LCOV - code coverage report
Current view: top level - include/linux - gfp.h (source / functions) Hit Total Coverage
Test: landlock.info Lines: 36 40 90.0 %
Date: 2021-04-22 12:43:58 Functions: 3 4 75.0 %

          Line data    Source code
       1             : /* SPDX-License-Identifier: GPL-2.0 */
       2             : #ifndef __LINUX_GFP_H
       3             : #define __LINUX_GFP_H
       4             : 
       5             : #include <linux/mmdebug.h>
       6             : #include <linux/mmzone.h>
       7             : #include <linux/stddef.h>
       8             : #include <linux/linkage.h>
       9             : #include <linux/topology.h>
      10             : 
      11             : /* The typedef is in types.h but we want the documentation here */
      12             : #if 0
      13             : /**
      14             :  * typedef gfp_t - Memory allocation flags.
      15             :  *
      16             :  * GFP flags are commonly used throughout Linux to indicate how memory
      17             :  * should be allocated.  The GFP acronym stands for get_free_pages(),
      18             :  * the underlying memory allocation function.  Not every GFP flag is
      19             :  * supported by every function which may allocate memory.  Most users
      20             :  * will want to use a plain ``GFP_KERNEL``.
      21             :  */
      22             : typedef unsigned int __bitwise gfp_t;
      23             : #endif
      24             : 
      25             : struct vm_area_struct;
      26             : 
      27             : /*
      28             :  * In case of changes, please don't forget to update
      29             :  * include/trace/events/mmflags.h and tools/perf/builtin-kmem.c
      30             :  */
      31             : 
      32             : /* Plain integer GFP bitmasks. Do not use this directly. */
      33             : #define ___GFP_DMA              0x01u
      34             : #define ___GFP_HIGHMEM          0x02u
      35             : #define ___GFP_DMA32            0x04u
      36             : #define ___GFP_MOVABLE          0x08u
      37             : #define ___GFP_RECLAIMABLE      0x10u
      38             : #define ___GFP_HIGH             0x20u
      39             : #define ___GFP_IO               0x40u
      40             : #define ___GFP_FS               0x80u
      41             : #define ___GFP_ZERO             0x100u
      42             : #define ___GFP_ATOMIC           0x200u
      43             : #define ___GFP_DIRECT_RECLAIM   0x400u
      44             : #define ___GFP_KSWAPD_RECLAIM   0x800u
      45             : #define ___GFP_WRITE            0x1000u
      46             : #define ___GFP_NOWARN           0x2000u
      47             : #define ___GFP_RETRY_MAYFAIL    0x4000u
      48             : #define ___GFP_NOFAIL           0x8000u
      49             : #define ___GFP_NORETRY          0x10000u
      50             : #define ___GFP_MEMALLOC         0x20000u
      51             : #define ___GFP_COMP             0x40000u
      52             : #define ___GFP_NOMEMALLOC       0x80000u
      53             : #define ___GFP_HARDWALL         0x100000u
      54             : #define ___GFP_THISNODE         0x200000u
      55             : #define ___GFP_ACCOUNT          0x400000u
      56             : #ifdef CONFIG_LOCKDEP
      57             : #define ___GFP_NOLOCKDEP        0x800000u
      58             : #else
      59             : #define ___GFP_NOLOCKDEP        0
      60             : #endif
      61             : /* If the above are modified, __GFP_BITS_SHIFT may need updating */
      62             : 
      63             : /*
      64             :  * Physical address zone modifiers (see linux/mmzone.h - low four bits)
      65             :  *
      66             :  * Do not put any conditional on these. If necessary modify the definitions
      67             :  * without the underscores and use them consistently. The definitions here may
      68             :  * be used in bit comparisons.
      69             :  */
      70             : #define __GFP_DMA       ((__force gfp_t)___GFP_DMA)
      71             : #define __GFP_HIGHMEM   ((__force gfp_t)___GFP_HIGHMEM)
      72             : #define __GFP_DMA32     ((__force gfp_t)___GFP_DMA32)
      73             : #define __GFP_MOVABLE   ((__force gfp_t)___GFP_MOVABLE)  /* ZONE_MOVABLE allowed */
      74             : #define GFP_ZONEMASK    (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
      75             : 
      76             : /**
      77             :  * DOC: Page mobility and placement hints
      78             :  *
      79             :  * Page mobility and placement hints
      80             :  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      81             :  *
      82             :  * These flags provide hints about how mobile the page is. Pages with similar
      83             :  * mobility are placed within the same pageblocks to minimise problems due
      84             :  * to external fragmentation.
      85             :  *
      86             :  * %__GFP_MOVABLE (also a zone modifier) indicates that the page can be
      87             :  * moved by page migration during memory compaction or can be reclaimed.
      88             :  *
      89             :  * %__GFP_RECLAIMABLE is used for slab allocations that specify
      90             :  * SLAB_RECLAIM_ACCOUNT and whose pages can be freed via shrinkers.
      91             :  *
      92             :  * %__GFP_WRITE indicates the caller intends to dirty the page. Where possible,
      93             :  * these pages will be spread between local zones to avoid all the dirty
      94             :  * pages being in one zone (fair zone allocation policy).
      95             :  *
      96             :  * %__GFP_HARDWALL enforces the cpuset memory allocation policy.
      97             :  *
      98             :  * %__GFP_THISNODE forces the allocation to be satisfied from the requested
      99             :  * node with no fallbacks or placement policy enforcements.
     100             :  *
     101             :  * %__GFP_ACCOUNT causes the allocation to be accounted to kmemcg.
     102             :  */
     103             : #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE)
     104             : #define __GFP_WRITE     ((__force gfp_t)___GFP_WRITE)
     105             : #define __GFP_HARDWALL   ((__force gfp_t)___GFP_HARDWALL)
     106             : #define __GFP_THISNODE  ((__force gfp_t)___GFP_THISNODE)
     107             : #define __GFP_ACCOUNT   ((__force gfp_t)___GFP_ACCOUNT)
     108             : 
     109             : /**
     110             :  * DOC: Watermark modifiers
     111             :  *
     112             :  * Watermark modifiers -- controls access to emergency reserves
     113             :  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     114             :  *
     115             :  * %__GFP_HIGH indicates that the caller is high-priority and that granting
     116             :  * the request is necessary before the system can make forward progress.
     117             :  * For example, creating an IO context to clean pages.
     118             :  *
     119             :  * %__GFP_ATOMIC indicates that the caller cannot reclaim or sleep and is
     120             :  * high priority. Users are typically interrupt handlers. This may be
     121             :  * used in conjunction with %__GFP_HIGH
     122             :  *
     123             :  * %__GFP_MEMALLOC allows access to all memory. This should only be used when
     124             :  * the caller guarantees the allocation will allow more memory to be freed
     125             :  * very shortly e.g. process exiting or swapping. Users either should
     126             :  * be the MM or co-ordinating closely with the VM (e.g. swap over NFS).
     127             :  * Users of this flag have to be extremely careful to not deplete the reserve
     128             :  * completely and implement a throttling mechanism which controls the
     129             :  * consumption of the reserve based on the amount of freed memory.
     130             :  * Usage of a pre-allocated pool (e.g. mempool) should be always considered
     131             :  * before using this flag.
     132             :  *
     133             :  * %__GFP_NOMEMALLOC is used to explicitly forbid access to emergency reserves.
     134             :  * This takes precedence over the %__GFP_MEMALLOC flag if both are set.
     135             :  */
     136             : #define __GFP_ATOMIC    ((__force gfp_t)___GFP_ATOMIC)
     137             : #define __GFP_HIGH      ((__force gfp_t)___GFP_HIGH)
     138             : #define __GFP_MEMALLOC  ((__force gfp_t)___GFP_MEMALLOC)
     139             : #define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC)
     140             : 
     141             : /**
     142             :  * DOC: Reclaim modifiers
     143             :  *
     144             :  * Reclaim modifiers
     145             :  * ~~~~~~~~~~~~~~~~~
     146             :  * Please note that all the following flags are only applicable to sleepable
     147             :  * allocations (e.g. %GFP_NOWAIT and %GFP_ATOMIC will ignore them).
     148             :  *
     149             :  * %__GFP_IO can start physical IO.
     150             :  *
     151             :  * %__GFP_FS can call down to the low-level FS. Clearing the flag avoids the
     152             :  * allocator recursing into the filesystem which might already be holding
     153             :  * locks.
     154             :  *
     155             :  * %__GFP_DIRECT_RECLAIM indicates that the caller may enter direct reclaim.
     156             :  * This flag can be cleared to avoid unnecessary delays when a fallback
     157             :  * option is available.
     158             :  *
     159             :  * %__GFP_KSWAPD_RECLAIM indicates that the caller wants to wake kswapd when
     160             :  * the low watermark is reached and have it reclaim pages until the high
     161             :  * watermark is reached. A caller may wish to clear this flag when fallback
     162             :  * options are available and the reclaim is likely to disrupt the system. The
     163             :  * canonical example is THP allocation where a fallback is cheap but
     164             :  * reclaim/compaction may cause indirect stalls.
     165             :  *
     166             :  * %__GFP_RECLAIM is shorthand to allow/forbid both direct and kswapd reclaim.
     167             :  *
     168             :  * The default allocator behavior depends on the request size. We have a concept
     169             :  * of so called costly allocations (with order > %PAGE_ALLOC_COSTLY_ORDER).
     170             :  * !costly allocations are too essential to fail so they are implicitly
     171             :  * non-failing by default (with some exceptions like OOM victims might fail so
     172             :  * the caller still has to check for failures) while costly requests try to be
     173             :  * not disruptive and back off even without invoking the OOM killer.
     174             :  * The following three modifiers might be used to override some of these
     175             :  * implicit rules
     176             :  *
     177             :  * %__GFP_NORETRY: The VM implementation will try only very lightweight
     178             :  * memory direct reclaim to get some memory under memory pressure (thus
     179             :  * it can sleep). It will avoid disruptive actions like OOM killer. The
     180             :  * caller must handle the failure which is quite likely to happen under
     181             :  * heavy memory pressure. The flag is suitable when failure can easily be
     182             :  * handled at small cost, such as reduced throughput
     183             :  *
     184             :  * %__GFP_RETRY_MAYFAIL: The VM implementation will retry memory reclaim
     185             :  * procedures that have previously failed if there is some indication
     186             :  * that progress has been made else where.  It can wait for other
     187             :  * tasks to attempt high level approaches to freeing memory such as
     188             :  * compaction (which removes fragmentation) and page-out.
     189             :  * There is still a definite limit to the number of retries, but it is
     190             :  * a larger limit than with %__GFP_NORETRY.
     191             :  * Allocations with this flag may fail, but only when there is
     192             :  * genuinely little unused memory. While these allocations do not
     193             :  * directly trigger the OOM killer, their failure indicates that
     194             :  * the system is likely to need to use the OOM killer soon.  The
     195             :  * caller must handle failure, but can reasonably do so by failing
     196             :  * a higher-level request, or completing it only in a much less
     197             :  * efficient manner.
     198             :  * If the allocation does fail, and the caller is in a position to
     199             :  * free some non-essential memory, doing so could benefit the system
     200             :  * as a whole.
     201             :  *
     202             :  * %__GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
     203             :  * cannot handle allocation failures. The allocation could block
     204             :  * indefinitely but will never return with failure. Testing for
     205             :  * failure is pointless.
     206             :  * New users should be evaluated carefully (and the flag should be
     207             :  * used only when there is no reasonable failure policy) but it is
     208             :  * definitely preferable to use the flag rather than opencode endless
     209             :  * loop around allocator.
     210             :  * Using this flag for costly allocations is _highly_ discouraged.
     211             :  */
     212             : #define __GFP_IO        ((__force gfp_t)___GFP_IO)
     213             : #define __GFP_FS        ((__force gfp_t)___GFP_FS)
     214             : #define __GFP_DIRECT_RECLAIM    ((__force gfp_t)___GFP_DIRECT_RECLAIM) /* Caller can reclaim */
     215             : #define __GFP_KSWAPD_RECLAIM    ((__force gfp_t)___GFP_KSWAPD_RECLAIM) /* kswapd can wake */
     216             : #define __GFP_RECLAIM ((__force gfp_t)(___GFP_DIRECT_RECLAIM|___GFP_KSWAPD_RECLAIM))
     217             : #define __GFP_RETRY_MAYFAIL     ((__force gfp_t)___GFP_RETRY_MAYFAIL)
     218             : #define __GFP_NOFAIL    ((__force gfp_t)___GFP_NOFAIL)
     219             : #define __GFP_NORETRY   ((__force gfp_t)___GFP_NORETRY)
     220             : 
     221             : /**
     222             :  * DOC: Action modifiers
     223             :  *
     224             :  * Action modifiers
     225             :  * ~~~~~~~~~~~~~~~~
     226             :  *
     227             :  * %__GFP_NOWARN suppresses allocation failure reports.
     228             :  *
     229             :  * %__GFP_COMP address compound page metadata.
     230             :  *
     231             :  * %__GFP_ZERO returns a zeroed page on success.
     232             :  */
     233             : #define __GFP_NOWARN    ((__force gfp_t)___GFP_NOWARN)
     234             : #define __GFP_COMP      ((__force gfp_t)___GFP_COMP)
     235             : #define __GFP_ZERO      ((__force gfp_t)___GFP_ZERO)
     236             : 
     237             : /* Disable lockdep for GFP context tracking */
     238             : #define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP)
     239             : 
     240             : /* Room for N __GFP_FOO bits */
     241             : #define __GFP_BITS_SHIFT (23 + IS_ENABLED(CONFIG_LOCKDEP))
     242             : #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
     243             : 
     244             : /**
     245             :  * DOC: Useful GFP flag combinations
     246             :  *
     247             :  * Useful GFP flag combinations
     248             :  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     249             :  *
     250             :  * Useful GFP flag combinations that are commonly used. It is recommended
     251             :  * that subsystems start with one of these combinations and then set/clear
     252             :  * %__GFP_FOO flags as necessary.
     253             :  *
     254             :  * %GFP_ATOMIC users can not sleep and need the allocation to succeed. A lower
     255             :  * watermark is applied to allow access to "atomic reserves".
     256             :  * The current implementation doesn't support NMI and few other strict
     257             :  * non-preemptive contexts (e.g. raw_spin_lock). The same applies to %GFP_NOWAIT.
     258             :  *
     259             :  * %GFP_KERNEL is typical for kernel-internal allocations. The caller requires
     260             :  * %ZONE_NORMAL or a lower zone for direct access but can direct reclaim.
     261             :  *
     262             :  * %GFP_KERNEL_ACCOUNT is the same as GFP_KERNEL, except the allocation is
     263             :  * accounted to kmemcg.
     264             :  *
     265             :  * %GFP_NOWAIT is for kernel allocations that should not stall for direct
     266             :  * reclaim, start physical IO or use any filesystem callback.
     267             :  *
     268             :  * %GFP_NOIO will use direct reclaim to discard clean pages or slab pages
     269             :  * that do not require the starting of any physical IO.
     270             :  * Please try to avoid using this flag directly and instead use
     271             :  * memalloc_noio_{save,restore} to mark the whole scope which cannot
     272             :  * perform any IO with a short explanation why. All allocation requests
     273             :  * will inherit GFP_NOIO implicitly.
     274             :  *
     275             :  * %GFP_NOFS will use direct reclaim but will not use any filesystem interfaces.
     276             :  * Please try to avoid using this flag directly and instead use
     277             :  * memalloc_nofs_{save,restore} to mark the whole scope which cannot/shouldn't
     278             :  * recurse into the FS layer with a short explanation why. All allocation
     279             :  * requests will inherit GFP_NOFS implicitly.
     280             :  *
     281             :  * %GFP_USER is for userspace allocations that also need to be directly
     282             :  * accessibly by the kernel or hardware. It is typically used by hardware
     283             :  * for buffers that are mapped to userspace (e.g. graphics) that hardware
     284             :  * still must DMA to. cpuset limits are enforced for these allocations.
     285             :  *
     286             :  * %GFP_DMA exists for historical reasons and should be avoided where possible.
     287             :  * The flags indicates that the caller requires that the lowest zone be
     288             :  * used (%ZONE_DMA or 16M on x86-64). Ideally, this would be removed but
     289             :  * it would require careful auditing as some users really require it and
     290             :  * others use the flag to avoid lowmem reserves in %ZONE_DMA and treat the
     291             :  * lowest zone as a type of emergency reserve.
     292             :  *
     293             :  * %GFP_DMA32 is similar to %GFP_DMA except that the caller requires a 32-bit
     294             :  * address.
     295             :  *
     296             :  * %GFP_HIGHUSER is for userspace allocations that may be mapped to userspace,
     297             :  * do not need to be directly accessible by the kernel but that cannot
     298             :  * move once in use. An example may be a hardware allocation that maps
     299             :  * data directly into userspace but has no addressing limitations.
     300             :  *
     301             :  * %GFP_HIGHUSER_MOVABLE is for userspace allocations that the kernel does not
     302             :  * need direct access to but can use kmap() when access is required. They
     303             :  * are expected to be movable via page reclaim or page migration. Typically,
     304             :  * pages on the LRU would also be allocated with %GFP_HIGHUSER_MOVABLE.
     305             :  *
     306             :  * %GFP_TRANSHUGE and %GFP_TRANSHUGE_LIGHT are used for THP allocations. They
     307             :  * are compound allocations that will generally fail quickly if memory is not
     308             :  * available and will not wake kswapd/kcompactd on failure. The _LIGHT
     309             :  * version does not attempt reclaim/compaction at all and is by default used
     310             :  * in page fault path, while the non-light is used by khugepaged.
     311             :  */
     312             : #define GFP_ATOMIC      (__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM)
     313             : #define GFP_KERNEL      (__GFP_RECLAIM | __GFP_IO | __GFP_FS)
     314             : #define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT)
     315             : #define GFP_NOWAIT      (__GFP_KSWAPD_RECLAIM)
     316             : #define GFP_NOIO        (__GFP_RECLAIM)
     317             : #define GFP_NOFS        (__GFP_RECLAIM | __GFP_IO)
     318             : #define GFP_USER        (__GFP_RECLAIM | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
     319             : #define GFP_DMA         __GFP_DMA
     320             : #define GFP_DMA32       __GFP_DMA32
     321             : #define GFP_HIGHUSER    (GFP_USER | __GFP_HIGHMEM)
     322             : #define GFP_HIGHUSER_MOVABLE    (GFP_HIGHUSER | __GFP_MOVABLE)
     323             : #define GFP_TRANSHUGE_LIGHT     ((GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
     324             :                          __GFP_NOMEMALLOC | __GFP_NOWARN) & ~__GFP_RECLAIM)
     325             : #define GFP_TRANSHUGE   (GFP_TRANSHUGE_LIGHT | __GFP_DIRECT_RECLAIM)
     326             : 
     327             : /* Convert GFP flags to their corresponding migrate type */
     328             : #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
     329             : #define GFP_MOVABLE_SHIFT 3
     330             : 
     331      193142 : static inline int gfp_migratetype(const gfp_t gfp_flags)
     332             : {
     333      193142 :         VM_WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
     334      193142 :         BUILD_BUG_ON((1UL << GFP_MOVABLE_SHIFT) != ___GFP_MOVABLE);
     335      193142 :         BUILD_BUG_ON((___GFP_MOVABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_MOVABLE);
     336             : 
     337      193142 :         if (unlikely(page_group_by_mobility_disabled))
     338             :                 return MIGRATE_UNMOVABLE;
     339             : 
     340             :         /* Group based on mobility */
     341      193142 :         return (gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;
     342             : }
     343             : #undef GFP_MOVABLE_MASK
     344             : #undef GFP_MOVABLE_SHIFT
     345             : 
     346     3111872 : static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
     347             : {
     348     3111872 :         return !!(gfp_flags & __GFP_DIRECT_RECLAIM);
     349             : }
     350             : 
     351             : /**
     352             :  * gfpflags_normal_context - is gfp_flags a normal sleepable context?
     353             :  * @gfp_flags: gfp_flags to test
     354             :  *
     355             :  * Test whether @gfp_flags indicates that the allocation is from the
     356             :  * %current context and allowed to sleep.
     357             :  *
     358             :  * An allocation being allowed to block doesn't mean it owns the %current
     359             :  * context.  When direct reclaim path tries to allocate memory, the
     360             :  * allocation context is nested inside whatever %current was doing at the
     361             :  * time of the original allocation.  The nested allocation may be allowed
     362             :  * to block but modifying anything %current owns can corrupt the outer
     363             :  * context's expectations.
     364             :  *
     365             :  * %true result from this function indicates that the allocation context
     366             :  * can sleep and use anything that's associated with %current.
     367             :  */
     368         411 : static inline bool gfpflags_normal_context(const gfp_t gfp_flags)
     369             : {
     370         411 :         return (gfp_flags & (__GFP_DIRECT_RECLAIM | __GFP_MEMALLOC)) ==
     371             :                 __GFP_DIRECT_RECLAIM;
     372             : }
     373             : 
     374             : #ifdef CONFIG_HIGHMEM
     375             : #define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
     376             : #else
     377             : #define OPT_ZONE_HIGHMEM ZONE_NORMAL
     378             : #endif
     379             : 
     380             : #ifdef CONFIG_ZONE_DMA
     381             : #define OPT_ZONE_DMA ZONE_DMA
     382             : #else
     383             : #define OPT_ZONE_DMA ZONE_NORMAL
     384             : #endif
     385             : 
     386             : #ifdef CONFIG_ZONE_DMA32
     387             : #define OPT_ZONE_DMA32 ZONE_DMA32
     388             : #else
     389             : #define OPT_ZONE_DMA32 ZONE_NORMAL
     390             : #endif
     391             : 
     392             : /*
     393             :  * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
     394             :  * zone to use given the lowest 4 bits of gfp_t. Entries are GFP_ZONES_SHIFT
     395             :  * bits long and there are 16 of them to cover all possible combinations of
     396             :  * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM.
     397             :  *
     398             :  * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
     399             :  * But GFP_MOVABLE is not only a zone specifier but also an allocation
     400             :  * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
     401             :  * Only 1 bit of the lowest 3 bits (DMA,DMA32,HIGHMEM) can be set to "1".
     402             :  *
     403             :  *       bit       result
     404             :  *       =================
     405             :  *       0x0    => NORMAL
     406             :  *       0x1    => DMA or NORMAL
     407             :  *       0x2    => HIGHMEM or NORMAL
     408             :  *       0x3    => BAD (DMA+HIGHMEM)
     409             :  *       0x4    => DMA32 or NORMAL
     410             :  *       0x5    => BAD (DMA+DMA32)
     411             :  *       0x6    => BAD (HIGHMEM+DMA32)
     412             :  *       0x7    => BAD (HIGHMEM+DMA32+DMA)
     413             :  *       0x8    => NORMAL (MOVABLE+0)
     414             :  *       0x9    => DMA or NORMAL (MOVABLE+DMA)
     415             :  *       0xa    => MOVABLE (Movable is valid only if HIGHMEM is set too)
     416             :  *       0xb    => BAD (MOVABLE+HIGHMEM+DMA)
     417             :  *       0xc    => DMA32 or NORMAL (MOVABLE+DMA32)
     418             :  *       0xd    => BAD (MOVABLE+DMA32+DMA)
     419             :  *       0xe    => BAD (MOVABLE+DMA32+HIGHMEM)
     420             :  *       0xf    => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
     421             :  *
     422             :  * GFP_ZONES_SHIFT must be <= 2 on 32 bit platforms.
     423             :  */
     424             : 
     425             : #if defined(CONFIG_ZONE_DEVICE) && (MAX_NR_ZONES-1) <= 4
     426             : /* ZONE_DEVICE is not a valid GFP zone specifier */
     427             : #define GFP_ZONES_SHIFT 2
     428             : #else
     429             : #define GFP_ZONES_SHIFT ZONES_SHIFT
     430             : #endif
     431             : 
     432             : #if 16 * GFP_ZONES_SHIFT > BITS_PER_LONG
     433             : #error GFP_ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
     434             : #endif
     435             : 
     436             : #define GFP_ZONE_TABLE ( \
     437             :         (ZONE_NORMAL << 0 * GFP_ZONES_SHIFT)                                     \
     438             :         | (OPT_ZONE_DMA << ___GFP_DMA * GFP_ZONES_SHIFT)                 \
     439             :         | (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * GFP_ZONES_SHIFT)         \
     440             :         | (OPT_ZONE_DMA32 << ___GFP_DMA32 * GFP_ZONES_SHIFT)                     \
     441             :         | (ZONE_NORMAL << ___GFP_MOVABLE * GFP_ZONES_SHIFT)                      \
     442             :         | (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * GFP_ZONES_SHIFT)    \
     443             :         | (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * GFP_ZONES_SHIFT)\
     444             :         | (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * GFP_ZONES_SHIFT)\
     445             : )
     446             : 
     447             : /*
     448             :  * GFP_ZONE_BAD is a bitmap for all combinations of __GFP_DMA, __GFP_DMA32
     449             :  * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
     450             :  * entry starting with bit 0. Bit is set if the combination is not
     451             :  * allowed.
     452             :  */
     453             : #define GFP_ZONE_BAD ( \
     454             :         1 << (___GFP_DMA | ___GFP_HIGHMEM)                                      \
     455             :         | 1 << (___GFP_DMA | ___GFP_DMA32)                                      \
     456             :         | 1 << (___GFP_DMA32 | ___GFP_HIGHMEM)                                  \
     457             :         | 1 << (___GFP_DMA | ___GFP_DMA32 | ___GFP_HIGHMEM)                     \
     458             :         | 1 << (___GFP_MOVABLE | ___GFP_HIGHMEM | ___GFP_DMA)                   \
     459             :         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA)                     \
     460             :         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_HIGHMEM)                 \
     461             :         | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA | ___GFP_HIGHMEM)  \
     462             : )
     463             : 
     464      221275 : static inline enum zone_type gfp_zone(gfp_t flags)
     465             : {
     466      221275 :         enum zone_type z;
     467      221275 :         int bit = (__force int) (flags & GFP_ZONEMASK);
     468             : 
     469      221275 :         z = (GFP_ZONE_TABLE >> (bit * GFP_ZONES_SHIFT)) &
     470             :                                          ((1 << GFP_ZONES_SHIFT) - 1);
     471      221268 :         VM_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
     472       28139 :         return z;
     473             : }
     474             : 
     475             : /*
     476             :  * There is only one page-allocator function, and two main namespaces to
     477             :  * it. The alloc_page*() variants return 'struct page *' and as such
     478             :  * can allocate highmem pages, the *get*page*() variants return
     479             :  * virtual kernel addresses to the allocated page(s).
     480             :  */
     481             : 
     482      220478 : static inline int gfp_zonelist(gfp_t flags)
     483             : {
     484             : #ifdef CONFIG_NUMA
     485      220478 :         if (unlikely(flags & __GFP_THISNODE))
     486          19 :                 return ZONELIST_NOFALLBACK;
     487             : #endif
     488             :         return ZONELIST_FALLBACK;
     489             : }
     490             : 
     491             : /*
     492             :  * We get the zone list from the current node and the gfp_mask.
     493             :  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
     494             :  * There are two zonelists per node, one for all zones with memory and
     495             :  * one containing just zones from the node the zonelist belongs to.
     496             :  *
     497             :  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
     498             :  * optimized to &contig_page_data at compile-time.
     499             :  */
     500      220478 : static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
     501             : {
     502      220497 :         return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
     503             : }
     504             : 
     505             : #ifndef HAVE_ARCH_FREE_PAGE
     506             : static inline void arch_free_page(struct page *page, int order) { }
     507             : #endif
     508             : #ifndef HAVE_ARCH_ALLOC_PAGE
     509      193031 : static inline void arch_alloc_page(struct page *page, int order) { }
     510             : #endif
     511             : #ifndef HAVE_ARCH_MAKE_PAGE_ACCESSIBLE
     512        1284 : static inline int arch_make_page_accessible(struct page *page)
     513             : {
     514        1284 :         return 0;
     515             : }
     516             : #endif
     517             : 
     518             : struct page *
     519             : __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,
     520             :                                                         nodemask_t *nodemask);
     521             : 
     522             : static inline struct page *
     523        4884 : __alloc_pages(gfp_t gfp_mask, unsigned int order, int preferred_nid)
     524             : {
     525        4867 :         return __alloc_pages_nodemask(gfp_mask, order, preferred_nid, NULL);
     526             : }
     527             : 
     528             : /*
     529             :  * Allocate pages, preferring the node given as nid. The node must be valid and
     530             :  * online. For more general interface, see alloc_pages_node().
     531             :  */
     532             : static inline struct page *
     533        1164 : __alloc_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
     534             : {
     535        1164 :         VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
     536        1202 :         VM_WARN_ON((gfp_mask & __GFP_THISNODE) && !node_online(nid));
     537             : 
     538        1164 :         return __alloc_pages(gfp_mask, order, nid);
     539             : }
     540             : 
     541             : /*
     542             :  * Allocate pages, preferring the node given as nid. When nid == NUMA_NO_NODE,
     543             :  * prefer the current CPU's closest node. Otherwise node must be valid and
     544             :  * online.
     545             :  */
     546        1109 : static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
     547             :                                                 unsigned int order)
     548             : {
     549        1109 :         if (nid == NUMA_NO_NODE)
     550         884 :                 nid = numa_mem_id();
     551             : 
     552        1109 :         return __alloc_pages_node(nid, gfp_mask, order);
     553             : }
     554             : 
     555             : #ifdef CONFIG_NUMA
     556             : extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
     557             : 
     558             : static inline struct page *
     559      117220 : alloc_pages(gfp_t gfp_mask, unsigned int order)
     560             : {
     561      117220 :         return alloc_pages_current(gfp_mask, order);
     562             : }
     563             : extern struct page *alloc_pages_vma(gfp_t gfp_mask, int order,
     564             :                         struct vm_area_struct *vma, unsigned long addr,
     565             :                         int node, bool hugepage);
     566             : #define alloc_hugepage_vma(gfp_mask, vma, addr, order) \
     567             :         alloc_pages_vma(gfp_mask, order, vma, addr, numa_node_id(), true)
     568             : #else
     569             : static inline struct page *alloc_pages(gfp_t gfp_mask, unsigned int order)
     570             : {
     571             :         return alloc_pages_node(numa_node_id(), gfp_mask, order);
     572             : }
     573             : #define alloc_pages_vma(gfp_mask, order, vma, addr, node, false)\
     574             :         alloc_pages(gfp_mask, order)
     575             : #define alloc_hugepage_vma(gfp_mask, vma, addr, order) \
     576             :         alloc_pages(gfp_mask, order)
     577             : #endif
     578             : #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
     579             : #define alloc_page_vma(gfp_mask, vma, addr)                     \
     580             :         alloc_pages_vma(gfp_mask, 0, vma, addr, numa_node_id(), false)
     581             : 
     582             : extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
     583             : extern unsigned long get_zeroed_page(gfp_t gfp_mask);
     584             : 
     585             : void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
     586             : void free_pages_exact(void *virt, size_t size);
     587             : void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask);
     588             : 
     589             : #define __get_free_page(gfp_mask) \
     590             :                 __get_free_pages((gfp_mask), 0)
     591             : 
     592             : #define __get_dma_pages(gfp_mask, order) \
     593             :                 __get_free_pages((gfp_mask) | GFP_DMA, (order))
     594             : 
     595             : extern void __free_pages(struct page *page, unsigned int order);
     596             : extern void free_pages(unsigned long addr, unsigned int order);
     597             : 
     598             : struct page_frag_cache;
     599             : extern void __page_frag_cache_drain(struct page *page, unsigned int count);
     600             : extern void *page_frag_alloc_align(struct page_frag_cache *nc,
     601             :                                    unsigned int fragsz, gfp_t gfp_mask,
     602             :                                    unsigned int align_mask);
     603             : 
     604           0 : static inline void *page_frag_alloc(struct page_frag_cache *nc,
     605             :                              unsigned int fragsz, gfp_t gfp_mask)
     606             : {
     607           0 :         return page_frag_alloc_align(nc, fragsz, gfp_mask, ~0u);
     608             : }
     609             : 
     610             : extern void page_frag_free(void *addr);
     611             : 
     612             : #define __free_page(page) __free_pages((page), 0)
     613             : #define free_page(addr) free_pages((addr), 0)
     614             : 
     615             : void page_alloc_init(void);
     616             : void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
     617             : void drain_all_pages(struct zone *zone);
     618             : void drain_local_pages(struct zone *zone);
     619             : 
     620             : void page_alloc_init_late(void);
     621             : 
     622             : /*
     623             :  * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what
     624             :  * GFP flags are used before interrupts are enabled. Once interrupts are
     625             :  * enabled, it is set to __GFP_BITS_MASK while the system is running. During
     626             :  * hibernation, it is used by PM to avoid I/O during memory allocation while
     627             :  * devices are suspended.
     628             :  */
     629             : extern gfp_t gfp_allowed_mask;
     630             : 
     631             : /* Returns true if the gfp_mask allows use of ALLOC_NO_WATERMARK */
     632             : bool gfp_pfmemalloc_allowed(gfp_t gfp_mask);
     633             : 
     634             : extern void pm_restrict_gfp_mask(void);
     635             : extern void pm_restore_gfp_mask(void);
     636             : 
     637             : extern gfp_t vma_thp_gfp_mask(struct vm_area_struct *vma);
     638             : 
     639             : #ifdef CONFIG_PM_SLEEP
     640             : extern bool pm_suspended_storage(void);
     641             : #else
     642           0 : static inline bool pm_suspended_storage(void)
     643             : {
     644           0 :         return false;
     645             : }
     646             : #endif /* CONFIG_PM_SLEEP */
     647             : 
     648             : #ifdef CONFIG_CONTIG_ALLOC
     649             : /* The below functions must be run on a range from a single zone. */
     650             : extern int alloc_contig_range(unsigned long start, unsigned long end,
     651             :                               unsigned migratetype, gfp_t gfp_mask);
     652             : extern struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask,
     653             :                                        int nid, nodemask_t *nodemask);
     654             : #endif
     655             : void free_contig_range(unsigned long pfn, unsigned int nr_pages);
     656             : 
     657             : #ifdef CONFIG_CMA
     658             : /* CMA stuff */
     659             : extern void init_cma_reserved_pageblock(struct page *page);
     660             : #endif
     661             : 
     662             : #endif /* __LINUX_GFP_H */

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