xref: /linux-6.15/include/linux/gfp.h (revision fc5dfebc)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_GFP_H
3 #define __LINUX_GFP_H
4 
5 #include <linux/gfp_types.h>
6 
7 #include <linux/mmzone.h>
8 #include <linux/topology.h>
9 
10 struct vm_area_struct;
11 
12 /* Convert GFP flags to their corresponding migrate type */
13 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
14 #define GFP_MOVABLE_SHIFT 3
15 
16 static inline int gfp_migratetype(const gfp_t gfp_flags)
17 {
18 	VM_WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
19 	BUILD_BUG_ON((1UL << GFP_MOVABLE_SHIFT) != ___GFP_MOVABLE);
20 	BUILD_BUG_ON((___GFP_MOVABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_MOVABLE);
21 	BUILD_BUG_ON((___GFP_RECLAIMABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_RECLAIMABLE);
22 	BUILD_BUG_ON(((___GFP_MOVABLE | ___GFP_RECLAIMABLE) >>
23 		      GFP_MOVABLE_SHIFT) != MIGRATE_HIGHATOMIC);
24 
25 	if (unlikely(page_group_by_mobility_disabled))
26 		return MIGRATE_UNMOVABLE;
27 
28 	/* Group based on mobility */
29 	return (__force unsigned long)(gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;
30 }
31 #undef GFP_MOVABLE_MASK
32 #undef GFP_MOVABLE_SHIFT
33 
34 static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
35 {
36 	return !!(gfp_flags & __GFP_DIRECT_RECLAIM);
37 }
38 
39 /**
40  * gfpflags_normal_context - is gfp_flags a normal sleepable context?
41  * @gfp_flags: gfp_flags to test
42  *
43  * Test whether @gfp_flags indicates that the allocation is from the
44  * %current context and allowed to sleep.
45  *
46  * An allocation being allowed to block doesn't mean it owns the %current
47  * context.  When direct reclaim path tries to allocate memory, the
48  * allocation context is nested inside whatever %current was doing at the
49  * time of the original allocation.  The nested allocation may be allowed
50  * to block but modifying anything %current owns can corrupt the outer
51  * context's expectations.
52  *
53  * %true result from this function indicates that the allocation context
54  * can sleep and use anything that's associated with %current.
55  */
56 static inline bool gfpflags_normal_context(const gfp_t gfp_flags)
57 {
58 	return (gfp_flags & (__GFP_DIRECT_RECLAIM | __GFP_MEMALLOC)) ==
59 		__GFP_DIRECT_RECLAIM;
60 }
61 
62 #ifdef CONFIG_HIGHMEM
63 #define OPT_ZONE_HIGHMEM ZONE_HIGHMEM
64 #else
65 #define OPT_ZONE_HIGHMEM ZONE_NORMAL
66 #endif
67 
68 #ifdef CONFIG_ZONE_DMA
69 #define OPT_ZONE_DMA ZONE_DMA
70 #else
71 #define OPT_ZONE_DMA ZONE_NORMAL
72 #endif
73 
74 #ifdef CONFIG_ZONE_DMA32
75 #define OPT_ZONE_DMA32 ZONE_DMA32
76 #else
77 #define OPT_ZONE_DMA32 ZONE_NORMAL
78 #endif
79 
80 /*
81  * GFP_ZONE_TABLE is a word size bitstring that is used for looking up the
82  * zone to use given the lowest 4 bits of gfp_t. Entries are GFP_ZONES_SHIFT
83  * bits long and there are 16 of them to cover all possible combinations of
84  * __GFP_DMA, __GFP_DMA32, __GFP_MOVABLE and __GFP_HIGHMEM.
85  *
86  * The zone fallback order is MOVABLE=>HIGHMEM=>NORMAL=>DMA32=>DMA.
87  * But GFP_MOVABLE is not only a zone specifier but also an allocation
88  * policy. Therefore __GFP_MOVABLE plus another zone selector is valid.
89  * Only 1 bit of the lowest 3 bits (DMA,DMA32,HIGHMEM) can be set to "1".
90  *
91  *       bit       result
92  *       =================
93  *       0x0    => NORMAL
94  *       0x1    => DMA or NORMAL
95  *       0x2    => HIGHMEM or NORMAL
96  *       0x3    => BAD (DMA+HIGHMEM)
97  *       0x4    => DMA32 or NORMAL
98  *       0x5    => BAD (DMA+DMA32)
99  *       0x6    => BAD (HIGHMEM+DMA32)
100  *       0x7    => BAD (HIGHMEM+DMA32+DMA)
101  *       0x8    => NORMAL (MOVABLE+0)
102  *       0x9    => DMA or NORMAL (MOVABLE+DMA)
103  *       0xa    => MOVABLE (Movable is valid only if HIGHMEM is set too)
104  *       0xb    => BAD (MOVABLE+HIGHMEM+DMA)
105  *       0xc    => DMA32 or NORMAL (MOVABLE+DMA32)
106  *       0xd    => BAD (MOVABLE+DMA32+DMA)
107  *       0xe    => BAD (MOVABLE+DMA32+HIGHMEM)
108  *       0xf    => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
109  *
110  * GFP_ZONES_SHIFT must be <= 2 on 32 bit platforms.
111  */
112 
113 #if defined(CONFIG_ZONE_DEVICE) && (MAX_NR_ZONES-1) <= 4
114 /* ZONE_DEVICE is not a valid GFP zone specifier */
115 #define GFP_ZONES_SHIFT 2
116 #else
117 #define GFP_ZONES_SHIFT ZONES_SHIFT
118 #endif
119 
120 #if 16 * GFP_ZONES_SHIFT > BITS_PER_LONG
121 #error GFP_ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
122 #endif
123 
124 #define GFP_ZONE_TABLE ( \
125 	(ZONE_NORMAL << 0 * GFP_ZONES_SHIFT)				       \
126 	| (OPT_ZONE_DMA << ___GFP_DMA * GFP_ZONES_SHIFT)		       \
127 	| (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * GFP_ZONES_SHIFT)	       \
128 	| (OPT_ZONE_DMA32 << ___GFP_DMA32 * GFP_ZONES_SHIFT)		       \
129 	| (ZONE_NORMAL << ___GFP_MOVABLE * GFP_ZONES_SHIFT)		       \
130 	| (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * GFP_ZONES_SHIFT)    \
131 	| (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * GFP_ZONES_SHIFT)\
132 	| (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * GFP_ZONES_SHIFT)\
133 )
134 
135 /*
136  * GFP_ZONE_BAD is a bitmap for all combinations of __GFP_DMA, __GFP_DMA32
137  * __GFP_HIGHMEM and __GFP_MOVABLE that are not permitted. One flag per
138  * entry starting with bit 0. Bit is set if the combination is not
139  * allowed.
140  */
141 #define GFP_ZONE_BAD ( \
142 	1 << (___GFP_DMA | ___GFP_HIGHMEM)				      \
143 	| 1 << (___GFP_DMA | ___GFP_DMA32)				      \
144 	| 1 << (___GFP_DMA32 | ___GFP_HIGHMEM)				      \
145 	| 1 << (___GFP_DMA | ___GFP_DMA32 | ___GFP_HIGHMEM)		      \
146 	| 1 << (___GFP_MOVABLE | ___GFP_HIGHMEM | ___GFP_DMA)		      \
147 	| 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA)		      \
148 	| 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_HIGHMEM)		      \
149 	| 1 << (___GFP_MOVABLE | ___GFP_DMA32 | ___GFP_DMA | ___GFP_HIGHMEM)  \
150 )
151 
152 static inline enum zone_type gfp_zone(gfp_t flags)
153 {
154 	enum zone_type z;
155 	int bit = (__force int) (flags & GFP_ZONEMASK);
156 
157 	z = (GFP_ZONE_TABLE >> (bit * GFP_ZONES_SHIFT)) &
158 					 ((1 << GFP_ZONES_SHIFT) - 1);
159 	VM_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
160 	return z;
161 }
162 
163 /*
164  * There is only one page-allocator function, and two main namespaces to
165  * it. The alloc_page*() variants return 'struct page *' and as such
166  * can allocate highmem pages, the *get*page*() variants return
167  * virtual kernel addresses to the allocated page(s).
168  */
169 
170 static inline int gfp_zonelist(gfp_t flags)
171 {
172 #ifdef CONFIG_NUMA
173 	if (unlikely(flags & __GFP_THISNODE))
174 		return ZONELIST_NOFALLBACK;
175 #endif
176 	return ZONELIST_FALLBACK;
177 }
178 
179 /*
180  * We get the zone list from the current node and the gfp_mask.
181  * This zone list contains a maximum of MAX_NUMNODES*MAX_NR_ZONES zones.
182  * There are two zonelists per node, one for all zones with memory and
183  * one containing just zones from the node the zonelist belongs to.
184  *
185  * For the case of non-NUMA systems the NODE_DATA() gets optimized to
186  * &contig_page_data at compile-time.
187  */
188 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
189 {
190 	return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
191 }
192 
193 #ifndef HAVE_ARCH_FREE_PAGE
194 static inline void arch_free_page(struct page *page, int order) { }
195 #endif
196 #ifndef HAVE_ARCH_ALLOC_PAGE
197 static inline void arch_alloc_page(struct page *page, int order) { }
198 #endif
199 
200 struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid,
201 		nodemask_t *nodemask);
202 struct folio *__folio_alloc(gfp_t gfp, unsigned int order, int preferred_nid,
203 		nodemask_t *nodemask);
204 
205 unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
206 				nodemask_t *nodemask, int nr_pages,
207 				struct list_head *page_list,
208 				struct page **page_array);
209 
210 unsigned long alloc_pages_bulk_array_mempolicy(gfp_t gfp,
211 				unsigned long nr_pages,
212 				struct page **page_array);
213 
214 /* Bulk allocate order-0 pages */
215 static inline unsigned long
216 alloc_pages_bulk_list(gfp_t gfp, unsigned long nr_pages, struct list_head *list)
217 {
218 	return __alloc_pages_bulk(gfp, numa_mem_id(), NULL, nr_pages, list, NULL);
219 }
220 
221 static inline unsigned long
222 alloc_pages_bulk_array(gfp_t gfp, unsigned long nr_pages, struct page **page_array)
223 {
224 	return __alloc_pages_bulk(gfp, numa_mem_id(), NULL, nr_pages, NULL, page_array);
225 }
226 
227 static inline unsigned long
228 alloc_pages_bulk_array_node(gfp_t gfp, int nid, unsigned long nr_pages, struct page **page_array)
229 {
230 	if (nid == NUMA_NO_NODE)
231 		nid = numa_mem_id();
232 
233 	return __alloc_pages_bulk(gfp, nid, NULL, nr_pages, NULL, page_array);
234 }
235 
236 /*
237  * Allocate pages, preferring the node given as nid. The node must be valid and
238  * online. For more general interface, see alloc_pages_node().
239  */
240 static inline struct page *
241 __alloc_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
242 {
243 	VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
244 	VM_WARN_ON((gfp_mask & __GFP_THISNODE) && !node_online(nid));
245 
246 	return __alloc_pages(gfp_mask, order, nid, NULL);
247 }
248 
249 static inline
250 struct folio *__folio_alloc_node(gfp_t gfp, unsigned int order, int nid)
251 {
252 	VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
253 	VM_WARN_ON((gfp & __GFP_THISNODE) && !node_online(nid));
254 
255 	return __folio_alloc(gfp, order, nid, NULL);
256 }
257 
258 /*
259  * Allocate pages, preferring the node given as nid. When nid == NUMA_NO_NODE,
260  * prefer the current CPU's closest node. Otherwise node must be valid and
261  * online.
262  */
263 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
264 						unsigned int order)
265 {
266 	if (nid == NUMA_NO_NODE)
267 		nid = numa_mem_id();
268 
269 	return __alloc_pages_node(nid, gfp_mask, order);
270 }
271 
272 #ifdef CONFIG_NUMA
273 struct page *alloc_pages(gfp_t gfp, unsigned int order);
274 struct folio *folio_alloc(gfp_t gfp, unsigned order);
275 struct folio *vma_alloc_folio(gfp_t gfp, int order, struct vm_area_struct *vma,
276 		unsigned long addr, bool hugepage);
277 #else
278 static inline struct page *alloc_pages(gfp_t gfp_mask, unsigned int order)
279 {
280 	return alloc_pages_node(numa_node_id(), gfp_mask, order);
281 }
282 static inline struct folio *folio_alloc(gfp_t gfp, unsigned int order)
283 {
284 	return __folio_alloc_node(gfp, order, numa_node_id());
285 }
286 #define vma_alloc_folio(gfp, order, vma, addr, hugepage)		\
287 	folio_alloc(gfp, order)
288 #endif
289 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
290 static inline struct page *alloc_page_vma(gfp_t gfp,
291 		struct vm_area_struct *vma, unsigned long addr)
292 {
293 	struct folio *folio = vma_alloc_folio(gfp, 0, vma, addr, false);
294 
295 	return &folio->page;
296 }
297 
298 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
299 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
300 
301 void *alloc_pages_exact(size_t size, gfp_t gfp_mask) __alloc_size(1);
302 void free_pages_exact(void *virt, size_t size);
303 __meminit void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask) __alloc_size(2);
304 
305 #define __get_free_page(gfp_mask) \
306 		__get_free_pages((gfp_mask), 0)
307 
308 #define __get_dma_pages(gfp_mask, order) \
309 		__get_free_pages((gfp_mask) | GFP_DMA, (order))
310 
311 extern void __free_pages(struct page *page, unsigned int order);
312 extern void free_pages(unsigned long addr, unsigned int order);
313 
314 struct page_frag_cache;
315 extern void __page_frag_cache_drain(struct page *page, unsigned int count);
316 extern void *page_frag_alloc_align(struct page_frag_cache *nc,
317 				   unsigned int fragsz, gfp_t gfp_mask,
318 				   unsigned int align_mask);
319 
320 static inline void *page_frag_alloc(struct page_frag_cache *nc,
321 			     unsigned int fragsz, gfp_t gfp_mask)
322 {
323 	return page_frag_alloc_align(nc, fragsz, gfp_mask, ~0u);
324 }
325 
326 extern void page_frag_free(void *addr);
327 
328 #define __free_page(page) __free_pages((page), 0)
329 #define free_page(addr) free_pages((addr), 0)
330 
331 void page_alloc_init(void);
332 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
333 void drain_all_pages(struct zone *zone);
334 void drain_local_pages(struct zone *zone);
335 
336 void page_alloc_init_late(void);
337 
338 /*
339  * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what
340  * GFP flags are used before interrupts are enabled. Once interrupts are
341  * enabled, it is set to __GFP_BITS_MASK while the system is running. During
342  * hibernation, it is used by PM to avoid I/O during memory allocation while
343  * devices are suspended.
344  */
345 extern gfp_t gfp_allowed_mask;
346 
347 /* Returns true if the gfp_mask allows use of ALLOC_NO_WATERMARK */
348 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask);
349 
350 extern void pm_restrict_gfp_mask(void);
351 extern void pm_restore_gfp_mask(void);
352 
353 extern gfp_t vma_thp_gfp_mask(struct vm_area_struct *vma);
354 
355 #ifdef CONFIG_PM_SLEEP
356 extern bool pm_suspended_storage(void);
357 #else
358 static inline bool pm_suspended_storage(void)
359 {
360 	return false;
361 }
362 #endif /* CONFIG_PM_SLEEP */
363 
364 #ifdef CONFIG_CONTIG_ALLOC
365 /* The below functions must be run on a range from a single zone. */
366 extern int alloc_contig_range(unsigned long start, unsigned long end,
367 			      unsigned migratetype, gfp_t gfp_mask);
368 extern struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask,
369 				       int nid, nodemask_t *nodemask);
370 #endif
371 void free_contig_range(unsigned long pfn, unsigned long nr_pages);
372 
373 #ifdef CONFIG_CMA
374 /* CMA stuff */
375 extern void init_cma_reserved_pageblock(struct page *page);
376 #endif
377 
378 #endif /* __LINUX_GFP_H */
379