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
 15static 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
 21static 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
 34static 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
 40static 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
 47static inline void policy_set_dirty(struct dm_cache_policy *p, dm_cblock_t cblock)
 48{
 49	p->set_dirty(p, cblock);
 50}
 51
 52static inline void policy_clear_dirty(struct dm_cache_policy *p, dm_cblock_t cblock)
 53{
 54	p->clear_dirty(p, cblock);
 55}
 56
 57static 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
 64static 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
 70static 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
 76static inline dm_cblock_t policy_residency(struct dm_cache_policy *p)
 77{
 78	return p->residency(p);
 79}
 80
 81static 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
 87static 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
 99static 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
105static 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 */
115static 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
120static 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
126static 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
132static 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 */
142struct 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 */
150void dm_cache_policy_destroy(struct dm_cache_policy *p);
151
152/*
153 * In case we've forgotten.
154 */
155const char *dm_cache_policy_get_name(struct dm_cache_policy *p);
156
157const unsigned *dm_cache_policy_get_version(struct dm_cache_policy *p);
158
159size_t dm_cache_policy_get_hint_size(struct dm_cache_policy *p);
160
161/*----------------------------------------------------------------*/
162
163#endif /* DM_CACHE_POLICY_INTERNAL_H */