1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SLAB_DEF_H
3 #define	_LINUX_SLAB_DEF_H
4 
5 #include <linux/reciprocal_div.h>
6 
7 /*
8  * Definitions unique to the original Linux SLAB allocator.
9  */
10 
11 struct kmem_cache {
12 	struct array_cache __percpu *cpu_cache;
13 
14 /* 1) Cache tunables. Protected by slab_mutex */
15 	unsigned int batchcount;
16 	unsigned int limit;
17 	unsigned int shared;
18 
19 	unsigned int size;
20 	struct reciprocal_value reciprocal_buffer_size;
21 /* 2) touched by every alloc & free from the backend */
22 
23 	slab_flags_t flags;		/* constant flags */
24 	unsigned int num;		/* # of objs per slab */
25 
26 /* 3) cache_grow/shrink */
27 	/* order of pgs per slab (2^n) */
28 	unsigned int gfporder;
29 
30 	/* force GFP flags, e.g. GFP_DMA */
31 	gfp_t allocflags;
32 
33 	size_t colour;			/* cache colouring range */
34 	unsigned int colour_off;	/* colour offset */
35 	struct kmem_cache *freelist_cache;
36 	unsigned int freelist_size;
37 
38 	/* constructor func */
39 	void (*ctor)(void *obj);
40 
41 /* 4) cache creation/removal */
42 	const char *name;
43 	struct list_head list;
44 	int refcount;
45 	int object_size;
46 	int align;
47 
48 /* 5) statistics */
49 #ifdef CONFIG_DEBUG_SLAB
50 	unsigned long num_active;
51 	unsigned long num_allocations;
52 	unsigned long high_mark;
53 	unsigned long grown;
54 	unsigned long reaped;
55 	unsigned long errors;
56 	unsigned long max_freeable;
57 	unsigned long node_allocs;
58 	unsigned long node_frees;
59 	unsigned long node_overflow;
60 	atomic_t allochit;
61 	atomic_t allocmiss;
62 	atomic_t freehit;
63 	atomic_t freemiss;
64 #ifdef CONFIG_DEBUG_SLAB_LEAK
65 	atomic_t store_user_clean;
66 #endif
67 
68 	/*
69 	 * If debugging is enabled, then the allocator can add additional
70 	 * fields and/or padding to every object. 'size' contains the total
71 	 * object size including these internal fields, while 'obj_offset'
72 	 * and 'object_size' contain the offset to the user object and its
73 	 * size.
74 	 */
75 	int obj_offset;
76 #endif /* CONFIG_DEBUG_SLAB */
77 
78 #ifdef CONFIG_MEMCG
79 	struct memcg_cache_params memcg_params;
80 #endif
81 #ifdef CONFIG_KASAN
82 	struct kasan_cache kasan_info;
83 #endif
84 
85 #ifdef CONFIG_SLAB_FREELIST_RANDOM
86 	unsigned int *random_seq;
87 #endif
88 
89 	unsigned int useroffset;	/* Usercopy region offset */
90 	unsigned int usersize;		/* Usercopy region size */
91 
92 	struct kmem_cache_node *node[MAX_NUMNODES];
93 };
94 
nearest_obj(struct kmem_cache * cache,struct page * page,void * x)95 static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
96 				void *x)
97 {
98 	void *object = x - (x - page->s_mem) % cache->size;
99 	void *last_object = page->s_mem + (cache->num - 1) * cache->size;
100 
101 	if (unlikely(object > last_object))
102 		return last_object;
103 	else
104 		return object;
105 }
106 
107 #endif	/* _LINUX_SLAB_DEF_H */
108