[linux-2.6-block.git] / include / linux / page-flags.h

/*
 * Macros for manipulating and testing page->flags
 */

#ifndef PAGE_FLAGS_H
#define PAGE_FLAGS_H

#include <linux/types.h>
#ifndef __GENERATING_BOUNDS_H
#include <linux/mm_types.h>
#include <generated/bounds.h>
#endif /* !__GENERATING_BOUNDS_H */

/*
 * Various page->flags bits:
 *
 * PG_reserved is set for special pages, which can never be swapped out. Some
 * of them might not even exist (eg empty_bad_page)...
 *
 * The PG_private bitflag is set on pagecache pages if they contain filesystem
 * specific data (which is normally at page->private). It can be used by
 * private allocations for its own usage.
 *
 * During initiation of disk I/O, PG_locked is set. This bit is set before I/O
 * and cleared when writeback _starts_ or when read _completes_. PG_writeback
 * is set before writeback starts and cleared when it finishes.
 *
 * PG_locked also pins a page in pagecache, and blocks truncation of the file
 * while it is held.
 *
 * page_waitqueue(page) is a wait queue of all tasks waiting for the page
 * to become unlocked.
 *
 * PG_uptodate tells whether the page's contents is valid.  When a read
 * completes, the page becomes uptodate, unless a disk I/O error happened.
 *
 * PG_referenced, PG_reclaim are used for page reclaim for anonymous and
 * file-backed pagecache (see mm/vmscan.c).
 *
 * PG_error is set to indicate that an I/O error occurred on this page.
 *
 * PG_arch_1 is an architecture specific page state bit.  The generic code
 * guarantees that this bit is cleared for a page when it first is entered into
 * the page cache.
 *
 * PG_highmem pages are not permanently mapped into the kernel virtual address
 * space, they need to be kmapped separately for doing IO on the pages.  The
 * struct page (these bits with information) are always mapped into kernel
 * address space...
 *
 * PG_buddy is set to indicate that the page is free and in the buddy system
 * (see mm/page_alloc.c).
 *
 * PG_hwpoison indicates that a page got corrupted in hardware and contains
 * data with incorrect ECC bits that triggered a machine check. Accessing is
 * not safe since it may cause another machine check. Don't touch!
 */

/*
 * Don't use the *_dontuse flags.  Use the macros.  Otherwise you'll break
 * locked- and dirty-page accounting.
 *
 * The page flags field is split into two parts, the main flags area
 * which extends from the low bits upwards, and the fields area which
 * extends from the high bits downwards.
 *
 *  | FIELD | ... | FLAGS |
 *  N-1           ^       0
 *               (NR_PAGEFLAGS)
 *
 * The fields area is reserved for fields mapping zone, node (for NUMA) and
 * SPARSEMEM section (for variants of SPARSEMEM that require section ids like
 * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP).
 */
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_arch_1,
	PG_reserved,
	PG_private,		/* If pagecache, has fs-private data */
	PG_private_2,		/* If pagecache, has fs aux data */
	PG_writeback,		/* Page is under writeback */
#ifdef CONFIG_PAGEFLAGS_EXTENDED
	PG_head,		/* A head page */
	PG_tail,		/* A tail page */
#else
	PG_compound,		/* A compound page */
#endif
	PG_swapcache,		/* Swap page: swp_entry_t in private */
	PG_mappedtodisk,	/* Has blocks allocated on-disk */
	PG_reclaim,		/* To be reclaimed asap */
	PG_buddy,		/* Page is free, on buddy lists */
	PG_swapbacked,		/* Page is backed by RAM/swap */
	PG_unevictable,		/* Page is "unevictable"  */
#ifdef CONFIG_MMU
	PG_mlocked,		/* Page is vma mlocked */
#endif
#ifdef CONFIG_ARCH_USES_PG_UNCACHED
	PG_uncached,		/* Page has been mapped as uncached */
#endif
#ifdef CONFIG_MEMORY_FAILURE
	PG_hwpoison,		/* hardware poisoned page. Don't touch */
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
	PG_compound_lock,
#endif
	__NR_PAGEFLAGS,

	/* Filesystems */
	PG_checked = PG_owner_priv_1,

	/* Two page bits are conscripted by FS-Cache to maintain local caching
	 * state.  These bits are set on pages belonging to the netfs's inodes
	 * when those inodes are being locally cached.
	 */
	PG_fscache = PG_private_2,	/* page backed by cache */

	/* XEN */
	PG_pinned = PG_owner_priv_1,
	PG_savepinned = PG_dirty,

	/* SLOB */
	PG_slob_free = PG_private,

	/* SLUB */
	PG_slub_frozen = PG_active,
};

#ifndef __GENERATING_BOUNDS_H

/*
 * Macros to create function definitions for page flags
 */
#define TESTPAGEFLAG(uname, lname)					\
static inline int Page##uname(struct page *page) 			\
			{ return test_bit(PG_##lname, &page->flags); }

#define SETPAGEFLAG(uname, lname)					\
static inline void SetPage##uname(struct page *page)			\
			{ set_bit(PG_##lname, &page->flags); }

#define CLEARPAGEFLAG(uname, lname)					\
static inline void ClearPage##uname(struct page *page)			\
			{ clear_bit(PG_##lname, &page->flags); }

#define __SETPAGEFLAG(uname, lname)					\
static inline void __SetPage##uname(struct page *page)			\
			{ __set_bit(PG_##lname, &page->flags); }

#define __CLEARPAGEFLAG(uname, lname)					\
static inline void __ClearPage##uname(struct page *page)		\
			{ __clear_bit(PG_##lname, &page->flags); }

#define TESTSETFLAG(uname, lname)					\
static inline int TestSetPage##uname(struct page *page)			\
		{ return test_and_set_bit(PG_##lname, &page->flags); }

#define TESTCLEARFLAG(uname, lname)					\
static inline int TestClearPage##uname(struct page *page)		\
		{ return test_and_clear_bit(PG_##lname, &page->flags); }

#define __TESTCLEARFLAG(uname, lname)					\
static inline int __TestClearPage##uname(struct page *page)		\
		{ return __test_and_clear_bit(PG_##lname, &page->flags); }

#define PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname)		\
	SETPAGEFLAG(uname, lname) CLEARPAGEFLAG(uname, lname)

#define __PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname)		\
	__SETPAGEFLAG(uname, lname)  __CLEARPAGEFLAG(uname, lname)

#define PAGEFLAG_FALSE(uname) 						\
static inline int Page##uname(struct page *page) 			\
			{ return 0; }

#define TESTSCFLAG(uname, lname)					\
	TESTSETFLAG(uname, lname) TESTCLEARFLAG(uname, lname)

#define SETPAGEFLAG_NOOP(uname)						\
static inline void SetPage##uname(struct page *page) {  }

#define CLEARPAGEFLAG_NOOP(uname)					\
static inline void ClearPage##uname(struct page *page) {  }

#define __CLEARPAGEFLAG_NOOP(uname)					\
static inline void __ClearPage##uname(struct page *page) {  }

#define TESTCLEARFLAG_FALSE(uname)					\
static inline int TestClearPage##uname(struct page *page) { return 0; }

#define __TESTCLEARFLAG_FALSE(uname)					\
static inline int __TestClearPage##uname(struct page *page) { return 0; }

struct page;	/* forward declaration */

TESTPAGEFLAG(Locked, locked) TESTSETFLAG(Locked, locked)
PAGEFLAG(Error, error) TESTCLEARFLAG(Error, error)
PAGEFLAG(Referenced, referenced) TESTCLEARFLAG(Referenced, referenced)
PAGEFLAG(Dirty, dirty) TESTSCFLAG(Dirty, dirty) __CLEARPAGEFLAG(Dirty, dirty)
PAGEFLAG(LRU, lru) __CLEARPAGEFLAG(LRU, lru)
PAGEFLAG(Active, active) __CLEARPAGEFLAG(Active, active)
	TESTCLEARFLAG(Active, active)
__PAGEFLAG(Slab, slab)
PAGEFLAG(Checked, checked)		/* Used by some filesystems */
PAGEFLAG(Pinned, pinned) TESTSCFLAG(Pinned, pinned)	/* Xen */
PAGEFLAG(SavePinned, savepinned);			/* Xen */
PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved)
PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked)

__PAGEFLAG(SlobFree, slob_free)

__PAGEFLAG(SlubFrozen, slub_frozen)

/*
 * Private page markings that may be used by the filesystem that owns the page
 * for its own purposes.
 * - PG_private and PG_private_2 cause releasepage() and co to be invoked
 */
PAGEFLAG(Private, private) __SETPAGEFLAG(Private, private)
	__CLEARPAGEFLAG(Private, private)
PAGEFLAG(Private2, private_2) TESTSCFLAG(Private2, private_2)
PAGEFLAG(OwnerPriv1, owner_priv_1) TESTCLEARFLAG(OwnerPriv1, owner_priv_1)

/*
 * Only test-and-set exist for PG_writeback.  The unconditional operators are
 * risky: they bypass page accounting.
 */
TESTPAGEFLAG(Writeback, writeback) TESTSCFLAG(Writeback, writeback)
__PAGEFLAG(Buddy, buddy)
PAGEFLAG(MappedToDisk, mappedtodisk)

/* PG_readahead is only used for file reads; PG_reclaim is only for writes */
PAGEFLAG(Reclaim, reclaim) TESTCLEARFLAG(Reclaim, reclaim)
PAGEFLAG(Readahead, reclaim)		/* Reminder to do async read-ahead */

#ifdef CONFIG_HIGHMEM
/*
 * Must use a macro here due to header dependency issues. page_zone() is not
 * available at this point.
 */
#define PageHighMem(__p) is_highmem(page_zone(__p))
#else
PAGEFLAG_FALSE(HighMem)
#endif

#ifdef CONFIG_SWAP
PAGEFLAG(SwapCache, swapcache)
#else
PAGEFLAG_FALSE(SwapCache)
	SETPAGEFLAG_NOOP(SwapCache) CLEARPAGEFLAG_NOOP(SwapCache)
#endif

PAGEFLAG(Unevictable, unevictable) __CLEARPAGEFLAG(Unevictable, unevictable)
	TESTCLEARFLAG(Unevictable, unevictable)

#ifdef CONFIG_MMU
PAGEFLAG(Mlocked, mlocked) __CLEARPAGEFLAG(Mlocked, mlocked)
	TESTSCFLAG(Mlocked, mlocked) __TESTCLEARFLAG(Mlocked, mlocked)
#else
PAGEFLAG_FALSE(Mlocked) SETPAGEFLAG_NOOP(Mlocked)
	TESTCLEARFLAG_FALSE(Mlocked) __TESTCLEARFLAG_FALSE(Mlocked)
#endif

#ifdef CONFIG_ARCH_USES_PG_UNCACHED
PAGEFLAG(Uncached, uncached)
#else
PAGEFLAG_FALSE(Uncached)
#endif

#ifdef CONFIG_MEMORY_FAILURE
PAGEFLAG(HWPoison, hwpoison)
TESTSCFLAG(HWPoison, hwpoison)
#define __PG_HWPOISON (1UL << PG_hwpoison)
#else
PAGEFLAG_FALSE(HWPoison)
#define __PG_HWPOISON 0
#endif

u64 stable_page_flags(struct page *page);

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);
}

static inline void SetPageUptodate(struct page *page)
{
#ifdef CONFIG_S390
	if (!test_and_set_bit(PG_uptodate, &page->flags))
		page_clear_dirty(page, 0);
#else
	/*
	 * 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
}

CLEARPAGEFLAG(Uptodate, uptodate)

extern void cancel_dirty_page(struct page *page, unsigned int account_size);

int test_clear_page_writeback(struct page *page);
int test_set_page_writeback(struct page *page);

static inline void set_page_writeback(struct page *page)
{
	test_set_page_writeback(page);
}

#ifdef CONFIG_PAGEFLAGS_EXTENDED
/*
 * System with lots of page flags available. This allows separate
 * flags for PageHead() and PageTail() checks of compound pages so that bit
 * tests can be used in performance sensitive paths. PageCompound is
 * generally not used in hot code paths.
 */
__PAGEFLAG(Head, head) CLEARPAGEFLAG(Head, head)
__PAGEFLAG(Tail, tail)

static inline int PageCompound(struct page *page)
{
	return page->flags & ((1L << PG_head) | (1L << PG_tail));

}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline void ClearPageCompound(struct page *page)
{
	BUG_ON(!PageHead(page));
	ClearPageHead(page);
}
#endif
#else
/*
 * Reduce page flag use as much as possible by overlapping
 * compound page flags with the flags used for page cache pages. Possible
 * because PageCompound is always set for compound pages and not for
 * pages on the LRU and/or pagecache.
 */
TESTPAGEFLAG(Compound, compound)
__PAGEFLAG(Head, compound)

/*
 * PG_reclaim is used in combination with PG_compound to mark the
 * head and tail of a compound page. This saves one page flag
 * but makes it impossible to use compound pages for the page cache.
 * The PG_reclaim bit would have to be used for reclaim or readahead
 * if compound pages enter the page cache.
 *
 * PG_compound & PG_reclaim	=> Tail page
 * PG_compound & ~PG_reclaim	=> Head page
 */
#define PG_head_tail_mask ((1L << PG_compound) | (1L << PG_reclaim))

static inline int PageTail(struct page *page)
{
	return ((page->flags & PG_head_tail_mask) == PG_head_tail_mask);
}

static inline void __SetPageTail(struct page *page)
{
	page->flags |= PG_head_tail_mask;
}

static inline void __ClearPageTail(struct page *page)
{
	page->flags &= ~PG_head_tail_mask;
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline void ClearPageCompound(struct page *page)
{
	BUG_ON((page->flags & PG_head_tail_mask) != (1 << PG_compound));
	clear_bit(PG_compound, &page->flags);
}
#endif

#endif /* !PAGEFLAGS_EXTENDED */

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/*
 * PageHuge() only returns true for hugetlbfs pages, but not for
 * normal or transparent huge pages.
 *
 * PageTransHuge() returns true for both transparent huge and
 * hugetlbfs pages, but not normal pages. PageTransHuge() can only be
 * called only in the core VM paths where hugetlbfs pages can't exist.
 */
static inline int PageTransHuge(struct page *page)
{
	VM_BUG_ON(PageTail(page));
	return PageHead(page);
}

static inline int PageTransCompound(struct page *page)
{
	return PageCompound(page);
}

#else

static inline int PageTransHuge(struct page *page)
{
	return 0;
}

static inline int PageTransCompound(struct page *page)
{
	return 0;
}
#endif

#ifdef CONFIG_MMU
#define __PG_MLOCKED		(1 << PG_mlocked)
#else
#define __PG_MLOCKED		0
#endif

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define __PG_COMPOUND_LOCK		(1 << PG_compound_lock)
#else
#define __PG_COMPOUND_LOCK		0
#endif

/*
 * Flags checked when a page is freed.  Pages being freed should not have
 * these flags set.  It they are, there is a problem.
 */
#define PAGE_FLAGS_CHECK_AT_FREE \
	(1 << PG_lru	 | 1 << PG_locked    | \
	 1 << PG_private | 1 << PG_private_2 | \
	 1 << PG_buddy	 | 1 << PG_writeback | 1 << PG_reserved | \
	 1 << PG_slab	 | 1 << PG_swapcache | 1 << PG_active | \
	 1 << PG_unevictable | __PG_MLOCKED | __PG_HWPOISON | \
	 __PG_COMPOUND_LOCK)

/*
 * Flags checked when a page is prepped for return by the page allocator.
 * Pages being prepped should not have any flags set.  It they are set,
 * there has been a kernel bug or struct page corruption.
 */
#define PAGE_FLAGS_CHECK_AT_PREP	((1 << NR_PAGEFLAGS) - 1)

#define PAGE_FLAGS_PRIVATE				\
	(1 << PG_private | 1 << PG_private_2)
/**
 * page_has_private - Determine if page has private stuff
 * @page: The page to be checked
 *
 * Determine if a page has private stuff, indicating that release routines
 * should be invoked upon it.
 */
static inline int page_has_private(struct page *page)
{
	return !!(page->flags & PAGE_FLAGS_PRIVATE);
}

#endif /* !__GENERATING_BOUNDS_H */

#endif	/* PAGE_FLAGS_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Macros for manipulating and testing page->flags
	3	*/
	4
	5	#ifndef PAGE_FLAGS_H
	6	#define PAGE_FLAGS_H
	7
f886ed44	8	#include <linux/types.h>
9223b419	9	#ifndef __GENERATING_BOUNDS_H
6d777953	10	#include <linux/mm_types.h>
01fc0ac1	11	#include <generated/bounds.h>
9223b419	12	#endif /* !__GENERATING_BOUNDS_H */
f886ed44	13
1da177e4 LT	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	*
da6052f7 NP	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.
1da177e4	23	*
da6052f7 NP	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.
1da177e4 LT	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	*
da6052f7 NP	37	* PG_referenced, PG_reclaim are used for page reclaim for anonymous and
da6052f7 NP	38	* file-backed pagecache (see mm/vmscan.c).
1da177e4 LT	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...
da6052f7 NP	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	*
d466f2fc AK	54	* PG_hwpoison indicates that a page got corrupted in hardware and contains
	55	* data with incorrect ECC bits that triggered a machine check. Accessing is
	56	* not safe since it may cause another machine check. Don't touch!
1da177e4 LT	57	*/
	58
	59	/*
	60	* Don't use the *_dontuse flags. Use the macros. Otherwise you'll break
91fc8ab3 AW	61	* locked- and dirty-page accounting.
	62	*
	63	* The page flags field is split into two parts, the main flags area
	64	* which extends from the low bits upwards, and the fields area which
	65	* extends from the high bits downwards.
	66	*
	67	* \| FIELD \| ... \| FLAGS \|
9223b419 CL	68	* N-1 ^ 0
9223b419 CL	69	* (NR_PAGEFLAGS)
91fc8ab3	70	*
9223b419 CL	71	* The fields area is reserved for fields mapping zone, node (for NUMA) and
	72	* SPARSEMEM section (for variants of SPARSEMEM that require section ids like
	73	* SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP).
1da177e4	74	*/
e2683181 CL	75	enum pageflags {
	76	PG_locked, /* Page is locked. Don't touch. */
	77	PG_error,
	78	PG_referenced,
	79	PG_uptodate,
	80	PG_dirty,
	81	PG_lru,
	82	PG_active,
	83	PG_slab,
	84	PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/
e2683181 CL	85	PG_arch_1,
	86	PG_reserved,
	87	PG_private, /* If pagecache, has fs-private data */
266cf658	88	PG_private_2, /* If pagecache, has fs aux data */
e2683181	89	PG_writeback, /* Page is under writeback */
e20b8cca CL	90	#ifdef CONFIG_PAGEFLAGS_EXTENDED
	91	PG_head, /* A head page */
	92	PG_tail, /* A tail page */
	93	#else
e2683181	94	PG_compound, /* A compound page */
e20b8cca	95	#endif
e2683181 CL	96	PG_swapcache, /* Swap page: swp_entry_t in private */
	97	PG_mappedtodisk, /* Has blocks allocated on-disk */
	98	PG_reclaim, /* To be reclaimed asap */
e2683181	99	PG_buddy, /* Page is free, on buddy lists */
b2e18538	100	PG_swapbacked, /* Page is backed by RAM/swap */
894bc310	101	PG_unevictable, /* Page is "unevictable" */
af8e3354	102	#ifdef CONFIG_MMU
b291f000	103	PG_mlocked, /* Page is vma mlocked */
894bc310	104	#endif
46cf98cd	105	#ifdef CONFIG_ARCH_USES_PG_UNCACHED
602c4d11	106	PG_uncached, /* Page has been mapped as uncached */
d466f2fc AK	107	#endif
	108	#ifdef CONFIG_MEMORY_FAILURE
	109	PG_hwpoison, /* hardware poisoned page. Don't touch */
e9da73d6 AA	110	#endif
	111	#ifdef CONFIG_TRANSPARENT_HUGEPAGE
	112	PG_compound_lock,
f886ed44	113	#endif
0cad47cf AW	114	__NR_PAGEFLAGS,
	115
	116	/* Filesystems */
	117	PG_checked = PG_owner_priv_1,
	118
266cf658 DH	119	/* Two page bits are conscripted by FS-Cache to maintain local caching
	120	* state. These bits are set on pages belonging to the netfs's inodes
	121	* when those inodes are being locally cached.
	122	*/
	123	PG_fscache = PG_private_2, /* page backed by cache */
	124
0cad47cf AW	125	/* XEN */
	126	PG_pinned = PG_owner_priv_1,
	127	PG_savepinned = PG_dirty,
8a38082d	128
9023cb7e	129	/* SLOB */
9023cb7e AW	130	PG_slob_free = PG_private,
9023cb7e AW	131
8a38082d AW	132	/* SLUB */
8a38082d AW	133	PG_slub_frozen = PG_active,
e2683181	134	};
1da177e4	135
9223b419 CL	136	#ifndef __GENERATING_BOUNDS_H
9223b419 CL	137
f94a62e9 CL	138	/*
	139	* Macros to create function definitions for page flags
	140	*/
	141	#define TESTPAGEFLAG(uname, lname) \
	142	static inline int Page##uname(struct page *page) \
	143	{ return test_bit(PG_##lname, &page->flags); }
	144
	145	#define SETPAGEFLAG(uname, lname) \
	146	static inline void SetPage##uname(struct page *page) \
	147	{ set_bit(PG_##lname, &page->flags); }
	148
	149	#define CLEARPAGEFLAG(uname, lname) \
	150	static inline void ClearPage##uname(struct page *page) \
	151	{ clear_bit(PG_##lname, &page->flags); }
	152
	153	#define __SETPAGEFLAG(uname, lname) \
	154	static inline void __SetPage##uname(struct page *page) \
	155	{ __set_bit(PG_##lname, &page->flags); }
	156
	157	#define __CLEARPAGEFLAG(uname, lname) \
	158	static inline void __ClearPage##uname(struct page *page) \
	159	{ __clear_bit(PG_##lname, &page->flags); }
	160
	161	#define TESTSETFLAG(uname, lname) \
	162	static inline int TestSetPage##uname(struct page *page) \
	163	{ return test_and_set_bit(PG_##lname, &page->flags); }
	164
	165	#define TESTCLEARFLAG(uname, lname) \
	166	static inline int TestClearPage##uname(struct page *page) \
	167	{ return test_and_clear_bit(PG_##lname, &page->flags); }
	168
451ea25d JW	169	#define __TESTCLEARFLAG(uname, lname) \
	170	static inline int __TestClearPage##uname(struct page *page) \
	171	{ return __test_and_clear_bit(PG_##lname, &page->flags); }
f94a62e9 CL	172
	173	#define PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \
	174	SETPAGEFLAG(uname, lname) CLEARPAGEFLAG(uname, lname)
	175
	176	#define __PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \
	177	__SETPAGEFLAG(uname, lname) __CLEARPAGEFLAG(uname, lname)
	178
ec7cade8 CL	179	#define PAGEFLAG_FALSE(uname) \
	180	static inline int Page##uname(struct page *page) \
	181	{ return 0; }
	182
f94a62e9 CL	183	#define TESTSCFLAG(uname, lname) \
	184	TESTSETFLAG(uname, lname) TESTCLEARFLAG(uname, lname)
	185
8a7a8544 LS	186	#define SETPAGEFLAG_NOOP(uname) \
	187	static inline void SetPage##uname(struct page *page) { }
	188
	189	#define CLEARPAGEFLAG_NOOP(uname) \
	190	static inline void ClearPage##uname(struct page *page) { }
	191
	192	#define __CLEARPAGEFLAG_NOOP(uname) \
	193	static inline void __ClearPage##uname(struct page *page) { }
	194
	195	#define TESTCLEARFLAG_FALSE(uname) \
	196	static inline int TestClearPage##uname(struct page *page) { return 0; }
	197
451ea25d JW	198	#define __TESTCLEARFLAG_FALSE(uname) \
	199	static inline int __TestClearPage##uname(struct page *page) { return 0; }
	200
6a1e7f77 CL	201	struct page; /* forward declaration */
6a1e7f77 CL	202
03fb3d2a	203	TESTPAGEFLAG(Locked, locked) TESTSETFLAG(Locked, locked)
212260aa	204	PAGEFLAG(Error, error) TESTCLEARFLAG(Error, error)
6a1e7f77 CL	205	PAGEFLAG(Referenced, referenced) TESTCLEARFLAG(Referenced, referenced)
	206	PAGEFLAG(Dirty, dirty) TESTSCFLAG(Dirty, dirty) __CLEARPAGEFLAG(Dirty, dirty)
	207	PAGEFLAG(LRU, lru) __CLEARPAGEFLAG(LRU, lru)
	208	PAGEFLAG(Active, active) __CLEARPAGEFLAG(Active, active)
894bc310	209	TESTCLEARFLAG(Active, active)
6a1e7f77	210	__PAGEFLAG(Slab, slab)
0cad47cf AW	211	PAGEFLAG(Checked, checked) /* Used by some filesystems */
	212	PAGEFLAG(Pinned, pinned) TESTSCFLAG(Pinned, pinned) /* Xen */
	213	PAGEFLAG(SavePinned, savepinned); /* Xen */
6a1e7f77	214	PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved)
b2e18538	215	PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked)
6a1e7f77	216
9023cb7e AW	217	__PAGEFLAG(SlobFree, slob_free)
9023cb7e AW	218
8a38082d	219	__PAGEFLAG(SlubFrozen, slub_frozen)
8a38082d	220
266cf658 DH	221	/*
	222	* Private page markings that may be used by the filesystem that owns the page
	223	* for its own purposes.
	224	* - PG_private and PG_private_2 cause releasepage() and co to be invoked
	225	*/
	226	PAGEFLAG(Private, private) __SETPAGEFLAG(Private, private)
	227	__CLEARPAGEFLAG(Private, private)
	228	PAGEFLAG(Private2, private_2) TESTSCFLAG(Private2, private_2)
	229	PAGEFLAG(OwnerPriv1, owner_priv_1) TESTCLEARFLAG(OwnerPriv1, owner_priv_1)
	230
6a1e7f77 CL	231	/*
	232	* Only test-and-set exist for PG_writeback. The unconditional operators are
	233	* risky: they bypass page accounting.
	234	*/
	235	TESTPAGEFLAG(Writeback, writeback) TESTSCFLAG(Writeback, writeback)
	236	__PAGEFLAG(Buddy, buddy)
	237	PAGEFLAG(MappedToDisk, mappedtodisk)
	238
	239	/* PG_readahead is only used for file reads; PG_reclaim is only for writes */
	240	PAGEFLAG(Reclaim, reclaim) TESTCLEARFLAG(Reclaim, reclaim)
0a128b2b	241	PAGEFLAG(Readahead, reclaim) /* Reminder to do async read-ahead */
6a1e7f77 CL	242
6a1e7f77 CL	243	#ifdef CONFIG_HIGHMEM
1da177e4	244	/*
6a1e7f77 CL	245	* Must use a macro here due to header dependency issues. page_zone() is not
6a1e7f77 CL	246	* available at this point.
1da177e4	247	*/
0a128b2b	248	#define PageHighMem(__p) is_highmem(page_zone(__p))
6a1e7f77	249	#else
ec7cade8	250	PAGEFLAG_FALSE(HighMem)
6a1e7f77 CL	251	#endif
	252
	253	#ifdef CONFIG_SWAP
	254	PAGEFLAG(SwapCache, swapcache)
	255	#else
ec7cade8	256	PAGEFLAG_FALSE(SwapCache)
6d91add0	257	SETPAGEFLAG_NOOP(SwapCache) CLEARPAGEFLAG_NOOP(SwapCache)
6a1e7f77 CL	258	#endif
6a1e7f77 CL	259
894bc310 LS	260	PAGEFLAG(Unevictable, unevictable) __CLEARPAGEFLAG(Unevictable, unevictable)
894bc310 LS	261	TESTCLEARFLAG(Unevictable, unevictable)
b291f000	262
af8e3354	263	#ifdef CONFIG_MMU
b291f000	264	PAGEFLAG(Mlocked, mlocked) __CLEARPAGEFLAG(Mlocked, mlocked)
451ea25d	265	TESTSCFLAG(Mlocked, mlocked) __TESTCLEARFLAG(Mlocked, mlocked)
894bc310	266	#else
451ea25d JW	267	PAGEFLAG_FALSE(Mlocked) SETPAGEFLAG_NOOP(Mlocked)
451ea25d JW	268	TESTCLEARFLAG_FALSE(Mlocked) __TESTCLEARFLAG_FALSE(Mlocked)
894bc310 LS	269	#endif
894bc310 LS	270
46cf98cd	271	#ifdef CONFIG_ARCH_USES_PG_UNCACHED
6a1e7f77	272	PAGEFLAG(Uncached, uncached)
602c4d11	273	#else
ec7cade8	274	PAGEFLAG_FALSE(Uncached)
6a1e7f77	275	#endif
1da177e4	276
d466f2fc AK	277	#ifdef CONFIG_MEMORY_FAILURE
d466f2fc AK	278	PAGEFLAG(HWPoison, hwpoison)
847ce401	279	TESTSCFLAG(HWPoison, hwpoison)
d466f2fc AK	280	#define __PG_HWPOISON (1UL << PG_hwpoison)
	281	#else
	282	PAGEFLAG_FALSE(HWPoison)
	283	#define __PG_HWPOISON 0
	284	#endif
	285
1a9b5b7f WF	286	u64 stable_page_flags(struct page *page);
1a9b5b7f WF	287
0ed361de NP	288	static inline int PageUptodate(struct page *page)
	289	{
	290	int ret = test_bit(PG_uptodate, &(page)->flags);
	291
	292	/*
	293	* Must ensure that the data we read out of the page is loaded
	294	* _after_ we've loaded page->flags to check for PageUptodate.
	295	* We can skip the barrier if the page is not uptodate, because
	296	* we wouldn't be reading anything from it.
	297	*
	298	* See SetPageUptodate() for the other side of the story.
	299	*/
	300	if (ret)
	301	smp_rmb();
	302
	303	return ret;
	304	}
	305
	306	static inline void __SetPageUptodate(struct page *page)
	307	{
	308	smp_wmb();
	309	__set_bit(PG_uptodate, &(page)->flags);
0ed361de NP	310	}
0ed361de NP	311
2dcea57a HC	312	static inline void SetPageUptodate(struct page *page)
2dcea57a HC	313	{
0ed361de	314	#ifdef CONFIG_S390
2dcea57a	315	if (!test_and_set_bit(PG_uptodate, &page->flags))
e2b8d7af	316	page_clear_dirty(page, 0);
f6ac2354	317	#else
0ed361de NP	318	/*
	319	* Memory barrier must be issued before setting the PG_uptodate bit,
	320	* so that all previous stores issued in order to bring the page
	321	* uptodate are actually visible before PageUptodate becomes true.
	322	*
	323	* s390 doesn't need an explicit smp_wmb here because the test and
	324	* set bit already provides full barriers.
	325	*/
	326	smp_wmb();
	327	set_bit(PG_uptodate, &(page)->flags);
1da177e4	328	#endif
0ed361de NP	329	}
0ed361de NP	330
6a1e7f77	331	CLEARPAGEFLAG(Uptodate, uptodate)
1da177e4	332
6a1e7f77	333	extern void cancel_dirty_page(struct page *page, unsigned int account_size);
d77c2d7c	334
6a1e7f77 CL	335	int test_clear_page_writeback(struct page *page);
6a1e7f77 CL	336	int test_set_page_writeback(struct page *page);
1da177e4	337
6a1e7f77 CL	338	static inline void set_page_writeback(struct page *page)
	339	{
	340	test_set_page_writeback(page);
	341	}
1da177e4	342
e20b8cca CL	343	#ifdef CONFIG_PAGEFLAGS_EXTENDED
	344	/*
	345	* System with lots of page flags available. This allows separate
	346	* flags for PageHead() and PageTail() checks of compound pages so that bit
	347	* tests can be used in performance sensitive paths. PageCompound is
	348	* generally not used in hot code paths.
	349	*/
4e6af67e	350	__PAGEFLAG(Head, head) CLEARPAGEFLAG(Head, head)
e20b8cca CL	351	__PAGEFLAG(Tail, tail)
	352
	353	static inline int PageCompound(struct page *page)
	354	{
	355	return page->flags & ((1L << PG_head) \| (1L << PG_tail));
	356
	357	}
4e6af67e AA	358	#ifdef CONFIG_TRANSPARENT_HUGEPAGE
	359	static inline void ClearPageCompound(struct page *page)
	360	{
	361	BUG_ON(!PageHead(page));
	362	ClearPageHead(page);
	363	}
	364	#endif
e20b8cca CL	365	#else
	366	/*
	367	* Reduce page flag use as much as possible by overlapping
	368	* compound page flags with the flags used for page cache pages. Possible
	369	* because PageCompound is always set for compound pages and not for
	370	* pages on the LRU and/or pagecache.
	371	*/
6a1e7f77 CL	372	TESTPAGEFLAG(Compound, compound)
6a1e7f77 CL	373	__PAGEFLAG(Head, compound)
1da177e4	374
d85f3385	375	/*
6d777953	376	* PG_reclaim is used in combination with PG_compound to mark the
6a1e7f77 CL	377	* head and tail of a compound page. This saves one page flag
	378	* but makes it impossible to use compound pages for the page cache.
	379	* The PG_reclaim bit would have to be used for reclaim or readahead
	380	* if compound pages enter the page cache.
6d777953 CL	381	*
	382	* PG_compound & PG_reclaim => Tail page
	383	* PG_compound & ~PG_reclaim => Head page
d85f3385	384	*/
6d777953 CL	385	#define PG_head_tail_mask ((1L << PG_compound) \| (1L << PG_reclaim))
6d777953 CL	386
6a1e7f77 CL	387	static inline int PageTail(struct page *page)
	388	{
	389	return ((page->flags & PG_head_tail_mask) == PG_head_tail_mask);
	390	}
6d777953 CL	391
	392	static inline void __SetPageTail(struct page *page)
	393	{
	394	page->flags \|= PG_head_tail_mask;
	395	}
	396
	397	static inline void __ClearPageTail(struct page *page)
	398	{
	399	page->flags &= ~PG_head_tail_mask;
	400	}
	401
4e6af67e AA	402	#ifdef CONFIG_TRANSPARENT_HUGEPAGE
	403	static inline void ClearPageCompound(struct page *page)
	404	{
	405	BUG_ON((page->flags & PG_head_tail_mask) != (1 << PG_compound));
	406	clear_bit(PG_compound, &page->flags);
	407	}
	408	#endif
	409
e20b8cca	410	#endif /* !PAGEFLAGS_EXTENDED */
dfa7e20c	411
936a5fe6	412	#ifdef CONFIG_TRANSPARENT_HUGEPAGE
71e3aac0 AA	413	/*
	414	* PageHuge() only returns true for hugetlbfs pages, but not for
	415	* normal or transparent huge pages.
	416	*
	417	* PageTransHuge() returns true for both transparent huge and
	418	* hugetlbfs pages, but not normal pages. PageTransHuge() can only be
	419	* called only in the core VM paths where hugetlbfs pages can't exist.
	420	*/
	421	static inline int PageTransHuge(struct page *page)
	422	{
	423	VM_BUG_ON(PageTail(page));
	424	return PageHead(page);
	425	}
	426
936a5fe6 AA	427	static inline int PageTransCompound(struct page *page)
	428	{
	429	return PageCompound(page);
	430	}
71e3aac0	431
936a5fe6	432	#else
71e3aac0 AA	433
	434	static inline int PageTransHuge(struct page *page)
	435	{
	436	return 0;
	437	}
	438
936a5fe6 AA	439	static inline int PageTransCompound(struct page *page)
	440	{
	441	return 0;
	442	}
	443	#endif
	444
af8e3354	445	#ifdef CONFIG_MMU
33925b25 DH	446	#define __PG_MLOCKED (1 << PG_mlocked)
33925b25 DH	447	#else
b291f000	448	#define __PG_MLOCKED 0
894bc310 LS	449	#endif
894bc310 LS	450
e9da73d6 AA	451	#ifdef CONFIG_TRANSPARENT_HUGEPAGE
	452	#define __PG_COMPOUND_LOCK (1 << PG_compound_lock)
	453	#else
	454	#define __PG_COMPOUND_LOCK 0
	455	#endif
	456
dfa7e20c RA	457	/*
	458	* Flags checked when a page is freed. Pages being freed should not have
	459	* these flags set. It they are, there is a problem.
	460	*/
79f4b7bf	461	#define PAGE_FLAGS_CHECK_AT_FREE \
266cf658 DH	462	(1 << PG_lru \| 1 << PG_locked \| \
	463	1 << PG_private \| 1 << PG_private_2 \| \
	464	1 << PG_buddy \| 1 << PG_writeback \| 1 << PG_reserved \| \
	465	1 << PG_slab \| 1 << PG_swapcache \| 1 << PG_active \| \
e9da73d6 AA	466	1 << PG_unevictable \| __PG_MLOCKED \| __PG_HWPOISON \| \
e9da73d6 AA	467	__PG_COMPOUND_LOCK)
dfa7e20c RA	468
	469	/*
	470	* Flags checked when a page is prepped for return by the page allocator.
79f4b7bf HD	471	* Pages being prepped should not have any flags set. It they are set,
79f4b7bf HD	472	* there has been a kernel bug or struct page corruption.
dfa7e20c	473	*/
79f4b7bf	474	#define PAGE_FLAGS_CHECK_AT_PREP ((1 << NR_PAGEFLAGS) - 1)
dfa7e20c	475
edcf4748 JW	476	#define PAGE_FLAGS_PRIVATE \
edcf4748 JW	477	(1 << PG_private \| 1 << PG_private_2)
266cf658 DH	478	/**
	479	* page_has_private - Determine if page has private stuff
	480	* @page: The page to be checked
	481	*
	482	* Determine if a page has private stuff, indicating that release routines
	483	* should be invoked upon it.
	484	*/
edcf4748 JW	485	static inline int page_has_private(struct page *page)
	486	{
	487	return !!(page->flags & PAGE_FLAGS_PRIVATE);
	488	}
	489
	490	#endif /* !__GENERATING_BOUNDS_H */
266cf658	491
1da177e4	492	#endif /* PAGE_FLAGS_H */