include/linux/zsmalloc.h

   1 /*
   2  * zsmalloc memory allocator
   3  *
   4  * Copyright (C) 2011  Nitin Gupta
   5  * Copyright (C) 2012, 2013 Minchan Kim
   6  *
   7  * This code is released using a dual license strategy: BSD/GPL
   8  * You can choose the license that better fits your requirements.
   9  *
  10  * Released under the terms of 3-clause BSD License
  11  * Released under the terms of GNU General Public License Version 2.0
  12  */
  13
  14 #ifndef _ZS_MALLOC_H_
  15 #define _ZS_MALLOC_H_
  16
  17 #include <linux/types.h>
  18
  19 /*
  20  * zsmalloc mapping modes
  21  *
  22  * NOTE: These only make a difference when a mapped object spans pages.
  23  * They also have no effect when PGTABLE_MAPPING is selected.
  24  */
  25 enum zs_mapmode {
  26         ZS_MM_RW, /* normal read-write mapping */
  27         ZS_MM_RO, /* read-only (no copy-out at unmap time) */
  28         ZS_MM_WO /* write-only (no copy-in at map time) */
  29         /*
  30          * NOTE: ZS_MM_WO should only be used for initializing new
  31          * (uninitialized) allocations.  Partial writes to already
  32          * initialized allocations should use ZS_MM_RW to preserve the
  33          * existing data.
  34          */
  35 };
  36
  37 struct zs_pool_stats {
  38         /* How many pages were migrated (freed) */
  39         unsigned long pages_compacted;
  40 };
  41
  42 struct zs_pool;
  43
  44 struct zs_pool *zs_create_pool(const char *name, gfp_t flags);
  45 void zs_destroy_pool(struct zs_pool *pool);
  46
  47 unsigned long zs_malloc(struct zs_pool *pool, size_t size);
  48 void zs_free(struct zs_pool *pool, unsigned long obj);
  49
  50 void *zs_map_object(struct zs_pool *pool, unsigned long handle,
  51                         enum zs_mapmode mm);
  52 void zs_unmap_object(struct zs_pool *pool, unsigned long handle);
  53
  54 unsigned long zs_get_total_pages(struct zs_pool *pool);
  55 unsigned long zs_compact(struct zs_pool *pool);
  56
  57 void zs_pool_stats(struct zs_pool *pool, struct zs_pool_stats *stats);
  58 #endif