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 struct 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 #define ___GFP_CMA 0x1000000u
48 /* If the above are modified, __GFP_BITS_SHIFT may need updating */
49
50 /*
51 * Physical address zone modifiers (see linux/mmzone.h - low four bits)
52 *
53 * Do not put any conditional on these. If necessary modify the definitions
54 * without the underscores and use them consistently. The definitions here may
55 * be used in bit comparisons.
56 */
57 #define __GFP_DMA ((__force gfp_t)___GFP_DMA)
58 #define __GFP_HIGHMEM ((__force gfp_t)___GFP_HIGHMEM)
59 #define __GFP_DMA32 ((__force gfp_t)___GFP_DMA32)
60 #define __GFP_MOVABLE ((__force gfp_t)___GFP_MOVABLE) /* ZONE_MOVABLE allowed */
61 #define __GFP_CMA ((__force gfp_t)___GFP_CMA)
62 #define GFP_ZONEMASK (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
63
64 /**
65 * DOC: Page mobility and placement hints
66 *
67 * Page mobility and placement hints
68 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
69 *
70 * These flags provide hints about how mobile the page is. Pages with similar
71 * mobility are placed within the same pageblocks to minimise problems due
72 * to external fragmentation.
73 *
74 * %__GFP_MOVABLE (also a zone modifier) indicates that the page can be
75 * moved by page migration during memory compaction or can be reclaimed.
76 *
77 * %__GFP_RECLAIMABLE is used for slab allocations that specify
78 * SLAB_RECLAIM_ACCOUNT and whose pages can be freed via shrinkers.
79 *
80 * %__GFP_WRITE indicates the caller intends to dirty the page. Where possible,
81 * these pages will be spread between local zones to avoid all the dirty
82 * pages being in one zone (fair zone allocation policy).
83 *
84 * %__GFP_HARDWALL enforces the cpuset memory allocation policy.
85 *
86 * %__GFP_THISNODE forces the allocation to be satisfied from the requested
87 * node with no fallbacks or placement policy enforcements.
88 *
89 * %__GFP_ACCOUNT causes the allocation to be accounted to kmemcg.
90 */
91 #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE)
92 #define __GFP_WRITE ((__force gfp_t)___GFP_WRITE)
93 #define __GFP_HARDWALL ((__force gfp_t)___GFP_HARDWALL)
94 #define __GFP_THISNODE ((__force gfp_t)___GFP_THISNODE)
95 #define __GFP_ACCOUNT ((__force gfp_t)___GFP_ACCOUNT)
96
97 /**
98 * DOC: Watermark modifiers
99 *
100 * Watermark modifiers -- controls access to emergency reserves
101 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
102 *
103 * %__GFP_HIGH indicates that the caller is high-priority and that granting
104 * the request is necessary before the system can make forward progress.
105 * For example, creating an IO context to clean pages.
106 *
107 * %__GFP_ATOMIC indicates that the caller cannot reclaim or sleep and is
108 * high priority. Users are typically interrupt handlers. This may be
109 * used in conjunction with %__GFP_HIGH
110 *
111 * %__GFP_MEMALLOC allows access to all memory. This should only be used when
112 * the caller guarantees the allocation will allow more memory to be freed
113 * very shortly e.g. process exiting or swapping. Users either should
114 * be the MM or co-ordinating closely with the VM (e.g. swap over NFS).
115 *
116 * %__GFP_NOMEMALLOC is used to explicitly forbid access to emergency reserves.
117 * This takes precedence over the %__GFP_MEMALLOC flag if both are set.
118 */
119 #define __GFP_ATOMIC ((__force gfp_t)___GFP_ATOMIC)
120 #define __GFP_HIGH ((__force gfp_t)___GFP_HIGH)
121 #define __GFP_MEMALLOC ((__force gfp_t)___GFP_MEMALLOC)
122 #define __GFP_NOMEMALLOC ((__force gfp_t)___GFP_NOMEMALLOC)
123
124 /**
125 * DOC: Reclaim modifiers
126 *
127 * Reclaim modifiers
128 * ~~~~~~~~~~~~~~~~~
129 *
130 * %__GFP_IO can start physical IO.
131 *
132 * %__GFP_FS can call down to the low-level FS. Clearing the flag avoids the
133 * allocator recursing into the filesystem which might already be holding
134 * locks.
135 *
136 * %__GFP_DIRECT_RECLAIM indicates that the caller may enter direct reclaim.
137 * This flag can be cleared to avoid unnecessary delays when a fallback
138 * option is available.
139 *
140 * %__GFP_KSWAPD_RECLAIM indicates that the caller wants to wake kswapd when
141 * the low watermark is reached and have it reclaim pages until the high
142 * watermark is reached. A caller may wish to clear this flag when fallback
143 * options are available and the reclaim is likely to disrupt the system. The
144 * canonical example is THP allocation where a fallback is cheap but
145 * reclaim/compaction may cause indirect stalls.
146 *
147 * %__GFP_RECLAIM is shorthand to allow/forbid both direct and kswapd reclaim.
148 *
149 * The default allocator behavior depends on the request size. We have a concept
150 * of so called costly allocations (with order > %PAGE_ALLOC_COSTLY_ORDER).
151 * !costly allocations are too essential to fail so they are implicitly
152 * non-failing by default (with some exceptions like OOM victims might fail so
153 * the caller still has to check for failures) while costly requests try to be
154 * not disruptive and back off even without invoking the OOM killer.
155 * The following three modifiers might be used to override some of these
156 * implicit rules
157 *
158 * %__GFP_NORETRY: The VM implementation will try only very lightweight
159 * memory direct reclaim to get some memory under memory pressure (thus
160 * it can sleep). It will avoid disruptive actions like OOM killer. The
161 * caller must handle the failure which is quite likely to happen under
162 * heavy memory pressure. The flag is suitable when failure can easily be
163 * handled at small cost, such as reduced throughput
164 *
165 * %__GFP_RETRY_MAYFAIL: The VM implementation will retry memory reclaim
166 * procedures that have previously failed if there is some indication
167 * that progress has been made else where. It can wait for other
168 * tasks to attempt high level approaches to freeing memory such as
169 * compaction (which removes fragmentation) and page-out.
170 * There is still a definite limit to the number of retries, but it is
171 * a larger limit than with %__GFP_NORETRY.
172 * Allocations with this flag may fail, but only when there is
173 * genuinely little unused memory. While these allocations do not
174 * directly trigger the OOM killer, their failure indicates that
175 * the system is likely to need to use the OOM killer soon. The
176 * caller must handle failure, but can reasonably do so by failing
177 * a higher-level request, or completing it only in a much less
178 * efficient manner.
179 * If the allocation does fail, and the caller is in a position to
180 * free some non-essential memory, doing so could benefit the system
181 * as a whole.
182 *
183 * %__GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
184 * cannot handle allocation failures. The allocation could block
185 * indefinitely but will never return with failure. Testing for
186 * failure is pointless.
187 * New users should be evaluated carefully (and the flag should be
188 * used only when there is no reasonable failure policy) but it is
189 * definitely preferable to use the flag rather than opencode endless
190 * loop around allocator.
191 * Using this flag for costly allocations is _highly_ discouraged.
192 */
193 #define __GFP_IO ((__force gfp_t)___GFP_IO)
194 #define __GFP_FS ((__force gfp_t)___GFP_FS)
195 #define __GFP_DIRECT_RECLAIM ((__force gfp_t)___GFP_DIRECT_RECLAIM) /* Caller can reclaim */
196 #define __GFP_KSWAPD_RECLAIM ((__force gfp_t)___GFP_KSWAPD_RECLAIM) /* kswapd can wake */
197 #define __GFP_RECLAIM ((__force gfp_t)(___GFP_DIRECT_RECLAIM|___GFP_KSWAPD_RECLAIM))
198 #define __GFP_RETRY_MAYFAIL ((__force gfp_t)___GFP_RETRY_MAYFAIL)
199 #define __GFP_NOFAIL ((__force gfp_t)___GFP_NOFAIL)
200 #define __GFP_NORETRY ((__force gfp_t)___GFP_NORETRY)
201
202 /**
203 * DOC: Action modifiers
204 *
205 * Action modifiers
206 * ~~~~~~~~~~~~~~~~
207 *
208 * %__GFP_NOWARN suppresses allocation failure reports.
209 *
210 * %__GFP_COMP address compound page metadata.
211 *
212 * %__GFP_ZERO returns a zeroed page on success.
213 */
214 #define __GFP_NOWARN ((__force gfp_t)___GFP_NOWARN)
215 #define __GFP_COMP ((__force gfp_t)___GFP_COMP)
216 #define __GFP_ZERO ((__force gfp_t)___GFP_ZERO)
217
218 /* Disable lockdep for GFP context tracking */
219 #define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP)
220
221 /* Room for N __GFP_FOO bits */
222 #define __GFP_BITS_SHIFT (25)
223 #ifdef CONFIG_LOCKDEP
224 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
225 #else
226 #define __GFP_BITS_MASK (((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1)) & \
227 ~0x800000u)
228 #endif
229
230 /**
231 * DOC: Useful GFP flag combinations
232 *
233 * Useful GFP flag combinations
234 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
235 *
236 * Useful GFP flag combinations that are commonly used. It is recommended
237 * that subsystems start with one of these combinations and then set/clear
238 * %__GFP_FOO flags as necessary.
239 *
240 * %GFP_ATOMIC users can not sleep and need the allocation to succeed. A lower
241 * watermark is applied to allow access to "atomic reserves"
242 *
243 * %GFP_KERNEL is typical for kernel-internal allocations. The caller requires
244 * %ZONE_NORMAL or a lower zone for direct access but can direct reclaim.
245 *
246 * %GFP_KERNEL_ACCOUNT is the same as GFP_KERNEL, except the allocation is
247 * accounted to kmemcg.
248 *
249 * %GFP_NOWAIT is for kernel allocations that should not stall for direct
250 * reclaim, start physical IO or use any filesystem callback.
251 *
252 * %GFP_NOIO will use direct reclaim to discard clean pages or slab pages
253 * that do not require the starting of any physical IO.
254 * Please try to avoid using this flag directly and instead use
255 * memalloc_noio_{save,restore} to mark the whole scope which cannot
256 * perform any IO with a short explanation why. All allocation requests
257 * will inherit GFP_NOIO implicitly.
258 *
259 * %GFP_NOFS will use direct reclaim but will not use any filesystem interfaces.
260 * Please try to avoid using this flag directly and instead use
261 * memalloc_nofs_{save,restore} to mark the whole scope which cannot/shouldn't
262 * recurse into the FS layer with a short explanation why. All allocation
263 * requests will inherit GFP_NOFS implicitly.
264 *
265 * %GFP_USER is for userspace allocations that also need to be directly
266 * accessibly by the kernel or hardware. It is typically used by hardware
267 * for buffers that are mapped to userspace (e.g. graphics) that hardware
268 * still must DMA to. cpuset limits are enforced for these allocations.
269 *
270 * %GFP_DMA exists for historical reasons and should be avoided where possible.
271 * The flags indicates that the caller requires that the lowest zone be
272 * used (%ZONE_DMA or 16M on x86-64). Ideally, this would be removed but
273 * it would require careful auditing as some users really require it and
274 * others use the flag to avoid lowmem reserves in %ZONE_DMA and treat the
275 * lowest zone as a type of emergency reserve.
276 *
277 * %GFP_DMA32 is similar to %GFP_DMA except that the caller requires a 32-bit
278 * address.
279 *
280 * %GFP_HIGHUSER is for userspace allocations that may be mapped to userspace,
281 * do not need to be directly accessible by the kernel but that cannot
282 * move once in use. An example may be a hardware allocation that maps
283 * data directly into userspace but has no addressing limitations.
284 *
285 * %GFP_HIGHUSER_MOVABLE is for userspace allocations that the kernel does not
286 * need direct access to but can use kmap() when access is required. They
287 * are expected to be movable via page reclaim or page migration. Typically,
288 * pages on the LRU would also be allocated with %GFP_HIGHUSER_MOVABLE.
289 *
290 * %GFP_TRANSHUGE and %GFP_TRANSHUGE_LIGHT are used for THP allocations. They
291 * are compound allocations that will generally fail quickly if memory is not
292 * available and will not wake kswapd/kcompactd on failure. The _LIGHT
293 * version does not attempt reclaim/compaction at all and is by default used
294 * in page fault path, while the non-light is used by khugepaged.
295 */
296 #define GFP_ATOMIC (__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM)
297 #define GFP_KERNEL (__GFP_RECLAIM | __GFP_IO | __GFP_FS)
298 #define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT)
299 #define GFP_NOWAIT (__GFP_KSWAPD_RECLAIM)
300 #define GFP_NOIO (__GFP_RECLAIM)
301 #define GFP_NOFS (__GFP_RECLAIM | __GFP_IO)
302 #define GFP_USER (__GFP_RECLAIM | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
303 #define GFP_DMA __GFP_DMA
304 #define GFP_DMA32 __GFP_DMA32
305 #define GFP_HIGHUSER (GFP_USER | __GFP_HIGHMEM)
306 #define GFP_HIGHUSER_MOVABLE (GFP_HIGHUSER | __GFP_MOVABLE)
307 #define GFP_TRANSHUGE_LIGHT ((GFP_HIGHUSER_MOVABLE | __GFP_COMP | \
308 __GFP_NOMEMALLOC | __GFP_NOWARN) & ~__GFP_RECLAIM)
309 #define GFP_TRANSHUGE (GFP_TRANSHUGE_LIGHT | __GFP_DIRECT_RECLAIM)
310
311 /* Convert GFP flags to their corresponding migrate type */
312 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
313 #define GFP_MOVABLE_SHIFT 3
314
gfpflags_to_migratetype(const gfp_t gfp_flags)315 static inline int gfpflags_to_migratetype(const gfp_t gfp_flags)
316 {
317 VM_WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
318 BUILD_BUG_ON((1UL << GFP_MOVABLE_SHIFT) != ___GFP_MOVABLE);
319 BUILD_BUG_ON((___GFP_MOVABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_MOVABLE);
320
321 if (unlikely(page_group_by_mobility_disabled))
322 return MIGRATE_UNMOVABLE;
323
324 /* Group based on mobility */
325 return (gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;
326 }
327 #undef GFP_MOVABLE_MASK
328 #undef GFP_MOVABLE_SHIFT
329
gfpflags_allow_blocking(const gfp_t gfp_flags)330 static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
331 {
332 return !!(gfp_flags & __GFP_DIRECT_RECLAIM);
333 }
334
335 /**
336 * gfpflags_normal_context - is gfp_flags a normal sleepable context?
337 * @gfp_flags: gfp_flags to test
338 *
339 * Test whether @gfp_flags indicates that the allocation is from the
340 * %current context and allowed to sleep.
341 *
342 * An allocation being allowed to block doesn't mean it owns the %current
343 * context. When direct reclaim path tries to allocate memory, the
344 * allocation context is nested inside whatever %current was doing at the
345 * time of the original allocation. The nested allocation may be allowed
346 * to block but modifying anything %current owns can corrupt the outer
347 * context's expectations.
348 *
349 * %true result from this function indicates that the allocation context
350 * can sleep and use anything that's associated with %current.
351 */
gfpflags_normal_context(const gfp_t gfp_flags)352 static inline bool gfpflags_normal_context(const gfp_t gfp_flags)
353 {
354 return (gfp_flags & (__GFP_DIRECT_RECLAIM | __GFP_MEMALLOC)) ==
355 __GFP_DIRECT_RECLAIM;
356 }
357
358 #ifdef CONFIG_HIGHMEM
359 #define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
360 #else
361 #define OPT_ZONE_HIGHMEM ZONE_NORMAL
362 #endif
363
364 #ifdef CONFIG_ZONE_DMA
365 #define OPT_ZONE_DMA ZONE_DMA
366 #else
367 #define OPT_ZONE_DMA ZONE_NORMAL
368 #endif
369
370 #ifdef CONFIG_ZONE_DMA32
371 #define OPT_ZONE_DMA32 ZONE_DMA32
372 #else
373 #define OPT_ZONE_DMA32 ZONE_NORMAL
374 #endif
375
376 /*
377 * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
378 * zone to use given the lowest 4 bits of gfp_t. Entries are GFP_ZONES_SHIFT
379 * bits long and there are 16 of them to cover all possible combinations of
380 * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM.
381 *
382 * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
383 * But GFP_MOVABLE is not only a zone specifier but also an allocation
384 * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
385 * Only 1 bit of the lowest 3 bits (DMA,DMA32,HIGHMEM) can be set to "1".
386 *
387 * bit result
388 * =================
389 * 0x0 => NORMAL
390 * 0x1 => DMA or NORMAL
391 * 0x2 => HIGHMEM or NORMAL
392 * 0x3 => BAD (DMA+HIGHMEM)
393 * 0x4 => DMA32 or NORMAL
394 * 0x5 => BAD (DMA+DMA32)
395 * 0x6 => BAD (HIGHMEM+DMA32)
396 * 0x7 => BAD (HIGHMEM+DMA32+DMA)
397 * 0x8 => NORMAL (MOVABLE+0)
398 * 0x9 => DMA or NORMAL (MOVABLE+DMA)
399 * 0xa => MOVABLE (Movable is valid only if HIGHMEM is set too)
400 * 0xb => BAD (MOVABLE+HIGHMEM+DMA)
401 * 0xc => DMA32 or NORMAL (MOVABLE+DMA32)
402 * 0xd => BAD (MOVABLE+DMA32+DMA)
403 * 0xe => BAD (MOVABLE+DMA32+HIGHMEM)
404 * 0xf => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
405 *
406 * GFP_ZONES_SHIFT must be <= 2 on 32 bit platforms.
407 */
408
409 #if defined(CONFIG_ZONE_DEVICE) && (MAX_NR_ZONES-1) <= 4
410 /* ZONE_DEVICE is not a valid GFP zone specifier */
411 #define GFP_ZONES_SHIFT 2
412 #else
413 #define GFP_ZONES_SHIFT ZONES_SHIFT
414 #endif
415
416 #if 16 * GFP_ZONES_SHIFT > BITS_PER_LONG
417 #error GFP_ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
418 #endif
419
420 #define GFP_ZONE_TABLE ( \
421 (ZONE_NORMAL << 0 * GFP_ZONES_SHIFT) \
422 | (OPT_ZONE_DMA << ___GFP_DMA * GFP_ZONES_SHIFT) \
423 | (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * GFP_ZONES_SHIFT) \
424 | (OPT_ZONE_DMA32 << ___GFP_DMA32 * GFP_ZONES_SHIFT) \
425 | (ZONE_NORMAL << ___GFP_MOVABLE * GFP_ZONES_SHIFT) \
426 | (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * GFP_ZONES_SHIFT) \
427 | (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * GFP_ZONES_SHIFT)\
428 | (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * GFP_ZONES_SHIFT)\
429 )
430
431 /*
432 * GFP_ZONE_BAD is a bitmap for all combinations of __GFP_DMA, __GFP_DMA32
433 * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
434 * entry starting with bit 0. Bit is set if the combination is not
435 * allowed.
436 */
437 #define GFP_ZONE_BAD ( \
438 1 << (___GFP_DMA | ___GFP_HIGHMEM) \
439 | 1 << (___GFP_DMA | ___GFP_DMA32) \
440 | 1 << (___GFP_DMA32 | ___GFP_HIGHMEM) \
441 | 1 << (___GFP_DMA | ___GFP_DMA32 | ___GFP_HIGHMEM) \
442 | 1 << (___GFP_MOVABLE | ___GFP_HIGHMEM | ___GFP_DMA) \
443 | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA) \
444 | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_HIGHMEM) \
445 | 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA | ___GFP_HIGHMEM) \
446 )
447
gfp_zone(gfp_t flags)448 static inline enum zone_type gfp_zone(gfp_t flags)
449 {
450 enum zone_type z;
451 int bit = (__force int) (flags & GFP_ZONEMASK);
452
453 z = (GFP_ZONE_TABLE >> (bit * GFP_ZONES_SHIFT)) &
454 ((1 << GFP_ZONES_SHIFT) - 1);
455 VM_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
456 return z;
457 }
458
459 /*
460 * There is only one page-allocator function, and two main namespaces to
461 * it. The alloc_page*() variants return 'struct page *' and as such
462 * can allocate highmem pages, the *get*page*() variants return
463 * virtual kernel addresses to the allocated page(s).
464 */
465
gfp_zonelist(gfp_t flags)466 static inline int gfp_zonelist(gfp_t flags)
467 {
468 #ifdef CONFIG_NUMA
469 if (unlikely(flags & __GFP_THISNODE))
470 return ZONELIST_NOFALLBACK;
471 #endif
472 return ZONELIST_FALLBACK;
473 }
474
475 /*
476 * We get the zone list from the current node and the gfp_mask.
477 * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
478 * There are two zonelists per node, one for all zones with memory and
479 * one containing just zones from the node the zonelist belongs to.
480 *
481 * For the case of non-NUMA systems the NODE_DATA() gets optimized to
482 * &contig_page_data at compile-time.
483 */
node_zonelist(int nid,gfp_t flags)484 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
485 {
486 return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
487 }
488
489 #ifndef HAVE_ARCH_FREE_PAGE
arch_free_page(struct page * page,int order)490 static inline void arch_free_page(struct page *page, int order) { }
491 #endif
492 #ifndef HAVE_ARCH_ALLOC_PAGE
arch_alloc_page(struct page * page,int order)493 static inline void arch_alloc_page(struct page *page, int order) { }
494 #endif
495
496 struct page *
497 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,
498 nodemask_t *nodemask);
499
500 static inline struct page *
__alloc_pages(gfp_t gfp_mask,unsigned int order,int preferred_nid)501 __alloc_pages(gfp_t gfp_mask, unsigned int order, int preferred_nid)
502 {
503 return __alloc_pages_nodemask(gfp_mask, order, preferred_nid, NULL);
504 }
505
506 /*
507 * Allocate pages, preferring the node given as nid. The node must be valid and
508 * online. For more general interface, see alloc_pages_node().
509 */
510 static inline struct page *
__alloc_pages_node(int nid,gfp_t gfp_mask,unsigned int order)511 __alloc_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
512 {
513 VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
514 VM_WARN_ON((gfp_mask & __GFP_THISNODE) && !node_online(nid));
515
516 return __alloc_pages(gfp_mask, order, nid);
517 }
518
519 /*
520 * Allocate pages, preferring the node given as nid. When nid == NUMA_NO_NODE,
521 * prefer the current CPU's closest node. Otherwise node must be valid and
522 * online.
523 */
alloc_pages_node(int nid,gfp_t gfp_mask,unsigned int order)524 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
525 unsigned int order)
526 {
527 if (nid == NUMA_NO_NODE)
528 nid = numa_mem_id();
529
530 return __alloc_pages_node(nid, gfp_mask, order);
531 }
532
533 #ifdef CONFIG_NUMA
534 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
535
536 static inline struct page *
alloc_pages(gfp_t gfp_mask,unsigned int order)537 alloc_pages(gfp_t gfp_mask, unsigned int order)
538 {
539 return alloc_pages_current(gfp_mask, order);
540 }
541 extern struct page *alloc_pages_vma(gfp_t gfp_mask, int order,
542 struct vm_area_struct *vma, unsigned long addr,
543 int node, bool hugepage);
544 #define alloc_hugepage_vma(gfp_mask, vma, addr, order) \
545 alloc_pages_vma(gfp_mask, order, vma, addr, numa_node_id(), true)
546 #else
547 #define alloc_pages(gfp_mask, order) \
548 alloc_pages_node(numa_node_id(), gfp_mask, order)
549 #define alloc_pages_vma(gfp_mask, order, vma, addr, node, false)\
550 alloc_pages(gfp_mask, order)
551 #define alloc_hugepage_vma(gfp_mask, vma, addr, order) \
552 alloc_pages(gfp_mask, order)
553 #endif
554 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
555 #define alloc_page_vma(gfp_mask, vma, addr) \
556 alloc_pages_vma(gfp_mask, 0, vma, addr, numa_node_id(), false)
557 #define alloc_page_vma_node(gfp_mask, vma, addr, node) \
558 alloc_pages_vma(gfp_mask, 0, vma, addr, node, false)
559
560 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
561 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
562
563 void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
564 void free_pages_exact(void *virt, size_t size);
565 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask);
566
567 #define __get_free_page(gfp_mask) \
568 __get_free_pages((gfp_mask), 0)
569
570 #define __get_dma_pages(gfp_mask, order) \
571 __get_free_pages((gfp_mask) | GFP_DMA, (order))
572
573 extern void __free_pages(struct page *page, unsigned int order);
574 extern void free_pages(unsigned long addr, unsigned int order);
575 extern void free_unref_page(struct page *page);
576 extern void free_unref_page_list(struct list_head *list);
577
578 struct page_frag_cache;
579 extern void __page_frag_cache_drain(struct page *page, unsigned int count);
580 extern void *page_frag_alloc(struct page_frag_cache *nc,
581 unsigned int fragsz, gfp_t gfp_mask);
582 extern void page_frag_free(void *addr);
583
584 #define __free_page(page) __free_pages((page), 0)
585 #define free_page(addr) free_pages((addr), 0)
586
587 void page_alloc_init(void);
588 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
589 void drain_all_pages(struct zone *zone);
590 void drain_local_pages(struct zone *zone);
591
592 void page_alloc_init_late(void);
593
594 /*
595 * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what
596 * GFP flags are used before interrupts are enabled. Once interrupts are
597 * enabled, it is set to __GFP_BITS_MASK while the system is running. During
598 * hibernation, it is used by PM to avoid I/O during memory allocation while
599 * devices are suspended.
600 */
601 extern gfp_t gfp_allowed_mask;
602
603 /* Returns true if the gfp_mask allows use of ALLOC_NO_WATERMARK */
604 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask);
605
606 extern void pm_restrict_gfp_mask(void);
607 extern void pm_restore_gfp_mask(void);
608
609 #ifdef CONFIG_PM_SLEEP
610 extern bool pm_suspended_storage(void);
611 #else
pm_suspended_storage(void)612 static inline bool pm_suspended_storage(void)
613 {
614 return false;
615 }
616 #endif /* CONFIG_PM_SLEEP */
617
618 /*
619 * Check if the gfp flags allow compaction - GFP_NOIO is a really
620 * tricky context because the migration might require IO.
621 */
gfp_compaction_allowed(gfp_t gfp_mask)622 static inline bool gfp_compaction_allowed(gfp_t gfp_mask)
623 {
624 return IS_ENABLED(CONFIG_COMPACTION) && (gfp_mask & __GFP_IO);
625 }
626
627 #ifdef CONFIG_CONTIG_ALLOC
628 /* The below functions must be run on a range from a single zone. */
629 extern int alloc_contig_range(unsigned long start, unsigned long end,
630 unsigned migratetype, gfp_t gfp_mask);
631 #endif
632 void free_contig_range(unsigned long pfn, unsigned int nr_pages);
633
634 #ifdef CONFIG_CMA
635 /* CMA stuff */
636 extern void init_cma_reserved_pageblock(struct page *page);
637 #endif
638
639 #endif /* __LINUX_GFP_H */
640