xref: /linux-6.15/include/linux/gfp.h (revision 4f193362)
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/config.h>
8 
9 struct vm_area_struct;
10 
11 /*
12  * GFP bitmasks..
13  */
14 /* Zone modifiers in GFP_ZONEMASK (see linux/mmzone.h - low three bits) */
15 #define __GFP_DMA	((__force gfp_t)0x01u)
16 #define __GFP_HIGHMEM	((__force gfp_t)0x02u)
17 #ifdef CONFIG_DMA_IS_DMA32
18 #define __GFP_DMA32	((__force gfp_t)0x01)	/* ZONE_DMA is ZONE_DMA32 */
19 #elif BITS_PER_LONG < 64
20 #define __GFP_DMA32	((__force gfp_t)0x00)	/* ZONE_NORMAL is ZONE_DMA32 */
21 #else
22 #define __GFP_DMA32	((__force gfp_t)0x04)	/* Has own ZONE_DMA32 */
23 #endif
24 
25 /*
26  * Action modifiers - doesn't change the zoning
27  *
28  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
29  * _might_ fail.  This depends upon the particular VM implementation.
30  *
31  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
32  * cannot handle allocation failures.
33  *
34  * __GFP_NORETRY: The VM implementation must not retry indefinitely.
35  */
36 #define __GFP_WAIT	((__force gfp_t)0x10u)	/* Can wait and reschedule? */
37 #define __GFP_HIGH	((__force gfp_t)0x20u)	/* Should access emergency pools? */
38 #define __GFP_IO	((__force gfp_t)0x40u)	/* Can start physical IO? */
39 #define __GFP_FS	((__force gfp_t)0x80u)	/* Can call down to low-level FS? */
40 #define __GFP_COLD	((__force gfp_t)0x100u)	/* Cache-cold page required */
41 #define __GFP_NOWARN	((__force gfp_t)0x200u)	/* Suppress page allocation failure warning */
42 #define __GFP_REPEAT	((__force gfp_t)0x400u)	/* Retry the allocation.  Might fail */
43 #define __GFP_NOFAIL	((__force gfp_t)0x800u)	/* Retry for ever.  Cannot fail */
44 #define __GFP_NORETRY	((__force gfp_t)0x1000u)/* Do not retry.  Might fail */
45 #define __GFP_NO_GROW	((__force gfp_t)0x2000u)/* Slab internal usage */
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 
51 #define __GFP_BITS_SHIFT 20	/* Room for 20 __GFP_FOO bits */
52 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
53 
54 /* if you forget to add the bitmask here kernel will crash, period */
55 #define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
56 			__GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
57 			__GFP_NOFAIL|__GFP_NORETRY|__GFP_NO_GROW|__GFP_COMP| \
58 			__GFP_NOMEMALLOC|__GFP_HARDWALL)
59 
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 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
70    platforms, used as appropriate on others */
71 
72 #define GFP_DMA		__GFP_DMA
73 
74 /* 4GB DMA on some platforms */
75 #define GFP_DMA32	__GFP_DMA32
76 
77 
78 static inline int gfp_zone(gfp_t gfp)
79 {
80 	int zone = GFP_ZONEMASK & (__force int) gfp;
81 	BUG_ON(zone >= GFP_ZONETYPES);
82 	return zone;
83 }
84 
85 /*
86  * There is only one page-allocator function, and two main namespaces to
87  * it. The alloc_page*() variants return 'struct page *' and as such
88  * can allocate highmem pages, the *get*page*() variants return
89  * virtual kernel addresses to the allocated page(s).
90  */
91 
92 /*
93  * We get the zone list from the current node and the gfp_mask.
94  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
95  *
96  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
97  * optimized to &contig_page_data at compile-time.
98  */
99 
100 #ifndef HAVE_ARCH_FREE_PAGE
101 static inline void arch_free_page(struct page *page, int order) { }
102 #endif
103 
104 extern struct page *
105 FASTCALL(__alloc_pages(gfp_t, unsigned int, struct zonelist *));
106 
107 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
108 						unsigned int order)
109 {
110 	if (unlikely(order >= MAX_ORDER))
111 		return NULL;
112 
113 	/* Unknown node is current node */
114 	if (nid < 0)
115 		nid = numa_node_id();
116 
117 	return __alloc_pages(gfp_mask, order,
118 		NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
119 }
120 
121 #ifdef CONFIG_NUMA
122 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
123 
124 static inline struct page *
125 alloc_pages(gfp_t gfp_mask, unsigned int order)
126 {
127 	if (unlikely(order >= MAX_ORDER))
128 		return NULL;
129 
130 	return alloc_pages_current(gfp_mask, order);
131 }
132 extern struct page *alloc_page_vma(gfp_t gfp_mask,
133 			struct vm_area_struct *vma, unsigned long addr);
134 #else
135 #define alloc_pages(gfp_mask, order) \
136 		alloc_pages_node(numa_node_id(), gfp_mask, order)
137 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
138 #endif
139 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
140 
141 extern unsigned long FASTCALL(__get_free_pages(gfp_t gfp_mask, unsigned int order));
142 extern unsigned long FASTCALL(get_zeroed_page(gfp_t gfp_mask));
143 
144 #define __get_free_page(gfp_mask) \
145 		__get_free_pages((gfp_mask),0)
146 
147 #define __get_dma_pages(gfp_mask, order) \
148 		__get_free_pages((gfp_mask) | GFP_DMA,(order))
149 
150 extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
151 extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
152 extern void FASTCALL(free_hot_page(struct page *page));
153 extern void FASTCALL(free_cold_page(struct page *page));
154 
155 #define __free_page(page) __free_pages((page), 0)
156 #define free_page(addr) free_pages((addr),0)
157 
158 void page_alloc_init(void);
159 #ifdef CONFIG_NUMA
160 void drain_remote_pages(void);
161 #else
162 static inline void drain_remote_pages(void) { };
163 #endif
164 
165 #endif /* __LINUX_GFP_H */
166