xref: /linux-6.15/include/linux/gfp.h (revision e73173db)
1 #ifndef __LINUX_GFP_H
2 #define __LINUX_GFP_H
3 
4 #include <linux/mmzone.h>
5 #include <linux/stddef.h>
6 #include <linux/linkage.h>
7 #include <linux/topology.h>
8 
9 struct vm_area_struct;
10 
11 /*
12  * GFP bitmasks..
13  *
14  * Zone modifiers (see linux/mmzone.h - low three bits)
15  *
16  * Do not put any conditional on these. If necessary modify the definitions
17  * without the underscores and use the consistently. The definitions here may
18  * be used in bit comparisons.
19  */
20 #define __GFP_DMA	((__force gfp_t)0x01u)
21 #define __GFP_HIGHMEM	((__force gfp_t)0x02u)
22 #define __GFP_DMA32	((__force gfp_t)0x04u)
23 
24 /*
25  * Action modifiers - doesn't change the zoning
26  *
27  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
28  * _might_ fail.  This depends upon the particular VM implementation.
29  *
30  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
31  * cannot handle allocation failures.
32  *
33  * __GFP_NORETRY: The VM implementation must not retry indefinitely.
34  *
35  * __GFP_MOVABLE: Flag that this page will be movable by the page migration
36  * mechanism or reclaimed
37  */
38 #define __GFP_WAIT	((__force gfp_t)0x10u)	/* Can wait and reschedule? */
39 #define __GFP_HIGH	((__force gfp_t)0x20u)	/* Should access emergency pools? */
40 #define __GFP_IO	((__force gfp_t)0x40u)	/* Can start physical IO? */
41 #define __GFP_FS	((__force gfp_t)0x80u)	/* Can call down to low-level FS? */
42 #define __GFP_COLD	((__force gfp_t)0x100u)	/* Cache-cold page required */
43 #define __GFP_NOWARN	((__force gfp_t)0x200u)	/* Suppress page allocation failure warning */
44 #define __GFP_REPEAT	((__force gfp_t)0x400u)	/* See above */
45 #define __GFP_NOFAIL	((__force gfp_t)0x800u)	/* See above */
46 #define __GFP_NORETRY	((__force gfp_t)0x1000u)/* See above */
47 #define __GFP_COMP	((__force gfp_t)0x4000u)/* Add compound page metadata */
48 #define __GFP_ZERO	((__force gfp_t)0x8000u)/* Return zeroed page on success */
49 #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
50 #define __GFP_HARDWALL   ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
51 #define __GFP_THISNODE	((__force gfp_t)0x40000u)/* No fallback, no policies */
52 #define __GFP_RECLAIMABLE ((__force gfp_t)0x80000u) /* Page is reclaimable */
53 #define __GFP_MOVABLE	((__force gfp_t)0x100000u)  /* Page is movable */
54 
55 #define __GFP_BITS_SHIFT 21	/* Room for 21 __GFP_FOO bits */
56 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
57 
58 /* This equals 0, but use constants in case they ever change */
59 #define GFP_NOWAIT	(GFP_ATOMIC & ~__GFP_HIGH)
60 /* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
61 #define GFP_ATOMIC	(__GFP_HIGH)
62 #define GFP_NOIO	(__GFP_WAIT)
63 #define GFP_NOFS	(__GFP_WAIT | __GFP_IO)
64 #define GFP_KERNEL	(__GFP_WAIT | __GFP_IO | __GFP_FS)
65 #define GFP_TEMPORARY	(__GFP_WAIT | __GFP_IO | __GFP_FS | \
66 			 __GFP_RECLAIMABLE)
67 #define GFP_USER	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
68 #define GFP_HIGHUSER	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
69 			 __GFP_HIGHMEM)
70 #define GFP_HIGHUSER_MOVABLE	(__GFP_WAIT | __GFP_IO | __GFP_FS | \
71 				 __GFP_HARDWALL | __GFP_HIGHMEM | \
72 				 __GFP_MOVABLE)
73 
74 #ifdef CONFIG_NUMA
75 #define GFP_THISNODE	(__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
76 #else
77 #define GFP_THISNODE	((__force gfp_t)0)
78 #endif
79 
80 /* This mask makes up all the page movable related flags */
81 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
82 
83 /* Control page allocator reclaim behavior */
84 #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
85 			__GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
86 			__GFP_NORETRY|__GFP_NOMEMALLOC)
87 
88 /* Control allocation constraints */
89 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
90 
91 /* Do not use these with a slab allocator */
92 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
93 
94 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
95    platforms, used as appropriate on others */
96 
97 #define GFP_DMA		__GFP_DMA
98 
99 /* 4GB DMA on some platforms */
100 #define GFP_DMA32	__GFP_DMA32
101 
102 /* Convert GFP flags to their corresponding migrate type */
103 static inline int allocflags_to_migratetype(gfp_t gfp_flags)
104 {
105 	WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
106 
107 	if (unlikely(page_group_by_mobility_disabled))
108 		return MIGRATE_UNMOVABLE;
109 
110 	/* Group based on mobility */
111 	return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
112 		((gfp_flags & __GFP_RECLAIMABLE) != 0);
113 }
114 
115 static inline enum zone_type gfp_zone(gfp_t flags)
116 {
117 #ifdef CONFIG_ZONE_DMA
118 	if (flags & __GFP_DMA)
119 		return ZONE_DMA;
120 #endif
121 #ifdef CONFIG_ZONE_DMA32
122 	if (flags & __GFP_DMA32)
123 		return ZONE_DMA32;
124 #endif
125 	if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
126 			(__GFP_HIGHMEM | __GFP_MOVABLE))
127 		return ZONE_MOVABLE;
128 #ifdef CONFIG_HIGHMEM
129 	if (flags & __GFP_HIGHMEM)
130 		return ZONE_HIGHMEM;
131 #endif
132 	return ZONE_NORMAL;
133 }
134 
135 /*
136  * There is only one page-allocator function, and two main namespaces to
137  * it. The alloc_page*() variants return 'struct page *' and as such
138  * can allocate highmem pages, the *get*page*() variants return
139  * virtual kernel addresses to the allocated page(s).
140  */
141 
142 static inline int gfp_zonelist(gfp_t flags)
143 {
144 	if (NUMA_BUILD && unlikely(flags & __GFP_THISNODE))
145 		return 1;
146 
147 	return 0;
148 }
149 
150 /*
151  * We get the zone list from the current node and the gfp_mask.
152  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
153  * There are two zonelists per node, one for all zones with memory and
154  * one containing just zones from the node the zonelist belongs to.
155  *
156  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
157  * optimized to &contig_page_data at compile-time.
158  */
159 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
160 {
161 	return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
162 }
163 
164 #ifndef HAVE_ARCH_FREE_PAGE
165 static inline void arch_free_page(struct page *page, int order) { }
166 #endif
167 #ifndef HAVE_ARCH_ALLOC_PAGE
168 static inline void arch_alloc_page(struct page *page, int order) { }
169 #endif
170 
171 struct page *
172 __alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
173 		       struct zonelist *zonelist, nodemask_t *nodemask);
174 
175 static inline struct page *
176 __alloc_pages(gfp_t gfp_mask, unsigned int order,
177 		struct zonelist *zonelist)
178 {
179 	return __alloc_pages_internal(gfp_mask, order, zonelist, NULL);
180 }
181 
182 static inline struct page *
183 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
184 		struct zonelist *zonelist, nodemask_t *nodemask)
185 {
186 	return __alloc_pages_internal(gfp_mask, order, zonelist, nodemask);
187 }
188 
189 
190 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
191 						unsigned int order)
192 {
193 	if (unlikely(order >= MAX_ORDER))
194 		return NULL;
195 
196 	/* Unknown node is current node */
197 	if (nid < 0)
198 		nid = numa_node_id();
199 
200 	return __alloc_pages(gfp_mask, order, node_zonelist(nid, gfp_mask));
201 }
202 
203 #ifdef CONFIG_NUMA
204 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
205 
206 static inline struct page *
207 alloc_pages(gfp_t gfp_mask, unsigned int order)
208 {
209 	if (unlikely(order >= MAX_ORDER))
210 		return NULL;
211 
212 	return alloc_pages_current(gfp_mask, order);
213 }
214 extern struct page *alloc_page_vma(gfp_t gfp_mask,
215 			struct vm_area_struct *vma, unsigned long addr);
216 #else
217 #define alloc_pages(gfp_mask, order) \
218 		alloc_pages_node(numa_node_id(), gfp_mask, order)
219 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
220 #endif
221 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
222 
223 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
224 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
225 
226 void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
227 void free_pages_exact(void *virt, size_t size);
228 
229 #define __get_free_page(gfp_mask) \
230 		__get_free_pages((gfp_mask),0)
231 
232 #define __get_dma_pages(gfp_mask, order) \
233 		__get_free_pages((gfp_mask) | GFP_DMA,(order))
234 
235 extern void __free_pages(struct page *page, unsigned int order);
236 extern void free_pages(unsigned long addr, unsigned int order);
237 extern void free_hot_page(struct page *page);
238 extern void free_cold_page(struct page *page);
239 
240 #define __free_page(page) __free_pages((page), 0)
241 #define free_page(addr) free_pages((addr),0)
242 
243 void page_alloc_init(void);
244 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
245 void drain_all_pages(void);
246 void drain_local_pages(void *dummy);
247 
248 #endif /* __LINUX_GFP_H */
249