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1#ifndef _LINUX_SLUB_DEF_H
2#define _LINUX_SLUB_DEF_H
3
4/*
5 * SLUB : A Slab allocator without object queues.
6 *
7 * (C) 2007 SGI, Christoph Lameter <clameter@sgi.com>
8 */
9#include <linux/types.h>
10#include <linux/gfp.h>
11#include <linux/workqueue.h>
12#include <linux/kobject.h>
13
14struct kmem_cache_cpu {
15 void **freelist;
16 struct page *page;
17 int node;
18 unsigned int offset;
19 unsigned int objsize;
20};
21
22struct kmem_cache_node {
23 spinlock_t list_lock; /* Protect partial list and nr_partial */
24 unsigned long nr_partial;
25 atomic_long_t nr_slabs;
26 struct list_head partial;
27#ifdef CONFIG_SLUB_DEBUG
28 struct list_head full;
29#endif
30};
31
32/*
33 * Slab cache management.
34 */
35struct kmem_cache {
36 /* Used for retriving partial slabs etc */
37 unsigned long flags;
38 int size; /* The size of an object including meta data */
39 int objsize; /* The size of an object without meta data */
40 int offset; /* Free pointer offset. */
41 int order;
42
43 /*
44 * Avoid an extra cache line for UP, SMP and for the node local to
45 * struct kmem_cache.
46 */
47 struct kmem_cache_node local_node;
48
49 /* Allocation and freeing of slabs */
50 int objects; /* Number of objects in slab */
51 int refcount; /* Refcount for slab cache destroy */
52 void (*ctor)(struct kmem_cache *, void *);
53 int inuse; /* Offset to metadata */
54 int align; /* Alignment */
55 const char *name; /* Name (only for display!) */
56 struct list_head list; /* List of slab caches */
57#ifdef CONFIG_SLUB_DEBUG
58 struct kobject kobj; /* For sysfs */
59#endif
60
61#ifdef CONFIG_NUMA
62 int defrag_ratio;
63 struct kmem_cache_node *node[MAX_NUMNODES];
64#endif
65#ifdef CONFIG_SMP
66 struct kmem_cache_cpu *cpu_slab[NR_CPUS];
67#else
68 struct kmem_cache_cpu cpu_slab;
69#endif
70};
71
72/*
73 * Kmalloc subsystem.
74 */
75#if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
76#define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
77#else
78#define KMALLOC_MIN_SIZE 8
79#endif
80
81#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
82
83/*
84 * We keep the general caches in an array of slab caches that are used for
85 * 2^x bytes of allocations.
86 */
87extern struct kmem_cache kmalloc_caches[PAGE_SHIFT];
88
89/*
90 * Sorry that the following has to be that ugly but some versions of GCC
91 * have trouble with constant propagation and loops.
92 */
93static __always_inline int kmalloc_index(size_t size)
94{
95 if (!size)
96 return 0;
97
98 if (size <= KMALLOC_MIN_SIZE)
99 return KMALLOC_SHIFT_LOW;
100
101 if (size > 64 && size <= 96)
102 return 1;
103 if (size > 128 && size <= 192)
104 return 2;
105 if (size <= 8) return 3;
106 if (size <= 16) return 4;
107 if (size <= 32) return 5;
108 if (size <= 64) return 6;
109 if (size <= 128) return 7;
110 if (size <= 256) return 8;
111 if (size <= 512) return 9;
112 if (size <= 1024) return 10;
113 if (size <= 2 * 1024) return 11;
114/*
115 * The following is only needed to support architectures with a larger page
116 * size than 4k.
117 */
118 if (size <= 4 * 1024) return 12;
119 if (size <= 8 * 1024) return 13;
120 if (size <= 16 * 1024) return 14;
121 if (size <= 32 * 1024) return 15;
122 if (size <= 64 * 1024) return 16;
123 if (size <= 128 * 1024) return 17;
124 if (size <= 256 * 1024) return 18;
125 if (size <= 512 * 1024) return 19;
126 if (size <= 1024 * 1024) return 20;
127 if (size <= 2 * 1024 * 1024) return 21;
128 return -1;
129
130/*
131 * What we really wanted to do and cannot do because of compiler issues is:
132 * int i;
133 * for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
134 * if (size <= (1 << i))
135 * return i;
136 */
137}
138
139/*
140 * Find the slab cache for a given combination of allocation flags and size.
141 *
142 * This ought to end up with a global pointer to the right cache
143 * in kmalloc_caches.
144 */
145static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
146{
147 int index = kmalloc_index(size);
148
149 if (index == 0)
150 return NULL;
151
152 return &kmalloc_caches[index];
153}
154
155#ifdef CONFIG_ZONE_DMA
156#define SLUB_DMA __GFP_DMA
157#else
158/* Disable DMA functionality */
159#define SLUB_DMA (__force gfp_t)0
160#endif
161
162void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
163void *__kmalloc(size_t size, gfp_t flags);
164
165static __always_inline void *kmalloc(size_t size, gfp_t flags)
166{
167 if (__builtin_constant_p(size)) {
168 if (size > PAGE_SIZE / 2)
169 return (void *)__get_free_pages(flags | __GFP_COMP,
170 get_order(size));
171
172 if (!(flags & SLUB_DMA)) {
173 struct kmem_cache *s = kmalloc_slab(size);
174
175 if (!s)
176 return ZERO_SIZE_PTR;
177
178 return kmem_cache_alloc(s, flags);
179 }
180 }
181 return __kmalloc(size, flags);
182}
183
184#ifdef CONFIG_NUMA
185void *__kmalloc_node(size_t size, gfp_t flags, int node);
186void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
187
188static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
189{
190 if (__builtin_constant_p(size) &&
191 size <= PAGE_SIZE / 2 && !(flags & SLUB_DMA)) {
192 struct kmem_cache *s = kmalloc_slab(size);
193
194 if (!s)
195 return ZERO_SIZE_PTR;
196
197 return kmem_cache_alloc_node(s, flags, node);
198 }
199 return __kmalloc_node(size, flags, node);
200}
201#endif
202
203#endif /* _LINUX_SLUB_DEF_H */