xref: /linux-6.15/include/linux/gfp.h (revision eb2bce7f)
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 #define __GFP_WAIT	((__force gfp_t)0x10u)	/* Can wait and reschedule? */
35 #define __GFP_HIGH	((__force gfp_t)0x20u)	/* Should access emergency pools? */
36 #define __GFP_IO	((__force gfp_t)0x40u)	/* Can start physical IO? */
37 #define __GFP_FS	((__force gfp_t)0x80u)	/* Can call down to low-level FS? */
38 #define __GFP_COLD	((__force gfp_t)0x100u)	/* Cache-cold page required */
39 #define __GFP_NOWARN	((__force gfp_t)0x200u)	/* Suppress page allocation failure warning */
40 #define __GFP_REPEAT	((__force gfp_t)0x400u)	/* Retry the allocation.  Might fail */
41 #define __GFP_NOFAIL	((__force gfp_t)0x800u)	/* Retry for ever.  Cannot fail */
42 #define __GFP_NORETRY	((__force gfp_t)0x1000u)/* Do not retry.  Might fail */
43 #define __GFP_COMP	((__force gfp_t)0x4000u)/* Add compound page metadata */
44 #define __GFP_ZERO	((__force gfp_t)0x8000u)/* Return zeroed page on success */
45 #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
46 #define __GFP_HARDWALL   ((__force gfp_t)0x20000u) /* Enforce hardwall cpuset memory allocs */
47 #define __GFP_THISNODE	((__force gfp_t)0x40000u)/* No fallback, no policies */
48 
49 #define __GFP_BITS_SHIFT 20	/* Room for 20 __GFP_FOO bits */
50 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
51 
52 /* if you forget to add the bitmask here kernel will crash, period */
53 #define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
54 			__GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
55 			__GFP_NOFAIL|__GFP_NORETRY|__GFP_COMP| \
56 			__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_THISNODE)
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_USER	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
66 #define GFP_HIGHUSER	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
67 			 __GFP_HIGHMEM)
68 
69 #ifdef CONFIG_NUMA
70 #define GFP_THISNODE	(__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
71 #else
72 #define GFP_THISNODE	((__force gfp_t)0)
73 #endif
74 
75 
76 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
77    platforms, used as appropriate on others */
78 
79 #define GFP_DMA		__GFP_DMA
80 
81 /* 4GB DMA on some platforms */
82 #define GFP_DMA32	__GFP_DMA32
83 
84 
85 static inline enum zone_type gfp_zone(gfp_t flags)
86 {
87 #ifdef CONFIG_ZONE_DMA
88 	if (flags & __GFP_DMA)
89 		return ZONE_DMA;
90 #endif
91 #ifdef CONFIG_ZONE_DMA32
92 	if (flags & __GFP_DMA32)
93 		return ZONE_DMA32;
94 #endif
95 #ifdef CONFIG_HIGHMEM
96 	if (flags & __GFP_HIGHMEM)
97 		return ZONE_HIGHMEM;
98 #endif
99 	return ZONE_NORMAL;
100 }
101 
102 /*
103  * There is only one page-allocator function, and two main namespaces to
104  * it. The alloc_page*() variants return 'struct page *' and as such
105  * can allocate highmem pages, the *get*page*() variants return
106  * virtual kernel addresses to the allocated page(s).
107  */
108 
109 /*
110  * We get the zone list from the current node and the gfp_mask.
111  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
112  *
113  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
114  * optimized to &contig_page_data at compile-time.
115  */
116 
117 #ifndef HAVE_ARCH_FREE_PAGE
118 static inline void arch_free_page(struct page *page, int order) { }
119 #endif
120 #ifndef HAVE_ARCH_ALLOC_PAGE
121 static inline void arch_alloc_page(struct page *page, int order) { }
122 #endif
123 
124 extern struct page *
125 FASTCALL(__alloc_pages(gfp_t, unsigned int, struct zonelist *));
126 
127 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
128 						unsigned int order)
129 {
130 	if (unlikely(order >= MAX_ORDER))
131 		return NULL;
132 
133 	/* Unknown node is current node */
134 	if (nid < 0)
135 		nid = numa_node_id();
136 
137 	return __alloc_pages(gfp_mask, order,
138 		NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
139 }
140 
141 #ifdef CONFIG_NUMA
142 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
143 
144 static inline struct page *
145 alloc_pages(gfp_t gfp_mask, unsigned int order)
146 {
147 	if (unlikely(order >= MAX_ORDER))
148 		return NULL;
149 
150 	return alloc_pages_current(gfp_mask, order);
151 }
152 extern struct page *alloc_page_vma(gfp_t gfp_mask,
153 			struct vm_area_struct *vma, unsigned long addr);
154 #else
155 #define alloc_pages(gfp_mask, order) \
156 		alloc_pages_node(numa_node_id(), gfp_mask, order)
157 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
158 #endif
159 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
160 
161 extern unsigned long FASTCALL(__get_free_pages(gfp_t gfp_mask, unsigned int order));
162 extern unsigned long FASTCALL(get_zeroed_page(gfp_t gfp_mask));
163 
164 #define __get_free_page(gfp_mask) \
165 		__get_free_pages((gfp_mask),0)
166 
167 #define __get_dma_pages(gfp_mask, order) \
168 		__get_free_pages((gfp_mask) | GFP_DMA,(order))
169 
170 extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
171 extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
172 extern void FASTCALL(free_hot_page(struct page *page));
173 extern void FASTCALL(free_cold_page(struct page *page));
174 
175 #define __free_page(page) __free_pages((page), 0)
176 #define free_page(addr) free_pages((addr),0)
177 
178 void page_alloc_init(void);
179 #ifdef CONFIG_NUMA
180 void drain_node_pages(int node);
181 #else
182 static inline void drain_node_pages(int node) { };
183 #endif
184 
185 #endif /* __LINUX_GFP_H */
186