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1/*
2 * linux/mm/page_isolation.c
3 */
4
5#include <linux/mm.h>
6#include <linux/page-isolation.h>
7#include <linux/pageblock-flags.h>
8#include "internal.h"
9
10static inline struct page *
11__first_valid_page(unsigned long pfn, unsigned long nr_pages)
12{
13 int i;
14 for (i = 0; i < nr_pages; i++)
15 if (pfn_valid_within(pfn + i))
16 break;
17 if (unlikely(i == nr_pages))
18 return NULL;
19 return pfn_to_page(pfn + i);
20}
21
22/*
23 * start_isolate_page_range() -- make page-allocation-type of range of pages
24 * to be MIGRATE_ISOLATE.
25 * @start_pfn: The lower PFN of the range to be isolated.
26 * @end_pfn: The upper PFN of the range to be isolated.
27 *
28 * Making page-allocation-type to be MIGRATE_ISOLATE means free pages in
29 * the range will never be allocated. Any free pages and pages freed in the
30 * future will not be allocated again.
31 *
32 * start_pfn/end_pfn must be aligned to pageblock_order.
33 * Returns 0 on success and -EBUSY if any part of range cannot be isolated.
34 */
35int
36start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn)
37{
38 unsigned long pfn;
39 unsigned long undo_pfn;
40 struct page *page;
41
42 BUG_ON((start_pfn) & (pageblock_nr_pages - 1));
43 BUG_ON((end_pfn) & (pageblock_nr_pages - 1));
44
45 for (pfn = start_pfn;
46 pfn < end_pfn;
47 pfn += pageblock_nr_pages) {
48 page = __first_valid_page(pfn, pageblock_nr_pages);
49 if (page && set_migratetype_isolate(page)) {
50 undo_pfn = pfn;
51 goto undo;
52 }
53 }
54 return 0;
55undo:
56 for (pfn = start_pfn;
57 pfn < undo_pfn;
58 pfn += pageblock_nr_pages)
59 unset_migratetype_isolate(pfn_to_page(pfn));
60
61 return -EBUSY;
62}
63
64/*
65 * Make isolated pages available again.
66 */
67int
68undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn)
69{
70 unsigned long pfn;
71 struct page *page;
72 BUG_ON((start_pfn) & (pageblock_nr_pages - 1));
73 BUG_ON((end_pfn) & (pageblock_nr_pages - 1));
74 for (pfn = start_pfn;
75 pfn < end_pfn;
76 pfn += pageblock_nr_pages) {
77 page = __first_valid_page(pfn, pageblock_nr_pages);
78 if (!page || get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
79 continue;
80 unset_migratetype_isolate(page);
81 }
82 return 0;
83}
84/*
85 * Test all pages in the range is free(means isolated) or not.
86 * all pages in [start_pfn...end_pfn) must be in the same zone.
87 * zone->lock must be held before call this.
88 *
89 * Returns 1 if all pages in the range is isolated.
90 */
91static int
92__test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn)
93{
94 struct page *page;
95
96 while (pfn < end_pfn) {
97 if (!pfn_valid_within(pfn)) {
98 pfn++;
99 continue;
100 }
101 page = pfn_to_page(pfn);
102 if (PageBuddy(page))
103 pfn += 1 << page_order(page);
104 else if (page_count(page) == 0 &&
105 page_private(page) == MIGRATE_ISOLATE)
106 pfn += 1;
107 else
108 break;
109 }
110 if (pfn < end_pfn)
111 return 0;
112 return 1;
113}
114
115int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
116{
117 unsigned long pfn, flags;
118 struct page *page;
119 struct zone *zone;
120 int ret;
121
122 /*
123 * Note: pageblock_nr_page != MAX_ORDER. Then, chunks of free page
124 * is not aligned to pageblock_nr_pages.
125 * Then we just check pagetype fist.
126 */
127 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
128 page = __first_valid_page(pfn, pageblock_nr_pages);
129 if (page && get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
130 break;
131 }
132 page = __first_valid_page(start_pfn, end_pfn - start_pfn);
133 if ((pfn < end_pfn) || !page)
134 return -EBUSY;
135 /* Check all pages are free or Marked as ISOLATED */
136 zone = page_zone(page);
137 spin_lock_irqsave(&zone->lock, flags);
138 ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn);
139 spin_unlock_irqrestore(&zone->lock, flags);
140 return ret ? 0 : -EBUSY;
141}
1/*
2 * linux/mm/page_isolation.c
3 */
4
5#include <linux/mm.h>
6#include <linux/page-isolation.h>
7#include <linux/pageblock-flags.h>
8#include "internal.h"
9
10static inline struct page *
11__first_valid_page(unsigned long pfn, unsigned long nr_pages)
12{
13 int i;
14 for (i = 0; i < nr_pages; i++)
15 if (pfn_valid_within(pfn + i))
16 break;
17 if (unlikely(i == nr_pages))
18 return NULL;
19 return pfn_to_page(pfn + i);
20}
21
22/*
23 * start_isolate_page_range() -- make page-allocation-type of range of pages
24 * to be MIGRATE_ISOLATE.
25 * @start_pfn: The lower PFN of the range to be isolated.
26 * @end_pfn: The upper PFN of the range to be isolated.
27 * @migratetype: migrate type to set in error recovery.
28 *
29 * Making page-allocation-type to be MIGRATE_ISOLATE means free pages in
30 * the range will never be allocated. Any free pages and pages freed in the
31 * future will not be allocated again.
32 *
33 * start_pfn/end_pfn must be aligned to pageblock_order.
34 * Returns 0 on success and -EBUSY if any part of range cannot be isolated.
35 */
36int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
37 unsigned migratetype)
38{
39 unsigned long pfn;
40 unsigned long undo_pfn;
41 struct page *page;
42
43 BUG_ON((start_pfn) & (pageblock_nr_pages - 1));
44 BUG_ON((end_pfn) & (pageblock_nr_pages - 1));
45
46 for (pfn = start_pfn;
47 pfn < end_pfn;
48 pfn += pageblock_nr_pages) {
49 page = __first_valid_page(pfn, pageblock_nr_pages);
50 if (page && set_migratetype_isolate(page)) {
51 undo_pfn = pfn;
52 goto undo;
53 }
54 }
55 return 0;
56undo:
57 for (pfn = start_pfn;
58 pfn < undo_pfn;
59 pfn += pageblock_nr_pages)
60 unset_migratetype_isolate(pfn_to_page(pfn), migratetype);
61
62 return -EBUSY;
63}
64
65/*
66 * Make isolated pages available again.
67 */
68int undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
69 unsigned migratetype)
70{
71 unsigned long pfn;
72 struct page *page;
73 BUG_ON((start_pfn) & (pageblock_nr_pages - 1));
74 BUG_ON((end_pfn) & (pageblock_nr_pages - 1));
75 for (pfn = start_pfn;
76 pfn < end_pfn;
77 pfn += pageblock_nr_pages) {
78 page = __first_valid_page(pfn, pageblock_nr_pages);
79 if (!page || get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
80 continue;
81 unset_migratetype_isolate(page, migratetype);
82 }
83 return 0;
84}
85/*
86 * Test all pages in the range is free(means isolated) or not.
87 * all pages in [start_pfn...end_pfn) must be in the same zone.
88 * zone->lock must be held before call this.
89 *
90 * Returns 1 if all pages in the range are isolated.
91 */
92static int
93__test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn)
94{
95 struct page *page;
96
97 while (pfn < end_pfn) {
98 if (!pfn_valid_within(pfn)) {
99 pfn++;
100 continue;
101 }
102 page = pfn_to_page(pfn);
103 if (PageBuddy(page))
104 pfn += 1 << page_order(page);
105 else if (page_count(page) == 0 &&
106 page_private(page) == MIGRATE_ISOLATE)
107 pfn += 1;
108 else
109 break;
110 }
111 if (pfn < end_pfn)
112 return 0;
113 return 1;
114}
115
116int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
117{
118 unsigned long pfn, flags;
119 struct page *page;
120 struct zone *zone;
121 int ret;
122
123 /*
124 * Note: pageblock_nr_page != MAX_ORDER. Then, chunks of free page
125 * is not aligned to pageblock_nr_pages.
126 * Then we just check pagetype fist.
127 */
128 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
129 page = __first_valid_page(pfn, pageblock_nr_pages);
130 if (page && get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
131 break;
132 }
133 page = __first_valid_page(start_pfn, end_pfn - start_pfn);
134 if ((pfn < end_pfn) || !page)
135 return -EBUSY;
136 /* Check all pages are free or Marked as ISOLATED */
137 zone = page_zone(page);
138 spin_lock_irqsave(&zone->lock, flags);
139 ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn);
140 spin_unlock_irqrestore(&zone->lock, flags);
141 return ret ? 0 : -EBUSY;
142}