[linux-block.git] / include / linux / slab_def.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_SLAB_DEF_H
#define	_LINUX_SLAB_DEF_H

#include <linux/kfence.h>
#include <linux/reciprocal_div.h>

/*
 * Definitions unique to the original Linux SLAB allocator.
 */

struct kmem_cache {
	struct array_cache __percpu *cpu_cache;

/* 1) Cache tunables. Protected by slab_mutex */
	unsigned int batchcount;
	unsigned int limit;
	unsigned int shared;

	unsigned int size;
	struct reciprocal_value reciprocal_buffer_size;
/* 2) touched by every alloc & free from the backend */

	slab_flags_t flags;		/* constant flags */
	unsigned int num;		/* # of objs per slab */

/* 3) cache_grow/shrink */
	/* order of pgs per slab (2^n) */
	unsigned int gfporder;

	/* force GFP flags, e.g. GFP_DMA */
	gfp_t allocflags;

	size_t colour;			/* cache colouring range */
	unsigned int colour_off;	/* colour offset */
	unsigned int freelist_size;

	/* constructor func */
	void (*ctor)(void *obj);

/* 4) cache creation/removal */
	const char *name;
	struct list_head list;
	int refcount;
	int object_size;
	int align;

/* 5) statistics */
#ifdef CONFIG_DEBUG_SLAB
	unsigned long num_active;
	unsigned long num_allocations;
	unsigned long high_mark;
	unsigned long grown;
	unsigned long reaped;
	unsigned long errors;
	unsigned long max_freeable;
	unsigned long node_allocs;
	unsigned long node_frees;
	unsigned long node_overflow;
	atomic_t allochit;
	atomic_t allocmiss;
	atomic_t freehit;
	atomic_t freemiss;

	/*
	 * If debugging is enabled, then the allocator can add additional
	 * fields and/or padding to every object. 'size' contains the total
	 * object size including these internal fields, while 'obj_offset'
	 * and 'object_size' contain the offset to the user object and its
	 * size.
	 */
	int obj_offset;
#endif /* CONFIG_DEBUG_SLAB */

#ifdef CONFIG_KASAN_GENERIC
	struct kasan_cache kasan_info;
#endif

#ifdef CONFIG_SLAB_FREELIST_RANDOM
	unsigned int *random_seq;
#endif

#ifdef CONFIG_HARDENED_USERCOPY
	unsigned int useroffset;	/* Usercopy region offset */
	unsigned int usersize;		/* Usercopy region size */
#endif

	struct kmem_cache_node *node[MAX_NUMNODES];
};

static inline void *nearest_obj(struct kmem_cache *cache, const struct slab *slab,
				void *x)
{
	void *object = x - (x - slab->s_mem) % cache->size;
	void *last_object = slab->s_mem + (cache->num - 1) * cache->size;

	if (unlikely(object > last_object))
		return last_object;
	else
		return object;
}

/*
 * We want to avoid an expensive divide : (offset / cache->size)
 *   Using the fact that size is a constant for a particular cache,
 *   we can replace (offset / cache->size) by
 *   reciprocal_divide(offset, cache->reciprocal_buffer_size)
 */
static inline unsigned int obj_to_index(const struct kmem_cache *cache,
					const struct slab *slab, void *obj)
{
	u32 offset = (obj - slab->s_mem);
	return reciprocal_divide(offset, cache->reciprocal_buffer_size);
}

static inline int objs_per_slab(const struct kmem_cache *cache,
				     const struct slab *slab)
{
	if (is_kfence_address(slab_address(slab)))
		return 1;
	return cache->num;
}

#endif	/* _LINUX_SLAB_DEF_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
2e892f43 CL	2	#ifndef _LINUX_SLAB_DEF_H
	3	#define _LINUX_SLAB_DEF_H
	4
d3fb45f3	5	#include <linux/kfence.h>
809fa972 HFS	6	#include <linux/reciprocal_div.h>
809fa972 HFS	7
2e892f43 CL	8	/*
2e892f43 CL	9	* Definitions unique to the original Linux SLAB allocator.
8eae985f PE	10	*/
	11
	12	struct kmem_cache {
bf0dea23 JK	13	struct array_cache __percpu *cpu_cache;
bf0dea23 JK	14
24755e2e	15	/* 1) Cache tunables. Protected by slab_mutex */
8eae985f PE	16	unsigned int batchcount;
	17	unsigned int limit;
	18	unsigned int shared;
	19
3b0efdfa	20	unsigned int size;
809fa972	21	struct reciprocal_value reciprocal_buffer_size;
b56efcf0	22	/* 2) touched by every alloc & free from the backend */
8eae985f	23
d50112ed	24	slab_flags_t flags; /* constant flags */
8eae985f PE	25	unsigned int num; /* # of objs per slab */
8eae985f PE	26
b56efcf0	27	/* 3) cache_grow/shrink */
8eae985f PE	28	/* order of pgs per slab (2^n) */
	29	unsigned int gfporder;
	30
	31	/* force GFP flags, e.g. GFP_DMA */
a618e89f	32	gfp_t allocflags;
8eae985f PE	33
	34	size_t colour; /* cache colouring range */
	35	unsigned int colour_off; /* colour offset */
8456a648	36	unsigned int freelist_size;
8eae985f PE	37
	38	/* constructor func */
	39	void (ctor)(void obj);
	40
b56efcf0	41	/* 4) cache creation/removal */
8eae985f	42	const char *name;
3b0efdfa CL	43	struct list_head list;
	44	int refcount;
	45	int object_size;
	46	int align;
8eae985f	47
b56efcf0	48	/* 5) statistics */
8eae985f PE	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
	65	/*
	66	* If debugging is enabled, then the allocator can add additional
05fec35e BH	67	* fields and/or padding to every object. 'size' contains the total
	68	* object size including these internal fields, while 'obj_offset'
	69	* and 'object_size' contain the offset to the user object and its
	70	* size.
8eae985f PE	71	*/
8eae985f PE	72	int obj_offset;
8eae985f	73	#endif /* CONFIG_DEBUG_SLAB */
127424c8	74
bbc61844	75	#ifdef CONFIG_KASAN_GENERIC
7ed2f9e6 AP	76	struct kasan_cache kasan_info;
7ed2f9e6 AP	77	#endif
8eae985f	78
c7ce4f60	79	#ifdef CONFIG_SLAB_FREELIST_RANDOM
7c00fce9	80	unsigned int *random_seq;
c7ce4f60 TG	81	#endif
c7ce4f60 TG	82
346907ce	83	#ifdef CONFIG_HARDENED_USERCOPY
7bbdb81e AD	84	unsigned int useroffset; /* Usercopy region offset */
7bbdb81e AD	85	unsigned int usersize; /* Usercopy region size */
346907ce	86	#endif
8eb8284b	87
bf0dea23	88	struct kmem_cache_node *node[MAX_NUMNODES];
8eae985f PE	89	};
8eae985f PE	90
40f3bf0c	91	static inline void nearest_obj(struct kmem_cache cache, const struct slab *slab,
80a9201a AP	92	void *x)
80a9201a AP	93	{
40f3bf0c VB	94	void *object = x - (x - slab->s_mem) % cache->size;
40f3bf0c VB	95	void last_object = slab->s_mem + (cache->num - 1) cache->size;
7ed2f9e6 AP	96
	97	if (unlikely(object > last_object))
	98	return last_object;
	99	else
	100	return object;
	101	}
	102
5b7c4148 AK	103	/*
	104	* We want to avoid an expensive divide : (offset / cache->size)
	105	* Using the fact that size is a constant for a particular cache,
	106	* we can replace (offset / cache->size) by
	107	* reciprocal_divide(offset, cache->reciprocal_buffer_size)
	108	*/
	109	static inline unsigned int obj_to_index(const struct kmem_cache *cache,
40f3bf0c	110	const struct slab slab, void obj)
5b7c4148	111	{
40f3bf0c	112	u32 offset = (obj - slab->s_mem);
5b7c4148 AK	113	return reciprocal_divide(offset, cache->reciprocal_buffer_size);
	114	}
	115
40f3bf0c VB	116	static inline int objs_per_slab(const struct kmem_cache *cache,
40f3bf0c VB	117	const struct slab *slab)
286e04b8	118	{
40f3bf0c	119	if (is_kfence_address(slab_address(slab)))
d3fb45f3	120	return 1;
286e04b8 RG	121	return cache->num;
	122	}
	123
2e892f43	124	#endif /* _LINUX_SLAB_DEF_H */