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