xref: /linux-6.15/include/linux/gfp.h (revision 4e57b681)
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 two bits) */
15 #define __GFP_DMA	((__force gfp_t)0x01u)
16 #define __GFP_HIGHMEM	((__force gfp_t)0x02u)
17 
18 /*
19  * Action modifiers - doesn't change the zoning
20  *
21  * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt
22  * _might_ fail.  This depends upon the particular VM implementation.
23  *
24  * __GFP_NOFAIL: The VM implementation _must_ retry infinitely: the caller
25  * cannot handle allocation failures.
26  *
27  * __GFP_NORETRY: The VM implementation must not retry indefinitely.
28  */
29 #define __GFP_WAIT	((__force gfp_t)0x10u)	/* Can wait and reschedule? */
30 #define __GFP_HIGH	((__force gfp_t)0x20u)	/* Should access emergency pools? */
31 #define __GFP_IO	((__force gfp_t)0x40u)	/* Can start physical IO? */
32 #define __GFP_FS	((__force gfp_t)0x80u)	/* Can call down to low-level FS? */
33 #define __GFP_COLD	((__force gfp_t)0x100u)	/* Cache-cold page required */
34 #define __GFP_NOWARN	((__force gfp_t)0x200u)	/* Suppress page allocation failure warning */
35 #define __GFP_REPEAT	((__force gfp_t)0x400u)	/* Retry the allocation.  Might fail */
36 #define __GFP_NOFAIL	((__force gfp_t)0x800u)	/* Retry for ever.  Cannot fail */
37 #define __GFP_NORETRY	((__force gfp_t)0x1000u)/* Do not retry.  Might fail */
38 #define __GFP_NO_GROW	((__force gfp_t)0x2000u)/* Slab internal usage */
39 #define __GFP_COMP	((__force gfp_t)0x4000u)/* Add compound page metadata */
40 #define __GFP_ZERO	((__force gfp_t)0x8000u)/* Return zeroed page on success */
41 #define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u) /* Don't use emergency reserves */
42 #define __GFP_NORECLAIM  ((__force gfp_t)0x20000u) /* No realy zone reclaim during allocation */
43 #define __GFP_HARDWALL   ((__force gfp_t)0x40000u) /* Enforce hardwall cpuset memory allocs */
44 
45 #define __GFP_BITS_SHIFT 20	/* Room for 20 __GFP_FOO bits */
46 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
47 
48 /* if you forget to add the bitmask here kernel will crash, period */
49 #define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
50 			__GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
51 			__GFP_NOFAIL|__GFP_NORETRY|__GFP_NO_GROW|__GFP_COMP| \
52 			__GFP_NOMEMALLOC|__GFP_NORECLAIM|__GFP_HARDWALL)
53 
54 #define GFP_ATOMIC	(__GFP_HIGH)
55 #define GFP_NOIO	(__GFP_WAIT)
56 #define GFP_NOFS	(__GFP_WAIT | __GFP_IO)
57 #define GFP_KERNEL	(__GFP_WAIT | __GFP_IO | __GFP_FS)
58 #define GFP_USER	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL)
59 #define GFP_HIGHUSER	(__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | \
60 			 __GFP_HIGHMEM)
61 
62 /* Flag - indicates that the buffer will be suitable for DMA.  Ignored on some
63    platforms, used as appropriate on others */
64 
65 #define GFP_DMA		__GFP_DMA
66 
67 #define gfp_zone(mask) ((__force int)((mask) & (__force gfp_t)GFP_ZONEMASK))
68 
69 /*
70  * There is only one page-allocator function, and two main namespaces to
71  * it. The alloc_page*() variants return 'struct page *' and as such
72  * can allocate highmem pages, the *get*page*() variants return
73  * virtual kernel addresses to the allocated page(s).
74  */
75 
76 /*
77  * We get the zone list from the current node and the gfp_mask.
78  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
79  *
80  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
81  * optimized to &contig_page_data at compile-time.
82  */
83 
84 #ifndef HAVE_ARCH_FREE_PAGE
85 static inline void arch_free_page(struct page *page, int order) { }
86 #endif
87 
88 extern struct page *
89 FASTCALL(__alloc_pages(gfp_t, unsigned int, struct zonelist *));
90 
91 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
92 						unsigned int order)
93 {
94 	if (unlikely(order >= MAX_ORDER))
95 		return NULL;
96 
97 	return __alloc_pages(gfp_mask, order,
98 		NODE_DATA(nid)->node_zonelists + gfp_zone(gfp_mask));
99 }
100 
101 #ifdef CONFIG_NUMA
102 extern struct page *alloc_pages_current(gfp_t gfp_mask, unsigned order);
103 
104 static inline struct page *
105 alloc_pages(gfp_t gfp_mask, unsigned int order)
106 {
107 	if (unlikely(order >= MAX_ORDER))
108 		return NULL;
109 
110 	return alloc_pages_current(gfp_mask, order);
111 }
112 extern struct page *alloc_page_vma(gfp_t gfp_mask,
113 			struct vm_area_struct *vma, unsigned long addr);
114 #else
115 #define alloc_pages(gfp_mask, order) \
116 		alloc_pages_node(numa_node_id(), gfp_mask, order)
117 #define alloc_page_vma(gfp_mask, vma, addr) alloc_pages(gfp_mask, 0)
118 #endif
119 #define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
120 
121 extern unsigned long FASTCALL(__get_free_pages(gfp_t gfp_mask, unsigned int order));
122 extern unsigned long FASTCALL(get_zeroed_page(gfp_t gfp_mask));
123 
124 #define __get_free_page(gfp_mask) \
125 		__get_free_pages((gfp_mask),0)
126 
127 #define __get_dma_pages(gfp_mask, order) \
128 		__get_free_pages((gfp_mask) | GFP_DMA,(order))
129 
130 extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
131 extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
132 extern void FASTCALL(free_hot_page(struct page *page));
133 extern void FASTCALL(free_cold_page(struct page *page));
134 
135 #define __free_page(page) __free_pages((page), 0)
136 #define free_page(addr) free_pages((addr),0)
137 
138 void page_alloc_init(void);
139 #ifdef CONFIG_NUMA
140 void drain_remote_pages(void);
141 #else
142 static inline void drain_remote_pages(void) { };
143 #endif
144 
145 #endif /* __LINUX_GFP_H */
146