/* SPDX-License-Identifier: GPL-2.0 */

  #ifndef __LINUX_GFP_H
  #define __LINUX_GFP_H

  #include <linux/mmdebug.h>

  #include <linux/mmzone.h>
  #include <linux/stddef.h>
  #include <linux/linkage.h>

  #include <linux/topology.h>

  
  struct vm_area_struct;

  /*
   * In case of changes, please don't forget to update

   * include/trace/events/mmflags.h and tools/perf/builtin-kmem.c

   */

  /* Plain integer GFP bitmasks. Do not use this directly. */
  #define ___GFP_DMA		0x01u
  #define ___GFP_HIGHMEM		0x02u
  #define ___GFP_DMA32		0x04u
  #define ___GFP_MOVABLE		0x08u

  #define ___GFP_RECLAIMABLE	0x10u

  #define ___GFP_HIGH		0x20u
  #define ___GFP_IO		0x40u
  #define ___GFP_FS		0x80u

  #define ___GFP_ZERO		0x100u
  #define ___GFP_ATOMIC		0x200u
  #define ___GFP_DIRECT_RECLAIM	0x400u
  #define ___GFP_KSWAPD_RECLAIM	0x800u
  #define ___GFP_WRITE		0x1000u
  #define ___GFP_NOWARN		0x2000u
  #define ___GFP_RETRY_MAYFAIL	0x4000u
  #define ___GFP_NOFAIL		0x8000u
  #define ___GFP_NORETRY		0x10000u
  #define ___GFP_MEMALLOC		0x20000u
  #define ___GFP_COMP		0x40000u
  #define ___GFP_NOMEMALLOC	0x80000u
  #define ___GFP_HARDWALL		0x100000u
  #define ___GFP_THISNODE		0x200000u
  #define ___GFP_ACCOUNT		0x400000u

  #ifdef CONFIG_CMA
  #define ___GFP_CMA		0x800000u
  #else
  #define ___GFP_CMA		0
  #endif

  #ifdef CONFIG_LOCKDEP

  #ifdef CONFIG_CMA
  #define ___GFP_NOLOCKDEP	0x1000000u
  #else

  #define ___GFP_NOLOCKDEP	0x800000u

  #endif

  #else
  #define ___GFP_NOLOCKDEP	0
  #endif

  /* If the above are modified, __GFP_BITS_SHIFT may need updating */

  /*

   * Physical address zone modifiers (see linux/mmzone.h - low four bits)

   *

   * Do not put any conditional on these. If necessary modify the definitions

   * without the underscores and use them consistently. The definitions here may

   * be used in bit comparisons.

   */

  #define __GFP_DMA	((__force gfp_t)___GFP_DMA)
  #define __GFP_HIGHMEM	((__force gfp_t)___GFP_HIGHMEM)
  #define __GFP_DMA32	((__force gfp_t)___GFP_DMA32)

  #define __GFP_MOVABLE	((__force gfp_t)___GFP_MOVABLE)  /* ZONE_MOVABLE allowed */

  #define __GFP_CMA	((__force gfp_t)___GFP_CMA)

  #define GFP_ZONEMASK	(__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)

  /**
   * DOC: Page mobility and placement hints
   *

   * Page mobility and placement hints

   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

   *

   * These flags provide hints about how mobile the page is. Pages with similar
   * mobility are placed within the same pageblocks to minimise problems due
   * to external fragmentation.

   *

   * %__GFP_MOVABLE (also a zone modifier) indicates that the page can be
   * moved by page migration during memory compaction or can be reclaimed.

   *

   * %__GFP_RECLAIMABLE is used for slab allocations that specify
   * SLAB_RECLAIM_ACCOUNT and whose pages can be freed via shrinkers.

   *

   * %__GFP_WRITE indicates the caller intends to dirty the page. Where possible,
   * these pages will be spread between local zones to avoid all the dirty
   * pages being in one zone (fair zone allocation policy).

   *

   * %__GFP_HARDWALL enforces the cpuset memory allocation policy.

   *

   * %__GFP_THISNODE forces the allocation to be satisfied from the requested

   * node with no fallbacks or placement policy enforcements.

   *

   * %__GFP_ACCOUNT causes the allocation to be accounted to kmemcg.

   */

  #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE)
  #define __GFP_WRITE	((__force gfp_t)___GFP_WRITE)
  #define __GFP_HARDWALL   ((__force gfp_t)___GFP_HARDWALL)
  #define __GFP_THISNODE	((__force gfp_t)___GFP_THISNODE)

  #define __GFP_ACCOUNT	((__force gfp_t)___GFP_ACCOUNT)

  /**
   * DOC: Watermark modifiers
   *

   * Watermark modifiers -- controls access to emergency reserves

   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

   *

   * %__GFP_HIGH indicates that the caller is high-priority and that granting
   * the request is necessary before the system can make forward progress.
   * For example, creating an IO context to clean pages.

   *

   * %__GFP_ATOMIC indicates that the caller cannot reclaim or sleep and is
   * high priority. Users are typically interrupt handlers. This may be
   * used in conjunction with %__GFP_HIGH

   *

   * %__GFP_MEMALLOC allows access to all memory. This should only be used when
   * the caller guarantees the allocation will allow more memory to be freed
   * very shortly e.g. process exiting or swapping. Users either should
   * be the MM or co-ordinating closely with the VM (e.g. swap over NFS).

   * Users of this flag have to be extremely careful to not deplete the reserve
   * completely and implement a throttling mechanism which controls the
   * consumption of the reserve based on the amount of freed memory.
   * Usage of a pre-allocated pool (e.g. mempool) should be always considered
   * before using this flag.

   *

   * %__GFP_NOMEMALLOC is used to explicitly forbid access to emergency reserves.
   * This takes precedence over the %__GFP_MEMALLOC flag if both are set.

   */

  #define __GFP_ATOMIC	((__force gfp_t)___GFP_ATOMIC)
  #define __GFP_HIGH	((__force gfp_t)___GFP_HIGH)
  #define __GFP_MEMALLOC	((__force gfp_t)___GFP_MEMALLOC)
  #define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC)

  /**
   * DOC: Reclaim modifiers
   *

   * Reclaim modifiers

   * ~~~~~~~~~~~~~~~~~

   * Please note that all the following flags are only applicable to sleepable
   * allocations (e.g. %GFP_NOWAIT and %GFP_ATOMIC will ignore them).

   *

   * %__GFP_IO can start physical IO.

   *

   * %__GFP_FS can call down to the low-level FS. Clearing the flag avoids the
   * allocator recursing into the filesystem which might already be holding
   * locks.

   *

   * %__GFP_DIRECT_RECLAIM indicates that the caller may enter direct reclaim.
   * This flag can be cleared to avoid unnecessary delays when a fallback
   * option is available.

   *

   * %__GFP_KSWAPD_RECLAIM indicates that the caller wants to wake kswapd when
   * the low watermark is reached and have it reclaim pages until the high
   * watermark is reached. A caller may wish to clear this flag when fallback
   * options are available and the reclaim is likely to disrupt the system. The
   * canonical example is THP allocation where a fallback is cheap but
   * reclaim/compaction may cause indirect stalls.

   *

   * %__GFP_RECLAIM is shorthand to allow/forbid both direct and kswapd reclaim.

   *

   * The default allocator behavior depends on the request size. We have a concept

   * of so called costly allocations (with order > %PAGE_ALLOC_COSTLY_ORDER).

   * !costly allocations are too essential to fail so they are implicitly
   * non-failing by default (with some exceptions like OOM victims might fail so
   * the caller still has to check for failures) while costly requests try to be
   * not disruptive and back off even without invoking the OOM killer.
   * The following three modifiers might be used to override some of these
   * implicit rules
   *

   * %__GFP_NORETRY: The VM implementation will try only very lightweight
   * memory direct reclaim to get some memory under memory pressure (thus
   * it can sleep). It will avoid disruptive actions like OOM killer. The
   * caller must handle the failure which is quite likely to happen under
   * heavy memory pressure. The flag is suitable when failure can easily be
   * handled at small cost, such as reduced throughput
   *
   * %__GFP_RETRY_MAYFAIL: The VM implementation will retry memory reclaim
   * procedures that have previously failed if there is some indication
   * that progress has been made else where.  It can wait for other
   * tasks to attempt high level approaches to freeing memory such as
   * compaction (which removes fragmentation) and page-out.
   * There is still a definite limit to the number of retries, but it is
   * a larger limit than with %__GFP_NORETRY.
   * Allocations with this flag may fail, but only when there is
   * genuinely little unused memory. While these allocations do not
   * directly trigger the OOM killer, their failure indicates that
   * the system is likely to need to use the OOM killer soon.  The
   * caller must handle failure, but can reasonably do so by failing
   * a higher-level request, or completing it only in a much less
   * efficient manner.
   * If the allocation does fail, and the caller is in a position to
   * free some non-essential memory, doing so could benefit the system
   * as a whole.
   *
   * %__GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
   * cannot handle allocation failures. The allocation could block
   * indefinitely but will never return with failure. Testing for
   * failure is pointless.
   * New users should be evaluated carefully (and the flag should be
   * used only when there is no reasonable failure policy) but it is
   * definitely preferable to use the flag rather than opencode endless
   * loop around allocator.
   * Using this flag for costly allocations is _highly_ discouraged.

   */
  #define __GFP_IO	((__force gfp_t)___GFP_IO)
  #define __GFP_FS	((__force gfp_t)___GFP_FS)

  #define __GFP_DIRECT_RECLAIM	((__force gfp_t)___GFP_DIRECT_RECLAIM) /* Caller can reclaim */
  #define __GFP_KSWAPD_RECLAIM	((__force gfp_t)___GFP_KSWAPD_RECLAIM) /* kswapd can wake */

  #define __GFP_RECLAIM ((__force gfp_t)(___GFP_DIRECT_RECLAIM|___GFP_KSWAPD_RECLAIM))

  #define __GFP_RETRY_MAYFAIL	((__force gfp_t)___GFP_RETRY_MAYFAIL)

  #define __GFP_NOFAIL	((__force gfp_t)___GFP_NOFAIL)
  #define __GFP_NORETRY	((__force gfp_t)___GFP_NORETRY)

  /**
   * DOC: Action modifiers
   *

   * Action modifiers

   * ~~~~~~~~~~~~~~~~

   *

   * %__GFP_NOWARN suppresses allocation failure reports.

   *

   * %__GFP_COMP address compound page metadata.

   *

   * %__GFP_ZERO returns a zeroed page on success.

   */

  #define __GFP_NOWARN	((__force gfp_t)___GFP_NOWARN)
  #define __GFP_COMP	((__force gfp_t)___GFP_COMP)
  #define __GFP_ZERO	((__force gfp_t)___GFP_ZERO)

  /* Disable lockdep for GFP context tracking */
  #define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP)

  /* Room for N __GFP_FOO bits */

  #ifdef CONFIG_CMA
  #define __GFP_BITS_SHIFT (24 + IS_ENABLED(CONFIG_LOCKDEP))
  #else

  #define __GFP_BITS_SHIFT (23 + IS_ENABLED(CONFIG_LOCKDEP))

  #endif

  #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))

  /**
   * DOC: Useful GFP flag combinations
   *
   * Useful GFP flag combinations
   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   *

   * Useful GFP flag combinations that are commonly used. It is recommended
   * that subsystems start with one of these combinations and then set/clear

   * %__GFP_FOO flags as necessary.
   *
   * %GFP_ATOMIC users can not sleep and need the allocation to succeed. A lower

   * watermark is applied to allow access to "atomic reserves".
   * The current implementation doesn't support NMI and few other strict
   * non-preemptive contexts (e.g. raw_spin_lock). The same applies to %GFP_NOWAIT.

   *
   * %GFP_KERNEL is typical for kernel-internal allocations. The caller requires
   * %ZONE_NORMAL or a lower zone for direct access but can direct reclaim.
   *
   * %GFP_KERNEL_ACCOUNT is the same as GFP_KERNEL, except the allocation is
   * accounted to kmemcg.
   *
   * %GFP_NOWAIT is for kernel allocations that should not stall for direct
   * reclaim, start physical IO or use any filesystem callback.
   *
   * %GFP_NOIO will use direct reclaim to discard clean pages or slab pages
   * that do not require the starting of any physical IO.
   * Please try to avoid using this flag directly and instead use
   * memalloc_noio_{save,restore} to mark the whole scope which cannot
   * perform any IO with a short explanation why. All allocation requests
   * will inherit GFP_NOIO implicitly.
   *
   * %GFP_NOFS will use direct reclaim but will not use any filesystem interfaces.
   * Please try to avoid using this flag directly and instead use
   * memalloc_nofs_{save,restore} to mark the whole scope which cannot/shouldn't
   * recurse into the FS layer with a short explanation why. All allocation
   * requests will inherit GFP_NOFS implicitly.
   *
   * %GFP_USER is for userspace allocations that also need to be directly
   * accessibly by the kernel or hardware. It is typically used by hardware
   * for buffers that are mapped to userspace (e.g. graphics) that hardware
   * still must DMA to. cpuset limits are enforced for these allocations.
   *
   * %GFP_DMA exists for historical reasons and should be avoided where possible.
   * The flags indicates that the caller requires that the lowest zone be
   * used (%ZONE_DMA or 16M on x86-64). Ideally, this would be removed but
   * it would require careful auditing as some users really require it and
   * others use the flag to avoid lowmem reserves in %ZONE_DMA and treat the
   * lowest zone as a type of emergency reserve.
   *
   * %GFP_DMA32 is similar to %GFP_DMA except that the caller requires a 32-bit
   * address.
   *
   * %GFP_HIGHUSER is for userspace allocations that may be mapped to userspace,
   * do not need to be directly accessible by the kernel but that cannot
   * move once in use. An example may be a hardware allocation that maps
   * data directly into userspace but has no addressing limitations.
   *
   * %GFP_HIGHUSER_MOVABLE is for userspace allocations that the kernel does not
   * need direct access to but can use kmap() when access is required. They
   * are expected to be movable via page reclaim or page migration. Typically,
   * pages on the LRU would also be allocated with %GFP_HIGHUSER_MOVABLE.
   *
   * %GFP_TRANSHUGE and %GFP_TRANSHUGE_LIGHT are used for THP allocations. They
   * are compound allocations that will generally fail quickly if memory is not
   * available and will not wake kswapd/kcompactd on failure. The _LIGHT
   * version does not attempt reclaim/compaction at all and is by default used
   * in page fault path, while the non-light is used by khugepaged.

   */
  #define GFP_ATOMIC	(__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM)

  #define GFP_KERNEL	(__GFP_RECLAIM | __GFP_IO | __GFP_FS)

  #define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT)

  #define GFP_NOWAIT	(__GFP_KSWAPD_RECLAIM)

  #define GFP_NOIO	(__GFP_RECLAIM)
  #define GFP_NOFS	(__GFP_RECLAIM | __GFP_IO)

  #define GFP_USER	(__GFP_RECLAIM | __GFP_IO | __GFP_FS | __GFP_HARDWALL)

  #define GFP_DMA		__GFP_DMA
  #define GFP_DMA32	__GFP_DMA32

  #define GFP_HIGHUSER	(GFP_USER | __GFP_HIGHMEM)
  #define GFP_HIGHUSER_MOVABLE	(GFP_HIGHUSER | __GFP_MOVABLE)

  #define GFP_TRANSHUGE_LIGHT	((GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
  			 __GFP_NOMEMALLOC | __GFP_NOWARN) & ~__GFP_RECLAIM)
  #define GFP_TRANSHUGE	(GFP_TRANSHUGE_LIGHT | __GFP_DIRECT_RECLAIM)

  /* Convert GFP flags to their corresponding migrate type */

  #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)

  #define GFP_MOVABLE_SHIFT 3

  static inline int gfp_migratetype(const gfp_t gfp_flags)

  {

  	VM_WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
  	BUILD_BUG_ON((1UL << GFP_MOVABLE_SHIFT) != ___GFP_MOVABLE);
  	BUILD_BUG_ON((___GFP_MOVABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_MOVABLE);

  
  	if (unlikely(page_group_by_mobility_disabled))
  		return MIGRATE_UNMOVABLE;
  
  	/* Group based on mobility */

  	return (gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;

  }

  #undef GFP_MOVABLE_MASK
  #undef GFP_MOVABLE_SHIFT

  static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
  {

  	return !!(gfp_flags & __GFP_DIRECT_RECLAIM);

  }

  /**
   * gfpflags_normal_context - is gfp_flags a normal sleepable context?
   * @gfp_flags: gfp_flags to test
   *
   * Test whether @gfp_flags indicates that the allocation is from the
   * %current context and allowed to sleep.
   *
   * An allocation being allowed to block doesn't mean it owns the %current
   * context.  When direct reclaim path tries to allocate memory, the
   * allocation context is nested inside whatever %current was doing at the
   * time of the original allocation.  The nested allocation may be allowed
   * to block but modifying anything %current owns can corrupt the outer
   * context's expectations.
   *
   * %true result from this function indicates that the allocation context
   * can sleep and use anything that's associated with %current.
   */
  static inline bool gfpflags_normal_context(const gfp_t gfp_flags)
  {
  	return (gfp_flags & (__GFP_DIRECT_RECLAIM | __GFP_MEMALLOC)) ==
  		__GFP_DIRECT_RECLAIM;
  }

  #ifdef CONFIG_HIGHMEM
  #define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
  #else
  #define OPT_ZONE_HIGHMEM ZONE_NORMAL
  #endif

  #ifdef CONFIG_ZONE_DMA

  #define OPT_ZONE_DMA ZONE_DMA
  #else
  #define OPT_ZONE_DMA ZONE_NORMAL

  #endif

  #ifdef CONFIG_ZONE_DMA32

  #define OPT_ZONE_DMA32 ZONE_DMA32
  #else
  #define OPT_ZONE_DMA32 ZONE_NORMAL

  #endif

  
  /*
   * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the

   * zone to use given the lowest 4 bits of gfp_t. Entries are GFP_ZONES_SHIFT
   * bits long and there are 16 of them to cover all possible combinations of

   * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM.

   *
   * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
   * But GFP_MOVABLE is not only a zone specifier but also an allocation
   * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.

   * Only 1 bit of the lowest 3 bits (DMA,DMA32,HIGHMEM) can be set to "1".

   *
   *       bit       result
   *       =================
   *       0x0    => NORMAL
   *       0x1    => DMA or NORMAL
   *       0x2    => HIGHMEM or NORMAL
   *       0x3    => BAD (DMA+HIGHMEM)

   *       0x4    => DMA32 or NORMAL

   *       0x5    => BAD (DMA+DMA32)
   *       0x6    => BAD (HIGHMEM+DMA32)
   *       0x7    => BAD (HIGHMEM+DMA32+DMA)
   *       0x8    => NORMAL (MOVABLE+0)
   *       0x9    => DMA or NORMAL (MOVABLE+DMA)
   *       0xa    => MOVABLE (Movable is valid only if HIGHMEM is set too)
   *       0xb    => BAD (MOVABLE+HIGHMEM+DMA)

   *       0xc    => DMA32 or NORMAL (MOVABLE+DMA32)

   *       0xd    => BAD (MOVABLE+DMA32+DMA)
   *       0xe    => BAD (MOVABLE+DMA32+HIGHMEM)
   *       0xf    => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
   *

   * GFP_ZONES_SHIFT must be <= 2 on 32 bit platforms.

   */

  #if defined(CONFIG_ZONE_DEVICE) && (MAX_NR_ZONES-1) <= 4
  /* ZONE_DEVICE is not a valid GFP zone specifier */
  #define GFP_ZONES_SHIFT 2
  #else
  #define GFP_ZONES_SHIFT ZONES_SHIFT
  #endif
  
  #if 16 * GFP_ZONES_SHIFT > BITS_PER_LONG
  #error GFP_ZONES_SHIFT too large to create GFP_ZONE_TABLE integer

  #endif
  
  #define GFP_ZONE_TABLE ( \

  	(ZONE_NORMAL << 0 * GFP_ZONES_SHIFT)				       \
  	| (OPT_ZONE_DMA << ___GFP_DMA * GFP_ZONES_SHIFT)		       \
  	| (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * GFP_ZONES_SHIFT)	       \
  	| (OPT_ZONE_DMA32 << ___GFP_DMA32 * GFP_ZONES_SHIFT)		       \
  	| (ZONE_NORMAL << ___GFP_MOVABLE * GFP_ZONES_SHIFT)		       \
  	| (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * GFP_ZONES_SHIFT)    \
  	| (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * GFP_ZONES_SHIFT)\
  	| (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * GFP_ZONES_SHIFT)\

  )
  
  /*

   * GFP_ZONE_BAD is a bitmap for all combinations of __GFP_DMA, __GFP_DMA32

   * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
   * entry starting with bit 0. Bit is set if the combination is not
   * allowed.
   */
  #define GFP_ZONE_BAD ( \

  	1 << (___GFP_DMA | ___GFP_HIGHMEM)				      \
  	| 1 << (___GFP_DMA | ___GFP_DMA32)				      \
  	| 1 << (___GFP_DMA32 | ___GFP_HIGHMEM)				      \
  	| 1 << (___GFP_DMA | ___GFP_DMA32 | ___GFP_HIGHMEM)		      \
  	| 1 << (___GFP_MOVABLE | ___GFP_HIGHMEM | ___GFP_DMA)		      \
  	| 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA)		      \
  	| 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_HIGHMEM)		      \
  	| 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA | ___GFP_HIGHMEM)  \

  )

  enum zone_type gfp_zone(gfp_t flags);

  /*
   * There is only one page-allocator function, and two main namespaces to
   * it. The alloc_page*() variants return 'struct page *' and as such
   * can allocate highmem pages, the *get*page*() variants return
   * virtual kernel addresses to the allocated page(s).
   */

  static inline int gfp_zonelist(gfp_t flags)
  {

  #ifdef CONFIG_NUMA
  	if (unlikely(flags & __GFP_THISNODE))
  		return ZONELIST_NOFALLBACK;
  #endif
  	return ZONELIST_FALLBACK;

  }

  /*
   * We get the zone list from the current node and the gfp_mask.
   * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.

   * There are two zonelists per node, one for all zones with memory and
   * one containing just zones from the node the zonelist belongs to.

   *
   * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
   * optimized to &contig_page_data at compile-time.
   */

  static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
  {

  	return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);

  }

  
  #ifndef HAVE_ARCH_FREE_PAGE
  static inline void arch_free_page(struct page *page, int order) { }
  #endif

  #ifndef HAVE_ARCH_ALLOC_PAGE
  static inline void arch_alloc_page(struct page *page, int order) { }
  #endif

  #ifndef HAVE_ARCH_MAKE_PAGE_ACCESSIBLE
  static inline int arch_make_page_accessible(struct page *page)
  {
  	return 0;
  }
  #endif

  struct page *

  __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,
  							nodemask_t *nodemask);

  
  static inline struct page *

  __alloc_pages(gfp_t gfp_mask, unsigned int order, int preferred_nid)

  {

  	return __alloc_pages_nodemask(gfp_mask, order, preferred_nid, NULL);

  }

  /*
   * Allocate pages, preferring the node given as nid. The node must be valid and
   * online. For more general interface, see alloc_pages_node().
   */
  static inline struct page *
  __alloc_pages_node(int nid, gfp_t gfp_mask, unsigned int order)

  {

  	VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);

  	VM_WARN_ON((gfp_mask & __GFP_THISNODE) && !node_online(nid));

  	return __alloc_pages(gfp_mask, order, nid);

  }

  /*
   * Allocate pages, preferring the node given as nid. When nid == NUMA_NO_NODE,

   * prefer the current CPU's closest node. Otherwise node must be valid and
   * online.

   */
  static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,

  						unsigned int order)
  {

  	if (nid == NUMA_NO_NODE)

  		nid = numa_mem_id();

  	return __alloc_pages_node(nid, gfp_mask, order);

  }

  #ifdef CONFIG_NUMA

  extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);

  
  static inline struct page *

  alloc_pages(gfp_t gfp_mask, unsigned int order)

  {

  	return alloc_pages_current(gfp_mask, order);
  }

  extern struct page *alloc_pages_vma(gfp_t gfp_mask, int order,

  			struct vm_area_struct *vma, unsigned long addr,

  			int node, bool hugepage);
  #define alloc_hugepage_vma(gfp_mask, vma, addr, order) \
  	alloc_pages_vma(gfp_mask, order, vma, addr, numa_node_id(), true)

  #else

  static inline struct page *alloc_pages(gfp_t gfp_mask, unsigned int order)
  {
  	return alloc_pages_node(numa_node_id(), gfp_mask, order);
  }

  #define alloc_pages_vma(gfp_mask, order, vma, addr, node, false)\
  	alloc_pages(gfp_mask, order)
  #define alloc_hugepage_vma(gfp_mask, vma, addr, order) \

  	alloc_pages(gfp_mask, order)

  #endif
  #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)

  #define alloc_page_vma(gfp_mask, vma, addr)			\

  	alloc_pages_vma(gfp_mask, 0, vma, addr, numa_node_id(), false)

  extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
  extern unsigned long get_zeroed_page(gfp_t gfp_mask);

  void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
  void free_pages_exact(void *virt, size_t size);

  void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask);

  #define __get_free_page(gfp_mask) \

  		__get_free_pages((gfp_mask), 0)

  
  #define __get_dma_pages(gfp_mask, order) \

  		__get_free_pages((gfp_mask) | GFP_DMA, (order))

  extern void __free_pages(struct page *page, unsigned int order);
  extern void free_pages(unsigned long addr, unsigned int order);

  extern void free_unref_page(struct page *page);
  extern void free_unref_page_list(struct list_head *list);

  struct page_frag_cache;

  extern void __page_frag_cache_drain(struct page *page, unsigned int count);

  extern void *page_frag_alloc(struct page_frag_cache *nc,
  			     unsigned int fragsz, gfp_t gfp_mask);
  extern void page_frag_free(void *addr);

  #define __free_page(page) __free_pages((page), 0)

  #define free_page(addr) free_pages((addr), 0)

  
  void page_alloc_init(void);

  void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);

  void drain_all_pages(struct zone *zone);
  void drain_local_pages(struct zone *zone);

  void page_alloc_init_late(void);

  /*
   * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what
   * GFP flags are used before interrupts are enabled. Once interrupts are
   * enabled, it is set to __GFP_BITS_MASK while the system is running. During
   * hibernation, it is used by PM to avoid I/O during memory allocation while
   * devices are suspended.
   */

  extern gfp_t gfp_allowed_mask;

  /* Returns true if the gfp_mask allows use of ALLOC_NO_WATERMARK */
  bool gfp_pfmemalloc_allowed(gfp_t gfp_mask);

  extern void pm_restrict_gfp_mask(void);
  extern void pm_restore_gfp_mask(void);

  #ifdef CONFIG_PM_SLEEP
  extern bool pm_suspended_storage(void);
  #else
  static inline bool pm_suspended_storage(void)
  {
  	return false;
  }
  #endif /* CONFIG_PM_SLEEP */

  #ifdef CONFIG_CONTIG_ALLOC

  /* The below functions must be run on a range from a single zone. */

  extern int alloc_contig_range(unsigned long start, unsigned long end,

  			      unsigned migratetype, gfp_t gfp_mask);

  extern struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask,
  				       int nid, nodemask_t *nodemask);

  #endif

  void free_contig_range(unsigned long pfn, unsigned int nr_pages);

  #ifdef CONFIG_CMA

  /* CMA stuff */
  extern void init_cma_reserved_pageblock(struct page *page);

  #endif

  #endif /* __LINUX_GFP_H */