drivers/md/dm-cache-policy-internal.h

   1 /*
   2  * Copyright (C) 2012 Red Hat. All rights reserved.
   3  *
   4  * This file is released under the GPL.
   5  */
   6
   7 #ifndef DM_CACHE_POLICY_INTERNAL_H
   8 #define DM_CACHE_POLICY_INTERNAL_H
   9
  10 #include <linux/vmalloc.h>
  11 #include "dm-cache-policy.h"
  12
  13 /*----------------------------------------------------------------*/
  14
  15 static inline int policy_lookup(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock,
  16                                 int data_dir, bool fast_copy, bool *background_queued)
  17 {
  18         return p->lookup(p, oblock, cblock, data_dir, fast_copy, background_queued);
  19 }
  20
  21 static inline int policy_lookup_with_work(struct dm_cache_policy *p,
  22                                           dm_oblock_t oblock, dm_cblock_t *cblock,
  23                                           int data_dir, bool fast_copy,
  24                                           struct policy_work **work)
  25 {
  26         if (!p->lookup_with_work) {
  27                 *work = NULL;
  28                 return p->lookup(p, oblock, cblock, data_dir, fast_copy, NULL);
  29         }
  30
  31         return p->lookup_with_work(p, oblock, cblock, data_dir, fast_copy, work);
  32 }
  33
  34 static inline int policy_get_background_work(struct dm_cache_policy *p,
  35                                              bool idle, struct policy_work **result)
  36 {
  37         return p->get_background_work(p, idle, result);
  38 }
  39
  40 static inline void policy_complete_background_work(struct dm_cache_policy *p,
  41                                                    struct policy_work *work,
  42                                                    bool success)
  43 {
  44         return p->complete_background_work(p, work, success);
  45 }
  46
  47 static inline void policy_set_dirty(struct dm_cache_policy *p, dm_cblock_t cblock)
  48 {
  49         p->set_dirty(p, cblock);
  50 }
  51
  52 static inline void policy_clear_dirty(struct dm_cache_policy *p, dm_cblock_t cblock)
  53 {
  54         p->clear_dirty(p, cblock);
  55 }
  56
  57 static inline int policy_load_mapping(struct dm_cache_policy *p,
  58                                       dm_oblock_t oblock, dm_cblock_t cblock,
  59                                       bool dirty, uint32_t hint, bool hint_valid)
  60 {
  61         return p->load_mapping(p, oblock, cblock, dirty, hint, hint_valid);
  62 }
  63
  64 static inline int policy_invalidate_mapping(struct dm_cache_policy *p,
  65                                             dm_cblock_t cblock)
  66 {
  67         return p->invalidate_mapping(p, cblock);
  68 }
  69
  70 static inline uint32_t policy_get_hint(struct dm_cache_policy *p,
  71                                        dm_cblock_t cblock)
  72 {
  73         return p->get_hint ? p->get_hint(p, cblock) : 0;
  74 }
  75
  76 static inline dm_cblock_t policy_residency(struct dm_cache_policy *p)
  77 {
  78         return p->residency(p);
  79 }
  80
  81 static inline void policy_tick(struct dm_cache_policy *p, bool can_block)
  82 {
  83         if (p->tick)
  84                 return p->tick(p, can_block);
  85 }
  86
  87 static inline int policy_emit_config_values(struct dm_cache_policy *p, char *result,
  88                                             unsigned maxlen, ssize_t *sz_ptr)
  89 {
  90         ssize_t sz = *sz_ptr;
  91         if (p->emit_config_values)
  92                 return p->emit_config_values(p, result, maxlen, sz_ptr);
  93
  94         DMEMIT("0 ");
  95         *sz_ptr = sz;
  96         return 0;
  97 }
  98
  99 static inline int policy_set_config_value(struct dm_cache_policy *p,
 100                                           const char *key, const char *value)
 101 {
 102         return p->set_config_value ? p->set_config_value(p, key, value) : -EINVAL;
 103 }
 104
 105 static inline void policy_allow_migrations(struct dm_cache_policy *p, bool allow)
 106 {
 107         return p->allow_migrations(p, allow);
 108 }
 109
 110 /*----------------------------------------------------------------*/
 111
 112 /*
 113  * Some utility functions commonly used by policies and the core target.
 114  */
 115 static inline size_t bitset_size_in_bytes(unsigned nr_entries)
 116 {
 117         return sizeof(unsigned long) * dm_div_up(nr_entries, BITS_PER_LONG);
 118 }
 119
 120 static inline unsigned long *alloc_bitset(unsigned nr_entries)
 121 {
 122         size_t s = bitset_size_in_bytes(nr_entries);
 123         return vzalloc(s);
 124 }
 125
 126 static inline void clear_bitset(void *bitset, unsigned nr_entries)
 127 {
 128         size_t s = bitset_size_in_bytes(nr_entries);
 129         memset(bitset, 0, s);
 130 }
 131
 132 static inline void free_bitset(unsigned long *bits)
 133 {
 134         vfree(bits);
 135 }
 136
 137 /*----------------------------------------------------------------*/
 138
 139 /*
 140  * Creates a new cache policy given a policy name, a cache size, an origin size and the block size.
 141  */
 142 struct dm_cache_policy *dm_cache_policy_create(const char *name, dm_cblock_t cache_size,
 143                                                sector_t origin_size, sector_t block_size);
 144
 145 /*
 146  * Destroys the policy.  This drops references to the policy module as well
 147  * as calling it's destroy method.  So always use this rather than calling
 148  * the policy->destroy method directly.
 149  */
 150 void dm_cache_policy_destroy(struct dm_cache_policy *p);
 151
 152 /*
 153  * In case we've forgotten.
 154  */
 155 const char *dm_cache_policy_get_name(struct dm_cache_policy *p);
 156
 157 const unsigned *dm_cache_policy_get_version(struct dm_cache_policy *p);
 158
 159 size_t dm_cache_policy_get_hint_size(struct dm_cache_policy *p);
 160
 161 /*----------------------------------------------------------------*/
 162
 163 #endif /* DM_CACHE_POLICY_INTERNAL_H */