Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Macros for manipulating and testing page->flags |
| 3 | */ |
| 4 | |
| 5 | #ifndef PAGE_FLAGS_H |
| 6 | #define PAGE_FLAGS_H |
| 7 | |
Andrew Morton | f886ed4 | 2006-06-23 02:03:06 -0700 | [diff] [blame] | 8 | #include <linux/types.h> |
Christoph Lameter | 9223b41 | 2008-04-28 02:12:48 -0700 | [diff] [blame] | 9 | #ifndef __GENERATING_BOUNDS_H |
Christoph Lameter | 6d77795 | 2007-05-06 14:49:40 -0700 | [diff] [blame] | 10 | #include <linux/mm_types.h> |
Christoph Lameter | 9223b41 | 2008-04-28 02:12:48 -0700 | [diff] [blame] | 11 | #include <linux/bounds.h> |
| 12 | #endif /* !__GENERATING_BOUNDS_H */ |
Andrew Morton | f886ed4 | 2006-06-23 02:03:06 -0700 | [diff] [blame] | 13 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | /* |
| 15 | * Various page->flags bits: |
| 16 | * |
| 17 | * PG_reserved is set for special pages, which can never be swapped out. Some |
| 18 | * of them might not even exist (eg empty_bad_page)... |
| 19 | * |
Nick Piggin | da6052f | 2006-09-25 23:31:35 -0700 | [diff] [blame] | 20 | * The PG_private bitflag is set on pagecache pages if they contain filesystem |
| 21 | * specific data (which is normally at page->private). It can be used by |
| 22 | * private allocations for its own usage. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | * |
Nick Piggin | da6052f | 2006-09-25 23:31:35 -0700 | [diff] [blame] | 24 | * During initiation of disk I/O, PG_locked is set. This bit is set before I/O |
| 25 | * and cleared when writeback _starts_ or when read _completes_. PG_writeback |
| 26 | * is set before writeback starts and cleared when it finishes. |
| 27 | * |
| 28 | * PG_locked also pins a page in pagecache, and blocks truncation of the file |
| 29 | * while it is held. |
| 30 | * |
| 31 | * page_waitqueue(page) is a wait queue of all tasks waiting for the page |
| 32 | * to become unlocked. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | * |
| 34 | * PG_uptodate tells whether the page's contents is valid. When a read |
| 35 | * completes, the page becomes uptodate, unless a disk I/O error happened. |
| 36 | * |
Nick Piggin | da6052f | 2006-09-25 23:31:35 -0700 | [diff] [blame] | 37 | * PG_referenced, PG_reclaim are used for page reclaim for anonymous and |
| 38 | * file-backed pagecache (see mm/vmscan.c). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | * |
| 40 | * PG_error is set to indicate that an I/O error occurred on this page. |
| 41 | * |
| 42 | * PG_arch_1 is an architecture specific page state bit. The generic code |
| 43 | * guarantees that this bit is cleared for a page when it first is entered into |
| 44 | * the page cache. |
| 45 | * |
| 46 | * PG_highmem pages are not permanently mapped into the kernel virtual address |
| 47 | * space, they need to be kmapped separately for doing IO on the pages. The |
| 48 | * struct page (these bits with information) are always mapped into kernel |
| 49 | * address space... |
Nick Piggin | da6052f | 2006-09-25 23:31:35 -0700 | [diff] [blame] | 50 | * |
| 51 | * PG_buddy is set to indicate that the page is free and in the buddy system |
| 52 | * (see mm/page_alloc.c). |
| 53 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | */ |
| 55 | |
| 56 | /* |
| 57 | * Don't use the *_dontuse flags. Use the macros. Otherwise you'll break |
Andy Whitcroft | 91fc8ab | 2006-04-10 22:53:01 -0700 | [diff] [blame] | 58 | * locked- and dirty-page accounting. |
| 59 | * |
| 60 | * The page flags field is split into two parts, the main flags area |
| 61 | * which extends from the low bits upwards, and the fields area which |
| 62 | * extends from the high bits downwards. |
| 63 | * |
| 64 | * | FIELD | ... | FLAGS | |
Christoph Lameter | 9223b41 | 2008-04-28 02:12:48 -0700 | [diff] [blame] | 65 | * N-1 ^ 0 |
| 66 | * (NR_PAGEFLAGS) |
Andy Whitcroft | 91fc8ab | 2006-04-10 22:53:01 -0700 | [diff] [blame] | 67 | * |
Christoph Lameter | 9223b41 | 2008-04-28 02:12:48 -0700 | [diff] [blame] | 68 | * The fields area is reserved for fields mapping zone, node (for NUMA) and |
| 69 | * SPARSEMEM section (for variants of SPARSEMEM that require section ids like |
| 70 | * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | */ |
Christoph Lameter | e268318 | 2008-04-28 02:12:47 -0700 | [diff] [blame] | 72 | enum pageflags { |
| 73 | PG_locked, /* Page is locked. Don't touch. */ |
| 74 | PG_error, |
| 75 | PG_referenced, |
| 76 | PG_uptodate, |
| 77 | PG_dirty, |
| 78 | PG_lru, |
| 79 | PG_active, |
| 80 | PG_slab, |
| 81 | PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/ |
Christoph Lameter | e268318 | 2008-04-28 02:12:47 -0700 | [diff] [blame] | 82 | PG_arch_1, |
| 83 | PG_reserved, |
| 84 | PG_private, /* If pagecache, has fs-private data */ |
David Howells | 266cf65 | 2009-04-03 16:42:36 +0100 | [diff] [blame] | 85 | PG_private_2, /* If pagecache, has fs aux data */ |
Christoph Lameter | e268318 | 2008-04-28 02:12:47 -0700 | [diff] [blame] | 86 | PG_writeback, /* Page is under writeback */ |
Christoph Lameter | e20b8cc | 2008-04-28 02:12:55 -0700 | [diff] [blame] | 87 | #ifdef CONFIG_PAGEFLAGS_EXTENDED |
| 88 | PG_head, /* A head page */ |
| 89 | PG_tail, /* A tail page */ |
| 90 | #else |
Christoph Lameter | e268318 | 2008-04-28 02:12:47 -0700 | [diff] [blame] | 91 | PG_compound, /* A compound page */ |
Christoph Lameter | e20b8cc | 2008-04-28 02:12:55 -0700 | [diff] [blame] | 92 | #endif |
Christoph Lameter | e268318 | 2008-04-28 02:12:47 -0700 | [diff] [blame] | 93 | PG_swapcache, /* Swap page: swp_entry_t in private */ |
| 94 | PG_mappedtodisk, /* Has blocks allocated on-disk */ |
| 95 | PG_reclaim, /* To be reclaimed asap */ |
Christoph Lameter | e268318 | 2008-04-28 02:12:47 -0700 | [diff] [blame] | 96 | PG_buddy, /* Page is free, on buddy lists */ |
Rik van Riel | b2e1853 | 2008-10-18 20:26:30 -0700 | [diff] [blame] | 97 | PG_swapbacked, /* Page is backed by RAM/swap */ |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 98 | #ifdef CONFIG_UNEVICTABLE_LRU |
| 99 | PG_unevictable, /* Page is "unevictable" */ |
David Howells | 33925b2 | 2009-03-31 15:23:26 -0700 | [diff] [blame] | 100 | #endif |
| 101 | #ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 102 | PG_mlocked, /* Page is vma mlocked */ |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 103 | #endif |
Christoph Lameter | 602c4d1 | 2008-04-28 02:12:52 -0700 | [diff] [blame] | 104 | #ifdef CONFIG_IA64_UNCACHED_ALLOCATOR |
| 105 | PG_uncached, /* Page has been mapped as uncached */ |
Andrew Morton | f886ed4 | 2006-06-23 02:03:06 -0700 | [diff] [blame] | 106 | #endif |
Andy Whitcroft | 0cad47c | 2008-07-23 21:27:16 -0700 | [diff] [blame] | 107 | __NR_PAGEFLAGS, |
| 108 | |
| 109 | /* Filesystems */ |
| 110 | PG_checked = PG_owner_priv_1, |
| 111 | |
David Howells | 266cf65 | 2009-04-03 16:42:36 +0100 | [diff] [blame] | 112 | /* Two page bits are conscripted by FS-Cache to maintain local caching |
| 113 | * state. These bits are set on pages belonging to the netfs's inodes |
| 114 | * when those inodes are being locally cached. |
| 115 | */ |
| 116 | PG_fscache = PG_private_2, /* page backed by cache */ |
| 117 | |
Andy Whitcroft | 0cad47c | 2008-07-23 21:27:16 -0700 | [diff] [blame] | 118 | /* XEN */ |
| 119 | PG_pinned = PG_owner_priv_1, |
| 120 | PG_savepinned = PG_dirty, |
Andy Whitcroft | 8a38082 | 2008-07-23 21:27:18 -0700 | [diff] [blame] | 121 | |
Andy Whitcroft | 9023cb7 | 2008-07-23 21:27:19 -0700 | [diff] [blame] | 122 | /* SLOB */ |
| 123 | PG_slob_page = PG_active, |
| 124 | PG_slob_free = PG_private, |
| 125 | |
Andy Whitcroft | 8a38082 | 2008-07-23 21:27:18 -0700 | [diff] [blame] | 126 | /* SLUB */ |
| 127 | PG_slub_frozen = PG_active, |
| 128 | PG_slub_debug = PG_error, |
Christoph Lameter | e268318 | 2008-04-28 02:12:47 -0700 | [diff] [blame] | 129 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | |
Christoph Lameter | 9223b41 | 2008-04-28 02:12:48 -0700 | [diff] [blame] | 131 | #ifndef __GENERATING_BOUNDS_H |
| 132 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | /* |
Christoph Lameter | f94a62e | 2008-04-28 02:12:49 -0700 | [diff] [blame] | 134 | * Macros to create function definitions for page flags |
| 135 | */ |
| 136 | #define TESTPAGEFLAG(uname, lname) \ |
| 137 | static inline int Page##uname(struct page *page) \ |
| 138 | { return test_bit(PG_##lname, &page->flags); } |
| 139 | |
| 140 | #define SETPAGEFLAG(uname, lname) \ |
| 141 | static inline void SetPage##uname(struct page *page) \ |
| 142 | { set_bit(PG_##lname, &page->flags); } |
| 143 | |
| 144 | #define CLEARPAGEFLAG(uname, lname) \ |
| 145 | static inline void ClearPage##uname(struct page *page) \ |
| 146 | { clear_bit(PG_##lname, &page->flags); } |
| 147 | |
| 148 | #define __SETPAGEFLAG(uname, lname) \ |
| 149 | static inline void __SetPage##uname(struct page *page) \ |
| 150 | { __set_bit(PG_##lname, &page->flags); } |
| 151 | |
| 152 | #define __CLEARPAGEFLAG(uname, lname) \ |
| 153 | static inline void __ClearPage##uname(struct page *page) \ |
| 154 | { __clear_bit(PG_##lname, &page->flags); } |
| 155 | |
| 156 | #define TESTSETFLAG(uname, lname) \ |
| 157 | static inline int TestSetPage##uname(struct page *page) \ |
| 158 | { return test_and_set_bit(PG_##lname, &page->flags); } |
| 159 | |
| 160 | #define TESTCLEARFLAG(uname, lname) \ |
| 161 | static inline int TestClearPage##uname(struct page *page) \ |
| 162 | { return test_and_clear_bit(PG_##lname, &page->flags); } |
| 163 | |
| 164 | |
| 165 | #define PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \ |
| 166 | SETPAGEFLAG(uname, lname) CLEARPAGEFLAG(uname, lname) |
| 167 | |
| 168 | #define __PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \ |
| 169 | __SETPAGEFLAG(uname, lname) __CLEARPAGEFLAG(uname, lname) |
| 170 | |
Christoph Lameter | ec7cade | 2008-04-28 02:12:53 -0700 | [diff] [blame] | 171 | #define PAGEFLAG_FALSE(uname) \ |
| 172 | static inline int Page##uname(struct page *page) \ |
| 173 | { return 0; } |
| 174 | |
Christoph Lameter | f94a62e | 2008-04-28 02:12:49 -0700 | [diff] [blame] | 175 | #define TESTSCFLAG(uname, lname) \ |
| 176 | TESTSETFLAG(uname, lname) TESTCLEARFLAG(uname, lname) |
| 177 | |
Lee Schermerhorn | 8a7a854 | 2008-10-18 20:26:37 -0700 | [diff] [blame] | 178 | #define SETPAGEFLAG_NOOP(uname) \ |
| 179 | static inline void SetPage##uname(struct page *page) { } |
| 180 | |
| 181 | #define CLEARPAGEFLAG_NOOP(uname) \ |
| 182 | static inline void ClearPage##uname(struct page *page) { } |
| 183 | |
| 184 | #define __CLEARPAGEFLAG_NOOP(uname) \ |
| 185 | static inline void __ClearPage##uname(struct page *page) { } |
| 186 | |
| 187 | #define TESTCLEARFLAG_FALSE(uname) \ |
| 188 | static inline int TestClearPage##uname(struct page *page) { return 0; } |
| 189 | |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 190 | struct page; /* forward declaration */ |
| 191 | |
David Howells | 03fb3d2 | 2009-04-03 16:42:35 +0100 | [diff] [blame] | 192 | TESTPAGEFLAG(Locked, locked) TESTSETFLAG(Locked, locked) |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 193 | PAGEFLAG(Error, error) |
| 194 | PAGEFLAG(Referenced, referenced) TESTCLEARFLAG(Referenced, referenced) |
| 195 | PAGEFLAG(Dirty, dirty) TESTSCFLAG(Dirty, dirty) __CLEARPAGEFLAG(Dirty, dirty) |
| 196 | PAGEFLAG(LRU, lru) __CLEARPAGEFLAG(LRU, lru) |
| 197 | PAGEFLAG(Active, active) __CLEARPAGEFLAG(Active, active) |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 198 | TESTCLEARFLAG(Active, active) |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 199 | __PAGEFLAG(Slab, slab) |
Andy Whitcroft | 0cad47c | 2008-07-23 21:27:16 -0700 | [diff] [blame] | 200 | PAGEFLAG(Checked, checked) /* Used by some filesystems */ |
| 201 | PAGEFLAG(Pinned, pinned) TESTSCFLAG(Pinned, pinned) /* Xen */ |
| 202 | PAGEFLAG(SavePinned, savepinned); /* Xen */ |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 203 | PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved) |
Rik van Riel | b2e1853 | 2008-10-18 20:26:30 -0700 | [diff] [blame] | 204 | PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked) |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 205 | |
Andy Whitcroft | 9023cb7 | 2008-07-23 21:27:19 -0700 | [diff] [blame] | 206 | __PAGEFLAG(SlobPage, slob_page) |
| 207 | __PAGEFLAG(SlobFree, slob_free) |
| 208 | |
Andy Whitcroft | 8a38082 | 2008-07-23 21:27:18 -0700 | [diff] [blame] | 209 | __PAGEFLAG(SlubFrozen, slub_frozen) |
| 210 | __PAGEFLAG(SlubDebug, slub_debug) |
| 211 | |
Christoph Lameter | f94a62e | 2008-04-28 02:12:49 -0700 | [diff] [blame] | 212 | /* |
David Howells | 266cf65 | 2009-04-03 16:42:36 +0100 | [diff] [blame] | 213 | * Private page markings that may be used by the filesystem that owns the page |
| 214 | * for its own purposes. |
| 215 | * - PG_private and PG_private_2 cause releasepage() and co to be invoked |
| 216 | */ |
| 217 | PAGEFLAG(Private, private) __SETPAGEFLAG(Private, private) |
| 218 | __CLEARPAGEFLAG(Private, private) |
| 219 | PAGEFLAG(Private2, private_2) TESTSCFLAG(Private2, private_2) |
| 220 | PAGEFLAG(OwnerPriv1, owner_priv_1) TESTCLEARFLAG(OwnerPriv1, owner_priv_1) |
| 221 | |
| 222 | /* |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 223 | * Only test-and-set exist for PG_writeback. The unconditional operators are |
| 224 | * risky: they bypass page accounting. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | */ |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 226 | TESTPAGEFLAG(Writeback, writeback) TESTSCFLAG(Writeback, writeback) |
| 227 | __PAGEFLAG(Buddy, buddy) |
| 228 | PAGEFLAG(MappedToDisk, mappedtodisk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 230 | /* PG_readahead is only used for file reads; PG_reclaim is only for writes */ |
| 231 | PAGEFLAG(Reclaim, reclaim) TESTCLEARFLAG(Reclaim, reclaim) |
Christoph Lameter | 0a128b2 | 2008-04-28 02:12:52 -0700 | [diff] [blame] | 232 | PAGEFLAG(Readahead, reclaim) /* Reminder to do async read-ahead */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 234 | #ifdef CONFIG_HIGHMEM |
| 235 | /* |
| 236 | * Must use a macro here due to header dependency issues. page_zone() is not |
| 237 | * available at this point. |
| 238 | */ |
Christoph Lameter | 0a128b2 | 2008-04-28 02:12:52 -0700 | [diff] [blame] | 239 | #define PageHighMem(__p) is_highmem(page_zone(__p)) |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 240 | #else |
Christoph Lameter | ec7cade | 2008-04-28 02:12:53 -0700 | [diff] [blame] | 241 | PAGEFLAG_FALSE(HighMem) |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 242 | #endif |
| 243 | |
| 244 | #ifdef CONFIG_SWAP |
| 245 | PAGEFLAG(SwapCache, swapcache) |
| 246 | #else |
Christoph Lameter | ec7cade | 2008-04-28 02:12:53 -0700 | [diff] [blame] | 247 | PAGEFLAG_FALSE(SwapCache) |
Hugh Dickins | 6d91add | 2009-01-06 14:39:24 -0800 | [diff] [blame] | 248 | SETPAGEFLAG_NOOP(SwapCache) CLEARPAGEFLAG_NOOP(SwapCache) |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 249 | #endif |
| 250 | |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 251 | #ifdef CONFIG_UNEVICTABLE_LRU |
| 252 | PAGEFLAG(Unevictable, unevictable) __CLEARPAGEFLAG(Unevictable, unevictable) |
| 253 | TESTCLEARFLAG(Unevictable, unevictable) |
| 254 | #else |
| 255 | PAGEFLAG_FALSE(Unevictable) TESTCLEARFLAG_FALSE(Unevictable) |
| 256 | SETPAGEFLAG_NOOP(Unevictable) CLEARPAGEFLAG_NOOP(Unevictable) |
| 257 | __CLEARPAGEFLAG_NOOP(Unevictable) |
| 258 | #endif |
| 259 | |
David Howells | 33925b2 | 2009-03-31 15:23:26 -0700 | [diff] [blame] | 260 | #ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT |
| 261 | #define MLOCK_PAGES 1 |
| 262 | PAGEFLAG(Mlocked, mlocked) __CLEARPAGEFLAG(Mlocked, mlocked) |
| 263 | TESTSCFLAG(Mlocked, mlocked) |
| 264 | #else |
| 265 | #define MLOCK_PAGES 0 |
| 266 | PAGEFLAG_FALSE(Mlocked) |
| 267 | SETPAGEFLAG_NOOP(Mlocked) TESTCLEARFLAG_FALSE(Mlocked) |
| 268 | #endif |
| 269 | |
Christoph Lameter | 602c4d1 | 2008-04-28 02:12:52 -0700 | [diff] [blame] | 270 | #ifdef CONFIG_IA64_UNCACHED_ALLOCATOR |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 271 | PAGEFLAG(Uncached, uncached) |
Christoph Lameter | 602c4d1 | 2008-04-28 02:12:52 -0700 | [diff] [blame] | 272 | #else |
Christoph Lameter | ec7cade | 2008-04-28 02:12:53 -0700 | [diff] [blame] | 273 | PAGEFLAG_FALSE(Uncached) |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 274 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | |
Nick Piggin | 0ed361d | 2008-02-04 22:29:34 -0800 | [diff] [blame] | 276 | static inline int PageUptodate(struct page *page) |
| 277 | { |
| 278 | int ret = test_bit(PG_uptodate, &(page)->flags); |
| 279 | |
| 280 | /* |
| 281 | * Must ensure that the data we read out of the page is loaded |
| 282 | * _after_ we've loaded page->flags to check for PageUptodate. |
| 283 | * We can skip the barrier if the page is not uptodate, because |
| 284 | * we wouldn't be reading anything from it. |
| 285 | * |
| 286 | * See SetPageUptodate() for the other side of the story. |
| 287 | */ |
| 288 | if (ret) |
| 289 | smp_rmb(); |
| 290 | |
| 291 | return ret; |
| 292 | } |
| 293 | |
| 294 | static inline void __SetPageUptodate(struct page *page) |
| 295 | { |
| 296 | smp_wmb(); |
| 297 | __set_bit(PG_uptodate, &(page)->flags); |
Nick Piggin | 0ed361d | 2008-02-04 22:29:34 -0800 | [diff] [blame] | 298 | } |
| 299 | |
Heiko Carstens | 2dcea57 | 2006-09-29 01:58:41 -0700 | [diff] [blame] | 300 | static inline void SetPageUptodate(struct page *page) |
| 301 | { |
Nick Piggin | 0ed361d | 2008-02-04 22:29:34 -0800 | [diff] [blame] | 302 | #ifdef CONFIG_S390 |
Heiko Carstens | 2dcea57 | 2006-09-29 01:58:41 -0700 | [diff] [blame] | 303 | if (!test_and_set_bit(PG_uptodate, &page->flags)) |
Martin Schwidefsky | 6c21048 | 2007-04-27 16:01:57 +0200 | [diff] [blame] | 304 | page_clear_dirty(page); |
Christoph Lameter | f6ac235 | 2006-06-30 01:55:32 -0700 | [diff] [blame] | 305 | #else |
Nick Piggin | 0ed361d | 2008-02-04 22:29:34 -0800 | [diff] [blame] | 306 | /* |
| 307 | * Memory barrier must be issued before setting the PG_uptodate bit, |
| 308 | * so that all previous stores issued in order to bring the page |
| 309 | * uptodate are actually visible before PageUptodate becomes true. |
| 310 | * |
| 311 | * s390 doesn't need an explicit smp_wmb here because the test and |
| 312 | * set bit already provides full barriers. |
| 313 | */ |
| 314 | smp_wmb(); |
| 315 | set_bit(PG_uptodate, &(page)->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | #endif |
Nick Piggin | 0ed361d | 2008-02-04 22:29:34 -0800 | [diff] [blame] | 317 | } |
| 318 | |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 319 | CLEARPAGEFLAG(Uptodate, uptodate) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | |
Linus Torvalds | fba2591 | 2006-12-20 13:46:42 -0800 | [diff] [blame] | 321 | extern void cancel_dirty_page(struct page *page, unsigned int account_size); |
| 322 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | int test_clear_page_writeback(struct page *page); |
| 324 | int test_set_page_writeback(struct page *page); |
| 325 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | static inline void set_page_writeback(struct page *page) |
| 327 | { |
| 328 | test_set_page_writeback(page); |
| 329 | } |
| 330 | |
Christoph Lameter | e20b8cc | 2008-04-28 02:12:55 -0700 | [diff] [blame] | 331 | #ifdef CONFIG_PAGEFLAGS_EXTENDED |
| 332 | /* |
| 333 | * System with lots of page flags available. This allows separate |
| 334 | * flags for PageHead() and PageTail() checks of compound pages so that bit |
| 335 | * tests can be used in performance sensitive paths. PageCompound is |
| 336 | * generally not used in hot code paths. |
| 337 | */ |
| 338 | __PAGEFLAG(Head, head) |
| 339 | __PAGEFLAG(Tail, tail) |
| 340 | |
| 341 | static inline int PageCompound(struct page *page) |
| 342 | { |
| 343 | return page->flags & ((1L << PG_head) | (1L << PG_tail)); |
| 344 | |
| 345 | } |
| 346 | #else |
| 347 | /* |
| 348 | * Reduce page flag use as much as possible by overlapping |
| 349 | * compound page flags with the flags used for page cache pages. Possible |
| 350 | * because PageCompound is always set for compound pages and not for |
| 351 | * pages on the LRU and/or pagecache. |
| 352 | */ |
Christoph Lameter | 6a1e7f7 | 2008-04-28 02:12:50 -0700 | [diff] [blame] | 353 | TESTPAGEFLAG(Compound, compound) |
| 354 | __PAGEFLAG(Head, compound) |
| 355 | |
| 356 | /* |
| 357 | * PG_reclaim is used in combination with PG_compound to mark the |
| 358 | * head and tail of a compound page. This saves one page flag |
| 359 | * but makes it impossible to use compound pages for the page cache. |
| 360 | * The PG_reclaim bit would have to be used for reclaim or readahead |
| 361 | * if compound pages enter the page cache. |
| 362 | * |
| 363 | * PG_compound & PG_reclaim => Tail page |
| 364 | * PG_compound & ~PG_reclaim => Head page |
| 365 | */ |
| 366 | #define PG_head_tail_mask ((1L << PG_compound) | (1L << PG_reclaim)) |
| 367 | |
| 368 | static inline int PageTail(struct page *page) |
| 369 | { |
| 370 | return ((page->flags & PG_head_tail_mask) == PG_head_tail_mask); |
| 371 | } |
| 372 | |
| 373 | static inline void __SetPageTail(struct page *page) |
| 374 | { |
| 375 | page->flags |= PG_head_tail_mask; |
| 376 | } |
| 377 | |
| 378 | static inline void __ClearPageTail(struct page *page) |
| 379 | { |
| 380 | page->flags &= ~PG_head_tail_mask; |
| 381 | } |
| 382 | |
Christoph Lameter | e20b8cc | 2008-04-28 02:12:55 -0700 | [diff] [blame] | 383 | #endif /* !PAGEFLAGS_EXTENDED */ |
Russ Anderson | dfa7e20 | 2008-06-09 11:18:45 -0500 | [diff] [blame] | 384 | |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 385 | #ifdef CONFIG_UNEVICTABLE_LRU |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 386 | #define __PG_UNEVICTABLE (1 << PG_unevictable) |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 387 | #else |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 388 | #define __PG_UNEVICTABLE 0 |
David Howells | 33925b2 | 2009-03-31 15:23:26 -0700 | [diff] [blame] | 389 | #endif |
| 390 | |
| 391 | #ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT |
| 392 | #define __PG_MLOCKED (1 << PG_mlocked) |
| 393 | #else |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 394 | #define __PG_MLOCKED 0 |
Lee Schermerhorn | 894bc31 | 2008-10-18 20:26:39 -0700 | [diff] [blame] | 395 | #endif |
| 396 | |
Russ Anderson | dfa7e20 | 2008-06-09 11:18:45 -0500 | [diff] [blame] | 397 | /* |
| 398 | * Flags checked when a page is freed. Pages being freed should not have |
| 399 | * these flags set. It they are, there is a problem. |
| 400 | */ |
Hugh Dickins | 79f4b7b | 2009-01-06 14:40:05 -0800 | [diff] [blame] | 401 | #define PAGE_FLAGS_CHECK_AT_FREE \ |
David Howells | 266cf65 | 2009-04-03 16:42:36 +0100 | [diff] [blame] | 402 | (1 << PG_lru | 1 << PG_locked | \ |
| 403 | 1 << PG_private | 1 << PG_private_2 | \ |
| 404 | 1 << PG_buddy | 1 << PG_writeback | 1 << PG_reserved | \ |
| 405 | 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \ |
Hugh Dickins | 79f4b7b | 2009-01-06 14:40:05 -0800 | [diff] [blame] | 406 | __PG_UNEVICTABLE | __PG_MLOCKED) |
Russ Anderson | dfa7e20 | 2008-06-09 11:18:45 -0500 | [diff] [blame] | 407 | |
| 408 | /* |
| 409 | * Flags checked when a page is prepped for return by the page allocator. |
Hugh Dickins | 79f4b7b | 2009-01-06 14:40:05 -0800 | [diff] [blame] | 410 | * Pages being prepped should not have any flags set. It they are set, |
| 411 | * there has been a kernel bug or struct page corruption. |
Russ Anderson | dfa7e20 | 2008-06-09 11:18:45 -0500 | [diff] [blame] | 412 | */ |
Hugh Dickins | 79f4b7b | 2009-01-06 14:40:05 -0800 | [diff] [blame] | 413 | #define PAGE_FLAGS_CHECK_AT_PREP ((1 << NR_PAGEFLAGS) - 1) |
Russ Anderson | dfa7e20 | 2008-06-09 11:18:45 -0500 | [diff] [blame] | 414 | |
Christoph Lameter | 9223b41 | 2008-04-28 02:12:48 -0700 | [diff] [blame] | 415 | #endif /* !__GENERATING_BOUNDS_H */ |
David Howells | 266cf65 | 2009-04-03 16:42:36 +0100 | [diff] [blame] | 416 | |
| 417 | /** |
| 418 | * page_has_private - Determine if page has private stuff |
| 419 | * @page: The page to be checked |
| 420 | * |
| 421 | * Determine if a page has private stuff, indicating that release routines |
| 422 | * should be invoked upon it. |
| 423 | */ |
| 424 | #define page_has_private(page) \ |
| 425 | ((page)->flags & ((1 << PG_private) | \ |
| 426 | (1 << PG_private_2))) |
| 427 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | #endif /* PAGE_FLAGS_H */ |