1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef _LINUX_SLAB_DEF_H
3*4882a593Smuzhiyun #define _LINUX_SLAB_DEF_H
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun #include <linux/kfence.h>
6*4882a593Smuzhiyun #include <linux/reciprocal_div.h>
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun /*
9*4882a593Smuzhiyun * Definitions unique to the original Linux SLAB allocator.
10*4882a593Smuzhiyun */
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun struct kmem_cache {
13*4882a593Smuzhiyun struct array_cache __percpu *cpu_cache;
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun /* 1) Cache tunables. Protected by slab_mutex */
16*4882a593Smuzhiyun unsigned int batchcount;
17*4882a593Smuzhiyun unsigned int limit;
18*4882a593Smuzhiyun unsigned int shared;
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun unsigned int size;
21*4882a593Smuzhiyun struct reciprocal_value reciprocal_buffer_size;
22*4882a593Smuzhiyun /* 2) touched by every alloc & free from the backend */
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun slab_flags_t flags; /* constant flags */
25*4882a593Smuzhiyun unsigned int num; /* # of objs per slab */
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun /* 3) cache_grow/shrink */
28*4882a593Smuzhiyun /* order of pgs per slab (2^n) */
29*4882a593Smuzhiyun unsigned int gfporder;
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun /* force GFP flags, e.g. GFP_DMA */
32*4882a593Smuzhiyun gfp_t allocflags;
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun size_t colour; /* cache colouring range */
35*4882a593Smuzhiyun unsigned int colour_off; /* colour offset */
36*4882a593Smuzhiyun struct kmem_cache *freelist_cache;
37*4882a593Smuzhiyun unsigned int freelist_size;
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun /* constructor func */
40*4882a593Smuzhiyun void (*ctor)(void *obj);
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun /* 4) cache creation/removal */
43*4882a593Smuzhiyun const char *name;
44*4882a593Smuzhiyun struct list_head list;
45*4882a593Smuzhiyun int refcount;
46*4882a593Smuzhiyun int object_size;
47*4882a593Smuzhiyun int align;
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun /* 5) statistics */
50*4882a593Smuzhiyun #ifdef CONFIG_DEBUG_SLAB
51*4882a593Smuzhiyun unsigned long num_active;
52*4882a593Smuzhiyun unsigned long num_allocations;
53*4882a593Smuzhiyun unsigned long high_mark;
54*4882a593Smuzhiyun unsigned long grown;
55*4882a593Smuzhiyun unsigned long reaped;
56*4882a593Smuzhiyun unsigned long errors;
57*4882a593Smuzhiyun unsigned long max_freeable;
58*4882a593Smuzhiyun unsigned long node_allocs;
59*4882a593Smuzhiyun unsigned long node_frees;
60*4882a593Smuzhiyun unsigned long node_overflow;
61*4882a593Smuzhiyun atomic_t allochit;
62*4882a593Smuzhiyun atomic_t allocmiss;
63*4882a593Smuzhiyun atomic_t freehit;
64*4882a593Smuzhiyun atomic_t freemiss;
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun /*
67*4882a593Smuzhiyun * If debugging is enabled, then the allocator can add additional
68*4882a593Smuzhiyun * fields and/or padding to every object. 'size' contains the total
69*4882a593Smuzhiyun * object size including these internal fields, while 'obj_offset'
70*4882a593Smuzhiyun * and 'object_size' contain the offset to the user object and its
71*4882a593Smuzhiyun * size.
72*4882a593Smuzhiyun */
73*4882a593Smuzhiyun int obj_offset;
74*4882a593Smuzhiyun #endif /* CONFIG_DEBUG_SLAB */
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun #ifdef CONFIG_KASAN
77*4882a593Smuzhiyun struct kasan_cache kasan_info;
78*4882a593Smuzhiyun #endif
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun #ifdef CONFIG_SLAB_FREELIST_RANDOM
81*4882a593Smuzhiyun unsigned int *random_seq;
82*4882a593Smuzhiyun #endif
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun unsigned int useroffset; /* Usercopy region offset */
85*4882a593Smuzhiyun unsigned int usersize; /* Usercopy region size */
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun struct kmem_cache_node *node[MAX_NUMNODES];
88*4882a593Smuzhiyun };
89*4882a593Smuzhiyun
nearest_obj(struct kmem_cache * cache,struct page * page,void * x)90*4882a593Smuzhiyun static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
91*4882a593Smuzhiyun void *x)
92*4882a593Smuzhiyun {
93*4882a593Smuzhiyun void *object = x - (x - page->s_mem) % cache->size;
94*4882a593Smuzhiyun void *last_object = page->s_mem + (cache->num - 1) * cache->size;
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun if (unlikely(object > last_object))
97*4882a593Smuzhiyun return last_object;
98*4882a593Smuzhiyun else
99*4882a593Smuzhiyun return object;
100*4882a593Smuzhiyun }
101*4882a593Smuzhiyun
102*4882a593Smuzhiyun /*
103*4882a593Smuzhiyun * We want to avoid an expensive divide : (offset / cache->size)
104*4882a593Smuzhiyun * Using the fact that size is a constant for a particular cache,
105*4882a593Smuzhiyun * we can replace (offset / cache->size) by
106*4882a593Smuzhiyun * reciprocal_divide(offset, cache->reciprocal_buffer_size)
107*4882a593Smuzhiyun */
obj_to_index(const struct kmem_cache * cache,const struct page * page,void * obj)108*4882a593Smuzhiyun static inline unsigned int obj_to_index(const struct kmem_cache *cache,
109*4882a593Smuzhiyun const struct page *page, void *obj)
110*4882a593Smuzhiyun {
111*4882a593Smuzhiyun u32 offset = (obj - page->s_mem);
112*4882a593Smuzhiyun return reciprocal_divide(offset, cache->reciprocal_buffer_size);
113*4882a593Smuzhiyun }
114*4882a593Smuzhiyun
objs_per_slab_page(const struct kmem_cache * cache,const struct page * page)115*4882a593Smuzhiyun static inline int objs_per_slab_page(const struct kmem_cache *cache,
116*4882a593Smuzhiyun const struct page *page)
117*4882a593Smuzhiyun {
118*4882a593Smuzhiyun if (is_kfence_address(page_address(page)))
119*4882a593Smuzhiyun return 1;
120*4882a593Smuzhiyun return cache->num;
121*4882a593Smuzhiyun }
122*4882a593Smuzhiyun
123*4882a593Smuzhiyun #endif /* _LINUX_SLAB_DEF_H */
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