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1da177e4 | 1 | /* |
2e892f43 CL |
2 | * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk). |
3 | * | |
cde53535 | 4 | * (C) SGI 2006, Christoph Lameter |
2e892f43 CL |
5 | * Cleaned up and restructured to ease the addition of alternative |
6 | * implementations of SLAB allocators. | |
1da177e4 LT |
7 | */ |
8 | ||
9 | #ifndef _LINUX_SLAB_H | |
10 | #define _LINUX_SLAB_H | |
11 | ||
1b1cec4b | 12 | #include <linux/gfp.h> |
1b1cec4b | 13 | #include <linux/types.h> |
1da177e4 | 14 | |
2e892f43 CL |
15 | /* |
16 | * Flags to pass to kmem_cache_create(). | |
17 | * The ones marked DEBUG are only valid if CONFIG_SLAB_DEBUG is set. | |
1da177e4 | 18 | */ |
55935a34 | 19 | #define SLAB_DEBUG_FREE 0x00000100UL /* DEBUG: Perform (expensive) checks on free */ |
55935a34 CL |
20 | #define SLAB_RED_ZONE 0x00000400UL /* DEBUG: Red zone objs in a cache */ |
21 | #define SLAB_POISON 0x00000800UL /* DEBUG: Poison objects */ | |
22 | #define SLAB_HWCACHE_ALIGN 0x00002000UL /* Align objs on cache lines */ | |
2e892f43 | 23 | #define SLAB_CACHE_DMA 0x00004000UL /* Use GFP_DMA memory */ |
2e892f43 | 24 | #define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */ |
2e892f43 | 25 | #define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */ |
d7de4c1d PZ |
26 | /* |
27 | * SLAB_DESTROY_BY_RCU - **WARNING** READ THIS! | |
28 | * | |
29 | * This delays freeing the SLAB page by a grace period, it does _NOT_ | |
30 | * delay object freeing. This means that if you do kmem_cache_free() | |
31 | * that memory location is free to be reused at any time. Thus it may | |
32 | * be possible to see another object there in the same RCU grace period. | |
33 | * | |
34 | * This feature only ensures the memory location backing the object | |
35 | * stays valid, the trick to using this is relying on an independent | |
36 | * object validation pass. Something like: | |
37 | * | |
38 | * rcu_read_lock() | |
39 | * again: | |
40 | * obj = lockless_lookup(key); | |
41 | * if (obj) { | |
42 | * if (!try_get_ref(obj)) // might fail for free objects | |
43 | * goto again; | |
44 | * | |
45 | * if (obj->key != key) { // not the object we expected | |
46 | * put_ref(obj); | |
47 | * goto again; | |
48 | * } | |
49 | * } | |
50 | * rcu_read_unlock(); | |
51 | * | |
52 | * See also the comment on struct slab_rcu in mm/slab.c. | |
53 | */ | |
2e892f43 | 54 | #define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */ |
101a5001 | 55 | #define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */ |
81819f0f | 56 | #define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */ |
1da177e4 | 57 | |
30327acf TG |
58 | /* Flag to prevent checks on free */ |
59 | #ifdef CONFIG_DEBUG_OBJECTS | |
60 | # define SLAB_DEBUG_OBJECTS 0x00400000UL | |
61 | #else | |
62 | # define SLAB_DEBUG_OBJECTS 0x00000000UL | |
63 | #endif | |
64 | ||
d5cff635 CM |
65 | #define SLAB_NOLEAKTRACE 0x00800000UL /* Avoid kmemleak tracing */ |
66 | ||
2dff4405 VN |
67 | /* Don't track use of uninitialized memory */ |
68 | #ifdef CONFIG_KMEMCHECK | |
69 | # define SLAB_NOTRACK 0x01000000UL | |
70 | #else | |
71 | # define SLAB_NOTRACK 0x00000000UL | |
72 | #endif | |
4c13dd3b DM |
73 | #ifdef CONFIG_FAILSLAB |
74 | # define SLAB_FAILSLAB 0x02000000UL /* Fault injection mark */ | |
75 | #else | |
76 | # define SLAB_FAILSLAB 0x00000000UL | |
77 | #endif | |
2dff4405 | 78 | |
e12ba74d MG |
79 | /* The following flags affect the page allocator grouping pages by mobility */ |
80 | #define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */ | |
81 | #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ | |
6cb8f913 CL |
82 | /* |
83 | * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. | |
84 | * | |
85 | * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. | |
86 | * | |
87 | * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can. | |
88 | * Both make kfree a no-op. | |
89 | */ | |
90 | #define ZERO_SIZE_PTR ((void *)16) | |
91 | ||
1d4ec7b1 | 92 | #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ |
6cb8f913 CL |
93 | (unsigned long)ZERO_SIZE_PTR) |
94 | ||
2e892f43 CL |
95 | /* |
96 | * struct kmem_cache related prototypes | |
97 | */ | |
98 | void __init kmem_cache_init(void); | |
81819f0f | 99 | int slab_is_available(void); |
1da177e4 | 100 | |
2e892f43 | 101 | struct kmem_cache *kmem_cache_create(const char *, size_t, size_t, |
ebe29738 | 102 | unsigned long, |
51cc5068 | 103 | void (*)(void *)); |
2e892f43 CL |
104 | void kmem_cache_destroy(struct kmem_cache *); |
105 | int kmem_cache_shrink(struct kmem_cache *); | |
2e892f43 CL |
106 | void kmem_cache_free(struct kmem_cache *, void *); |
107 | unsigned int kmem_cache_size(struct kmem_cache *); | |
2e892f43 | 108 | |
0a31bd5f CL |
109 | /* |
110 | * Please use this macro to create slab caches. Simply specify the | |
111 | * name of the structure and maybe some flags that are listed above. | |
112 | * | |
113 | * The alignment of the struct determines object alignment. If you | |
114 | * f.e. add ____cacheline_aligned_in_smp to the struct declaration | |
115 | * then the objects will be properly aligned in SMP configurations. | |
116 | */ | |
117 | #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\ | |
118 | sizeof(struct __struct), __alignof__(struct __struct),\ | |
20c2df83 | 119 | (__flags), NULL) |
0a31bd5f | 120 | |
0aa817f0 CL |
121 | /* |
122 | * The largest kmalloc size supported by the slab allocators is | |
123 | * 32 megabyte (2^25) or the maximum allocatable page order if that is | |
124 | * less than 32 MB. | |
125 | * | |
126 | * WARNING: Its not easy to increase this value since the allocators have | |
127 | * to do various tricks to work around compiler limitations in order to | |
128 | * ensure proper constant folding. | |
129 | */ | |
debee076 CL |
130 | #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ |
131 | (MAX_ORDER + PAGE_SHIFT - 1) : 25) | |
0aa817f0 CL |
132 | |
133 | #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_HIGH) | |
134 | #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_HIGH - PAGE_SHIFT) | |
135 | ||
90810645 CL |
136 | /* |
137 | * Some archs want to perform DMA into kmalloc caches and need a guaranteed | |
138 | * alignment larger than the alignment of a 64-bit integer. | |
139 | * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that. | |
140 | */ | |
3192b920 CL |
141 | #ifdef ARCH_DMA_MINALIGN |
142 | #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN | |
143 | #else | |
144 | #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) | |
145 | #endif | |
146 | ||
90810645 CL |
147 | /* |
148 | * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. | |
149 | * Intended for arches that get misalignment faults even for 64 bit integer | |
150 | * aligned buffers. | |
151 | */ | |
3192b920 CL |
152 | #ifndef ARCH_SLAB_MINALIGN |
153 | #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) | |
154 | #endif | |
155 | ||
2e892f43 CL |
156 | /* |
157 | * Common kmalloc functions provided by all allocators | |
158 | */ | |
93bc4e89 | 159 | void * __must_check __krealloc(const void *, size_t, gfp_t); |
fd76bab2 | 160 | void * __must_check krealloc(const void *, size_t, gfp_t); |
2e892f43 | 161 | void kfree(const void *); |
3ef0e5ba | 162 | void kzfree(const void *); |
fd76bab2 | 163 | size_t ksize(const void *); |
2e892f43 | 164 | |
81cda662 CL |
165 | /* |
166 | * Allocator specific definitions. These are mainly used to establish optimized | |
167 | * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by | |
168 | * selecting the appropriate general cache at compile time. | |
169 | * | |
170 | * Allocators must define at least: | |
171 | * | |
172 | * kmem_cache_alloc() | |
173 | * __kmalloc() | |
174 | * kmalloc() | |
175 | * | |
176 | * Those wishing to support NUMA must also define: | |
177 | * | |
178 | * kmem_cache_alloc_node() | |
179 | * kmalloc_node() | |
180 | * | |
181 | * See each allocator definition file for additional comments and | |
182 | * implementation notes. | |
183 | */ | |
184 | #ifdef CONFIG_SLUB | |
185 | #include <linux/slub_def.h> | |
186 | #elif defined(CONFIG_SLOB) | |
187 | #include <linux/slob_def.h> | |
188 | #else | |
189 | #include <linux/slab_def.h> | |
190 | #endif | |
191 | ||
2e892f43 CL |
192 | /** |
193 | * kcalloc - allocate memory for an array. The memory is set to zero. | |
194 | * @n: number of elements. | |
195 | * @size: element size. | |
196 | * @flags: the type of memory to allocate. | |
800590f5 PD |
197 | * |
198 | * The @flags argument may be one of: | |
199 | * | |
200 | * %GFP_USER - Allocate memory on behalf of user. May sleep. | |
201 | * | |
202 | * %GFP_KERNEL - Allocate normal kernel ram. May sleep. | |
203 | * | |
6193a2ff | 204 | * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools. |
800590f5 PD |
205 | * For example, use this inside interrupt handlers. |
206 | * | |
207 | * %GFP_HIGHUSER - Allocate pages from high memory. | |
208 | * | |
209 | * %GFP_NOIO - Do not do any I/O at all while trying to get memory. | |
210 | * | |
211 | * %GFP_NOFS - Do not make any fs calls while trying to get memory. | |
212 | * | |
6193a2ff PM |
213 | * %GFP_NOWAIT - Allocation will not sleep. |
214 | * | |
215 | * %GFP_THISNODE - Allocate node-local memory only. | |
216 | * | |
217 | * %GFP_DMA - Allocation suitable for DMA. | |
218 | * Should only be used for kmalloc() caches. Otherwise, use a | |
219 | * slab created with SLAB_DMA. | |
220 | * | |
800590f5 PD |
221 | * Also it is possible to set different flags by OR'ing |
222 | * in one or more of the following additional @flags: | |
223 | * | |
224 | * %__GFP_COLD - Request cache-cold pages instead of | |
225 | * trying to return cache-warm pages. | |
226 | * | |
800590f5 PD |
227 | * %__GFP_HIGH - This allocation has high priority and may use emergency pools. |
228 | * | |
800590f5 PD |
229 | * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail |
230 | * (think twice before using). | |
231 | * | |
232 | * %__GFP_NORETRY - If memory is not immediately available, | |
233 | * then give up at once. | |
234 | * | |
235 | * %__GFP_NOWARN - If allocation fails, don't issue any warnings. | |
236 | * | |
237 | * %__GFP_REPEAT - If allocation fails initially, try once more before failing. | |
6193a2ff PM |
238 | * |
239 | * There are other flags available as well, but these are not intended | |
240 | * for general use, and so are not documented here. For a full list of | |
241 | * potential flags, always refer to linux/gfp.h. | |
800590f5 | 242 | */ |
6193a2ff | 243 | static inline void *kcalloc(size_t n, size_t size, gfp_t flags) |
1da177e4 | 244 | { |
9ca908f4 | 245 | if (size != 0 && n > ULONG_MAX / size) |
6193a2ff | 246 | return NULL; |
81cda662 | 247 | return __kmalloc(n * size, flags | __GFP_ZERO); |
1da177e4 LT |
248 | } |
249 | ||
6193a2ff PM |
250 | #if !defined(CONFIG_NUMA) && !defined(CONFIG_SLOB) |
251 | /** | |
252 | * kmalloc_node - allocate memory from a specific node | |
253 | * @size: how many bytes of memory are required. | |
254 | * @flags: the type of memory to allocate (see kcalloc). | |
255 | * @node: node to allocate from. | |
256 | * | |
257 | * kmalloc() for non-local nodes, used to allocate from a specific node | |
258 | * if available. Equivalent to kmalloc() in the non-NUMA single-node | |
259 | * case. | |
260 | */ | |
55935a34 CL |
261 | static inline void *kmalloc_node(size_t size, gfp_t flags, int node) |
262 | { | |
263 | return kmalloc(size, flags); | |
264 | } | |
265 | ||
266 | static inline void *__kmalloc_node(size_t size, gfp_t flags, int node) | |
267 | { | |
268 | return __kmalloc(size, flags); | |
269 | } | |
6193a2ff PM |
270 | |
271 | void *kmem_cache_alloc(struct kmem_cache *, gfp_t); | |
272 | ||
273 | static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep, | |
274 | gfp_t flags, int node) | |
275 | { | |
276 | return kmem_cache_alloc(cachep, flags); | |
277 | } | |
278 | #endif /* !CONFIG_NUMA && !CONFIG_SLOB */ | |
55935a34 | 279 | |
1d2c8eea CH |
280 | /* |
281 | * kmalloc_track_caller is a special version of kmalloc that records the | |
282 | * calling function of the routine calling it for slab leak tracking instead | |
283 | * of just the calling function (confusing, eh?). | |
284 | * It's useful when the call to kmalloc comes from a widely-used standard | |
285 | * allocator where we care about the real place the memory allocation | |
286 | * request comes from. | |
287 | */ | |
7adde04a XF |
288 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) || \ |
289 | (defined(CONFIG_SLAB) && defined(CONFIG_TRACING)) | |
ce71e27c | 290 | extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long); |
1d2c8eea | 291 | #define kmalloc_track_caller(size, flags) \ |
ce71e27c | 292 | __kmalloc_track_caller(size, flags, _RET_IP_) |
2e892f43 CL |
293 | #else |
294 | #define kmalloc_track_caller(size, flags) \ | |
295 | __kmalloc(size, flags) | |
296 | #endif /* DEBUG_SLAB */ | |
1da177e4 | 297 | |
97e2bde4 | 298 | #ifdef CONFIG_NUMA |
8b98c169 CH |
299 | /* |
300 | * kmalloc_node_track_caller is a special version of kmalloc_node that | |
301 | * records the calling function of the routine calling it for slab leak | |
302 | * tracking instead of just the calling function (confusing, eh?). | |
303 | * It's useful when the call to kmalloc_node comes from a widely-used | |
304 | * standard allocator where we care about the real place the memory | |
305 | * allocation request comes from. | |
306 | */ | |
7adde04a XF |
307 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) || \ |
308 | (defined(CONFIG_SLAB) && defined(CONFIG_TRACING)) | |
ce71e27c | 309 | extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long); |
8b98c169 CH |
310 | #define kmalloc_node_track_caller(size, flags, node) \ |
311 | __kmalloc_node_track_caller(size, flags, node, \ | |
ce71e27c | 312 | _RET_IP_) |
2e892f43 CL |
313 | #else |
314 | #define kmalloc_node_track_caller(size, flags, node) \ | |
315 | __kmalloc_node(size, flags, node) | |
8b98c169 | 316 | #endif |
2e892f43 | 317 | |
8b98c169 | 318 | #else /* CONFIG_NUMA */ |
8b98c169 CH |
319 | |
320 | #define kmalloc_node_track_caller(size, flags, node) \ | |
321 | kmalloc_track_caller(size, flags) | |
97e2bde4 | 322 | |
dfcd3610 | 323 | #endif /* CONFIG_NUMA */ |
10cef602 | 324 | |
81cda662 CL |
325 | /* |
326 | * Shortcuts | |
327 | */ | |
328 | static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) | |
329 | { | |
330 | return kmem_cache_alloc(k, flags | __GFP_ZERO); | |
331 | } | |
332 | ||
333 | /** | |
334 | * kzalloc - allocate memory. The memory is set to zero. | |
335 | * @size: how many bytes of memory are required. | |
336 | * @flags: the type of memory to allocate (see kmalloc). | |
337 | */ | |
338 | static inline void *kzalloc(size_t size, gfp_t flags) | |
339 | { | |
340 | return kmalloc(size, flags | __GFP_ZERO); | |
341 | } | |
342 | ||
979b0fea JL |
343 | /** |
344 | * kzalloc_node - allocate zeroed memory from a particular memory node. | |
345 | * @size: how many bytes of memory are required. | |
346 | * @flags: the type of memory to allocate (see kmalloc). | |
347 | * @node: memory node from which to allocate | |
348 | */ | |
349 | static inline void *kzalloc_node(size_t size, gfp_t flags, int node) | |
350 | { | |
351 | return kmalloc_node(size, flags | __GFP_ZERO, node); | |
352 | } | |
353 | ||
7e85ee0c PE |
354 | void __init kmem_cache_init_late(void); |
355 | ||
1da177e4 | 356 | #endif /* _LINUX_SLAB_H */ |