1 /* 2 * Written by Mark Hemment, 1996 ([email protected]). 3 * 4 * (C) SGI 2006, Christoph Lameter <[email protected]> 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_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */ 28 #define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */ 29 #define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */ 30 #define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */ 31 32 /* The following flags affect the page allocator grouping pages by mobility */ 33 #define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */ 34 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ 35 /* 36 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. 37 * 38 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. 39 * 40 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can. 41 * Both make kfree a no-op. 42 */ 43 #define ZERO_SIZE_PTR ((void *)16) 44 45 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ 46 (unsigned long)ZERO_SIZE_PTR) 47 48 /* 49 * struct kmem_cache related prototypes 50 */ 51 void __init kmem_cache_init(void); 52 int slab_is_available(void); 53 54 struct kmem_cache *kmem_cache_create(const char *, size_t, size_t, 55 unsigned long, 56 void (*)(struct kmem_cache *, void *)); 57 void kmem_cache_destroy(struct kmem_cache *); 58 int kmem_cache_shrink(struct kmem_cache *); 59 void kmem_cache_free(struct kmem_cache *, void *); 60 unsigned int kmem_cache_size(struct kmem_cache *); 61 const char *kmem_cache_name(struct kmem_cache *); 62 int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr); 63 64 /* 65 * Please use this macro to create slab caches. Simply specify the 66 * name of the structure and maybe some flags that are listed above. 67 * 68 * The alignment of the struct determines object alignment. If you 69 * f.e. add ____cacheline_aligned_in_smp to the struct declaration 70 * then the objects will be properly aligned in SMP configurations. 71 */ 72 #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\ 73 sizeof(struct __struct), __alignof__(struct __struct),\ 74 (__flags), NULL) 75 76 /* 77 * The largest kmalloc size supported by the slab allocators is 78 * 32 megabyte (2^25) or the maximum allocatable page order if that is 79 * less than 32 MB. 80 * 81 * WARNING: Its not easy to increase this value since the allocators have 82 * to do various tricks to work around compiler limitations in order to 83 * ensure proper constant folding. 84 */ 85 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ 86 (MAX_ORDER + PAGE_SHIFT - 1) : 25) 87 88 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_HIGH) 89 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_HIGH - PAGE_SHIFT) 90 91 /* 92 * Common kmalloc functions provided by all allocators 93 */ 94 void * __must_check krealloc(const void *, size_t, gfp_t); 95 void kfree(const void *); 96 size_t ksize(const void *); 97 98 /* 99 * Allocator specific definitions. These are mainly used to establish optimized 100 * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by 101 * selecting the appropriate general cache at compile time. 102 * 103 * Allocators must define at least: 104 * 105 * kmem_cache_alloc() 106 * __kmalloc() 107 * kmalloc() 108 * 109 * Those wishing to support NUMA must also define: 110 * 111 * kmem_cache_alloc_node() 112 * kmalloc_node() 113 * 114 * See each allocator definition file for additional comments and 115 * implementation notes. 116 */ 117 #ifdef CONFIG_SLUB 118 #include <linux/slub_def.h> 119 #elif defined(CONFIG_SLOB) 120 #include <linux/slob_def.h> 121 #else 122 #include <linux/slab_def.h> 123 #endif 124 125 /** 126 * kcalloc - allocate memory for an array. The memory is set to zero. 127 * @n: number of elements. 128 * @size: element size. 129 * @flags: the type of memory to allocate. 130 * 131 * The @flags argument may be one of: 132 * 133 * %GFP_USER - Allocate memory on behalf of user. May sleep. 134 * 135 * %GFP_KERNEL - Allocate normal kernel ram. May sleep. 136 * 137 * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools. 138 * For example, use this inside interrupt handlers. 139 * 140 * %GFP_HIGHUSER - Allocate pages from high memory. 141 * 142 * %GFP_NOIO - Do not do any I/O at all while trying to get memory. 143 * 144 * %GFP_NOFS - Do not make any fs calls while trying to get memory. 145 * 146 * %GFP_NOWAIT - Allocation will not sleep. 147 * 148 * %GFP_THISNODE - Allocate node-local memory only. 149 * 150 * %GFP_DMA - Allocation suitable for DMA. 151 * Should only be used for kmalloc() caches. Otherwise, use a 152 * slab created with SLAB_DMA. 153 * 154 * Also it is possible to set different flags by OR'ing 155 * in one or more of the following additional @flags: 156 * 157 * %__GFP_COLD - Request cache-cold pages instead of 158 * trying to return cache-warm pages. 159 * 160 * %__GFP_HIGH - This allocation has high priority and may use emergency pools. 161 * 162 * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail 163 * (think twice before using). 164 * 165 * %__GFP_NORETRY - If memory is not immediately available, 166 * then give up at once. 167 * 168 * %__GFP_NOWARN - If allocation fails, don't issue any warnings. 169 * 170 * %__GFP_REPEAT - If allocation fails initially, try once more before failing. 171 * 172 * There are other flags available as well, but these are not intended 173 * for general use, and so are not documented here. For a full list of 174 * potential flags, always refer to linux/gfp.h. 175 */ 176 static inline void *kcalloc(size_t n, size_t size, gfp_t flags) 177 { 178 if (n != 0 && size > ULONG_MAX / n) 179 return NULL; 180 return __kmalloc(n * size, flags | __GFP_ZERO); 181 } 182 183 #if !defined(CONFIG_NUMA) && !defined(CONFIG_SLOB) 184 /** 185 * kmalloc_node - allocate memory from a specific node 186 * @size: how many bytes of memory are required. 187 * @flags: the type of memory to allocate (see kcalloc). 188 * @node: node to allocate from. 189 * 190 * kmalloc() for non-local nodes, used to allocate from a specific node 191 * if available. Equivalent to kmalloc() in the non-NUMA single-node 192 * case. 193 */ 194 static inline void *kmalloc_node(size_t size, gfp_t flags, int node) 195 { 196 return kmalloc(size, flags); 197 } 198 199 static inline void *__kmalloc_node(size_t size, gfp_t flags, int node) 200 { 201 return __kmalloc(size, flags); 202 } 203 204 void *kmem_cache_alloc(struct kmem_cache *, gfp_t); 205 206 static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep, 207 gfp_t flags, int node) 208 { 209 return kmem_cache_alloc(cachep, flags); 210 } 211 #endif /* !CONFIG_NUMA && !CONFIG_SLOB */ 212 213 /* 214 * kmalloc_track_caller is a special version of kmalloc that records the 215 * calling function of the routine calling it for slab leak tracking instead 216 * of just the calling function (confusing, eh?). 217 * It's useful when the call to kmalloc comes from a widely-used standard 218 * allocator where we care about the real place the memory allocation 219 * request comes from. 220 */ 221 #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) 222 extern void *__kmalloc_track_caller(size_t, gfp_t, void*); 223 #define kmalloc_track_caller(size, flags) \ 224 __kmalloc_track_caller(size, flags, __builtin_return_address(0)) 225 #else 226 #define kmalloc_track_caller(size, flags) \ 227 __kmalloc(size, flags) 228 #endif /* DEBUG_SLAB */ 229 230 #ifdef CONFIG_NUMA 231 /* 232 * kmalloc_node_track_caller is a special version of kmalloc_node that 233 * records the calling function of the routine calling it for slab leak 234 * tracking instead of just the calling function (confusing, eh?). 235 * It's useful when the call to kmalloc_node comes from a widely-used 236 * standard allocator where we care about the real place the memory 237 * allocation request comes from. 238 */ 239 #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) 240 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, void *); 241 #define kmalloc_node_track_caller(size, flags, node) \ 242 __kmalloc_node_track_caller(size, flags, node, \ 243 __builtin_return_address(0)) 244 #else 245 #define kmalloc_node_track_caller(size, flags, node) \ 246 __kmalloc_node(size, flags, node) 247 #endif 248 249 #else /* CONFIG_NUMA */ 250 251 #define kmalloc_node_track_caller(size, flags, node) \ 252 kmalloc_track_caller(size, flags) 253 254 #endif /* DEBUG_SLAB */ 255 256 /* 257 * Shortcuts 258 */ 259 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 260 { 261 return kmem_cache_alloc(k, flags | __GFP_ZERO); 262 } 263 264 /** 265 * kzalloc - allocate memory. The memory is set to zero. 266 * @size: how many bytes of memory are required. 267 * @flags: the type of memory to allocate (see kmalloc). 268 */ 269 static inline void *kzalloc(size_t size, gfp_t flags) 270 { 271 return kmalloc(size, flags | __GFP_ZERO); 272 } 273 274 #endif /* __KERNEL__ */ 275 #endif /* _LINUX_SLAB_H */ 276