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, phys: -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, algo: pool->algo, data: 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, algo: pool->algo, data: 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__ */ |
223 | |