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1/*
2 * Basic general purpose allocator for managing special purpose
3 * memory, for example, memory that is not managed by the regular
4 * kmalloc/kfree interface. Uses for this includes on-device special
5 * memory, uncached memory etc.
6 *
7 * It is safe to use the allocator in NMI handlers and other special
8 * unblockable contexts that could otherwise deadlock on locks. This
9 * is implemented by using atomic operations and retries on any
10 * conflicts. The disadvantage is that there may be livelocks in
11 * extreme cases. For better scalability, one allocator can be used
12 * for each CPU.
13 *
14 * The lockless operation only works if there is enough memory
15 * available. If new memory is added to the pool a lock has to be
16 * still taken. So any user relying on locklessness has to ensure
17 * that sufficient memory is preallocated.
18 *
19 * The basic atomic operation of this allocator is cmpxchg on long.
20 * On architectures that don't have NMI-safe cmpxchg implementation,
21 * the allocator can NOT be used in NMI handler. So code uses the
22 * allocator in NMI handler should depend on
23 * CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
24 *
25 * This source code is licensed under the GNU General Public License,
26 * Version 2. See the file COPYING for more details.
27 */
28
29
30#ifndef __GENALLOC_H__
31#define __GENALLOC_H__
32
33#include <linux/types.h>
34#include <linux/spinlock_types.h>
35
36struct device;
37struct device_node;
38struct gen_pool;
39
40/**
41 * Allocation callback function type definition
42 * @map: Pointer to bitmap
43 * @size: The bitmap size in bits
44 * @start: The bitnumber to start searching at
45 * @nr: The number of zeroed bits we're looking for
46 * @data: optional additional data used by @genpool_algo_t
47 */
48typedef unsigned long (*genpool_algo_t)(unsigned long *map,
49 unsigned long size,
50 unsigned long start,
51 unsigned int nr,
52 void *data, struct gen_pool *pool);
53
54/*
55 * General purpose special memory pool descriptor.
56 */
57struct gen_pool {
58 spinlock_t lock;
59 struct list_head chunks; /* list of chunks in this pool */
60 int min_alloc_order; /* minimum allocation order */
61
62 genpool_algo_t algo; /* allocation function */
63 void *data;
64
65 const char *name;
66};
67
68/*
69 * General purpose special memory pool chunk descriptor.
70 */
71struct gen_pool_chunk {
72 struct list_head next_chunk; /* next chunk in pool */
73 atomic_t avail;
74 phys_addr_t phys_addr; /* physical starting address of memory chunk */
75 unsigned long start_addr; /* start address of memory chunk */
76 unsigned long end_addr; /* end address of memory chunk (inclusive) */
77 unsigned long bits[0]; /* bitmap for allocating memory chunk */
78};
79
80/*
81 * gen_pool data descriptor for gen_pool_first_fit_align.
82 */
83struct genpool_data_align {
84 int align; /* alignment by bytes for starting address */
85};
86
87/*
88 * gen_pool data descriptor for gen_pool_fixed_alloc.
89 */
90struct genpool_data_fixed {
91 unsigned long offset; /* The offset of the specific region */
92};
93
94extern struct gen_pool *gen_pool_create(int, int);
95extern phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long);
96extern int gen_pool_add_virt(struct gen_pool *, unsigned long, phys_addr_t,
97 size_t, int);
98/**
99 * gen_pool_add - add a new chunk of special memory to the pool
100 * @pool: pool to add new memory chunk to
101 * @addr: starting address of memory chunk to add to pool
102 * @size: size in bytes of the memory chunk to add to pool
103 * @nid: node id of the node the chunk structure and bitmap should be
104 * allocated on, or -1
105 *
106 * Add a new chunk of special memory to the specified pool.
107 *
108 * Returns 0 on success or a -ve errno on failure.
109 */
110static inline int gen_pool_add(struct gen_pool *pool, unsigned long addr,
111 size_t size, int nid)
112{
113 return gen_pool_add_virt(pool, addr, -1, size, nid);
114}
115extern void gen_pool_destroy(struct gen_pool *);
116extern unsigned long gen_pool_alloc(struct gen_pool *, size_t);
117extern unsigned long gen_pool_alloc_algo(struct gen_pool *, size_t,
118 genpool_algo_t algo, void *data);
119extern void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size,
120 dma_addr_t *dma);
121extern void gen_pool_free(struct gen_pool *, unsigned long, size_t);
122extern void gen_pool_for_each_chunk(struct gen_pool *,
123 void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *);
124extern size_t gen_pool_avail(struct gen_pool *);
125extern size_t gen_pool_size(struct gen_pool *);
126
127extern void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo,
128 void *data);
129
130extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size,
131 unsigned long start, unsigned int nr, void *data,
132 struct gen_pool *pool);
133
134extern unsigned long gen_pool_fixed_alloc(unsigned long *map,
135 unsigned long size, unsigned long start, unsigned int nr,
136 void *data, struct gen_pool *pool);
137
138extern unsigned long gen_pool_first_fit_align(unsigned long *map,
139 unsigned long size, unsigned long start, unsigned int nr,
140 void *data, struct gen_pool *pool);
141
142
143extern unsigned long gen_pool_first_fit_order_align(unsigned long *map,
144 unsigned long size, unsigned long start, unsigned int nr,
145 void *data, struct gen_pool *pool);
146
147extern unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size,
148 unsigned long start, unsigned int nr, void *data,
149 struct gen_pool *pool);
150
151
152extern struct gen_pool *devm_gen_pool_create(struct device *dev,
153 int min_alloc_order, int nid, const char *name);
154extern struct gen_pool *gen_pool_get(struct device *dev, const char *name);
155
156bool addr_in_gen_pool(struct gen_pool *pool, unsigned long start,
157 size_t size);
158
159#ifdef CONFIG_OF
160extern struct gen_pool *of_gen_pool_get(struct device_node *np,
161 const char *propname, int index);
162#else
163static inline struct gen_pool *of_gen_pool_get(struct device_node *np,
164 const char *propname, int index)
165{
166 return NULL;
167}
168#endif
169#endif /* __GENALLOC_H__ */