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 */
164