* FLAGS_RESERVED which defines the width of the fields section
* (see linux/mmzone.h). New flags must _not_ overlap with this area.
*/
-#define PG_locked 0 /* Page is locked. Don't touch. */
-#define PG_error 1
-#define PG_referenced 2
-#define PG_uptodate 3
-
-#define PG_dirty 4
-#define PG_lru 5
-#define PG_active 6
-#define PG_slab 7 /* slab debug (Suparna wants this) */
-
-#define PG_owner_priv_1 8 /* Owner use. If pagecache, fs may use*/
-#define PG_arch_1 9
-#define PG_reserved 10
-#define PG_private 11 /* If pagecache, has fs-private data */
-
-#define PG_writeback 12 /* Page is under writeback */
-#define PG_compound 14 /* Part of a compound page */
-#define PG_swapcache 15 /* Swap page: swp_entry_t in private */
-
-#define PG_mappedtodisk 16 /* Has blocks allocated on-disk */
-#define PG_reclaim 17 /* To be reclaimed asap */
-#define PG_buddy 19 /* Page is free, on buddy lists */
-
-/* PG_owner_priv_1 users should have descriptive aliases */
-#define PG_checked PG_owner_priv_1 /* Used by some filesystems */
-#define PG_pinned PG_owner_priv_1 /* Xen pinned pagetable */
+enum pageflags {
+ PG_locked, /* Page is locked. Don't touch. */
+ PG_error,
+ PG_referenced,
+ PG_uptodate,
+ PG_dirty,
+ PG_lru,
+ PG_active,
+ PG_slab,
+ PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/
+ PG_checked = PG_owner_priv_1, /* Used by some filesystems */
+ PG_pinned = PG_owner_priv_1, /* Xen pinned pagetable */
+ PG_arch_1,
+ PG_reserved,
+ PG_private, /* If pagecache, has fs-private data */
+ PG_writeback, /* Page is under writeback */
+ PG_compound, /* A compound page */
+ PG_swapcache, /* Swap page: swp_entry_t in private */
+ PG_mappedtodisk, /* Has blocks allocated on-disk */
+ PG_reclaim, /* To be reclaimed asap */
+ /* PG_readahead is only used for file reads; PG_reclaim is only for writes */
+ PG_readahead = PG_reclaim, /* Reminder to do async read-ahead */
+ PG_buddy, /* Page is free, on buddy lists */
#if (BITS_PER_LONG > 32)
/*
* 64 bit | FIELDS | ?????? FLAGS |
* 63 32 0
*/
-#define PG_uncached 31 /* Page has been mapped as uncached */
+ PG_uncached = 31, /* Page has been mapped as uncached */
#endif
+ NR_PAGEFLAGS
+};
/*
* Manipulation of page state flags
#define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags)
#define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags)
-#define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags)
+static inline int PageUptodate(struct page *page)
+{
+ int ret = test_bit(PG_uptodate, &(page)->flags);
+
+ /*
+ * Must ensure that the data we read out of the page is loaded
+ * _after_ we've loaded page->flags to check for PageUptodate.
+ * We can skip the barrier if the page is not uptodate, because
+ * we wouldn't be reading anything from it.
+ *
+ * See SetPageUptodate() for the other side of the story.
+ */
+ if (ret)
+ smp_rmb();
+
+ return ret;
+}
+
+static inline void __SetPageUptodate(struct page *page)
+{
+ smp_wmb();
+ __set_bit(PG_uptodate, &(page)->flags);
#ifdef CONFIG_S390
+ page_clear_dirty(page);
+#endif
+}
+
static inline void SetPageUptodate(struct page *page)
{
+#ifdef CONFIG_S390
if (!test_and_set_bit(PG_uptodate, &page->flags))
page_clear_dirty(page);
-}
#else
-#define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags)
+ /*
+ * Memory barrier must be issued before setting the PG_uptodate bit,
+ * so that all previous stores issued in order to bring the page
+ * uptodate are actually visible before PageUptodate becomes true.
+ *
+ * s390 doesn't need an explicit smp_wmb here because the test and
+ * set bit already provides full barriers.
+ */
+ smp_wmb();
+ set_bit(PG_uptodate, &(page)->flags);
#endif
+}
+
#define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags)
#define PageDirty(page) test_bit(PG_dirty, &(page)->flags)
#define __SetPagePrivate(page) __set_bit(PG_private, &(page)->flags)
#define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags)
+/*
+ * Only test-and-set exist for PG_writeback. The unconditional operators are
+ * risky: they bypass page accounting.
+ */
#define PageWriteback(page) test_bit(PG_writeback, &(page)->flags)
-#define SetPageWriteback(page) \
- do { \
- if (!test_and_set_bit(PG_writeback, \
- &(page)->flags)) \
- inc_zone_page_state(page, NR_WRITEBACK); \
- } while (0)
-#define TestSetPageWriteback(page) \
- ({ \
- int ret; \
- ret = test_and_set_bit(PG_writeback, \
- &(page)->flags); \
- if (!ret) \
- inc_zone_page_state(page, NR_WRITEBACK); \
- ret; \
- })
-#define ClearPageWriteback(page) \
- do { \
- if (test_and_clear_bit(PG_writeback, \
- &(page)->flags)) \
- dec_zone_page_state(page, NR_WRITEBACK); \
- } while (0)
-#define TestClearPageWriteback(page) \
- ({ \
- int ret; \
- ret = test_and_clear_bit(PG_writeback, \
- &(page)->flags); \
- if (ret) \
- dec_zone_page_state(page, NR_WRITEBACK); \
- ret; \
- })
+#define TestSetPageWriteback(page) test_and_set_bit(PG_writeback, \
+ &(page)->flags)
+#define TestClearPageWriteback(page) test_and_clear_bit(PG_writeback, \
+ &(page)->flags)
#define PageBuddy(page) test_bit(PG_buddy, &(page)->flags)
#define __SetPageBuddy(page) __set_bit(PG_buddy, &(page)->flags)
#define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags)
#define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags)
+#define PageReadahead(page) test_bit(PG_readahead, &(page)->flags)
+#define SetPageReadahead(page) set_bit(PG_readahead, &(page)->flags)
+#define ClearPageReadahead(page) clear_bit(PG_readahead, &(page)->flags)
+
#define PageReclaim(page) test_bit(PG_reclaim, &(page)->flags)
#define SetPageReclaim(page) set_bit(PG_reclaim, &(page)->flags)
#define ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags)
#define PG_head_tail_mask ((1L << PG_compound) | (1L << PG_reclaim))
-#define PageTail(page) ((page->flags & PG_head_tail_mask) \
+#define PageTail(page) (((page)->flags & PG_head_tail_mask) \
== PG_head_tail_mask)
static inline void __SetPageTail(struct page *page)
page->flags &= ~PG_head_tail_mask;
}
-#define PageHead(page) ((page->flags & PG_head_tail_mask) \
+#define PageHead(page) (((page)->flags & PG_head_tail_mask) \
== (1L << PG_compound))
#define __SetPageHead(page) __SetPageCompound(page)
#define __ClearPageHead(page) __ClearPageCompound(page)
projects / linux-2.6-omap-h63xx.git / blobdiff