SIZE;
17                 if (addr == end)
18                         break;
19                 pte++;
20         }
21
22         pte_unmap(pte);
23         return err;
24 }
25
26 static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
27                           struct mm_walk *walk)
28 {
29         pmd_t *pmd;
30         unsigned long next;
31         int err = 0;
32
33         pmd = pmd_offset(pud, addr);
34         do {
35                 next = pmd_addr_end(addr, end);
36                 if (pmd_none_or_clear_bad(pmd)) {
37                         if (walk->pte_hole)
38                                 err = walk->pte_hole(addr, next, walk);
39                         if (err)
40                                 break;
41                         continue;
42                 }
43                 if (walk->pmd_entry)
44                         err = walk->pmd_entry(pmd, addr, next, walk);
45                 if (!err && walk->pte_entry)
46                         err = walk_pte_range(pmd, addr, next, walk);
47                 if (err)
48                         break;
49         } while (pmd++, addr = next, addr != end);
50
51         return err;
52 }
53
54 static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
55                           struct mm_walk *walk)
56 {
57         pud_t *pud;
58         unsigned long next;
59         int err = 0;
60
61         pud = pud_offset(pgd, addr);
62         do {
63                 next = pud_addr_end(addr, end);
64                 if (pud_none_or_clear_bad(pud)) {
65                         if (walk->pte_hole)
66                                 err = walk->pte_hole(addr, next, walk);
67                         if (err)
68                                 break;
69                         continue;
70                 }
71                 if (walk->pud_entry)
72                         err = walk->pud_entry(pud, addr, next, walk);
73                 if (!err && (walk->pmd_entry || walk->pte_entry))
74                         err = walk_pmd_range(pud, addr, next, walk);
75                 if (err)
76                         break;
77         } while (pud++, addr = next, addr != end);
78
79         return err;
80 }
81
82 /**
83  * walk_page_range - walk a memory map's page tables with a callback
84  * @mm: memory map to walk
85  * @addr: starting address
86  * @end: ending address
87  * @walk: set of callbacks to invoke for each level of the tree
88  *
89  * Recursively walk the page table for the memory area in a VMA,
90  * calling supplied callbacks. Callbacks are called in-order (first
91  * PGD, first PUD, first PMD, first PTE, second PTE... second PMD,
92  * etc.). If lower-level callbacks are omitted, walking depth is reduced.
93  *
94  * Each callback receives an entry pointer and the start and end of the
95  * associated range, and a copy of the original mm_walk for access to
96  * the ->private or ->mm fields.
97  *
98  * No locks are taken, but the bottom level iterator will map PTE
99  * directories from highmem if necessary.
100  *
101  * If any callback returns a non-zero value, the walk is aborted and
102  * the return value is propagated back to the caller. Otherwise 0 is returned.
103  */
104 int walk_page_range(unsigned long addr, unsigned long end,
105                     struct mm_walk *walk)
106 {
107         pgd_t *pgd;
108         unsigned long next;
109         int err = 0;
110
111         if (addr >= end)
112                 return err;
113
114         if (!walk->mm)
115                 return -EINVAL;
116
117         pgd = pgd_offset(walk->mm, addr);
118         do {
119                 next = pgd_addr_end(addr, end);
120                 if (pgd_none_or_clear_bad(pgd)) {
121                         if (walk->pte_hole)
122                                 err = walk->pte_hole(addr, next, walk);
123                         if (err)
124                                 break;
125                         continue;
126                 }
127                 if (walk->pgd_entry)
128                         err = walk->pgd_entry(pgd, addr, next, walk);
129                 if (!err &&
130                     (walk->pud_entry || walk->pmd_entry || walk->pte_entry))
131                         err = walk_pud_range(pgd, addr, next, walk);
132                 if (err)
133                         break;
134         } while (pgd++, addr = next, addr != end);
135
136         return err;
137 }