include/linux/slab.h

   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 typedef struct kmem_cache kmem_cache_t __deprecated;
  18
  19 /*
  20  * Flags to pass to kmem_cache_create().
  21  * The ones marked DEBUG are only valid if CONFIG_SLAB_DEBUG is set.
  22  */
  23 #define SLAB_DEBUG_FREE         0x00000100UL    /* DEBUG: Perform (expensive) checks on free */
  24 #define SLAB_RED_ZONE           0x00000400UL    /* DEBUG: Red zone objs in a cache */
  25 #define SLAB_POISON             0x00000800UL    /* DEBUG: Poison objects */
  26 #define SLAB_HWCACHE_ALIGN      0x00002000UL    /* Align objs on cache lines */
  27 #define SLAB_CACHE_DMA          0x00004000UL    /* Use GFP_DMA memory */
  28 #define SLAB_STORE_USER         0x00010000UL    /* DEBUG: Store the last owner for bug hunting */
  29 #define SLAB_RECLAIM_ACCOUNT    0x00020000UL    /* Objects are reclaimable */
  30 #define SLAB_PANIC              0x00040000UL    /* Panic if kmem_cache_create() fails */
  31 #define SLAB_DESTROY_BY_RCU     0x00080000UL    /* Defer freeing slabs to RCU */
  32 #define SLAB_MEM_SPREAD         0x00100000UL    /* Spread some memory over cpuset */
  33 #define SLAB_TRACE              0x00200000UL    /* Trace allocations and frees */
  34
  35 /*
  36  * struct kmem_cache related prototypes
  37  */
  38 void __init kmem_cache_init(void);
  39 int slab_is_available(void);
  40
  41 struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
  42                         unsigned long,
  43                         void (*)(void *, struct kmem_cache *, unsigned long),
  44                         void (*)(void *, struct kmem_cache *, unsigned long));
  45 void kmem_cache_destroy(struct kmem_cache *);
  46 int kmem_cache_shrink(struct kmem_cache *);
  47 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
  48 void *kmem_cache_zalloc(struct kmem_cache *, gfp_t);
  49 void kmem_cache_free(struct kmem_cache *, void *);
  50 unsigned int kmem_cache_size(struct kmem_cache *);
  51 const char *kmem_cache_name(struct kmem_cache *);
  52 int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr);
  53
  54 /*
  55  * Please use this macro to create slab caches. Simply specify the
  56  * name of the structure and maybe some flags that are listed above.
  57  *
  58  * The alignment of the struct determines object alignment. If you
  59  * f.e. add ____cacheline_aligned_in_smp to the struct declaration
  60  * then the objects will be properly aligned in SMP configurations.
  61  */
  62 #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
  63                 sizeof(struct __struct), __alignof__(struct __struct),\
  64                 (__flags), NULL, NULL)
  65
  66 #ifdef CONFIG_NUMA
  67 extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
  68 #else
  69 static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep,
  70                                         gfp_t flags, int node)
  71 {
  72         return kmem_cache_alloc(cachep, flags);
  73 }
  74 #endif
  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) <= 25 ? \
  86                                 (MAX_ORDER + PAGE_SHIFT) : 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 *__kmalloc(size_t, gfp_t);
  95 void *__kzalloc(size_t, gfp_t);
  96 void * __must_check krealloc(const void *, size_t, gfp_t);
  97 void kfree(const void *);
  98 size_t ksize(const void *);
  99
 100 /**
 101  * kcalloc - allocate memory for an array. The memory is set to zero.
 102  * @n: number of elements.
 103  * @size: element size.
 104  * @flags: the type of memory to allocate.
 105  */
 106 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
 107 {
 108         if (n != 0 && size > ULONG_MAX / n)
 109                 return NULL;
 110         return __kzalloc(n * size, flags);
 111 }
 112
 113 /*
 114  * Allocator specific definitions. These are mainly used to establish optimized
 115  * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by selecting
 116  * the appropriate general cache at compile time.
 117  */
 118
 119 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB)
 120 #ifdef CONFIG_SLUB
 121 #include <linux/slub_def.h>
 122 #else
 123 #include <linux/slab_def.h>
 124 #endif /* !CONFIG_SLUB */
 125 #else
 126
 127 /*
 128  * Fallback definitions for an allocator not wanting to provide
 129  * its own optimized kmalloc definitions (like SLOB).
 130  */
 131
 132 /**
 133  * kmalloc - allocate memory
 134  * @size: how many bytes of memory are required.
 135  * @flags: the type of memory to allocate.
 136  *
 137  * kmalloc is the normal method of allocating memory
 138  * in the kernel.
 139  *
 140  * The @flags argument may be one of:
 141  *
 142  * %GFP_USER - Allocate memory on behalf of user.  May sleep.
 143  *
 144  * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
 145  *
 146  * %GFP_ATOMIC - Allocation will not sleep.
 147  *   For example, use this inside interrupt handlers.
 148  *
 149  * %GFP_HIGHUSER - Allocate pages from high memory.
 150  *
 151  * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
 152  *
 153  * %GFP_NOFS - Do not make any fs calls while trying to get memory.
 154  *
 155  * Also it is possible to set different flags by OR'ing
 156  * in one or more of the following additional @flags:
 157  *
 158  * %__GFP_COLD - Request cache-cold pages instead of
 159  *   trying to return cache-warm pages.
 160  *
 161  * %__GFP_DMA - Request memory from the DMA-capable zone.
 162  *
 163  * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
 164  *
 165  * %__GFP_HIGHMEM - Allocated memory may be from highmem.
 166  *
 167  * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
 168  *   (think twice before using).
 169  *
 170  * %__GFP_NORETRY - If memory is not immediately available,
 171  *   then give up at once.
 172  *
 173  * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
 174  *
 175  * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
 176  */
 177 static inline void *kmalloc(size_t size, gfp_t flags)
 178 {
 179         return __kmalloc(size, flags);
 180 }
 181
 182 /**
 183  * kzalloc - allocate memory. The memory is set to zero.
 184  * @size: how many bytes of memory are required.
 185  * @flags: the type of memory to allocate (see kmalloc).
 186  */
 187 static inline void *kzalloc(size_t size, gfp_t flags)
 188 {
 189         return __kzalloc(size, flags);
 190 }
 191 #endif
 192
 193 #ifndef CONFIG_NUMA
 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 #endif /* !CONFIG_NUMA */
 204
 205 /*
 206  * kmalloc_track_caller is a special version of kmalloc that records the
 207  * calling function of the routine calling it for slab leak tracking instead
 208  * of just the calling function (confusing, eh?).
 209  * It's useful when the call to kmalloc comes from a widely-used standard
 210  * allocator where we care about the real place the memory allocation
 211  * request comes from.
 212  */
 213 #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB)
 214 extern void *__kmalloc_track_caller(size_t, gfp_t, void*);
 215 #define kmalloc_track_caller(size, flags) \
 216         __kmalloc_track_caller(size, flags, __builtin_return_address(0))
 217 #else
 218 #define kmalloc_track_caller(size, flags) \
 219         __kmalloc(size, flags)
 220 #endif /* DEBUG_SLAB */
 221
 222 #ifdef CONFIG_NUMA
 223 /*
 224  * kmalloc_node_track_caller is a special version of kmalloc_node that
 225  * records the calling function of the routine calling it for slab leak
 226  * tracking instead of just the calling function (confusing, eh?).
 227  * It's useful when the call to kmalloc_node comes from a widely-used
 228  * standard allocator where we care about the real place the memory
 229  * allocation request comes from.
 230  */
 231 #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB)
 232 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, void *);
 233 #define kmalloc_node_track_caller(size, flags, node) \
 234         __kmalloc_node_track_caller(size, flags, node, \
 235                         __builtin_return_address(0))
 236 #else
 237 #define kmalloc_node_track_caller(size, flags, node) \
 238         __kmalloc_node(size, flags, node)
 239 #endif
 240
 241 #else /* CONFIG_NUMA */
 242
 243 #define kmalloc_node_track_caller(size, flags, node) \
 244         kmalloc_track_caller(size, flags)
 245
 246 #endif /* DEBUG_SLAB */
 247
 248 #endif  /* __KERNEL__ */
 249 #endif  /* _LINUX_SLAB_H */
 250