1/* 2 * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk). 3 * 4 * (C) SGI 2006, Christoph Lameter 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#include <linux/gfp.h> 13#include <linux/types.h> 14 15/* 16 * Flags to pass to kmem_cache_create(). 17 * The ones marked DEBUG are only valid if CONFIG_SLAB_DEBUG is set. 18 */ 19#define SLAB_DEBUG_FREE 0x00000100UL /* DEBUG: Perform (expensive) checks on free */ 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 */ 23#define SLAB_CACHE_DMA 0x00004000UL /* Use GFP_DMA memory */ 24#define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */ 25#define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */ 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 */ 54#define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */ 55#define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */ 56#define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */ 57 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 65#define SLAB_NOLEAKTRACE 0x00800000UL /* Avoid kmemleak tracing */ 66 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 73#ifdef CONFIG_FAILSLAB 74# define SLAB_FAILSLAB 0x02000000UL /* Fault injection mark */ 75#else 76# define SLAB_FAILSLAB 0x00000000UL 77#endif 78 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 */ 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 92#define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ 93 (unsigned long)ZERO_SIZE_PTR) 94 95/* 96 * struct kmem_cache related prototypes 97 */ 98void __init kmem_cache_init(void); 99int slab_is_available(void); 100 101struct kmem_cache *kmem_cache_create(const char *, size_t, size_t, 102 unsigned long, 103 void (*)(void *)); 104void kmem_cache_destroy(struct kmem_cache *); 105int kmem_cache_shrink(struct kmem_cache *); 106void kmem_cache_free(struct kmem_cache *, void *); 107unsigned int kmem_cache_size(struct kmem_cache *); 108const char *kmem_cache_name(struct kmem_cache *); 109int kern_ptr_validate(const void *ptr, unsigned long size); 110int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr); 111 112/* 113 * Please use this macro to create slab caches. Simply specify the 114 * name of the structure and maybe some flags that are listed above. 115 * 116 * The alignment of the struct determines object alignment. If you 117 * f.e. add ____cacheline_aligned_in_smp to the struct declaration 118 * then the objects will be properly aligned in SMP configurations. 119 */ 120#define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\ 121 sizeof(struct __struct), __alignof__(struct __struct),\ 122 (__flags), NULL) 123 124#define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ 125 (MAX_ORDER + PAGE_SHIFT - 1) : 25) 126 127#define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_HIGH) 128#define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_HIGH - PAGE_SHIFT) 129 130/* 131 * Common kmalloc functions provided by all allocators 132 */ 133void * __must_check __krealloc(const void *, size_t, gfp_t); 134void * __must_check krealloc(const void *, size_t, gfp_t); 135void kfree(const void *); 136void kzfree(const void *); 137size_t ksize(const void *); 138 139/* 140 * Allocator specific definitions. These are mainly used to establish optimized 141 * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by 142 * selecting the appropriate general cache at compile time. 143 * 144 * Allocators must define at least: 145 * 146 * kmem_cache_alloc() 147 * __kmalloc() 148 * kmalloc() 149 * 150 * Those wishing to support NUMA must also define: 151 * 152 * kmem_cache_alloc_node() 153 * kmalloc_node() 154 * 155 * See each allocator definition file for additional comments and 156 * implementation notes. 157 */ 158#ifdef CONFIG_SLUB 159#include <linux/slub_def.h> 160#elif defined(CONFIG_SLOB) 161#include <linux/slob_def.h> 162#else 163#include <linux/slab_def.h> 164#endif 165 166/** 167 * kcalloc - allocate memory for an array. The memory is set to zero. 168 * @n: number of elements. 169 * @size: element size. 170 * @flags: the type of memory to allocate. 171 * 172 * The @flags argument may be one of: 173 * 174 * %GFP_USER - Allocate memory on behalf of user. May sleep. 175 * 176 * %GFP_KERNEL - Allocate normal kernel ram. May sleep. 177 * 178 * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools. 179 * For example, use this inside interrupt handlers. 180 * 181 * %GFP_HIGHUSER - Allocate pages from high memory. 182 * 183 * %GFP_NOIO - Do not do any I/O at all while trying to get memory. 184 * 185 * %GFP_NOFS - Do not make any fs calls while trying to get memory. 186 * 187 * %GFP_NOWAIT - Allocation will not sleep. 188 * 189 * %GFP_THISNODE - Allocate node-local memory only. 190 * 191 * %GFP_DMA - Allocation suitable for DMA. 192 * Should only be used for kmalloc() caches. Otherwise, use a 193 * slab created with SLAB_DMA. 194 * 195 * Also it is possible to set different flags by OR'ing 196 * in one or more of the following additional @flags: 197 * 198 * %__GFP_COLD - Request cache-cold pages instead of 199 * trying to return cache-warm pages. 200 * 201 * %__GFP_HIGH - This allocation has high priority and may use emergency pools. 202 * 203 * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail 204 * (think twice before using). 205 * 206 * %__GFP_NORETRY - If memory is not immediately available, 207 * then give up at once. 208 * 209 * %__GFP_NOWARN - If allocation fails, don't issue any warnings. 210 * 211 * %__GFP_REPEAT - If allocation fails initially, try once more before failing. 212 * 213 * There are other flags available as well, but these are not intended 214 * for general use, and so are not documented here. For a full list of 215 * potential flags, always refer to linux/gfp.h. 216 */ 217static inline void *kcalloc(size_t n, size_t size, gfp_t flags) 218{ 219 if (size != 0 && n > ULONG_MAX / size) 220 return NULL; 221 return __kmalloc(n * size, flags | __GFP_ZERO); 222} 223 224#if !defined(CONFIG_NUMA) && !defined(CONFIG_SLOB) 225/** 226 * kmalloc_node - allocate memory from a specific node 227 * @size: how many bytes of memory are required. 228 * @flags: the type of memory to allocate (see kcalloc). 229 * @node: node to allocate from. 230 * 231 * kmalloc() for non-local nodes, used to allocate from a specific node 232 * if available. Equivalent to kmalloc() in the non-NUMA single-node 233 * case. 234 */ 235static inline void *kmalloc_node(size_t size, gfp_t flags, int node) 236{ 237 return kmalloc(size, flags); 238} 239 240static inline void *__kmalloc_node(size_t size, gfp_t flags, int node) 241{ 242 return __kmalloc(size, flags); 243} 244 245void *kmem_cache_alloc(struct kmem_cache *, gfp_t); 246 247static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep, 248 gfp_t flags, int node) 249{ 250 return kmem_cache_alloc(cachep, flags); 251} 252#endif /* !CONFIG_NUMA && !CONFIG_SLOB */ 253 254/* 255 * kmalloc_track_caller is a special version of kmalloc that records the 256 * calling function of the routine calling it for slab leak tracking instead 257 * of just the calling function (confusing, eh?). 258 * It's useful when the call to kmalloc comes from a widely-used standard 259 * allocator where we care about the real place the memory allocation 260 * request comes from. 261 */ 262#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) || (defined(CONFIG_SLAB) && \ 263 defined(CONFIG_TRACING)) 264extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long); 265#define kmalloc_track_caller(size, flags) \ 266 __kmalloc_track_caller(size, flags, _RET_IP_) 267#else 268#define kmalloc_track_caller(size, flags) \ 269 __kmalloc(size, flags) 270#endif /* DEBUG_SLAB */ 271 272#ifdef CONFIG_NUMA 273/* 274 * kmalloc_node_track_caller is a special version of kmalloc_node that 275 * records the calling function of the routine calling it for slab leak 276 * tracking instead of just the calling function (confusing, eh?). 277 * It's useful when the call to kmalloc_node comes from a widely-used 278 * standard allocator where we care about the real place the memory 279 * allocation request comes from. 280 */ 281#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) || (defined(CONFIG_SLAB) && \ 282 defined(CONFIG_TRACING)) 283extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long); 284#define kmalloc_node_track_caller(size, flags, node) \ 285 __kmalloc_node_track_caller(size, flags, node, \ 286 _RET_IP_) 287#else 288#define kmalloc_node_track_caller(size, flags, node) \ 289 __kmalloc_node(size, flags, node) 290#endif 291 292#else /* CONFIG_NUMA */ 293 294#define kmalloc_node_track_caller(size, flags, node) \ 295 kmalloc_track_caller(size, flags) 296 297#endif /* CONFIG_NUMA */ 298 299/* 300 * Shortcuts 301 */ 302static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags) 303{ 304 return kmem_cache_alloc(k, flags | __GFP_ZERO); 305} 306 307/** 308 * kzalloc - allocate memory. The memory is set to zero. 309 * @size: how many bytes of memory are required. 310 * @flags: the type of memory to allocate (see kmalloc). 311 */ 312static inline void *kzalloc(size_t size, gfp_t flags) 313{ 314 return kmalloc(size, flags | __GFP_ZERO); 315} 316 317/** 318 * kzalloc_node - allocate zeroed memory from a particular memory node. 319 * @size: how many bytes of memory are required. 320 * @flags: the type of memory to allocate (see kmalloc). 321 * @node: memory node from which to allocate 322 */ 323static inline void *kzalloc_node(size_t size, gfp_t flags, int node) 324{ 325 return kmalloc_node(size, flags | __GFP_ZERO, node); 326} 327 328void __init kmem_cache_init_late(void); 329 330#endif /* _LINUX_SLAB_H */ 331