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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - include/linux/genalloc.h
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.
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
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.
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.
25 * This source code is licensed under the GNU General Public License,
26 * Version 2. See the file COPYING for more details.
30 #ifndef __GENALLOC_H__
31 #define __GENALLOC_H__
33 #include <linux/types.h>
34 #include <linux/spinlock_types.h>
35 #include <linux/atomic.h>
42 * typedef genpool_algo_t: Allocation callback function type definition
43 * @map: Pointer to bitmap
44 * @size: The bitmap size in bits
45 * @start: The bitnumber to start searching at
46 * @nr: The number of zeroed bits we're looking for
47 * @data: optional additional data used by the callback
48 * @pool: the pool being allocated from
50 typedef unsigned long (*genpool_algo_t
)(unsigned long *map
,
54 void *data
, struct gen_pool
*pool
,
55 unsigned long start_addr
);
58 * General purpose special memory pool descriptor.
62 struct list_head chunks
; /* list of chunks in this pool */
63 int min_alloc_order
; /* minimum allocation order */
65 genpool_algo_t algo
; /* allocation function */
72 * General purpose special memory pool chunk descriptor.
74 struct gen_pool_chunk
{
75 struct list_head next_chunk
; /* next chunk in pool */
77 phys_addr_t phys_addr
; /* physical starting address of memory chunk */
78 unsigned long start_addr
; /* start address of memory chunk */
79 unsigned long end_addr
; /* end address of memory chunk (inclusive) */
80 unsigned long bits
[0]; /* bitmap for allocating memory chunk */
84 * gen_pool data descriptor for gen_pool_first_fit_align.
86 struct genpool_data_align
{
87 int align
; /* alignment by bytes for starting address */
91 * gen_pool data descriptor for gen_pool_fixed_alloc.
93 struct genpool_data_fixed
{
94 unsigned long offset
; /* The offset of the specific region */
97 extern struct gen_pool
*gen_pool_create(int, int);
98 extern phys_addr_t
gen_pool_virt_to_phys(struct gen_pool
*pool
, unsigned long);
99 extern int gen_pool_add_virt(struct gen_pool
*, unsigned long, phys_addr_t
,
102 * gen_pool_add - add a new chunk of special memory to the pool
103 * @pool: pool to add new memory chunk to
104 * @addr: starting address of memory chunk to add to pool
105 * @size: size in bytes of the memory chunk to add to pool
106 * @nid: node id of the node the chunk structure and bitmap should be
107 * allocated on, or -1
109 * Add a new chunk of special memory to the specified pool.
111 * Returns 0 on success or a -ve errno on failure.
113 static inline int gen_pool_add(struct gen_pool
*pool
, unsigned long addr
,
114 size_t size
, int nid
)
116 return gen_pool_add_virt(pool
, addr
, -1, size
, nid
);
118 extern void gen_pool_destroy(struct gen_pool
*);
119 extern unsigned long gen_pool_alloc(struct gen_pool
*, size_t);
120 extern unsigned long gen_pool_alloc_algo(struct gen_pool
*, size_t,
121 genpool_algo_t algo
, void *data
);
122 extern void *gen_pool_dma_alloc(struct gen_pool
*pool
, size_t size
,
124 extern void gen_pool_free(struct gen_pool
*, unsigned long, size_t);
125 extern void gen_pool_for_each_chunk(struct gen_pool
*,
126 void (*)(struct gen_pool
*, struct gen_pool_chunk
*, void *), void *);
127 extern size_t gen_pool_avail(struct gen_pool
*);
128 extern size_t gen_pool_size(struct gen_pool
*);
130 extern void gen_pool_set_algo(struct gen_pool
*pool
, genpool_algo_t algo
,
133 extern unsigned long gen_pool_first_fit(unsigned long *map
, unsigned long size
,
134 unsigned long start
, unsigned int nr
, void *data
,
135 struct gen_pool
*pool
, unsigned long start_addr
);
137 extern unsigned long gen_pool_fixed_alloc(unsigned long *map
,
138 unsigned long size
, unsigned long start
, unsigned int nr
,
139 void *data
, struct gen_pool
*pool
, unsigned long start_addr
);
141 extern unsigned long gen_pool_first_fit_align(unsigned long *map
,
142 unsigned long size
, unsigned long start
, unsigned int nr
,
143 void *data
, struct gen_pool
*pool
, unsigned long start_addr
);
146 extern unsigned long gen_pool_first_fit_order_align(unsigned long *map
,
147 unsigned long size
, unsigned long start
, unsigned int nr
,
148 void *data
, struct gen_pool
*pool
, unsigned long start_addr
);
150 extern unsigned long gen_pool_best_fit(unsigned long *map
, unsigned long size
,
151 unsigned long start
, unsigned int nr
, void *data
,
152 struct gen_pool
*pool
, unsigned long start_addr
);
155 extern struct gen_pool
*devm_gen_pool_create(struct device
*dev
,
156 int min_alloc_order
, int nid
, const char *name
);
157 extern struct gen_pool
*gen_pool_get(struct device
*dev
, const char *name
);
159 bool addr_in_gen_pool(struct gen_pool
*pool
, unsigned long start
,
163 extern struct gen_pool
*of_gen_pool_get(struct device_node
*np
,
164 const char *propname
, int index
);
166 static inline struct gen_pool
*of_gen_pool_get(struct device_node
*np
,
167 const char *propname
, int index
)
172 #endif /* __GENALLOC_H__ */