include/linux/genalloc.h

   1 /*
   2  * Basic general purpose allocator for managing special purpose memory
   3  * not managed by the regular kmalloc/kfree interface.
   4  * Uses for this includes on-device special memory, uncached memory
   5  * etc.
   6  *
   7  * This source code is licensed under the GNU General Public License,
   8  * Version 2.  See the file COPYING for more details.
   9  */
  10
  11
  12 #ifndef __GENALLOC_H__
  13 #define __GENALLOC_H__
  14 /*
  15  *  General purpose special memory pool descriptor.
  16  */
  17 struct gen_pool {
  18         rwlock_t lock;
  19         struct list_head chunks;        /* list of chunks in this pool */
  20         int min_alloc_order;            /* minimum allocation order */
  21 };
  22
  23 /*
  24  *  General purpose special memory pool chunk descriptor.
  25  */
  26 struct gen_pool_chunk {
  27         spinlock_t lock;
  28         struct list_head next_chunk;    /* next chunk in pool */
  29         phys_addr_t phys_addr;          /* physical starting address of memory chunk */
  30         unsigned long start_addr;       /* starting address of memory chunk */
  31         unsigned long end_addr;         /* ending address of memory chunk */
  32         unsigned long bits[0];          /* bitmap for allocating memory chunk */
  33 };
  34
  35 extern struct gen_pool *gen_pool_create(int, int);
  36 extern phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long);
  37 extern int gen_pool_add_virt(struct gen_pool *, unsigned long, phys_addr_t,
  38                              size_t, int);
  39 /**
  40  * gen_pool_add - add a new chunk of special memory to the pool
  41  * @pool: pool to add new memory chunk to
  42  * @addr: starting address of memory chunk to add to pool
  43  * @size: size in bytes of the memory chunk to add to pool
  44  * @nid: node id of the node the chunk structure and bitmap should be
  45  *       allocated on, or -1
  46  *
  47  * Add a new chunk of special memory to the specified pool.
  48  *
  49  * Returns 0 on success or a -ve errno on failure.
  50  */
  51 static inline int gen_pool_add(struct gen_pool *pool, unsigned long addr,
  52                                size_t size, int nid)
  53 {
  54         return gen_pool_add_virt(pool, addr, -1, size, nid);
  55 }
  56 extern void gen_pool_destroy(struct gen_pool *);
  57 extern unsigned long gen_pool_alloc(struct gen_pool *, size_t);
  58 extern void gen_pool_free(struct gen_pool *, unsigned long, size_t);
  59 #endif /* __GENALLOC_H__ */