cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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gfp.h (27899B)


      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 */
     22typedef unsigned int __bitwise gfp_t;
     23#endif
     24
     25struct 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#define ___GFP_ZEROTAGS		0x800000u
     57#ifdef CONFIG_KASAN_HW_TAGS
     58#define ___GFP_SKIP_ZERO		0x1000000u
     59#define ___GFP_SKIP_KASAN_UNPOISON	0x2000000u
     60#define ___GFP_SKIP_KASAN_POISON	0x4000000u
     61#else
     62#define ___GFP_SKIP_ZERO		0
     63#define ___GFP_SKIP_KASAN_UNPOISON	0
     64#define ___GFP_SKIP_KASAN_POISON	0
     65#endif
     66#ifdef CONFIG_LOCKDEP
     67#define ___GFP_NOLOCKDEP	0x8000000u
     68#else
     69#define ___GFP_NOLOCKDEP	0
     70#endif
     71/* If the above are modified, __GFP_BITS_SHIFT may need updating */
     72
     73/*
     74 * Physical address zone modifiers (see linux/mmzone.h - low four bits)
     75 *
     76 * Do not put any conditional on these. If necessary modify the definitions
     77 * without the underscores and use them consistently. The definitions here may
     78 * be used in bit comparisons.
     79 */
     80#define __GFP_DMA	((__force gfp_t)___GFP_DMA)
     81#define __GFP_HIGHMEM	((__force gfp_t)___GFP_HIGHMEM)
     82#define __GFP_DMA32	((__force gfp_t)___GFP_DMA32)
     83#define __GFP_MOVABLE	((__force gfp_t)___GFP_MOVABLE)  /* ZONE_MOVABLE allowed */
     84#define GFP_ZONEMASK	(__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
     85
     86/**
     87 * DOC: Page mobility and placement hints
     88 *
     89 * Page mobility and placement hints
     90 * ---------------------------------
     91 *
     92 * These flags provide hints about how mobile the page is. Pages with similar
     93 * mobility are placed within the same pageblocks to minimise problems due
     94 * to external fragmentation.
     95 *
     96 * %__GFP_MOVABLE (also a zone modifier) indicates that the page can be
     97 * moved by page migration during memory compaction or can be reclaimed.
     98 *
     99 * %__GFP_RECLAIMABLE is used for slab allocations that specify
    100 * SLAB_RECLAIM_ACCOUNT and whose pages can be freed via shrinkers.
    101 *
    102 * %__GFP_WRITE indicates the caller intends to dirty the page. Where possible,
    103 * these pages will be spread between local zones to avoid all the dirty
    104 * pages being in one zone (fair zone allocation policy).
    105 *
    106 * %__GFP_HARDWALL enforces the cpuset memory allocation policy.
    107 *
    108 * %__GFP_THISNODE forces the allocation to be satisfied from the requested
    109 * node with no fallbacks or placement policy enforcements.
    110 *
    111 * %__GFP_ACCOUNT causes the allocation to be accounted to kmemcg.
    112 */
    113#define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE)
    114#define __GFP_WRITE	((__force gfp_t)___GFP_WRITE)
    115#define __GFP_HARDWALL   ((__force gfp_t)___GFP_HARDWALL)
    116#define __GFP_THISNODE	((__force gfp_t)___GFP_THISNODE)
    117#define __GFP_ACCOUNT	((__force gfp_t)___GFP_ACCOUNT)
    118
    119/**
    120 * DOC: Watermark modifiers
    121 *
    122 * Watermark modifiers -- controls access to emergency reserves
    123 * ------------------------------------------------------------
    124 *
    125 * %__GFP_HIGH indicates that the caller is high-priority and that granting
    126 * the request is necessary before the system can make forward progress.
    127 * For example, creating an IO context to clean pages.
    128 *
    129 * %__GFP_ATOMIC indicates that the caller cannot reclaim or sleep and is
    130 * high priority. Users are typically interrupt handlers. This may be
    131 * used in conjunction with %__GFP_HIGH
    132 *
    133 * %__GFP_MEMALLOC allows access to all memory. This should only be used when
    134 * the caller guarantees the allocation will allow more memory to be freed
    135 * very shortly e.g. process exiting or swapping. Users either should
    136 * be the MM or co-ordinating closely with the VM (e.g. swap over NFS).
    137 * Users of this flag have to be extremely careful to not deplete the reserve
    138 * completely and implement a throttling mechanism which controls the
    139 * consumption of the reserve based on the amount of freed memory.
    140 * Usage of a pre-allocated pool (e.g. mempool) should be always considered
    141 * before using this flag.
    142 *
    143 * %__GFP_NOMEMALLOC is used to explicitly forbid access to emergency reserves.
    144 * This takes precedence over the %__GFP_MEMALLOC flag if both are set.
    145 */
    146#define __GFP_ATOMIC	((__force gfp_t)___GFP_ATOMIC)
    147#define __GFP_HIGH	((__force gfp_t)___GFP_HIGH)
    148#define __GFP_MEMALLOC	((__force gfp_t)___GFP_MEMALLOC)
    149#define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC)
    150
    151/**
    152 * DOC: Reclaim modifiers
    153 *
    154 * Reclaim modifiers
    155 * -----------------
    156 * Please note that all the following flags are only applicable to sleepable
    157 * allocations (e.g. %GFP_NOWAIT and %GFP_ATOMIC will ignore them).
    158 *
    159 * %__GFP_IO can start physical IO.
    160 *
    161 * %__GFP_FS can call down to the low-level FS. Clearing the flag avoids the
    162 * allocator recursing into the filesystem which might already be holding
    163 * locks.
    164 *
    165 * %__GFP_DIRECT_RECLAIM indicates that the caller may enter direct reclaim.
    166 * This flag can be cleared to avoid unnecessary delays when a fallback
    167 * option is available.
    168 *
    169 * %__GFP_KSWAPD_RECLAIM indicates that the caller wants to wake kswapd when
    170 * the low watermark is reached and have it reclaim pages until the high
    171 * watermark is reached. A caller may wish to clear this flag when fallback
    172 * options are available and the reclaim is likely to disrupt the system. The
    173 * canonical example is THP allocation where a fallback is cheap but
    174 * reclaim/compaction may cause indirect stalls.
    175 *
    176 * %__GFP_RECLAIM is shorthand to allow/forbid both direct and kswapd reclaim.
    177 *
    178 * The default allocator behavior depends on the request size. We have a concept
    179 * of so called costly allocations (with order > %PAGE_ALLOC_COSTLY_ORDER).
    180 * !costly allocations are too essential to fail so they are implicitly
    181 * non-failing by default (with some exceptions like OOM victims might fail so
    182 * the caller still has to check for failures) while costly requests try to be
    183 * not disruptive and back off even without invoking the OOM killer.
    184 * The following three modifiers might be used to override some of these
    185 * implicit rules
    186 *
    187 * %__GFP_NORETRY: The VM implementation will try only very lightweight
    188 * memory direct reclaim to get some memory under memory pressure (thus
    189 * it can sleep). It will avoid disruptive actions like OOM killer. The
    190 * caller must handle the failure which is quite likely to happen under
    191 * heavy memory pressure. The flag is suitable when failure can easily be
    192 * handled at small cost, such as reduced throughput
    193 *
    194 * %__GFP_RETRY_MAYFAIL: The VM implementation will retry memory reclaim
    195 * procedures that have previously failed if there is some indication
    196 * that progress has been made else where.  It can wait for other
    197 * tasks to attempt high level approaches to freeing memory such as
    198 * compaction (which removes fragmentation) and page-out.
    199 * There is still a definite limit to the number of retries, but it is
    200 * a larger limit than with %__GFP_NORETRY.
    201 * Allocations with this flag may fail, but only when there is
    202 * genuinely little unused memory. While these allocations do not
    203 * directly trigger the OOM killer, their failure indicates that
    204 * the system is likely to need to use the OOM killer soon.  The
    205 * caller must handle failure, but can reasonably do so by failing
    206 * a higher-level request, or completing it only in a much less
    207 * efficient manner.
    208 * If the allocation does fail, and the caller is in a position to
    209 * free some non-essential memory, doing so could benefit the system
    210 * as a whole.
    211 *
    212 * %__GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
    213 * cannot handle allocation failures. The allocation could block
    214 * indefinitely but will never return with failure. Testing for
    215 * failure is pointless.
    216 * New users should be evaluated carefully (and the flag should be
    217 * used only when there is no reasonable failure policy) but it is
    218 * definitely preferable to use the flag rather than opencode endless
    219 * loop around allocator.
    220 * Using this flag for costly allocations is _highly_ discouraged.
    221 */
    222#define __GFP_IO	((__force gfp_t)___GFP_IO)
    223#define __GFP_FS	((__force gfp_t)___GFP_FS)
    224#define __GFP_DIRECT_RECLAIM	((__force gfp_t)___GFP_DIRECT_RECLAIM) /* Caller can reclaim */
    225#define __GFP_KSWAPD_RECLAIM	((__force gfp_t)___GFP_KSWAPD_RECLAIM) /* kswapd can wake */
    226#define __GFP_RECLAIM ((__force gfp_t)(___GFP_DIRECT_RECLAIM|___GFP_KSWAPD_RECLAIM))
    227#define __GFP_RETRY_MAYFAIL	((__force gfp_t)___GFP_RETRY_MAYFAIL)
    228#define __GFP_NOFAIL	((__force gfp_t)___GFP_NOFAIL)
    229#define __GFP_NORETRY	((__force gfp_t)___GFP_NORETRY)
    230
    231/**
    232 * DOC: Action modifiers
    233 *
    234 * Action modifiers
    235 * ----------------
    236 *
    237 * %__GFP_NOWARN suppresses allocation failure reports.
    238 *
    239 * %__GFP_COMP address compound page metadata.
    240 *
    241 * %__GFP_ZERO returns a zeroed page on success.
    242 *
    243 * %__GFP_ZEROTAGS zeroes memory tags at allocation time if the memory itself
    244 * is being zeroed (either via __GFP_ZERO or via init_on_alloc, provided that
    245 * __GFP_SKIP_ZERO is not set). This flag is intended for optimization: setting
    246 * memory tags at the same time as zeroing memory has minimal additional
    247 * performace impact.
    248 *
    249 * %__GFP_SKIP_KASAN_UNPOISON makes KASAN skip unpoisoning on page allocation.
    250 * Only effective in HW_TAGS mode.
    251 *
    252 * %__GFP_SKIP_KASAN_POISON makes KASAN skip poisoning on page deallocation.
    253 * Typically, used for userspace pages. Only effective in HW_TAGS mode.
    254 */
    255#define __GFP_NOWARN	((__force gfp_t)___GFP_NOWARN)
    256#define __GFP_COMP	((__force gfp_t)___GFP_COMP)
    257#define __GFP_ZERO	((__force gfp_t)___GFP_ZERO)
    258#define __GFP_ZEROTAGS	((__force gfp_t)___GFP_ZEROTAGS)
    259#define __GFP_SKIP_ZERO ((__force gfp_t)___GFP_SKIP_ZERO)
    260#define __GFP_SKIP_KASAN_UNPOISON ((__force gfp_t)___GFP_SKIP_KASAN_UNPOISON)
    261#define __GFP_SKIP_KASAN_POISON   ((__force gfp_t)___GFP_SKIP_KASAN_POISON)
    262
    263/* Disable lockdep for GFP context tracking */
    264#define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP)
    265
    266/* Room for N __GFP_FOO bits */
    267#define __GFP_BITS_SHIFT (27 + IS_ENABLED(CONFIG_LOCKDEP))
    268#define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
    269
    270/**
    271 * DOC: Useful GFP flag combinations
    272 *
    273 * Useful GFP flag combinations
    274 * ----------------------------
    275 *
    276 * Useful GFP flag combinations that are commonly used. It is recommended
    277 * that subsystems start with one of these combinations and then set/clear
    278 * %__GFP_FOO flags as necessary.
    279 *
    280 * %GFP_ATOMIC users can not sleep and need the allocation to succeed. A lower
    281 * watermark is applied to allow access to "atomic reserves".
    282 * The current implementation doesn't support NMI and few other strict
    283 * non-preemptive contexts (e.g. raw_spin_lock). The same applies to %GFP_NOWAIT.
    284 *
    285 * %GFP_KERNEL is typical for kernel-internal allocations. The caller requires
    286 * %ZONE_NORMAL or a lower zone for direct access but can direct reclaim.
    287 *
    288 * %GFP_KERNEL_ACCOUNT is the same as GFP_KERNEL, except the allocation is
    289 * accounted to kmemcg.
    290 *
    291 * %GFP_NOWAIT is for kernel allocations that should not stall for direct
    292 * reclaim, start physical IO or use any filesystem callback.
    293 *
    294 * %GFP_NOIO will use direct reclaim to discard clean pages or slab pages
    295 * that do not require the starting of any physical IO.
    296 * Please try to avoid using this flag directly and instead use
    297 * memalloc_noio_{save,restore} to mark the whole scope which cannot
    298 * perform any IO with a short explanation why. All allocation requests
    299 * will inherit GFP_NOIO implicitly.
    300 *
    301 * %GFP_NOFS will use direct reclaim but will not use any filesystem interfaces.
    302 * Please try to avoid using this flag directly and instead use
    303 * memalloc_nofs_{save,restore} to mark the whole scope which cannot/shouldn't
    304 * recurse into the FS layer with a short explanation why. All allocation
    305 * requests will inherit GFP_NOFS implicitly.
    306 *
    307 * %GFP_USER is for userspace allocations that also need to be directly
    308 * accessibly by the kernel or hardware. It is typically used by hardware
    309 * for buffers that are mapped to userspace (e.g. graphics) that hardware
    310 * still must DMA to. cpuset limits are enforced for these allocations.
    311 *
    312 * %GFP_DMA exists for historical reasons and should be avoided where possible.
    313 * The flags indicates that the caller requires that the lowest zone be
    314 * used (%ZONE_DMA or 16M on x86-64). Ideally, this would be removed but
    315 * it would require careful auditing as some users really require it and
    316 * others use the flag to avoid lowmem reserves in %ZONE_DMA and treat the
    317 * lowest zone as a type of emergency reserve.
    318 *
    319 * %GFP_DMA32 is similar to %GFP_DMA except that the caller requires a 32-bit
    320 * address. Note that kmalloc(..., GFP_DMA32) does not return DMA32 memory
    321 * because the DMA32 kmalloc cache array is not implemented.
    322 * (Reason: there is no such user in kernel).
    323 *
    324 * %GFP_HIGHUSER is for userspace allocations that may be mapped to userspace,
    325 * do not need to be directly accessible by the kernel but that cannot
    326 * move once in use. An example may be a hardware allocation that maps
    327 * data directly into userspace but has no addressing limitations.
    328 *
    329 * %GFP_HIGHUSER_MOVABLE is for userspace allocations that the kernel does not
    330 * need direct access to but can use kmap() when access is required. They
    331 * are expected to be movable via page reclaim or page migration. Typically,
    332 * pages on the LRU would also be allocated with %GFP_HIGHUSER_MOVABLE.
    333 *
    334 * %GFP_TRANSHUGE and %GFP_TRANSHUGE_LIGHT are used for THP allocations. They
    335 * are compound allocations that will generally fail quickly if memory is not
    336 * available and will not wake kswapd/kcompactd on failure. The _LIGHT
    337 * version does not attempt reclaim/compaction at all and is by default used
    338 * in page fault path, while the non-light is used by khugepaged.
    339 */
    340#define GFP_ATOMIC	(__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM)
    341#define GFP_KERNEL	(__GFP_RECLAIM | __GFP_IO | __GFP_FS)
    342#define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT)
    343#define GFP_NOWAIT	(__GFP_KSWAPD_RECLAIM)
    344#define GFP_NOIO	(__GFP_RECLAIM)
    345#define GFP_NOFS	(__GFP_RECLAIM | __GFP_IO)
    346#define GFP_USER	(__GFP_RECLAIM | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
    347#define GFP_DMA		__GFP_DMA
    348#define GFP_DMA32	__GFP_DMA32
    349#define GFP_HIGHUSER	(GFP_USER | __GFP_HIGHMEM)
    350#define GFP_HIGHUSER_MOVABLE	(GFP_HIGHUSER | __GFP_MOVABLE | \
    351			 __GFP_SKIP_KASAN_POISON)
    352#define GFP_TRANSHUGE_LIGHT	((GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
    353			 __GFP_NOMEMALLOC | __GFP_NOWARN) & ~__GFP_RECLAIM)
    354#define GFP_TRANSHUGE	(GFP_TRANSHUGE_LIGHT | __GFP_DIRECT_RECLAIM)
    355
    356/* Convert GFP flags to their corresponding migrate type */
    357#define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
    358#define GFP_MOVABLE_SHIFT 3
    359
    360static inline int gfp_migratetype(const gfp_t gfp_flags)
    361{
    362	VM_WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
    363	BUILD_BUG_ON((1UL << GFP_MOVABLE_SHIFT) != ___GFP_MOVABLE);
    364	BUILD_BUG_ON((___GFP_MOVABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_MOVABLE);
    365
    366	if (unlikely(page_group_by_mobility_disabled))
    367		return MIGRATE_UNMOVABLE;
    368
    369	/* Group based on mobility */
    370	return (__force unsigned long)(gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;
    371}
    372#undef GFP_MOVABLE_MASK
    373#undef GFP_MOVABLE_SHIFT
    374
    375static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
    376{
    377	return !!(gfp_flags & __GFP_DIRECT_RECLAIM);
    378}
    379
    380/**
    381 * gfpflags_normal_context - is gfp_flags a normal sleepable context?
    382 * @gfp_flags: gfp_flags to test
    383 *
    384 * Test whether @gfp_flags indicates that the allocation is from the
    385 * %current context and allowed to sleep.
    386 *
    387 * An allocation being allowed to block doesn't mean it owns the %current
    388 * context.  When direct reclaim path tries to allocate memory, the
    389 * allocation context is nested inside whatever %current was doing at the
    390 * time of the original allocation.  The nested allocation may be allowed
    391 * to block but modifying anything %current owns can corrupt the outer
    392 * context's expectations.
    393 *
    394 * %true result from this function indicates that the allocation context
    395 * can sleep and use anything that's associated with %current.
    396 */
    397static inline bool gfpflags_normal_context(const gfp_t gfp_flags)
    398{
    399	return (gfp_flags & (__GFP_DIRECT_RECLAIM | __GFP_MEMALLOC)) ==
    400		__GFP_DIRECT_RECLAIM;
    401}
    402
    403#ifdef CONFIG_HIGHMEM
    404#define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
    405#else
    406#define OPT_ZONE_HIGHMEM ZONE_NORMAL
    407#endif
    408
    409#ifdef CONFIG_ZONE_DMA
    410#define OPT_ZONE_DMA ZONE_DMA
    411#else
    412#define OPT_ZONE_DMA ZONE_NORMAL
    413#endif
    414
    415#ifdef CONFIG_ZONE_DMA32
    416#define OPT_ZONE_DMA32 ZONE_DMA32
    417#else
    418#define OPT_ZONE_DMA32 ZONE_NORMAL
    419#endif
    420
    421/*
    422 * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
    423 * zone to use given the lowest 4 bits of gfp_t. Entries are GFP_ZONES_SHIFT
    424 * bits long and there are 16 of them to cover all possible combinations of
    425 * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM.
    426 *
    427 * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
    428 * But GFP_MOVABLE is not only a zone specifier but also an allocation
    429 * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
    430 * Only 1 bit of the lowest 3 bits (DMA,DMA32,HIGHMEM) can be set to "1".
    431 *
    432 *       bit       result
    433 *       =================
    434 *       0x0    => NORMAL
    435 *       0x1    => DMA or NORMAL
    436 *       0x2    => HIGHMEM or NORMAL
    437 *       0x3    => BAD (DMA+HIGHMEM)
    438 *       0x4    => DMA32 or NORMAL
    439 *       0x5    => BAD (DMA+DMA32)
    440 *       0x6    => BAD (HIGHMEM+DMA32)
    441 *       0x7    => BAD (HIGHMEM+DMA32+DMA)
    442 *       0x8    => NORMAL (MOVABLE+0)
    443 *       0x9    => DMA or NORMAL (MOVABLE+DMA)
    444 *       0xa    => MOVABLE (Movable is valid only if HIGHMEM is set too)
    445 *       0xb    => BAD (MOVABLE+HIGHMEM+DMA)
    446 *       0xc    => DMA32 or NORMAL (MOVABLE+DMA32)
    447 *       0xd    => BAD (MOVABLE+DMA32+DMA)
    448 *       0xe    => BAD (MOVABLE+DMA32+HIGHMEM)
    449 *       0xf    => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
    450 *
    451 * GFP_ZONES_SHIFT must be <= 2 on 32 bit platforms.
    452 */
    453
    454#if defined(CONFIG_ZONE_DEVICE) && (MAX_NR_ZONES-1) <= 4
    455/* ZONE_DEVICE is not a valid GFP zone specifier */
    456#define GFP_ZONES_SHIFT 2
    457#else
    458#define GFP_ZONES_SHIFT ZONES_SHIFT
    459#endif
    460
    461#if 16 * GFP_ZONES_SHIFT > BITS_PER_LONG
    462#error GFP_ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
    463#endif
    464
    465#define GFP_ZONE_TABLE ( \
    466	(ZONE_NORMAL << 0 * GFP_ZONES_SHIFT)				       \
    467	| (OPT_ZONE_DMA << ___GFP_DMA * GFP_ZONES_SHIFT)		       \
    468	| (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * GFP_ZONES_SHIFT)	       \
    469	| (OPT_ZONE_DMA32 << ___GFP_DMA32 * GFP_ZONES_SHIFT)		       \
    470	| (ZONE_NORMAL << ___GFP_MOVABLE * GFP_ZONES_SHIFT)		       \
    471	| (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * GFP_ZONES_SHIFT)    \
    472	| (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * GFP_ZONES_SHIFT)\
    473	| (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * GFP_ZONES_SHIFT)\
    474)
    475
    476/*
    477 * GFP_ZONE_BAD is a bitmap for all combinations of __GFP_DMA, __GFP_DMA32
    478 * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
    479 * entry starting with bit 0. Bit is set if the combination is not
    480 * allowed.
    481 */
    482#define GFP_ZONE_BAD ( \
    483	1 << (___GFP_DMA | ___GFP_HIGHMEM)				      \
    484	| 1 << (___GFP_DMA | ___GFP_DMA32)				      \
    485	| 1 << (___GFP_DMA32 | ___GFP_HIGHMEM)				      \
    486	| 1 << (___GFP_DMA | ___GFP_DMA32 | ___GFP_HIGHMEM)		      \
    487	| 1 << (___GFP_MOVABLE | ___GFP_HIGHMEM | ___GFP_DMA)		      \
    488	| 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA)		      \
    489	| 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_HIGHMEM)		      \
    490	| 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA | ___GFP_HIGHMEM)  \
    491)
    492
    493static inline enum zone_type gfp_zone(gfp_t flags)
    494{
    495	enum zone_type z;
    496	int bit = (__force int) (flags & GFP_ZONEMASK);
    497
    498	z = (GFP_ZONE_TABLE >> (bit * GFP_ZONES_SHIFT)) &
    499					 ((1 << GFP_ZONES_SHIFT) - 1);
    500	VM_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
    501	return z;
    502}
    503
    504/*
    505 * There is only one page-allocator function, and two main namespaces to
    506 * it. The alloc_page*() variants return 'struct page *' and as such
    507 * can allocate highmem pages, the *get*page*() variants return
    508 * virtual kernel addresses to the allocated page(s).
    509 */
    510
    511static inline int gfp_zonelist(gfp_t flags)
    512{
    513#ifdef CONFIG_NUMA
    514	if (unlikely(flags & __GFP_THISNODE))
    515		return ZONELIST_NOFALLBACK;
    516#endif
    517	return ZONELIST_FALLBACK;
    518}
    519
    520/*
    521 * We get the zone list from the current node and the gfp_mask.
    522 * This zone list contains a maximum of MAX_NUMNODES*MAX_NR_ZONES zones.
    523 * There are two zonelists per node, one for all zones with memory and
    524 * one containing just zones from the node the zonelist belongs to.
    525 *
    526 * For the case of non-NUMA systems the NODE_DATA() gets optimized to
    527 * &contig_page_data at compile-time.
    528 */
    529static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
    530{
    531	return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
    532}
    533
    534#ifndef HAVE_ARCH_FREE_PAGE
    535static inline void arch_free_page(struct page *page, int order) { }
    536#endif
    537#ifndef HAVE_ARCH_ALLOC_PAGE
    538static inline void arch_alloc_page(struct page *page, int order) { }
    539#endif
    540
    541struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid,
    542		nodemask_t *nodemask);
    543struct folio *__folio_alloc(gfp_t gfp, unsigned int order, int preferred_nid,
    544		nodemask_t *nodemask);
    545
    546unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
    547				nodemask_t *nodemask, int nr_pages,
    548				struct list_head *page_list,
    549				struct page **page_array);
    550
    551unsigned long alloc_pages_bulk_array_mempolicy(gfp_t gfp,
    552				unsigned long nr_pages,
    553				struct page **page_array);
    554
    555/* Bulk allocate order-0 pages */
    556static inline unsigned long
    557alloc_pages_bulk_list(gfp_t gfp, unsigned long nr_pages, struct list_head *list)
    558{
    559	return __alloc_pages_bulk(gfp, numa_mem_id(), NULL, nr_pages, list, NULL);
    560}
    561
    562static inline unsigned long
    563alloc_pages_bulk_array(gfp_t gfp, unsigned long nr_pages, struct page **page_array)
    564{
    565	return __alloc_pages_bulk(gfp, numa_mem_id(), NULL, nr_pages, NULL, page_array);
    566}
    567
    568static inline unsigned long
    569alloc_pages_bulk_array_node(gfp_t gfp, int nid, unsigned long nr_pages, struct page **page_array)
    570{
    571	if (nid == NUMA_NO_NODE)
    572		nid = numa_mem_id();
    573
    574	return __alloc_pages_bulk(gfp, nid, NULL, nr_pages, NULL, page_array);
    575}
    576
    577/*
    578 * Allocate pages, preferring the node given as nid. The node must be valid and
    579 * online. For more general interface, see alloc_pages_node().
    580 */
    581static inline struct page *
    582__alloc_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
    583{
    584	VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
    585	VM_WARN_ON((gfp_mask & __GFP_THISNODE) && !node_online(nid));
    586
    587	return __alloc_pages(gfp_mask, order, nid, NULL);
    588}
    589
    590static inline
    591struct folio *__folio_alloc_node(gfp_t gfp, unsigned int order, int nid)
    592{
    593	VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
    594	VM_WARN_ON((gfp & __GFP_THISNODE) && !node_online(nid));
    595
    596	return __folio_alloc(gfp, order, nid, NULL);
    597}
    598
    599/*
    600 * Allocate pages, preferring the node given as nid. When nid == NUMA_NO_NODE,
    601 * prefer the current CPU's closest node. Otherwise node must be valid and
    602 * online.
    603 */
    604static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
    605						unsigned int order)
    606{
    607	if (nid == NUMA_NO_NODE)
    608		nid = numa_mem_id();
    609
    610	return __alloc_pages_node(nid, gfp_mask, order);
    611}
    612
    613#ifdef CONFIG_NUMA
    614struct page *alloc_pages(gfp_t gfp, unsigned int order);
    615struct folio *folio_alloc(gfp_t gfp, unsigned order);
    616struct folio *vma_alloc_folio(gfp_t gfp, int order, struct vm_area_struct *vma,
    617		unsigned long addr, bool hugepage);
    618#else
    619static inline struct page *alloc_pages(gfp_t gfp_mask, unsigned int order)
    620{
    621	return alloc_pages_node(numa_node_id(), gfp_mask, order);
    622}
    623static inline struct folio *folio_alloc(gfp_t gfp, unsigned int order)
    624{
    625	return __folio_alloc_node(gfp, order, numa_node_id());
    626}
    627#define vma_alloc_folio(gfp, order, vma, addr, hugepage)		\
    628	folio_alloc(gfp, order)
    629#endif
    630#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
    631static inline struct page *alloc_page_vma(gfp_t gfp,
    632		struct vm_area_struct *vma, unsigned long addr)
    633{
    634	struct folio *folio = vma_alloc_folio(gfp, 0, vma, addr, false);
    635
    636	return &folio->page;
    637}
    638
    639extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
    640extern unsigned long get_zeroed_page(gfp_t gfp_mask);
    641
    642void *alloc_pages_exact(size_t size, gfp_t gfp_mask) __alloc_size(1);
    643void free_pages_exact(void *virt, size_t size);
    644__meminit void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask) __alloc_size(2);
    645
    646#define __get_free_page(gfp_mask) \
    647		__get_free_pages((gfp_mask), 0)
    648
    649#define __get_dma_pages(gfp_mask, order) \
    650		__get_free_pages((gfp_mask) | GFP_DMA, (order))
    651
    652extern void __free_pages(struct page *page, unsigned int order);
    653extern void free_pages(unsigned long addr, unsigned int order);
    654
    655struct page_frag_cache;
    656extern void __page_frag_cache_drain(struct page *page, unsigned int count);
    657extern void *page_frag_alloc_align(struct page_frag_cache *nc,
    658				   unsigned int fragsz, gfp_t gfp_mask,
    659				   unsigned int align_mask);
    660
    661static inline void *page_frag_alloc(struct page_frag_cache *nc,
    662			     unsigned int fragsz, gfp_t gfp_mask)
    663{
    664	return page_frag_alloc_align(nc, fragsz, gfp_mask, ~0u);
    665}
    666
    667extern void page_frag_free(void *addr);
    668
    669#define __free_page(page) __free_pages((page), 0)
    670#define free_page(addr) free_pages((addr), 0)
    671
    672void page_alloc_init(void);
    673void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
    674void drain_all_pages(struct zone *zone);
    675void drain_local_pages(struct zone *zone);
    676
    677void page_alloc_init_late(void);
    678
    679/*
    680 * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what
    681 * GFP flags are used before interrupts are enabled. Once interrupts are
    682 * enabled, it is set to __GFP_BITS_MASK while the system is running. During
    683 * hibernation, it is used by PM to avoid I/O during memory allocation while
    684 * devices are suspended.
    685 */
    686extern gfp_t gfp_allowed_mask;
    687
    688/* Returns true if the gfp_mask allows use of ALLOC_NO_WATERMARK */
    689bool gfp_pfmemalloc_allowed(gfp_t gfp_mask);
    690
    691extern void pm_restrict_gfp_mask(void);
    692extern void pm_restore_gfp_mask(void);
    693
    694extern gfp_t vma_thp_gfp_mask(struct vm_area_struct *vma);
    695
    696#ifdef CONFIG_PM_SLEEP
    697extern bool pm_suspended_storage(void);
    698#else
    699static inline bool pm_suspended_storage(void)
    700{
    701	return false;
    702}
    703#endif /* CONFIG_PM_SLEEP */
    704
    705#ifdef CONFIG_CONTIG_ALLOC
    706/* The below functions must be run on a range from a single zone. */
    707extern int alloc_contig_range(unsigned long start, unsigned long end,
    708			      unsigned migratetype, gfp_t gfp_mask);
    709extern struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask,
    710				       int nid, nodemask_t *nodemask);
    711#endif
    712void free_contig_range(unsigned long pfn, unsigned long nr_pages);
    713
    714#ifdef CONFIG_CMA
    715/* CMA stuff */
    716extern void init_cma_reserved_pageblock(struct page *page);
    717#endif
    718
    719#endif /* __LINUX_GFP_H */