blob: b8730d9ebaee651244d0d7e46e687792b46b0c9f [file] [log] [blame]
Alexey Dobriyan6d80e532008-10-06 14:26:12 +04001#include <linux/bootmem.h>
2#include <linux/compiler.h>
3#include <linux/fs.h>
4#include <linux/init.h>
Hugh Dickins9a840892009-09-21 17:02:01 -07005#include <linux/ksm.h>
Alexey Dobriyan6d80e532008-10-06 14:26:12 +04006#include <linux/mm.h>
7#include <linux/mmzone.h>
8#include <linux/proc_fs.h>
9#include <linux/seq_file.h>
Wu Fengguang20a03072009-06-16 15:32:22 -070010#include <linux/hugetlb.h>
Wu Fengguang1a9b5b72009-12-16 12:19:59 +010011#include <linux/kernel-page-flags.h>
Alexey Dobriyan6d80e532008-10-06 14:26:12 +040012#include <asm/uaccess.h>
13#include "internal.h"
14
15#define KPMSIZE sizeof(u64)
16#define KPMMASK (KPMSIZE - 1)
Wu Fengguanged7ce0f2009-06-16 15:32:23 -070017
Alexey Dobriyan6d80e532008-10-06 14:26:12 +040018/* /proc/kpagecount - an array exposing page counts
19 *
20 * Each entry is a u64 representing the corresponding
21 * physical page count.
22 */
23static ssize_t kpagecount_read(struct file *file, char __user *buf,
24 size_t count, loff_t *ppos)
25{
26 u64 __user *out = (u64 __user *)buf;
27 struct page *ppage;
28 unsigned long src = *ppos;
29 unsigned long pfn;
30 ssize_t ret = 0;
31 u64 pcount;
32
33 pfn = src / KPMSIZE;
34 count = min_t(size_t, count, (max_pfn * KPMSIZE) - src);
35 if (src & KPMMASK || count & KPMMASK)
36 return -EINVAL;
37
38 while (count > 0) {
Alexey Dobriyan6d80e532008-10-06 14:26:12 +040039 if (pfn_valid(pfn))
40 ppage = pfn_to_page(pfn);
Wu Fengguanged7ce0f2009-06-16 15:32:23 -070041 else
42 ppage = NULL;
Petr Holaseka6fc86d2011-01-12 17:00:34 -080043 if (!ppage || PageSlab(ppage))
Alexey Dobriyan6d80e532008-10-06 14:26:12 +040044 pcount = 0;
45 else
46 pcount = page_mapcount(ppage);
47
Wu Fengguanged7ce0f2009-06-16 15:32:23 -070048 if (put_user(pcount, out)) {
Alexey Dobriyan6d80e532008-10-06 14:26:12 +040049 ret = -EFAULT;
50 break;
51 }
52
Wu Fengguanged7ce0f2009-06-16 15:32:23 -070053 pfn++;
54 out++;
Alexey Dobriyan6d80e532008-10-06 14:26:12 +040055 count -= KPMSIZE;
56 }
57
58 *ppos += (char __user *)out - buf;
59 if (!ret)
60 ret = (char __user *)out - buf;
61 return ret;
62}
63
64static const struct file_operations proc_kpagecount_operations = {
65 .llseek = mem_lseek,
66 .read = kpagecount_read,
67};
68
69/* /proc/kpageflags - an array exposing page flags
70 *
71 * Each entry is a u64 representing the corresponding
72 * physical page flags.
73 */
74
Wu Fengguang17797542009-06-16 15:32:24 -070075static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
76{
77 return ((kflags >> kbit) & 1) << ubit;
78}
79
Wu Fengguang1a9b5b72009-12-16 12:19:59 +010080u64 stable_page_flags(struct page *page)
Wu Fengguang17797542009-06-16 15:32:24 -070081{
82 u64 k;
83 u64 u;
84
85 /*
86 * pseudo flag: KPF_NOPAGE
87 * it differentiates a memory hole from a page with no flags
88 */
89 if (!page)
90 return 1 << KPF_NOPAGE;
91
92 k = page->flags;
93 u = 0;
94
95 /*
96 * pseudo flags for the well known (anonymous) memory mapped pages
97 *
98 * Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the
99 * simple test in page_mapped() is not enough.
100 */
101 if (!PageSlab(page) && page_mapped(page))
102 u |= 1 << KPF_MMAP;
103 if (PageAnon(page))
104 u |= 1 << KPF_ANON;
Hugh Dickins9a840892009-09-21 17:02:01 -0700105 if (PageKsm(page))
106 u |= 1 << KPF_KSM;
Wu Fengguang17797542009-06-16 15:32:24 -0700107
108 /*
109 * compound pages: export both head/tail info
110 * they together define a compound page's start/end pos and order
111 */
112 if (PageHead(page))
113 u |= 1 << KPF_COMPOUND_HEAD;
114 if (PageTail(page))
115 u |= 1 << KPF_COMPOUND_TAIL;
116 if (PageHuge(page))
117 u |= 1 << KPF_HUGE;
Naoya Horiguchi7a719322012-10-08 16:33:47 -0700118 /*
119 * PageTransCompound can be true for non-huge compound pages (slab
120 * pages or pages allocated by drivers with __GFP_COMP) because it
121 * just checks PG_head/PG_tail, so we need to check PageLRU to make
122 * sure a given page is a thp, not a non-huge compound page.
123 */
124 else if (PageTransCompound(page) && PageLRU(compound_trans_head(page)))
Naoya Horiguchie873c492012-03-21 16:33:58 -0700125 u |= 1 << KPF_THP;
Wu Fengguang17797542009-06-16 15:32:24 -0700126
Andrea Arcangeli5f24ce52011-01-13 15:47:00 -0800127 /*
128 * Caveats on high order pages: page->_count will only be set
129 * -1 on the head page; SLUB/SLQB do the same for PG_slab;
130 * SLOB won't set PG_slab at all on compound pages.
131 */
132 if (PageBuddy(page))
133 u |= 1 << KPF_BUDDY;
134
Wu Fengguang17797542009-06-16 15:32:24 -0700135 u |= kpf_copy_bit(k, KPF_LOCKED, PG_locked);
136
Wu Fengguang17797542009-06-16 15:32:24 -0700137 u |= kpf_copy_bit(k, KPF_SLAB, PG_slab);
Wu Fengguang17797542009-06-16 15:32:24 -0700138
139 u |= kpf_copy_bit(k, KPF_ERROR, PG_error);
140 u |= kpf_copy_bit(k, KPF_DIRTY, PG_dirty);
141 u |= kpf_copy_bit(k, KPF_UPTODATE, PG_uptodate);
142 u |= kpf_copy_bit(k, KPF_WRITEBACK, PG_writeback);
143
144 u |= kpf_copy_bit(k, KPF_LRU, PG_lru);
145 u |= kpf_copy_bit(k, KPF_REFERENCED, PG_referenced);
146 u |= kpf_copy_bit(k, KPF_ACTIVE, PG_active);
147 u |= kpf_copy_bit(k, KPF_RECLAIM, PG_reclaim);
148
149 u |= kpf_copy_bit(k, KPF_SWAPCACHE, PG_swapcache);
150 u |= kpf_copy_bit(k, KPF_SWAPBACKED, PG_swapbacked);
151
Wu Fengguang17797542009-06-16 15:32:24 -0700152 u |= kpf_copy_bit(k, KPF_UNEVICTABLE, PG_unevictable);
153 u |= kpf_copy_bit(k, KPF_MLOCKED, PG_mlocked);
Wu Fengguang17797542009-06-16 15:32:24 -0700154
Wu Fengguang253fb022009-10-07 16:32:27 -0700155#ifdef CONFIG_MEMORY_FAILURE
156 u |= kpf_copy_bit(k, KPF_HWPOISON, PG_hwpoison);
157#endif
158
Takashi Iwaied430fe2010-09-09 16:37:36 -0700159#ifdef CONFIG_ARCH_USES_PG_UNCACHED
Wu Fengguang17797542009-06-16 15:32:24 -0700160 u |= kpf_copy_bit(k, KPF_UNCACHED, PG_uncached);
161#endif
162
163 u |= kpf_copy_bit(k, KPF_RESERVED, PG_reserved);
164 u |= kpf_copy_bit(k, KPF_MAPPEDTODISK, PG_mappedtodisk);
165 u |= kpf_copy_bit(k, KPF_PRIVATE, PG_private);
166 u |= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2);
167 u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1);
168 u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
169
170 return u;
171};
Alexey Dobriyan6d80e532008-10-06 14:26:12 +0400172
173static ssize_t kpageflags_read(struct file *file, char __user *buf,
174 size_t count, loff_t *ppos)
175{
176 u64 __user *out = (u64 __user *)buf;
177 struct page *ppage;
178 unsigned long src = *ppos;
179 unsigned long pfn;
180 ssize_t ret = 0;
Alexey Dobriyan6d80e532008-10-06 14:26:12 +0400181
182 pfn = src / KPMSIZE;
183 count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
184 if (src & KPMMASK || count & KPMMASK)
185 return -EINVAL;
186
187 while (count > 0) {
Alexey Dobriyan6d80e532008-10-06 14:26:12 +0400188 if (pfn_valid(pfn))
189 ppage = pfn_to_page(pfn);
Wu Fengguanged7ce0f2009-06-16 15:32:23 -0700190 else
191 ppage = NULL;
Alexey Dobriyan6d80e532008-10-06 14:26:12 +0400192
Wu Fengguang1a9b5b72009-12-16 12:19:59 +0100193 if (put_user(stable_page_flags(ppage), out)) {
Alexey Dobriyan6d80e532008-10-06 14:26:12 +0400194 ret = -EFAULT;
195 break;
196 }
197
Wu Fengguanged7ce0f2009-06-16 15:32:23 -0700198 pfn++;
199 out++;
Alexey Dobriyan6d80e532008-10-06 14:26:12 +0400200 count -= KPMSIZE;
201 }
202
203 *ppos += (char __user *)out - buf;
204 if (!ret)
205 ret = (char __user *)out - buf;
206 return ret;
207}
208
209static const struct file_operations proc_kpageflags_operations = {
210 .llseek = mem_lseek,
211 .read = kpageflags_read,
212};
213
214static int __init proc_page_init(void)
215{
216 proc_create("kpagecount", S_IRUSR, NULL, &proc_kpagecount_operations);
217 proc_create("kpageflags", S_IRUSR, NULL, &proc_kpageflags_operations);
218 return 0;
219}
220module_init(proc_page_init);