blob: 0afd2387e507d8f8deed9697f1971fc953f4b4b6 [file] [log] [blame]
Matt Mackalle6473092008-02-04 22:29:01 -08001#include <linux/mm.h>
2#include <linux/highmem.h>
3#include <linux/sched.h>
4
5static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
6 const struct mm_walk *walk, void *private)
7{
8 pte_t *pte;
9 int err = 0;
10
11 pte = pte_offset_map(pmd, addr);
Johannes Weiner556637c2008-04-28 02:11:47 -070012 for (;;) {
Matt Mackalle6473092008-02-04 22:29:01 -080013 err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, private);
14 if (err)
15 break;
Johannes Weiner556637c2008-04-28 02:11:47 -070016 addr += PAGE_SIZE;
17 if (addr == end)
18 break;
19 pte++;
20 }
Matt Mackalle6473092008-02-04 22:29:01 -080021
22 pte_unmap(pte);
23 return err;
24}
25
26static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
27 const struct mm_walk *walk, void *private)
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, private);
39 if (err)
40 break;
41 continue;
42 }
43 if (walk->pmd_entry)
44 err = walk->pmd_entry(pmd, addr, next, private);
45 if (!err && walk->pte_entry)
46 err = walk_pte_range(pmd, addr, next, walk, private);
47 if (err)
48 break;
49 } while (pmd++, addr = next, addr != end);
50
51 return err;
52}
53
54static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
55 const struct mm_walk *walk, void *private)
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, private);
67 if (err)
68 break;
69 continue;
70 }
71 if (walk->pud_entry)
72 err = walk->pud_entry(pud, addr, next, private);
73 if (!err && (walk->pmd_entry || walk->pte_entry))
74 err = walk_pmd_range(pud, addr, next, walk, private);
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
Randy Dunlap76824862008-03-19 17:00:40 -070084 * @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 * @private: private data passed to the callback function
Matt Mackalle6473092008-02-04 22:29:01 -080089 *
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, the start and end of the
96 * associated range, and a caller-supplied private data pointer.
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 */
104int walk_page_range(const struct mm_struct *mm,
105 unsigned long addr, unsigned long end,
106 const struct mm_walk *walk, void *private)
107{
108 pgd_t *pgd;
109 unsigned long next;
110 int err = 0;
111
112 if (addr >= end)
113 return err;
114
115 pgd = pgd_offset(mm, addr);
116 do {
117 next = pgd_addr_end(addr, end);
118 if (pgd_none_or_clear_bad(pgd)) {
119 if (walk->pte_hole)
120 err = walk->pte_hole(addr, next, private);
121 if (err)
122 break;
123 continue;
124 }
125 if (walk->pgd_entry)
126 err = walk->pgd_entry(pgd, addr, next, private);
127 if (!err &&
128 (walk->pud_entry || walk->pmd_entry || walk->pte_entry))
129 err = walk_pud_range(pgd, addr, next, walk, private);
130 if (err)
131 break;
132 } while (pgd++, addr = next, addr != end);
133
134 return err;
135}