xref: /linux-6.15/include/linux/slab.h (revision b454cc66)
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 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_DEBUG_INITIAL	0x00000200UL	/* DEBUG: Call constructor (as verifier) */
25 #define SLAB_RED_ZONE		0x00000400UL	/* DEBUG: Red zone objs in a cache */
26 #define SLAB_POISON		0x00000800UL	/* DEBUG: Poison objects */
27 #define SLAB_HWCACHE_ALIGN	0x00002000UL	/* Align objs on cache lines */
28 #define SLAB_CACHE_DMA		0x00004000UL	/* Use GFP_DMA memory */
29 #define SLAB_MUST_HWCACHE_ALIGN	0x00008000UL	/* Force alignment even if debuggin is active */
30 #define SLAB_STORE_USER		0x00010000UL	/* DEBUG: Store the last owner for bug hunting */
31 #define SLAB_RECLAIM_ACCOUNT	0x00020000UL	/* Objects are reclaimable */
32 #define SLAB_PANIC		0x00040000UL	/* Panic if kmem_cache_create() fails */
33 #define SLAB_DESTROY_BY_RCU	0x00080000UL	/* Defer freeing slabs to RCU */
34 #define SLAB_MEM_SPREAD		0x00100000UL	/* Spread some memory over cpuset */
35 
36 /* Flags passed to a constructor functions */
37 #define SLAB_CTOR_CONSTRUCTOR	0x001UL		/* If not set, then deconstructor */
38 #define SLAB_CTOR_ATOMIC	0x002UL		/* Tell constructor it can't sleep */
39 #define SLAB_CTOR_VERIFY	0x004UL		/* Tell constructor it's a verify call */
40 
41 /*
42  * struct kmem_cache related prototypes
43  */
44 void __init kmem_cache_init(void);
45 extern int slab_is_available(void);
46 
47 struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
48 			unsigned long,
49 			void (*)(void *, struct kmem_cache *, unsigned long),
50 			void (*)(void *, struct kmem_cache *, unsigned long));
51 void kmem_cache_destroy(struct kmem_cache *);
52 int kmem_cache_shrink(struct kmem_cache *);
53 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
54 void *kmem_cache_zalloc(struct kmem_cache *, gfp_t);
55 void kmem_cache_free(struct kmem_cache *, void *);
56 unsigned int kmem_cache_size(struct kmem_cache *);
57 const char *kmem_cache_name(struct kmem_cache *);
58 int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr);
59 
60 #ifdef CONFIG_NUMA
61 extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
62 #else
63 static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep,
64 					gfp_t flags, int node)
65 {
66 	return kmem_cache_alloc(cachep, flags);
67 }
68 #endif
69 
70 /*
71  * Common kmalloc functions provided by all allocators
72  */
73 void *__kmalloc(size_t, gfp_t);
74 void *__kzalloc(size_t, gfp_t);
75 void kfree(const void *);
76 unsigned int ksize(const void *);
77 
78 /**
79  * kcalloc - allocate memory for an array. The memory is set to zero.
80  * @n: number of elements.
81  * @size: element size.
82  * @flags: the type of memory to allocate.
83  */
84 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
85 {
86 	if (n != 0 && size > ULONG_MAX / n)
87 		return NULL;
88 	return __kzalloc(n * size, flags);
89 }
90 
91 /*
92  * Allocator specific definitions. These are mainly used to establish optimized
93  * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by selecting
94  * the appropriate general cache at compile time.
95  */
96 
97 #ifdef CONFIG_SLAB
98 #include <linux/slab_def.h>
99 #else
100 /*
101  * Fallback definitions for an allocator not wanting to provide
102  * its own optimized kmalloc definitions (like SLOB).
103  */
104 
105 /**
106  * kmalloc - allocate memory
107  * @size: how many bytes of memory are required.
108  * @flags: the type of memory to allocate.
109  *
110  * kmalloc is the normal method of allocating memory
111  * in the kernel.
112  *
113  * The @flags argument may be one of:
114  *
115  * %GFP_USER - Allocate memory on behalf of user.  May sleep.
116  *
117  * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
118  *
119  * %GFP_ATOMIC - Allocation will not sleep.
120  *   For example, use this inside interrupt handlers.
121  *
122  * %GFP_HIGHUSER - Allocate pages from high memory.
123  *
124  * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
125  *
126  * %GFP_NOFS - Do not make any fs calls while trying to get memory.
127  *
128  * Also it is possible to set different flags by OR'ing
129  * in one or more of the following additional @flags:
130  *
131  * %__GFP_COLD - Request cache-cold pages instead of
132  *   trying to return cache-warm pages.
133  *
134  * %__GFP_DMA - Request memory from the DMA-capable zone.
135  *
136  * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
137  *
138  * %__GFP_HIGHMEM - Allocated memory may be from highmem.
139  *
140  * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
141  *   (think twice before using).
142  *
143  * %__GFP_NORETRY - If memory is not immediately available,
144  *   then give up at once.
145  *
146  * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
147  *
148  * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
149  */
150 static inline void *kmalloc(size_t size, gfp_t flags)
151 {
152 	return __kmalloc(size, flags);
153 }
154 
155 /**
156  * kzalloc - allocate memory. The memory is set to zero.
157  * @size: how many bytes of memory are required.
158  * @flags: the type of memory to allocate (see kmalloc).
159  */
160 static inline void *kzalloc(size_t size, gfp_t flags)
161 {
162 	return __kzalloc(size, flags);
163 }
164 #endif
165 
166 #ifndef CONFIG_NUMA
167 static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
168 {
169 	return kmalloc(size, flags);
170 }
171 
172 static inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
173 {
174 	return __kmalloc(size, flags);
175 }
176 #endif /* !CONFIG_NUMA */
177 
178 /*
179  * kmalloc_track_caller is a special version of kmalloc that records the
180  * calling function of the routine calling it for slab leak tracking instead
181  * of just the calling function (confusing, eh?).
182  * It's useful when the call to kmalloc comes from a widely-used standard
183  * allocator where we care about the real place the memory allocation
184  * request comes from.
185  */
186 #ifdef CONFIG_DEBUG_SLAB
187 extern void *__kmalloc_track_caller(size_t, gfp_t, void*);
188 #define kmalloc_track_caller(size, flags) \
189 	__kmalloc_track_caller(size, flags, __builtin_return_address(0))
190 #else
191 #define kmalloc_track_caller(size, flags) \
192 	__kmalloc(size, flags)
193 #endif /* DEBUG_SLAB */
194 
195 #ifdef CONFIG_NUMA
196 /*
197  * kmalloc_node_track_caller is a special version of kmalloc_node that
198  * records the calling function of the routine calling it for slab leak
199  * tracking instead of just the calling function (confusing, eh?).
200  * It's useful when the call to kmalloc_node comes from a widely-used
201  * standard allocator where we care about the real place the memory
202  * allocation request comes from.
203  */
204 #ifdef CONFIG_DEBUG_SLAB
205 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, void *);
206 #define kmalloc_node_track_caller(size, flags, node) \
207 	__kmalloc_node_track_caller(size, flags, node, \
208 			__builtin_return_address(0))
209 #else
210 #define kmalloc_node_track_caller(size, flags, node) \
211 	__kmalloc_node(size, flags, node)
212 #endif
213 
214 #else /* CONFIG_NUMA */
215 
216 #define kmalloc_node_track_caller(size, flags, node) \
217 	kmalloc_track_caller(size, flags)
218 
219 #endif /* DEBUG_SLAB */
220 
221 #endif	/* __KERNEL__ */
222 #endif	/* _LINUX_SLAB_H */
223 
224