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- /*
- * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk).
- *
- * (C) SGI 2006, Christoph Lameter
- * Cleaned up and restructured to ease the addition of alternative
- * implementations of SLAB allocators.
- */
- #ifndef _LINUX_SLAB_H
- #define _LINUX_SLAB_H
- #include <linux/gfp.h>
- #include <linux/types.h>
- /*
- * Flags to pass to kmem_cache_create().
- * The ones marked DEBUG are only valid if CONFIG_SLAB_DEBUG is set.
- */
- #define SLAB_DEBUG_FREE 0x00000100UL /* DEBUG: Perform (expensive) checks on free */
- #define SLAB_RED_ZONE 0x00000400UL /* DEBUG: Red zone objs in a cache */
- #define SLAB_POISON 0x00000800UL /* DEBUG: Poison objects */
- #define SLAB_HWCACHE_ALIGN 0x00002000UL /* Align objs on cache lines */
- #define SLAB_CACHE_DMA 0x00004000UL /* Use GFP_DMA memory */
- #define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */
- #define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */
- /*
- * SLAB_DESTROY_BY_RCU - **WARNING** READ THIS!
- *
- * This delays freeing the SLAB page by a grace period, it does _NOT_
- * delay object freeing. This means that if you do kmem_cache_free()
- * that memory location is free to be reused at any time. Thus it may
- * be possible to see another object there in the same RCU grace period.
- *
- * This feature only ensures the memory location backing the object
- * stays valid, the trick to using this is relying on an independent
- * object validation pass. Something like:
- *
- * rcu_read_lock()
- * again:
- * obj = lockless_lookup(key);
- * if (obj) {
- * if (!try_get_ref(obj)) // might fail for free objects
- * goto again;
- *
- * if (obj->key != key) { // not the object we expected
- * put_ref(obj);
- * goto again;
- * }
- * }
- * rcu_read_unlock();
- *
- * See also the comment on struct slab_rcu in mm/slab.c.
- */
- #define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */
- #define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */
- #define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */
- /* Flag to prevent checks on free */
- #ifdef CONFIG_DEBUG_OBJECTS
- # define SLAB_DEBUG_OBJECTS 0x00400000UL
- #else
- # define SLAB_DEBUG_OBJECTS 0x00000000UL
- #endif
- #define SLAB_NOLEAKTRACE 0x00800000UL /* Avoid kmemleak tracing */
- /* Don't track use of uninitialized memory */
- #ifdef CONFIG_KMEMCHECK
- # define SLAB_NOTRACK 0x01000000UL
- #else
- # define SLAB_NOTRACK 0x00000000UL
- #endif
- #ifdef CONFIG_FAILSLAB
- # define SLAB_FAILSLAB 0x02000000UL /* Fault injection mark */
- #else
- # define SLAB_FAILSLAB 0x00000000UL
- #endif
- /* The following flags affect the page allocator grouping pages by mobility */
- #define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */
- #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
- /*
- * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
- *
- * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
- *
- * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
- * Both make kfree a no-op.
- */
- #define ZERO_SIZE_PTR ((void *)16)
- #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
- (unsigned long)ZERO_SIZE_PTR)
- /*
- * struct kmem_cache related prototypes
- */
- void __init kmem_cache_init(void);
- int slab_is_available(void);
- struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
- unsigned long,
- void (*)(void *));
- void kmem_cache_destroy(struct kmem_cache *);
- int kmem_cache_shrink(struct kmem_cache *);
- void kmem_cache_free(struct kmem_cache *, void *);
- unsigned int kmem_cache_size(struct kmem_cache *);
- /*
- * Please use this macro to create slab caches. Simply specify the
- * name of the structure and maybe some flags that are listed above.
- *
- * The alignment of the struct determines object alignment. If you
- * f.e. add ____cacheline_aligned_in_smp to the struct declaration
- * then the objects will be properly aligned in SMP configurations.
- */
- #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
- sizeof(struct __struct), __alignof__(struct __struct),\
- (__flags), NULL)
- /*
- * The largest kmalloc size supported by the slab allocators is
- * 32 megabyte (2^25) or the maximum allocatable page order if that is
- * less than 32 MB.
- *
- * WARNING: Its not easy to increase this value since the allocators have
- * to do various tricks to work around compiler limitations in order to
- * ensure proper constant folding.
- */
- #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
- (MAX_ORDER + PAGE_SHIFT - 1) : 25)
- #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_HIGH)
- #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_HIGH - PAGE_SHIFT)
- /*
- * Some archs want to perform DMA into kmalloc caches and need a guaranteed
- * alignment larger than the alignment of a 64-bit integer.
- * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
- */
- #ifdef ARCH_DMA_MINALIGN
- #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
- #else
- #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
- #endif
- /*
- * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
- * Intended for arches that get misalignment faults even for 64 bit integer
- * aligned buffers.
- */
- #ifndef ARCH_SLAB_MINALIGN
- #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
- #endif
- /*
- * Common kmalloc functions provided by all allocators
- */
- void * __must_check __krealloc(const void *, size_t, gfp_t);
- void * __must_check krealloc(const void *, size_t, gfp_t);
- void kfree(const void *);
- void kzfree(const void *);
- size_t ksize(const void *);
- /*
- * Allocator specific definitions. These are mainly used to establish optimized
- * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by
- * selecting the appropriate general cache at compile time.
- *
- * Allocators must define at least:
- *
- * kmem_cache_alloc()
- * __kmalloc()
- * kmalloc()
- *
- * Those wishing to support NUMA must also define:
- *
- * kmem_cache_alloc_node()
- * kmalloc_node()
- *
- * See each allocator definition file for additional comments and
- * implementation notes.
- */
- #ifdef CONFIG_SLUB
- #include <linux/slub_def.h>
- #elif defined(CONFIG_SLOB)
- #include <linux/slob_def.h>
- #else
- #include <linux/slab_def.h>
- #endif
- /**
- * kmalloc_array - allocate memory for an array.
- * @n: number of elements.
- * @size: element size.
- * @flags: the type of memory to allocate.
- *
- * The @flags argument may be one of:
- *
- * %GFP_USER - Allocate memory on behalf of user. May sleep.
- *
- * %GFP_KERNEL - Allocate normal kernel ram. May sleep.
- *
- * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools.
- * For example, use this inside interrupt handlers.
- *
- * %GFP_HIGHUSER - Allocate pages from high memory.
- *
- * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
- *
- * %GFP_NOFS - Do not make any fs calls while trying to get memory.
- *
- * %GFP_NOWAIT - Allocation will not sleep.
- *
- * %GFP_THISNODE - Allocate node-local memory only.
- *
- * %GFP_DMA - Allocation suitable for DMA.
- * Should only be used for kmalloc() caches. Otherwise, use a
- * slab created with SLAB_DMA.
- *
- * Also it is possible to set different flags by OR'ing
- * in one or more of the following additional @flags:
- *
- * %__GFP_COLD - Request cache-cold pages instead of
- * trying to return cache-warm pages.
- *
- * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
- *
- * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
- * (think twice before using).
- *
- * %__GFP_NORETRY - If memory is not immediately available,
- * then give up at once.
- *
- * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
- *
- * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
- *
- * There are other flags available as well, but these are not intended
- * for general use, and so are not documented here. For a full list of
- * potential flags, always refer to linux/gfp.h.
- */
- static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
- {
- if (size != 0 && n > SIZE_MAX / size)
- return NULL;
- return __kmalloc(n * size, flags);
- }
- /**
- * kcalloc - allocate memory for an array. The memory is set to zero.
- * @n: number of elements.
- * @size: element size.
- * @flags: the type of memory to allocate (see kmalloc).
- */
- static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
- {
- return kmalloc_array(n, size, flags | __GFP_ZERO);
- }
- #if !defined(CONFIG_NUMA) && !defined(CONFIG_SLOB)
- /**
- * kmalloc_node - allocate memory from a specific node
- * @size: how many bytes of memory are required.
- * @flags: the type of memory to allocate (see kcalloc).
- * @node: node to allocate from.
- *
- * kmalloc() for non-local nodes, used to allocate from a specific node
- * if available. Equivalent to kmalloc() in the non-NUMA single-node
- * case.
- */
- static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
- {
- return kmalloc(size, flags);
- }
- static inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
- {
- return __kmalloc(size, flags);
- }
- void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
- static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep,
- gfp_t flags, int node)
- {
- return kmem_cache_alloc(cachep, flags);
- }
- #endif /* !CONFIG_NUMA && !CONFIG_SLOB */
- /*
- * kmalloc_track_caller is a special version of kmalloc that records the
- * calling function of the routine calling it for slab leak tracking instead
- * of just the calling function (confusing, eh?).
- * It's useful when the call to kmalloc comes from a widely-used standard
- * allocator where we care about the real place the memory allocation
- * request comes from.
- */
- #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) || \
- (defined(CONFIG_SLAB) && defined(CONFIG_TRACING))
- extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
- #define kmalloc_track_caller(size, flags) \
- __kmalloc_track_caller(size, flags, _RET_IP_)
- #else
- #define kmalloc_track_caller(size, flags) \
- __kmalloc(size, flags)
- #endif /* DEBUG_SLAB */
- #ifdef CONFIG_NUMA
- /*
- * kmalloc_node_track_caller is a special version of kmalloc_node that
- * records the calling function of the routine calling it for slab leak
- * tracking instead of just the calling function (confusing, eh?).
- * It's useful when the call to kmalloc_node comes from a widely-used
- * standard allocator where we care about the real place the memory
- * allocation request comes from.
- */
- #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) || \
- (defined(CONFIG_SLAB) && defined(CONFIG_TRACING))
- extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
- #define kmalloc_node_track_caller(size, flags, node) \
- __kmalloc_node_track_caller(size, flags, node, \
- _RET_IP_)
- #else
- #define kmalloc_node_track_caller(size, flags, node) \
- __kmalloc_node(size, flags, node)
- #endif
- #else /* CONFIG_NUMA */
- #define kmalloc_node_track_caller(size, flags, node) \
- kmalloc_track_caller(size, flags)
- #endif /* CONFIG_NUMA */
- /*
- * Shortcuts
- */
- static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
- {
- return kmem_cache_alloc(k, flags | __GFP_ZERO);
- }
- /**
- * kzalloc - allocate memory. The memory is set to zero.
- * @size: how many bytes of memory are required.
- * @flags: the type of memory to allocate (see kmalloc).
- */
- static inline void *kzalloc(size_t size, gfp_t flags)
- {
- return kmalloc(size, flags | __GFP_ZERO);
- }
- /**
- * kzalloc_node - allocate zeroed memory from a particular memory node.
- * @size: how many bytes of memory are required.
- * @flags: the type of memory to allocate (see kmalloc).
- * @node: memory node from which to allocate
- */
- static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
- {
- return kmalloc_node(size, flags | __GFP_ZERO, node);
- }
- void __init kmem_cache_init_late(void);
- #endif /* _LINUX_SLAB_H */
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