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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4065 | Serge | 1 | /* |
| 2 | * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk). |
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| 3 | * |
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| 4 | * (C) SGI 2006, Christoph Lameter |
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| 5 | * Cleaned up and restructured to ease the addition of alternative |
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| 6 | * implementations of SLAB allocators. |
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| 4103 | Serge | 7 | * (C) Linux Foundation 2008-2013 |
| 8 | * Unified interface for all slab allocators |
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| 4065 | Serge | 9 | */ |
| 1964 | serge | 10 | |
| 4065 | Serge | 11 | #ifndef _LINUX_SLAB_H |
| 12 | #define _LINUX_SLAB_H |
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| 13 | |||
| 5270 | serge | 14 | #include |
| 15 | #include |
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| 16 | #include |
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| 17 | |||
| 18 | |||
| 19 | /* |
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| 20 | * Flags to pass to kmem_cache_create(). |
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| 21 | * The ones marked DEBUG are only valid if CONFIG_SLAB_DEBUG is set. |
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| 22 | */ |
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| 23 | #define SLAB_DEBUG_FREE 0x00000100UL /* DEBUG: Perform (expensive) checks on free */ |
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| 24 | #define SLAB_RED_ZONE 0x00000400UL /* DEBUG: Red zone objs in a cache */ |
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| 25 | #define SLAB_POISON 0x00000800UL /* DEBUG: Poison objects */ |
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| 26 | #define SLAB_HWCACHE_ALIGN 0x00002000UL /* Align objs on cache lines */ |
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| 27 | #define SLAB_CACHE_DMA 0x00004000UL /* Use GFP_DMA memory */ |
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| 28 | #define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */ |
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| 29 | #define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */ |
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| 30 | /* |
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| 31 | * SLAB_DESTROY_BY_RCU - **WARNING** READ THIS! |
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| 32 | * |
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| 33 | * This delays freeing the SLAB page by a grace period, it does _NOT_ |
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| 34 | * delay object freeing. This means that if you do kmem_cache_free() |
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| 35 | * that memory location is free to be reused at any time. Thus it may |
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| 36 | * be possible to see another object there in the same RCU grace period. |
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| 37 | * |
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| 38 | * This feature only ensures the memory location backing the object |
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| 39 | * stays valid, the trick to using this is relying on an independent |
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| 40 | * object validation pass. Something like: |
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| 41 | * |
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| 42 | * rcu_read_lock() |
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| 43 | * again: |
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| 44 | * obj = lockless_lookup(key); |
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| 45 | * if (obj) { |
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| 46 | * if (!try_get_ref(obj)) // might fail for free objects |
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| 47 | * goto again; |
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| 48 | * |
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| 49 | * if (obj->key != key) { // not the object we expected |
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| 50 | * put_ref(obj); |
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| 51 | * goto again; |
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| 52 | * } |
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| 53 | * } |
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| 54 | * rcu_read_unlock(); |
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| 55 | * |
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| 56 | * This is useful if we need to approach a kernel structure obliquely, |
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| 57 | * from its address obtained without the usual locking. We can lock |
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| 58 | * the structure to stabilize it and check it's still at the given address, |
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| 59 | * only if we can be sure that the memory has not been meanwhile reused |
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| 60 | * for some other kind of object (which our subsystem's lock might corrupt). |
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| 61 | * |
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| 62 | * rcu_read_lock before reading the address, then rcu_read_unlock after |
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| 63 | * taking the spinlock within the structure expected at that address. |
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| 64 | */ |
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| 65 | #define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */ |
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| 66 | #define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */ |
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| 67 | #define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */ |
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| 68 | |||
| 69 | /* Flag to prevent checks on free */ |
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| 70 | #ifdef CONFIG_DEBUG_OBJECTS |
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| 71 | # define SLAB_DEBUG_OBJECTS 0x00400000UL |
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| 72 | #else |
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| 73 | # define SLAB_DEBUG_OBJECTS 0x00000000UL |
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| 74 | #endif |
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| 75 | |||
| 76 | #define SLAB_NOLEAKTRACE 0x00800000UL /* Avoid kmemleak tracing */ |
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| 77 | |||
| 78 | /* Don't track use of uninitialized memory */ |
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| 79 | #ifdef CONFIG_KMEMCHECK |
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| 80 | # define SLAB_NOTRACK 0x01000000UL |
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| 81 | #else |
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| 82 | # define SLAB_NOTRACK 0x00000000UL |
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| 83 | #endif |
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| 84 | #ifdef CONFIG_FAILSLAB |
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| 85 | # define SLAB_FAILSLAB 0x02000000UL /* Fault injection mark */ |
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| 86 | #else |
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| 87 | # define SLAB_FAILSLAB 0x00000000UL |
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| 88 | #endif |
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| 89 | |||
| 90 | /* The following flags affect the page allocator grouping pages by mobility */ |
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| 91 | #define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */ |
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| 92 | #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ |
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| 93 | /* |
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| 94 | * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. |
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| 95 | * |
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| 96 | * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. |
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| 97 | * |
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| 98 | * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can. |
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| 99 | * Both make kfree a no-op. |
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| 100 | */ |
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| 101 | #define ZERO_SIZE_PTR ((void *)16) |
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| 102 | |||
| 103 | #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \ |
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| 104 | (unsigned long)ZERO_SIZE_PTR) |
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| 105 | |||
| 106 | void __init kmem_cache_init(void); |
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| 107 | int slab_is_available(void); |
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| 108 | void kmem_cache_destroy(struct kmem_cache *); |
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| 109 | int kmem_cache_shrink(struct kmem_cache *); |
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| 110 | void kmem_cache_free(struct kmem_cache *, void *); |
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| 111 | |||
| 112 | static inline void *krealloc(void *p, size_t new_size, gfp_t flags) |
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| 113 | { |
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| 114 | return __builtin_realloc(p, new_size); |
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| 115 | } |
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| 116 | |||
| 117 | static inline void kfree(void *p) |
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| 118 | { |
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| 119 | __builtin_free(p); |
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| 120 | } |
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| 121 | static __always_inline void *kmalloc(size_t size, gfp_t flags) |
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| 122 | { |
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| 123 | return __builtin_malloc(size); |
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| 124 | } |
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| 125 | |||
| 126 | /** |
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| 127 | * kzalloc - allocate memory. The memory is set to zero. |
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| 128 | * @size: how many bytes of memory are required. |
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| 129 | * @flags: the type of memory to allocate (see kmalloc). |
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| 130 | */ |
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| 131 | static inline void *kzalloc(size_t size, gfp_t flags) |
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| 132 | { |
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| 133 | void *ret = __builtin_malloc(size); |
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| 134 | memset(ret, 0, size); |
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| 135 | return ret; |
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| 136 | } |
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| 137 | |||
| 138 | static inline void *kcalloc(size_t n, size_t size, uint32_t flags) |
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| 139 | { |
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| 140 | return (void*)kzalloc(n * size, 0); |
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| 141 | } |
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| 142 | |||
| 143 | static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags) |
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| 144 | { |
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| 145 | // if (size != 0 && n > SIZE_MAX / size) |
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| 146 | // return NULL; |
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| 147 | return (void*)kmalloc(n * size, flags); |
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| 148 | } |
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| 149 | |||
| 4065 | Serge | 150 | #endif /* _LINUX_SLAB_H */ |