fs/xfs/linux-2.6/kmem.h

   1 /*
   2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #ifndef __XFS_SUPPORT_KMEM_H__
  19 #define __XFS_SUPPORT_KMEM_H__
  20
  21 #include <linux/slab.h>
  22 #include <linux/sched.h>
  23 #include <linux/mm.h>
  24
  25 /*
  26  * General memory allocation interfaces
  27  */
  28
  29 #define KM_SLEEP        0x0001u
  30 #define KM_NOSLEEP      0x0002u
  31 #define KM_NOFS         0x0004u
  32 #define KM_MAYFAIL      0x0008u
  33
  34 /*
  35  * We use a special process flag to avoid recursive callbacks into
  36  * the filesystem during transactions.  We will also issue our own
  37  * warnings, so we explicitly skip any generic ones (silly of us).
  38  */
  39 static inline gfp_t
  40 kmem_flags_convert(unsigned int __nocast flags)
  41 {
  42         gfp_t   lflags;
  43
  44         BUG_ON(flags & ~(KM_SLEEP|KM_NOSLEEP|KM_NOFS|KM_MAYFAIL));
  45
  46         if (flags & KM_NOSLEEP) {
  47                 lflags = GFP_ATOMIC | __GFP_NOWARN;
  48         } else {
  49                 lflags = GFP_KERNEL | __GFP_NOWARN;
  50                 if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
  51                         lflags &= ~__GFP_FS;
  52         }
  53         return lflags;
  54 }
  55
  56 extern void *kmem_alloc(size_t, unsigned int __nocast);
  57 extern void *kmem_realloc(void *, size_t, size_t, unsigned int __nocast);
  58 extern void *kmem_zalloc(size_t, unsigned int __nocast);
  59 extern void  kmem_free(void *, size_t);
  60
  61 /*
  62  * Zone interfaces
  63  */
  64
  65 #define KM_ZONE_HWALIGN SLAB_HWCACHE_ALIGN
  66 #define KM_ZONE_RECLAIM SLAB_RECLAIM_ACCOUNT
  67 #define KM_ZONE_SPREAD  SLAB_MEM_SPREAD
  68
  69 #define kmem_zone       kmem_cache
  70 #define kmem_zone_t     struct kmem_cache
  71
  72 static inline kmem_zone_t *
  73 kmem_zone_init(int size, char *zone_name)
  74 {
  75         return kmem_cache_create(zone_name, size, 0, 0, NULL, NULL);
  76 }
  77
  78 static inline kmem_zone_t *
  79 kmem_zone_init_flags(int size, char *zone_name, unsigned long flags,
  80                      void (*construct)(void *, kmem_zone_t *, unsigned long))
  81 {
  82         return kmem_cache_create(zone_name, size, 0, flags, construct, NULL);
  83 }
  84
  85 static inline void
  86 kmem_zone_free(kmem_zone_t *zone, void *ptr)
  87 {
  88         kmem_cache_free(zone, ptr);
  89 }
  90
  91 static inline void
  92 kmem_zone_destroy(kmem_zone_t *zone)
  93 {
  94         if (zone)
  95                 kmem_cache_destroy(zone);
  96 }
  97
  98 extern void *kmem_zone_alloc(kmem_zone_t *, unsigned int __nocast);
  99 extern void *kmem_zone_zalloc(kmem_zone_t *, unsigned int __nocast);
 100
 101 /*
 102  * Low memory cache shrinkers
 103  */
 104
 105 typedef struct shrinker *kmem_shaker_t;
 106 typedef int (*kmem_shake_func_t)(int, gfp_t);
 107
 108 static inline kmem_shaker_t
 109 kmem_shake_register(kmem_shake_func_t sfunc)
 110 {
 111         return set_shrinker(DEFAULT_SEEKS, sfunc);
 112 }
 113
 114 static inline void
 115 kmem_shake_deregister(kmem_shaker_t shrinker)
 116 {
 117         remove_shrinker(shrinker);
 118 }
 119
 120 static inline int
 121 kmem_shake_allow(gfp_t gfp_mask)
 122 {
 123         return (gfp_mask & __GFP_WAIT);
 124 }
 125
 126 #endif /* __XFS_SUPPORT_KMEM_H__ */