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