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  * Process flags handling
  27  */
  28
  29 #define PFLAGS_TEST_NOIO()              (current->flags & PF_NOIO)
  30 #define PFLAGS_TEST_FSTRANS()           (current->flags & PF_FSTRANS)
  31
  32 #define PFLAGS_SET_NOIO() do {          \
  33         current->flags |= PF_NOIO;      \
  34 } while (0)
  35
  36 #define PFLAGS_CLEAR_NOIO() do {        \
  37         current->flags &= ~PF_NOIO;     \
  38 } while (0)
  39
  40 /* these could be nested, so we save state */
  41 #define PFLAGS_SET_FSTRANS(STATEP) do { \
  42         *(STATEP) = current->flags;     \
  43         current->flags |= PF_FSTRANS;   \
  44 } while (0)
  45
  46 #define PFLAGS_CLEAR_FSTRANS(STATEP) do { \
  47         *(STATEP) = current->flags;     \
  48         current->flags &= ~PF_FSTRANS;  \
  49 } while (0)
  50
  51 /* Restore the PF_FSTRANS state to what was saved in STATEP */
  52 #define PFLAGS_RESTORE_FSTRANS(STATEP) do {                     \
  53         current->flags = ((current->flags & ~PF_FSTRANS) |      \
  54                           (*(STATEP) & PF_FSTRANS));            \
  55 } while (0)
  56
  57 #define PFLAGS_DUP(OSTATEP, NSTATEP) do { \
  58         *(NSTATEP) = *(OSTATEP);        \
  59 } while (0)
  60
  61 /*
  62  * General memory allocation interfaces
  63  */
  64
  65 #define KM_SLEEP        0x0001u
  66 #define KM_NOSLEEP      0x0002u
  67 #define KM_NOFS         0x0004u
  68 #define KM_MAYFAIL      0x0008u
  69
  70 /*
  71  * We use a special process flag to avoid recursive callbacks into
  72  * the filesystem during transactions.  We will also issue our own
  73  * warnings, so we explicitly skip any generic ones (silly of us).
  74  */
  75 static inline gfp_t
  76 kmem_flags_convert(unsigned int __nocast flags)
  77 {
  78         gfp_t   lflags;
  79
  80         BUG_ON(flags & ~(KM_SLEEP|KM_NOSLEEP|KM_NOFS|KM_MAYFAIL));
  81
  82         if (flags & KM_NOSLEEP) {
  83                 lflags = GFP_ATOMIC | __GFP_NOWARN;
  84         } else {
  85                 lflags = GFP_KERNEL | __GFP_NOWARN;
  86                 if (PFLAGS_TEST_FSTRANS() || (flags & KM_NOFS))
  87                         lflags &= ~__GFP_FS;
  88         }
  89         return lflags;
  90 }
  91
  92 extern void *kmem_alloc(size_t, unsigned int __nocast);
  93 extern void *kmem_realloc(void *, size_t, size_t, unsigned int __nocast);
  94 extern void *kmem_zalloc(size_t, unsigned int __nocast);
  95 extern void  kmem_free(void *, size_t);
  96
  97 /*
  98  * Zone interfaces
  99  */
 100
 101 #define KM_ZONE_HWALIGN SLAB_HWCACHE_ALIGN
 102 #define KM_ZONE_RECLAIM SLAB_RECLAIM_ACCOUNT
 103 #define KM_ZONE_SPREAD  SLAB_MEM_SPREAD
 104
 105 #define kmem_zone       kmem_cache
 106 #define kmem_zone_t     struct kmem_cache
 107
 108 static inline kmem_zone_t *
 109 kmem_zone_init(int size, char *zone_name)
 110 {
 111         return kmem_cache_create(zone_name, size, 0, 0, NULL, NULL);
 112 }
 113
 114 static inline kmem_zone_t *
 115 kmem_zone_init_flags(int size, char *zone_name, unsigned long flags,
 116                      void (*construct)(void *, kmem_zone_t *, unsigned long))
 117 {
 118         return kmem_cache_create(zone_name, size, 0, flags, construct, NULL);
 119 }
 120
 121 static inline void
 122 kmem_zone_free(kmem_zone_t *zone, void *ptr)
 123 {
 124         kmem_cache_free(zone, ptr);
 125 }
 126
 127 static inline void
 128 kmem_zone_destroy(kmem_zone_t *zone)
 129 {
 130         if (zone && kmem_cache_destroy(zone))
 131                 BUG();
 132 }
 133
 134 extern void *kmem_zone_alloc(kmem_zone_t *, unsigned int __nocast);
 135 extern void *kmem_zone_zalloc(kmem_zone_t *, unsigned int __nocast);
 136
 137 /*
 138  * Low memory cache shrinkers
 139  */
 140
 141 typedef struct shrinker *kmem_shaker_t;
 142 typedef int (*kmem_shake_func_t)(int, gfp_t);
 143
 144 static inline kmem_shaker_t
 145 kmem_shake_register(kmem_shake_func_t sfunc)
 146 {
 147         return set_shrinker(DEFAULT_SEEKS, sfunc);
 148 }
 149
 150 static inline void
 151 kmem_shake_deregister(kmem_shaker_t shrinker)
 152 {
 153         remove_shrinker(shrinker);
 154 }
 155
 156 static inline int
 157 kmem_shake_allow(gfp_t gfp_mask)
 158 {
 159         return (gfp_mask & __GFP_WAIT);
 160 }
 161
 162 #endif /* __XFS_SUPPORT_KMEM_H__ */