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1 | /* SPDX-License-Identifier: GPL-2.0-only */ | |
2 | /* | |
3 | * Basic general purpose allocator for managing special purpose | |
4 | * memory, for example, memory that is not managed by the regular | |
5 | * kmalloc/kfree interface. Uses for this includes on-device special | |
6 | * memory, uncached memory etc. | |
7 | * | |
8 | * It is safe to use the allocator in NMI handlers and other special | |
9 | * unblockable contexts that could otherwise deadlock on locks. This | |
10 | * is implemented by using atomic operations and retries on any | |
11 | * conflicts. The disadvantage is that there may be livelocks in | |
12 | * extreme cases. For better scalability, one allocator can be used | |
13 | * for each CPU. | |
14 | * | |
15 | * The lockless operation only works if there is enough memory | |
16 | * available. If new memory is added to the pool a lock has to be | |
17 | * still taken. So any user relying on locklessness has to ensure | |
18 | * that sufficient memory is preallocated. | |
19 | * | |
20 | * The basic atomic operation of this allocator is cmpxchg on long. | |
21 | * On architectures that don't have NMI-safe cmpxchg implementation, | |
22 | * the allocator can NOT be used in NMI handler. So code uses the | |
23 | * allocator in NMI handler should depend on | |
24 | * CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG. | |
25 | */ | |
26 | ||
27 | ||
28 | #ifndef __GENALLOC_H__ | |
29 | #define __GENALLOC_H__ | |
30 | ||
31 | #include <linux/types.h> | |
32 | #include <linux/spinlock_types.h> | |
33 | #include <linux/atomic.h> | |
34 | ||
35 | struct device; | |
36 | struct device_node; | |
37 | struct gen_pool; | |
38 | ||
39 | /** | |
40 | * typedef genpool_algo_t: Allocation callback function type definition | |
41 | * @map: Pointer to bitmap | |
42 | * @size: The bitmap size in bits | |
43 | * @start: The bitnumber to start searching at | |
44 | * @nr: The number of zeroed bits we're looking for | |
45 | * @data: optional additional data used by the callback | |
46 | * @pool: the pool being allocated from | |
47 | */ | |
48 | typedef 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 | unsigned long start_addr); | |
54 | ||
55 | /* | |
56 | * General purpose special memory pool descriptor. | |
57 | */ | |
58 | struct gen_pool { | |
59 | spinlock_t lock; | |
60 | struct list_head chunks; /* list of chunks in this pool */ | |
61 | int min_alloc_order; /* minimum allocation order */ | |
62 | ||
63 | genpool_algo_t algo; /* allocation function */ | |
64 | void *data; | |
65 | ||
66 | const char *name; | |
67 | }; | |
68 | ||
69 | /* | |
70 | * General purpose special memory pool chunk descriptor. | |
71 | */ | |
72 | struct gen_pool_chunk { | |
73 | struct list_head next_chunk; /* next chunk in pool */ | |
74 | atomic_long_t avail; | |
75 | phys_addr_t phys_addr; /* physical starting address of memory chunk */ | |
76 | void *owner; /* private data to retrieve at alloc time */ | |
77 | unsigned long start_addr; /* start address of memory chunk */ | |
78 | unsigned long end_addr; /* end address of memory chunk (inclusive) */ | |
79 | unsigned long bits[]; /* bitmap for allocating memory chunk */ | |
80 | }; | |
81 | ||
82 | /* | |
83 | * gen_pool data descriptor for gen_pool_first_fit_align. | |
84 | */ | |
85 | struct genpool_data_align { | |
86 | int align; /* alignment by bytes for starting address */ | |
87 | }; | |
88 | ||
89 | /* | |
90 | * gen_pool data descriptor for gen_pool_fixed_alloc. | |
91 | */ | |
92 | struct genpool_data_fixed { | |
93 | unsigned long offset; /* The offset of the specific region */ | |
94 | }; | |
95 | ||
96 | extern struct gen_pool *gen_pool_create(int, int); | |
97 | extern phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long); | |
98 | extern int gen_pool_add_owner(struct gen_pool *, unsigned long, phys_addr_t, | |
99 | size_t, int, void *); | |
100 | ||
101 | static inline int gen_pool_add_virt(struct gen_pool *pool, unsigned long addr, | |
102 | phys_addr_t phys, size_t size, int nid) | |
103 | { | |
104 | return gen_pool_add_owner(pool, addr, phys, size, nid, NULL); | |
105 | } | |
106 | ||
107 | /** | |
108 | * gen_pool_add - add a new chunk of special memory to the pool | |
109 | * @pool: pool to add new memory chunk to | |
110 | * @addr: starting address of memory chunk to add to pool | |
111 | * @size: size in bytes of the memory chunk to add to pool | |
112 | * @nid: node id of the node the chunk structure and bitmap should be | |
113 | * allocated on, or -1 | |
114 | * | |
115 | * Add a new chunk of special memory to the specified pool. | |
116 | * | |
117 | * Returns 0 on success or a -ve errno on failure. | |
118 | */ | |
119 | static inline int gen_pool_add(struct gen_pool *pool, unsigned long addr, | |
120 | size_t size, int nid) | |
121 | { | |
122 | return gen_pool_add_virt(pool, addr, -1, size, nid); | |
123 | } | |
124 | extern void gen_pool_destroy(struct gen_pool *); | |
125 | unsigned long gen_pool_alloc_algo_owner(struct gen_pool *pool, size_t size, | |
126 | genpool_algo_t algo, void *data, void **owner); | |
127 | ||
128 | static inline unsigned long gen_pool_alloc_owner(struct gen_pool *pool, | |
129 | size_t size, void **owner) | |
130 | { | |
131 | return gen_pool_alloc_algo_owner(pool, size, pool->algo, pool->data, | |
132 | owner); | |
133 | } | |
134 | ||
135 | static inline unsigned long gen_pool_alloc_algo(struct gen_pool *pool, | |
136 | size_t size, genpool_algo_t algo, void *data) | |
137 | { | |
138 | return gen_pool_alloc_algo_owner(pool, size, algo, data, NULL); | |
139 | } | |
140 | ||
141 | /** | |
142 | * gen_pool_alloc - allocate special memory from the pool | |
143 | * @pool: pool to allocate from | |
144 | * @size: number of bytes to allocate from the pool | |
145 | * | |
146 | * Allocate the requested number of bytes from the specified pool. | |
147 | * Uses the pool allocation function (with first-fit algorithm by default). | |
148 | * Can not be used in NMI handler on architectures without | |
149 | * NMI-safe cmpxchg implementation. | |
150 | */ | |
151 | static inline unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size) | |
152 | { | |
153 | return gen_pool_alloc_algo(pool, size, pool->algo, pool->data); | |
154 | } | |
155 | ||
156 | extern void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, | |
157 | dma_addr_t *dma); | |
158 | extern void *gen_pool_dma_alloc_algo(struct gen_pool *pool, size_t size, | |
159 | dma_addr_t *dma, genpool_algo_t algo, void *data); | |
160 | extern void *gen_pool_dma_alloc_align(struct gen_pool *pool, size_t size, | |
161 | dma_addr_t *dma, int align); | |
162 | extern void *gen_pool_dma_zalloc(struct gen_pool *pool, size_t size, dma_addr_t *dma); | |
163 | extern void *gen_pool_dma_zalloc_algo(struct gen_pool *pool, size_t size, | |
164 | dma_addr_t *dma, genpool_algo_t algo, void *data); | |
165 | extern void *gen_pool_dma_zalloc_align(struct gen_pool *pool, size_t size, | |
166 | dma_addr_t *dma, int align); | |
167 | extern void gen_pool_free_owner(struct gen_pool *pool, unsigned long addr, | |
168 | size_t size, void **owner); | |
169 | static inline void gen_pool_free(struct gen_pool *pool, unsigned long addr, | |
170 | size_t size) | |
171 | { | |
172 | gen_pool_free_owner(pool, addr, size, NULL); | |
173 | } | |
174 | ||
175 | extern void gen_pool_for_each_chunk(struct gen_pool *, | |
176 | void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *); | |
177 | extern size_t gen_pool_avail(struct gen_pool *); | |
178 | extern size_t gen_pool_size(struct gen_pool *); | |
179 | ||
180 | extern void gen_pool_set_algo(struct gen_pool *pool, genpool_algo_t algo, | |
181 | void *data); | |
182 | ||
183 | extern unsigned long gen_pool_first_fit(unsigned long *map, unsigned long size, | |
184 | unsigned long start, unsigned int nr, void *data, | |
185 | struct gen_pool *pool, unsigned long start_addr); | |
186 | ||
187 | extern unsigned long gen_pool_fixed_alloc(unsigned long *map, | |
188 | unsigned long size, unsigned long start, unsigned int nr, | |
189 | void *data, struct gen_pool *pool, unsigned long start_addr); | |
190 | ||
191 | extern unsigned long gen_pool_first_fit_align(unsigned long *map, | |
192 | unsigned long size, unsigned long start, unsigned int nr, | |
193 | void *data, struct gen_pool *pool, unsigned long start_addr); | |
194 | ||
195 | ||
196 | extern unsigned long gen_pool_first_fit_order_align(unsigned long *map, | |
197 | unsigned long size, unsigned long start, unsigned int nr, | |
198 | void *data, struct gen_pool *pool, unsigned long start_addr); | |
199 | ||
200 | extern unsigned long gen_pool_best_fit(unsigned long *map, unsigned long size, | |
201 | unsigned long start, unsigned int nr, void *data, | |
202 | struct gen_pool *pool, unsigned long start_addr); | |
203 | ||
204 | ||
205 | extern struct gen_pool *devm_gen_pool_create(struct device *dev, | |
206 | int min_alloc_order, int nid, const char *name); | |
207 | extern struct gen_pool *gen_pool_get(struct device *dev, const char *name); | |
208 | ||
209 | extern bool gen_pool_has_addr(struct gen_pool *pool, unsigned long start, | |
210 | size_t size); | |
211 | ||
212 | #ifdef CONFIG_OF | |
213 | extern struct gen_pool *of_gen_pool_get(struct device_node *np, | |
214 | const char *propname, int index); | |
215 | #else | |
216 | static inline struct gen_pool *of_gen_pool_get(struct device_node *np, | |
217 | const char *propname, int index) | |
218 | { | |
219 | return NULL; | |
220 | } | |
221 | #endif | |
222 | #endif /* __GENALLOC_H__ */ |