xref: /linux-6.15/include/linux/gfp.h (revision d289bf7b)
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 
8 struct vm_area_struct;
9 
10 /*
11  * GFP bitmasks..
12  *
13  * Zone modifiers (see linux/mmzone.h - low three bits)
14  *
15  * Do not put any conditional on these. If necessary modify the definitions
16  * without the underscores and use the consistently. The definitions here may
17  * be used in bit comparisons.
18  */
19 #define __GFP_DMA	((__force gfp_t)0x01u)
20 #define __GFP_HIGHMEM	((__force gfp_t)0x02u)
21 #define __GFP_DMA32	((__force gfp_t)0x04u)
22 
23 /*
24  * Action modifiers - doesn't change the zoning
25  *
26  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
27  * _might_ fail.  This depends upon the particular VM implementation.
28  *
29  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
30  * cannot handle allocation failures.
31  *
32  * __GFP_NORETRY: The VM implementation must not retry indefinitely.
33  *
34  * __GFP_MOVABLE: Flag that this page will be movable by the page migration
35  * mechanism or reclaimed
36  */
37 #define __GFP_WAIT	((__force gfp_t)0x10u)	/* Can wait and reschedule? */
38 #define __GFP_HIGH	((__force gfp_t)0x20u)	/* Should access emergency pools? */
39 #define __GFP_IO	((__force gfp_t)0x40u)	/* Can start physical IO? */
40 #define __GFP_FS	((__force gfp_t)0x80u)	/* Can call down to low-level FS? */
41 #define __GFP_COLD	((__force gfp_t)0x100u)	/* Cache-cold page required */
42 #define __GFP_NOWARN	((__force gfp_t)0x200u)	/* Suppress page allocation failure warning */
43 #define __GFP_REPEAT	((__force gfp_t)0x400u)	/* Retry the allocation.  Might fail */
44 #define __GFP_NOFAIL	((__force gfp_t)0x800u)	/* Retry for ever.  Cannot fail */
45 #define __GFP_NORETRY	((__force gfp_t)0x1000u)/* Do not retry.  Might fail */
46 #define __GFP_COMP	((__force gfp_t)0x4000u)/* Add compound page metadata */
47 #define __GFP_ZERO	((__force gfp_t)0x8000u)/* Return zeroed page on success */
48 #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
49 #define __GFP_HARDWALL   ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
50 #define __GFP_THISNODE	((__force gfp_t)0x40000u)/* No fallback, no policies */
51 #define __GFP_RECLAIMABLE ((__force gfp_t)0x80000u) /* Page is reclaimable */
52 #define __GFP_MOVABLE	((__force gfp_t)0x100000u)  /* Page is movable */
53 
54 #define __GFP_BITS_SHIFT 21	/* Room for 21 __GFP_FOO bits */
55 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
56 
57 /* This equals 0, but use constants in case they ever change */
58 #define GFP_NOWAIT	(GFP_ATOMIC & ~__GFP_HIGH)
59 /* GFP_ATOMIC means both !wait (__GFP_WAIT not set) and use emergency pool */
60 #define GFP_ATOMIC	(__GFP_HIGH)
61 #define GFP_NOIO	(__GFP_WAIT)
62 #define GFP_NOFS	(__GFP_WAIT | __GFP_IO)
63 #define GFP_KERNEL	(__GFP_WAIT | __GFP_IO | __GFP_FS)
64 #define GFP_TEMPORARY	(__GFP_WAIT | __GFP_IO | __GFP_FS | \
65 			 __GFP_RECLAIMABLE)
66 #define GFP_USER	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
67 #define GFP_HIGHUSER	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
68 			 __GFP_HIGHMEM)
69 #define GFP_HIGHUSER_MOVABLE	(__GFP_WAIT | __GFP_IO | __GFP_FS | \
70 				 __GFP_HARDWALL | __GFP_HIGHMEM | \
71 				 __GFP_MOVABLE)
72 #define GFP_NOFS_PAGECACHE	(__GFP_WAIT | __GFP_IO | __GFP_MOVABLE)
73 #define GFP_USER_PAGECACHE	(__GFP_WAIT | __GFP_IO | __GFP_FS | \
74 				 __GFP_HARDWALL | __GFP_MOVABLE)
75 #define GFP_HIGHUSER_PAGECACHE	(__GFP_WAIT | __GFP_IO | __GFP_FS | \
76 				 __GFP_HARDWALL | __GFP_HIGHMEM | \
77 				 __GFP_MOVABLE)
78 
79 #ifdef CONFIG_NUMA
80 #define GFP_THISNODE	(__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
81 #else
82 #define GFP_THISNODE	((__force gfp_t)0)
83 #endif
84 
85 /* This mask makes up all the page movable related flags */
86 #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)
87 
88 /* Control page allocator reclaim behavior */
89 #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\
90 			__GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
91 			__GFP_NORETRY|__GFP_NOMEMALLOC)
92 
93 /* Control allocation constraints */
94 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
95 
96 /* Do not use these with a slab allocator */
97 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
98 
99 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
100    platforms, used as appropriate on others */
101 
102 #define GFP_DMA		__GFP_DMA
103 
104 /* 4GB DMA on some platforms */
105 #define GFP_DMA32	__GFP_DMA32
106 
107 /* Convert GFP flags to their corresponding migrate type */
108 static inline int allocflags_to_migratetype(gfp_t gfp_flags)
109 {
110 	WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
111 
112 	if (unlikely(page_group_by_mobility_disabled))
113 		return MIGRATE_UNMOVABLE;
114 
115 	/* Group based on mobility */
116 	return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
117 		((gfp_flags & __GFP_RECLAIMABLE) != 0);
118 }
119 
120 static inline enum zone_type gfp_zone(gfp_t flags)
121 {
122 	int base = 0;
123 
124 #ifdef CONFIG_NUMA
125 	if (flags & __GFP_THISNODE)
126 		base = MAX_NR_ZONES;
127 #endif
128 
129 #ifdef CONFIG_ZONE_DMA
130 	if (flags & __GFP_DMA)
131 		return base + ZONE_DMA;
132 #endif
133 #ifdef CONFIG_ZONE_DMA32
134 	if (flags & __GFP_DMA32)
135 		return base + ZONE_DMA32;
136 #endif
137 	if ((flags & (__GFP_HIGHMEM | __GFP_MOVABLE)) ==
138 			(__GFP_HIGHMEM | __GFP_MOVABLE))
139 		return base + ZONE_MOVABLE;
140 #ifdef CONFIG_HIGHMEM
141 	if (flags & __GFP_HIGHMEM)
142 		return base + ZONE_HIGHMEM;
143 #endif
144 	return base + ZONE_NORMAL;
145 }
146 
147 static inline gfp_t set_migrateflags(gfp_t gfp, gfp_t migrate_flags)
148 {
149 	BUG_ON((gfp & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
150 	return (gfp & ~(GFP_MOVABLE_MASK)) | migrate_flags;
151 }
152 
153 /*
154  * There is only one page-allocator function, and two main namespaces to
155  * it. The alloc_page*() variants return 'struct page *' and as such
156  * can allocate highmem pages, the *get*page*() variants return
157  * virtual kernel addresses to the allocated page(s).
158  */
159 
160 /*
161  * We get the zone list from the current node and the gfp_mask.
162  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
163  *
164  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
165  * optimized to &contig_page_data at compile-time.
166  */
167 
168 #ifndef HAVE_ARCH_FREE_PAGE
169 static inline void arch_free_page(struct page *page, int order) { }
170 #endif
171 #ifndef HAVE_ARCH_ALLOC_PAGE
172 static inline void arch_alloc_page(struct page *page, int order) { }
173 #endif
174 
175 extern struct page *__alloc_pages(gfp_t, unsigned int, struct zonelist *);
176 
177 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
178 						unsigned int order)
179 {
180 	if (unlikely(order >= MAX_ORDER))
181 		return NULL;
182 
183 	/* Unknown node is current node */
184 	if (nid < 0)
185 		nid = numa_node_id();
186 
187 	return __alloc_pages(gfp_mask, order,
188 		NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
189 }
190 
191 #ifdef CONFIG_NUMA
192 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
193 
194 static inline struct page *
195 alloc_pages(gfp_t gfp_mask, unsigned int order)
196 {
197 	if (unlikely(order >= MAX_ORDER))
198 		return NULL;
199 
200 	return alloc_pages_current(gfp_mask, order);
201 }
202 extern struct page *alloc_page_vma(gfp_t gfp_mask,
203 			struct vm_area_struct *vma, unsigned long addr);
204 #else
205 #define alloc_pages(gfp_mask, order) \
206 		alloc_pages_node(numa_node_id(), gfp_mask, order)
207 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
208 #endif
209 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
210 
211 extern unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order);
212 extern unsigned long get_zeroed_page(gfp_t gfp_mask);
213 
214 #define __get_free_page(gfp_mask) \
215 		__get_free_pages((gfp_mask),0)
216 
217 #define __get_dma_pages(gfp_mask, order) \
218 		__get_free_pages((gfp_mask) | GFP_DMA,(order))
219 
220 extern void __free_pages(struct page *page, unsigned int order);
221 extern void free_pages(unsigned long addr, unsigned int order);
222 extern void free_hot_page(struct page *page);
223 extern void free_cold_page(struct page *page);
224 
225 #define __free_page(page) __free_pages((page), 0)
226 #define free_page(addr) free_pages((addr),0)
227 
228 void page_alloc_init(void);
229 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
230 void drain_all_pages(void);
231 void drain_local_pages(void *dummy);
232 
233 #endif /* __LINUX_GFP_H */
234