]>
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>
41 * typedef genpool_algo_t: 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 the callback
47 * @pool: the pool being allocated from
49 typedef unsigned long (*genpool_algo_t
)(unsigned long *map
,
53 void *data
, struct gen_pool
*pool
);
56 * General purpose special memory pool descriptor.
60 struct list_head chunks
; /* list of chunks in this pool */
61 int min_alloc_order
; /* minimum allocation order */
63 genpool_algo_t algo
; /* allocation function */
70 * General purpose special memory pool chunk descriptor.
72 struct gen_pool_chunk
{
73 struct list_head next_chunk
; /* next chunk in pool */
75 phys_addr_t phys_addr
; /* physical starting address of memory chunk */
76 unsigned long start_addr
; /* start address of memory chunk */
77 unsigned long end_addr
; /* end address of memory chunk (inclusive) */
78 unsigned long bits
[0]; /* bitmap for allocating memory chunk */
82 * gen_pool data descriptor for gen_pool_first_fit_align.
84 struct genpool_data_align
{
85 int align
; /* alignment by bytes for starting address */
89 * gen_pool data descriptor for gen_pool_fixed_alloc.
91 struct genpool_data_fixed
{
92 unsigned long offset
; /* The offset of the specific region */
95 extern struct gen_pool
*gen_pool_create(int, int);
96 extern phys_addr_t
gen_pool_virt_to_phys(struct gen_pool
*pool
, unsigned long);
97 extern int gen_pool_add_virt(struct gen_pool
*, unsigned long, phys_addr_t
,
100 * gen_pool_add - add a new chunk of special memory to the pool
101 * @pool: pool to add new memory chunk to
102 * @addr: starting address of memory chunk to add to pool
103 * @size: size in bytes of the memory chunk to add to pool
104 * @nid: node id of the node the chunk structure and bitmap should be
105 * allocated on, or -1
107 * Add a new chunk of special memory to the specified pool.
109 * Returns 0 on success or a -ve errno on failure.
111 static inline int gen_pool_add(struct gen_pool
*pool
, unsigned long addr
,
112 size_t size
, int nid
)
114 return gen_pool_add_virt(pool
, addr
, -1, size
, nid
);
116 extern void gen_pool_destroy(struct gen_pool
*);
117 extern unsigned long gen_pool_alloc(struct gen_pool
*, size_t);
118 extern unsigned long gen_pool_alloc_algo(struct gen_pool
*, size_t,
119 genpool_algo_t algo
, void *data
);
120 extern void *gen_pool_dma_alloc(struct gen_pool
*pool
, size_t size
,
122 extern void gen_pool_free(struct gen_pool
*, unsigned long, size_t);
123 extern void gen_pool_for_each_chunk(struct gen_pool
*,
124 void (*)(struct gen_pool
*, struct gen_pool_chunk
*, void *), void *);
125 extern size_t gen_pool_avail(struct gen_pool
*);
126 extern size_t gen_pool_size(struct gen_pool
*);
128 extern void gen_pool_set_algo(struct gen_pool
*pool
, genpool_algo_t algo
,
131 extern unsigned long gen_pool_first_fit(unsigned long *map
, unsigned long size
,
132 unsigned long start
, unsigned int nr
, void *data
,
133 struct gen_pool
*pool
);
135 extern unsigned long gen_pool_fixed_alloc(unsigned long *map
,
136 unsigned long size
, unsigned long start
, unsigned int nr
,
137 void *data
, struct gen_pool
*pool
);
139 extern unsigned long gen_pool_first_fit_align(unsigned long *map
,
140 unsigned long size
, unsigned long start
, unsigned int nr
,
141 void *data
, struct gen_pool
*pool
);
144 extern unsigned long gen_pool_first_fit_order_align(unsigned long *map
,
145 unsigned long size
, unsigned long start
, unsigned int nr
,
146 void *data
, struct gen_pool
*pool
);
148 extern unsigned long gen_pool_best_fit(unsigned long *map
, unsigned long size
,
149 unsigned long start
, unsigned int nr
, void *data
,
150 struct gen_pool
*pool
);
153 extern struct gen_pool
*devm_gen_pool_create(struct device
*dev
,
154 int min_alloc_order
, int nid
, const char *name
);
155 extern struct gen_pool
*gen_pool_get(struct device
*dev
, const char *name
);
157 bool addr_in_gen_pool(struct gen_pool
*pool
, unsigned long start
,
161 extern struct gen_pool
*of_gen_pool_get(struct device_node
*np
,
162 const char *propname
, int index
);
164 static inline struct gen_pool
*of_gen_pool_get(struct device_node
*np
,
165 const char *propname
, int index
)
170 #endif /* __GENALLOC_H__ */