summaryrefslogtreecommitdiffstats
path: root/include/linux/genalloc.h
blob: 5b14a0f381241de51ac575d483847af8fb8b5b3b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Basic general purpose allocator for managing special purpose
 * memory, for example, memory that is not managed by the regular
 * kmalloc/kfree interface.  Uses for this includes on-device special
 * memory, uncached memory etc.
 *
 * It is safe to use the allocator in NMI handlers and other special
 * unblockable contexts that could otherwise deadlock on locks.  This
 * is implemented by using atomic operations and retries on any
 * conflicts.  The disadvantage is that there may be livelocks in
 * extreme cases.  For better scalability, one allocator can be used
 * for each CPU.
 *
 * The lockless operation only works if there is enough memory
 * available.  If new memory is added to the pool a lock has to be
 * still taken.  So any user relying on locklessness has to ensure
 * that sufficient memory is preallocated.
 *
 * The basic atomic operation of this allocator is cmpxchg on long.
 * On architectures that don't have NMI-safe cmpxchg implementation,
 * the allocator can NOT be used in NMI handler.  So code uses the
 * allocator in NMI handler should depend on
 * CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
 */


#ifndef __GENALLOC_H__
#define __GENALLOC_H__

#include <linux/types.h>
#include <linux/spinlock_types.h>
#include <linux/atomic.h>

struct device;
struct device_node;
struct gen_pool;

/**
 * typedef genpool_algo_t: Allocation callback function type definition
 * @map: Pointer to bitmap
 * @size: The bitmap size in bits
 * @start: The bitnumber to start searching at
 * @nr: The number of zeroed bits we're looking for
 * @data: optional additional data used by the callback
 * @pool: the pool being allocated from
 */
typedef unsigned long (*genpool_algo_t)(unsigned long *map,
			unsigned long size,
			unsigned long start,
			unsigned int nr,
			void *data, struct gen_pool *pool,
			unsigned long start_addr);

/*
 *  General purpose special memory pool descriptor.
 */
struct gen_pool {
	spinlock_t lock;
	struct list_head chunks;	/* list of chunks in this pool */
	int min_alloc_order;		/* minimum allocation order */

	genpool_algo_t algo;		/* allocation function */
	void *data;

	const char *name;
};

/*
 *  General purpose special memory pool chunk descriptor.
 */
struct gen_pool_chunk {
	struct list_head next_chunk;	/* next chunk in pool */
	atomic_long_t avail;
	phys_addr_t phys_addr;		/* physical starting address of memory chunk */
	void *owner;			/* private data to retrieve at alloc time */
	unsigned long start_addr;	/* start address of memory chunk */
	unsigned long end_addr;		/* end address of memory chunk (inclusive) */
	unsigned long bits[0];		/* bitmap for allocating memory chunk */
};

/*
 *  gen_pool data descriptor for gen_pool_first_fit_align.
 */
struct genpool_data_align {
	int align;		/* alignment by bytes for starting address */
};

/*
 *  gen_pool data descriptor for gen_pool_fixed_alloc.
 */
struct genpool_data_fixed {
	unsigned long offset;		/* The offset of the specific region */
};

extern struct gen_pool *gen_pool_create(int, int);
extern phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long);
extern int gen_pool_add_owner(struct gen_pool *, unsigned long, phys_addr_t,
			     size_t, int, void *);

static inline int gen_pool_add_virt(struct gen_pool *pool, unsigned long addr,
		phys_addr_t phys, size_t size, int nid)
{
	return gen_pool_add_owner(pool, addr, phys, size, nid, NULL);
}

/**
 * gen_pool_add - add a new chunk of special memory to the pool
 * @pool: pool to add new memory chunk to
 * @addr: starting address of memory chunk to add to pool
 * @size: size in bytes of the memory chunk to add to pool
 * @nid: node id of the node the chunk structure and bitmap should be
 *       allocated on, or -1
 *
 * Add a new chunk of special memory to the specified pool.
 *
 * Returns 0 on success or a -ve errno on failure.
 */
static inline int gen_pool_add(struct gen_pool *pool, unsigned long addr,
			       size_t size, int nid)
{
	return gen_pool_add_virt(pool, addr, -1, size, nid);
}
extern void gen_pool_destroy(struct gen_pool *);
unsigned long gen_pool_alloc_algo_owner(struct gen_pool *pool, size_t size,
		genpool_algo_t algo, void *data, void **owner);

static inline unsigned long gen_pool_alloc_owner(struct gen_pool *pool,
		size_t size, void **owner)
{
	return gen_pool_alloc_algo_owner(pool, size, pool->algo, pool->data,
			owner);
}

static inline unsigned long gen_pool_alloc_algo(struct gen_pool *pool,
		size_t size, genpool_algo_t algo, void *data)
{
	return gen_pool_alloc_algo_owner(pool, size, algo, data, NULL);
}

/**
 * gen_pool_alloc - allocate special memory from the pool
 * @pool: pool to allocate from
 * @size: number of bytes to allocate from the pool
 *
 * Allocate the requested number of bytes from the specified pool.
 * Uses the pool allocation function (with first-fit algorithm by default).
 * Can not be used in NMI handler on architectures without
 * NMI-safe cmpxchg implementation.
 */
static inline unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
{
	return gen_pool_alloc_algo(pool, size, pool->algo, pool->data);
}

extern void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size,
		dma_addr_t *dma);
extern void *gen_pool_dma_alloc_algo(struct gen_pool *pool, size_t size,
		dma_addr_t *dma, genpool_algo_t algo, void *data);
extern void *gen_pool_dma_alloc_align(struct gen_pool *pool, size_t size,
		dma_addr_t *dma, int align);
extern void *gen_pool_dma_zalloc(struct gen_pool *pool, size_t size, dma_addr_t *dma);
extern void *gen_pool_dma_zalloc_algo(struct gen_pool *pool, size_t size,
		dma_addr_t *dma, genpool_algo_t algo, void *data);
extern void *gen_pool_dma_zalloc_align(struct gen_pool *pool, size_t size,
		dma_addr_t *dma, int align);
extern void gen_pool_free_owner(struct gen_pool *pool, unsigned long addr,
		size_t size, void **owner);
static inline void gen_pool_free(struct gen_pool *pool, unsigned long addr,
                size_t size)
{
	gen_pool_free_owner(pool, addr, size, NULL);
}

extern void gen_pool_for_each_chunk(struct gen_pool *,
	void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *);
extern size_t gen_pool_avail(struct gen_pool *);
extern size_t gen_pool_size(struct gen_pool *);

extern void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo,
		void *data);

extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,
		unsigned long start, unsigned int nr, void *data,
		struct gen_pool *pool, unsigned long start_addr);

extern unsigned long gen_pool_fixed_alloc(unsigned long *map,
		unsigned long size, unsigned long start, unsigned int nr,
		void *data, struct gen_pool *pool, unsigned long start_addr);

extern unsigned long gen_pool_first_fit_align(unsigned long *map,
		unsigned long size, unsigned long start, unsigned int nr,
		void *data, struct gen_pool *pool, unsigned long start_addr);


extern unsigned long gen_pool_first_fit_order_align(unsigned long *map,
		unsigned long size, unsigned long start, unsigned int nr,
		void *data, struct gen_pool *pool, unsigned long start_addr);

extern unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size,
		unsigned long start, unsigned int nr, void *data,
		struct gen_pool *pool, unsigned long start_addr);


extern struct gen_pool *devm_gen_pool_create(struct device *dev,
		int min_alloc_order, int nid, const char *name);
extern struct gen_pool *gen_pool_get(struct device *dev, const char *name);

extern bool gen_pool_has_addr(struct gen_pool *pool, unsigned long start,
			size_t size);

#ifdef CONFIG_OF
extern struct gen_pool *of_gen_pool_get(struct device_node *np,
	const char *propname, int index);
#else
static inline struct gen_pool *of_gen_pool_get(struct device_node *np,
	const char *propname, int index)
{
	return NULL;
}
#endif
#endif /* __GENALLOC_H__ */