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1 | /* | |
2 | * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk). | |
3 | * | |
4 | * (C) SGI 2006, Christoph Lameter <clameter@sgi.com> | |
5 | * Cleaned up and restructured to ease the addition of alternative | |
6 | * implementations of SLAB allocators. | |
7 | */ | |
8 | ||
9 | #ifndef _LINUX_SLAB_H | |
10 | #define _LINUX_SLAB_H | |
11 | ||
12 | #ifdef __KERNEL__ | |
13 | ||
14 | #include <linux/gfp.h> | |
15 | #include <linux/types.h> | |
16 | ||
17 | /* | |
18 | * Flags to pass to kmem_cache_create(). | |
19 | * The ones marked DEBUG are only valid if CONFIG_SLAB_DEBUG is set. | |
20 | */ | |
21 | #define SLAB_DEBUG_FREE 0x00000100UL /* DEBUG: Perform (expensive) checks on free */ | |
22 | #define SLAB_RED_ZONE 0x00000400UL /* DEBUG: Red zone objs in a cache */ | |
23 | #define SLAB_POISON 0x00000800UL /* DEBUG: Poison objects */ | |
24 | #define SLAB_HWCACHE_ALIGN 0x00002000UL /* Align objs on cache lines */ | |
25 | #define SLAB_CACHE_DMA 0x00004000UL /* Use GFP_DMA memory */ | |
26 | #define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */ | |
27 | #define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */ | |
28 | #define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */ | |
29 | #define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */ | |
30 | #define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */ | |
31 | #define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */ | |
32 | ||
33 | /* | |
34 | * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. | |
35 | * | |
36 | * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. | |
37 | * | |
38 | * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can. | |
39 | * Both make kfree a no-op. | |
40 | */ | |
41 | #define ZERO_SIZE_PTR ((void *)16) | |
42 | ||
43 | #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ | |
44 | (unsigned long)ZERO_SIZE_PTR) | |
45 | ||
46 | /* | |
47 | * struct kmem_cache related prototypes | |
48 | */ | |
49 | void __init kmem_cache_init(void); | |
50 | int slab_is_available(void); | |
51 | ||
52 | struct kmem_cache *kmem_cache_create(const char *, size_t, size_t, | |
53 | unsigned long, | |
54 | void (*)(void *, struct kmem_cache *, unsigned long)); | |
55 | void kmem_cache_destroy(struct kmem_cache *); | |
56 | int kmem_cache_shrink(struct kmem_cache *); | |
57 | void kmem_cache_free(struct kmem_cache *, void *); | |
58 | unsigned int kmem_cache_size(struct kmem_cache *); | |
59 | const char *kmem_cache_name(struct kmem_cache *); | |
60 | int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr); | |
61 | ||
62 | /* | |
63 | * Please use this macro to create slab caches. Simply specify the | |
64 | * name of the structure and maybe some flags that are listed above. | |
65 | * | |
66 | * The alignment of the struct determines object alignment. If you | |
67 | * f.e. add ____cacheline_aligned_in_smp to the struct declaration | |
68 | * then the objects will be properly aligned in SMP configurations. | |
69 | */ | |
70 | #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\ | |
71 | sizeof(struct __struct), __alignof__(struct __struct),\ | |
72 | (__flags), NULL) | |
73 | ||
74 | /* | |
75 | * The largest kmalloc size supported by the slab allocators is | |
76 | * 32 megabyte (2^25) or the maximum allocatable page order if that is | |
77 | * less than 32 MB. | |
78 | * | |
79 | * WARNING: Its not easy to increase this value since the allocators have | |
80 | * to do various tricks to work around compiler limitations in order to | |
81 | * ensure proper constant folding. | |
82 | */ | |
83 | #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ | |
84 | (MAX_ORDER + PAGE_SHIFT - 1) : 25) | |
85 | ||
86 | #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_HIGH) | |
87 | #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_HIGH - PAGE_SHIFT) | |
88 | ||
89 | /* | |
90 | * Common kmalloc functions provided by all allocators | |
91 | */ | |
92 | void * __must_check krealloc(const void *, size_t, gfp_t); | |
93 | void kfree(const void *); | |
94 | size_t ksize(const void *); | |
95 | ||
96 | /* | |
97 | * Allocator specific definitions. These are mainly used to establish optimized | |
98 | * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by | |
99 | * selecting the appropriate general cache at compile time. | |
100 | * | |
101 | * Allocators must define at least: | |
102 | * | |
103 | * kmem_cache_alloc() | |
104 | * __kmalloc() | |
105 | * kmalloc() | |
106 | * | |
107 | * Those wishing to support NUMA must also define: | |
108 | * | |
109 | * kmem_cache_alloc_node() | |
110 | * kmalloc_node() | |
111 | * | |
112 | * See each allocator definition file for additional comments and | |
113 | * implementation notes. | |
114 | */ | |
115 | #ifdef CONFIG_SLUB | |
116 | #include <linux/slub_def.h> | |
117 | #elif defined(CONFIG_SLOB) | |
118 | #include <linux/slob_def.h> | |
119 | #else | |
120 | #include <linux/slab_def.h> | |
121 | #endif | |
122 | ||
123 | /** | |
124 | * kcalloc - allocate memory for an array. The memory is set to zero. | |
125 | * @n: number of elements. | |
126 | * @size: element size. | |
127 | * @flags: the type of memory to allocate. | |
128 | * | |
129 | * The @flags argument may be one of: | |
130 | * | |
131 | * %GFP_USER - Allocate memory on behalf of user. May sleep. | |
132 | * | |
133 | * %GFP_KERNEL - Allocate normal kernel ram. May sleep. | |
134 | * | |
135 | * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools. | |
136 | * For example, use this inside interrupt handlers. | |
137 | * | |
138 | * %GFP_HIGHUSER - Allocate pages from high memory. | |
139 | * | |
140 | * %GFP_NOIO - Do not do any I/O at all while trying to get memory. | |
141 | * | |
142 | * %GFP_NOFS - Do not make any fs calls while trying to get memory. | |
143 | * | |
144 | * %GFP_NOWAIT - Allocation will not sleep. | |
145 | * | |
146 | * %GFP_THISNODE - Allocate node-local memory only. | |
147 | * | |
148 | * %GFP_DMA - Allocation suitable for DMA. | |
149 | * Should only be used for kmalloc() caches. Otherwise, use a | |
150 | * slab created with SLAB_DMA. | |
151 | * | |
152 | * Also it is possible to set different flags by OR'ing | |
153 | * in one or more of the following additional @flags: | |
154 | * | |
155 | * %__GFP_COLD - Request cache-cold pages instead of | |
156 | * trying to return cache-warm pages. | |
157 | * | |
158 | * %__GFP_HIGH - This allocation has high priority and may use emergency pools. | |
159 | * | |
160 | * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail | |
161 | * (think twice before using). | |
162 | * | |
163 | * %__GFP_NORETRY - If memory is not immediately available, | |
164 | * then give up at once. | |
165 | * | |
166 | * %__GFP_NOWARN - If allocation fails, don't issue any warnings. | |
167 | * | |
168 | * %__GFP_REPEAT - If allocation fails initially, try once more before failing. | |
169 | * | |
170 | * There are other flags available as well, but these are not intended | |
171 | * for general use, and so are not documented here. For a full list of | |
172 | * potential flags, always refer to linux/gfp.h. | |
173 | */ | |
174 | static inline void *kcalloc(size_t n, size_t size, gfp_t flags) | |
175 | { | |
176 | if (n != 0 && size > ULONG_MAX / n) | |
177 | return NULL; | |
178 | return __kmalloc(n * size, flags | __GFP_ZERO); | |
179 | } | |
180 | ||
181 | #if !defined(CONFIG_NUMA) && !defined(CONFIG_SLOB) | |
182 | /** | |
183 | * kmalloc_node - allocate memory from a specific node | |
184 | * @size: how many bytes of memory are required. | |
185 | * @flags: the type of memory to allocate (see kcalloc). | |
186 | * @node: node to allocate from. | |
187 | * | |
188 | * kmalloc() for non-local nodes, used to allocate from a specific node | |
189 | * if available. Equivalent to kmalloc() in the non-NUMA single-node | |
190 | * case. | |
191 | */ | |
192 | static inline void *kmalloc_node(size_t size, gfp_t flags, int node) | |
193 | { | |
194 | return kmalloc(size, flags); | |
195 | } | |
196 | ||
197 | static inline void *__kmalloc_node(size_t size, gfp_t flags, int node) | |
198 | { | |
199 | return __kmalloc(size, flags); | |
200 | } | |
201 | ||
202 | void *kmem_cache_alloc(struct kmem_cache *, gfp_t); | |
203 | ||
204 | static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep, | |
205 | gfp_t flags, int node) | |
206 | { | |
207 | return kmem_cache_alloc(cachep, flags); | |
208 | } | |
209 | #endif /* !CONFIG_NUMA && !CONFIG_SLOB */ | |
210 | ||
211 | /* | |
212 | * kmalloc_track_caller is a special version of kmalloc that records the | |
213 | * calling function of the routine calling it for slab leak tracking instead | |
214 | * of just the calling function (confusing, eh?). | |
215 | * It's useful when the call to kmalloc comes from a widely-used standard | |
216 | * allocator where we care about the real place the memory allocation | |
217 | * request comes from. | |
218 | */ | |
219 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) | |
220 | extern void *__kmalloc_track_caller(size_t, gfp_t, void*); | |
221 | #define kmalloc_track_caller(size, flags) \ | |
222 | __kmalloc_track_caller(size, flags, __builtin_return_address(0)) | |
223 | #else | |
224 | #define kmalloc_track_caller(size, flags) \ | |
225 | __kmalloc(size, flags) | |
226 | #endif /* DEBUG_SLAB */ | |
227 | ||
228 | #ifdef CONFIG_NUMA | |
229 | /* | |
230 | * kmalloc_node_track_caller is a special version of kmalloc_node that | |
231 | * records the calling function of the routine calling it for slab leak | |
232 | * tracking instead of just the calling function (confusing, eh?). | |
233 | * It's useful when the call to kmalloc_node comes from a widely-used | |
234 | * standard allocator where we care about the real place the memory | |
235 | * allocation request comes from. | |
236 | */ | |
237 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) | |
238 | extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, void *); | |
239 | #define kmalloc_node_track_caller(size, flags, node) \ | |
240 | __kmalloc_node_track_caller(size, flags, node, \ | |
241 | __builtin_return_address(0)) | |
242 | #else | |
243 | #define kmalloc_node_track_caller(size, flags, node) \ | |
244 | __kmalloc_node(size, flags, node) | |
245 | #endif | |
246 | ||
247 | #else /* CONFIG_NUMA */ | |
248 | ||
249 | #define kmalloc_node_track_caller(size, flags, node) \ | |
250 | kmalloc_track_caller(size, flags) | |
251 | ||
252 | #endif /* DEBUG_SLAB */ | |
253 | ||
254 | /* | |
255 | * Shortcuts | |
256 | */ | |
257 | static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) | |
258 | { | |
259 | return kmem_cache_alloc(k, flags | __GFP_ZERO); | |
260 | } | |
261 | ||
262 | /** | |
263 | * kzalloc - allocate memory. The memory is set to zero. | |
264 | * @size: how many bytes of memory are required. | |
265 | * @flags: the type of memory to allocate (see kmalloc). | |
266 | */ | |
267 | static inline void *kzalloc(size_t size, gfp_t flags) | |
268 | { | |
269 | return kmalloc(size, flags | __GFP_ZERO); | |
270 | } | |
271 | ||
272 | #endif /* __KERNEL__ */ | |
273 | #endif /* _LINUX_SLAB_H */ |