1 #ifndef _LINUX_SLAB_DEF_H
2 #define _LINUX_SLAB_DEF_H
3
4 /*
5 * Definitions unique to the original Linux SLAB allocator.
6 *
7 * What we provide here is a way to optimize the frequent kmalloc
8 * calls in the kernel by selecting the appropriate general cache
9 * if kmalloc was called with a size that can be established at
10 * compile time.
11 */
12
13 #include <linux/init.h>
14 #include <asm/page.h> /* kmalloc_sizes.h needs PAGE_SIZE */
15 #include <asm/cache.h> /* kmalloc_sizes.h needs L1_CACHE_BYTES */
16 #include <linux/compiler.h>
17
18 #include <trace/events/kmem.h>
19
20 /*
21 * Enforce a minimum alignment for the kmalloc caches.
22 * Usually, the kmalloc caches are cache_line_size() aligned, except when
23 * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
24 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
25 * alignment larger than the alignment of a 64-bit integer.
26 * ARCH_KMALLOC_MINALIGN allows that.
27 * Note that increasing this value may disable some debug features.
28 */
29 #ifdef ARCH_DMA_MINALIGN
30 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
31 #else
32 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
33 #endif
34
35 #ifndef ARCH_SLAB_MINALIGN
36 /*
37 * Enforce a minimum alignment for all caches.
38 * Intended for archs that get misalignment faults even for BYTES_PER_WORD
39 * aligned buffers. Includes ARCH_KMALLOC_MINALIGN.
40 * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables
41 * some debug features.
42 */
43 #define ARCH_SLAB_MINALIGN 0
44 #endif
45
46 /*
47 * struct kmem_cache
48 *
49 * manages a cache.
50 */
51
52 struct kmem_cache {
53 /* 1) per-cpu data, touched during every alloc/free */
54 struct array_cache *array[NR_CPUS];
55 /* 2) Cache tunables. Protected by cache_chain_mutex */
56 unsigned int batchcount;
57 unsigned int limit;
58 unsigned int shared;
59
60 unsigned int buffer_size;
61 u32 reciprocal_buffer_size;
62 /* 3) touched by every alloc & free from the backend */
63
64 unsigned int flags; /* constant flags */
65 unsigned int num; /* # of objs per slab */
66
67 /* 4) cache_grow/shrink */
68 /* order of pgs per slab (2^n) */
69 unsigned int gfporder;
70
71 /* force GFP flags, e.g. GFP_DMA */
72 gfp_t gfpflags;
73
74 size_t colour; /* cache colouring range */
75 unsigned int colour_off; /* colour offset */
76 struct kmem_cache *slabp_cache;
77 unsigned int slab_size;
78 unsigned int dflags; /* dynamic flags */
79
80 /* constructor func */
81 void (*ctor)(void *obj);
82
83 /* 5) cache creation/removal */
84 const char *name;
85 struct list_head next;
86
87 /* 6) statistics */
88 #ifdef CONFIG_DEBUG_SLAB
89 unsigned long num_active;
90 unsigned long num_allocations;
91 unsigned long high_mark;
92 unsigned long grown;
93 unsigned long reaped;
94 unsigned long errors;
95 unsigned long max_freeable;
96 unsigned long node_allocs;
97 unsigned long node_frees;
98 unsigned long node_overflow;
99 atomic_t allochit;
100 atomic_t allocmiss;
101 atomic_t freehit;
102 atomic_t freemiss;
103
104 /*
105 * If debugging is enabled, then the allocator can add additional
106 * fields and/or padding to every object. buffer_size contains the total
107 * object size including these internal fields, the following two
108 * variables contain the offset to the user object and its size.
109 */
110 int obj_offset;
111 int obj_size;
112 #endif /* CONFIG_DEBUG_SLAB */
113
114 /*
115 * We put nodelists[] at the end of kmem_cache, because we want to size
116 * this array to nr_node_ids slots instead of MAX_NUMNODES
117 * (see kmem_cache_init())
118 * We still use [MAX_NUMNODES] and not [1] or [0] because cache_cache
119 * is statically defined, so we reserve the max number of nodes.
120 */
121 struct kmem_list3 *nodelists[MAX_NUMNODES];
122 /*
123 * Do not add fields after nodelists[]
124 */
125 };
126
127 /* Size description struct for general caches. */
128 struct cache_sizes {
129 size_t cs_size;
130 struct kmem_cache *cs_cachep;
131 #ifdef CONFIG_ZONE_DMA
132 struct kmem_cache *cs_dmacachep;
133 #endif
134 };
135 extern struct cache_sizes malloc_sizes[];
136
137 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
138 void *__kmalloc(size_t size, gfp_t flags);
139
140 #ifdef CONFIG_TRACING
141 extern void *kmem_cache_alloc_trace(size_t size,
142 struct kmem_cache *cachep, gfp_t flags);
143 extern size_t slab_buffer_size(struct kmem_cache *cachep);
144 #else
145 static __always_inline void *
kmem_cache_alloc_trace(size_t size,struct kmem_cache * cachep,gfp_t flags)146 kmem_cache_alloc_trace(size_t size, struct kmem_cache *cachep, gfp_t flags)
147 {
148 return kmem_cache_alloc(cachep, flags);
149 }
slab_buffer_size(struct kmem_cache * cachep)150 static inline size_t slab_buffer_size(struct kmem_cache *cachep)
151 {
152 return 0;
153 }
154 #endif
155
kmalloc(size_t size,gfp_t flags)156 static __always_inline void *kmalloc(size_t size, gfp_t flags)
157 {
158 struct kmem_cache *cachep;
159 void *ret;
160
161 if (__builtin_constant_p(size)) {
162 int i = 0;
163
164 if (!size)
165 return ZERO_SIZE_PTR;
166
167 #define CACHE(x) \
168 if (size <= x) \
169 goto found; \
170 else \
171 i++;
172 #include <linux/kmalloc_sizes.h>
173 #undef CACHE
174 return NULL;
175 found:
176 #ifdef CONFIG_ZONE_DMA
177 if (flags & GFP_DMA)
178 cachep = malloc_sizes[i].cs_dmacachep;
179 else
180 #endif
181 cachep = malloc_sizes[i].cs_cachep;
182
183 ret = kmem_cache_alloc_trace(size, cachep, flags);
184
185 return ret;
186 }
187 return __kmalloc(size, flags);
188 }
189
190 #ifdef CONFIG_NUMA
191 extern void *__kmalloc_node(size_t size, gfp_t flags, int node);
192 extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
193
194 #ifdef CONFIG_TRACING
195 extern void *kmem_cache_alloc_node_trace(size_t size,
196 struct kmem_cache *cachep,
197 gfp_t flags,
198 int nodeid);
199 #else
200 static __always_inline void *
kmem_cache_alloc_node_trace(size_t size,struct kmem_cache * cachep,gfp_t flags,int nodeid)201 kmem_cache_alloc_node_trace(size_t size,
202 struct kmem_cache *cachep,
203 gfp_t flags,
204 int nodeid)
205 {
206 return kmem_cache_alloc_node(cachep, flags, nodeid);
207 }
208 #endif
209
kmalloc_node(size_t size,gfp_t flags,int node)210 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
211 {
212 struct kmem_cache *cachep;
213
214 if (__builtin_constant_p(size)) {
215 int i = 0;
216
217 if (!size)
218 return ZERO_SIZE_PTR;
219
220 #define CACHE(x) \
221 if (size <= x) \
222 goto found; \
223 else \
224 i++;
225 #include <linux/kmalloc_sizes.h>
226 #undef CACHE
227 return NULL;
228 found:
229 #ifdef CONFIG_ZONE_DMA
230 if (flags & GFP_DMA)
231 cachep = malloc_sizes[i].cs_dmacachep;
232 else
233 #endif
234 cachep = malloc_sizes[i].cs_cachep;
235
236 return kmem_cache_alloc_node_trace(size, cachep, flags, node);
237 }
238 return __kmalloc_node(size, flags, node);
239 }
240
241 #endif /* CONFIG_NUMA */
242
243 #endif /* _LINUX_SLAB_DEF_H */
244