1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 Red Hat. All rights reserved.
4  *
5  * This file is released under the GPL.
6  */
7 
8 #ifndef DM_CACHE_POLICY_INTERNAL_H
9 #define DM_CACHE_POLICY_INTERNAL_H
10 
11 #include <linux/vmalloc.h>
12 #include "dm-cache-policy.h"
13 
14 /*----------------------------------------------------------------*/
15 
16 static inline int policy_lookup(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock,
17 				int data_dir, bool fast_copy, bool *background_queued)
18 {
19 	return p->lookup(p, oblock, cblock, data_dir, fast_copy, background_queued);
20 }
21 
22 static inline int policy_lookup_with_work(struct dm_cache_policy *p,
23 					  dm_oblock_t oblock, dm_cblock_t *cblock,
24 					  int data_dir, bool fast_copy,
25 					  struct policy_work **work)
26 {
27 	if (!p->lookup_with_work) {
28 		*work = NULL;
29 		return p->lookup(p, oblock, cblock, data_dir, fast_copy, NULL);
30 	}
31 
32 	return p->lookup_with_work(p, oblock, cblock, data_dir, fast_copy, work);
33 }
34 
35 static inline int policy_get_background_work(struct dm_cache_policy *p,
36 					     bool idle, struct policy_work **result)
37 {
38 	return p->get_background_work(p, idle, result);
39 }
40 
41 static inline void policy_complete_background_work(struct dm_cache_policy *p,
42 						   struct policy_work *work,
43 						   bool success)
44 {
45 	return p->complete_background_work(p, work, success);
46 }
47 
48 static inline void policy_set_dirty(struct dm_cache_policy *p, dm_cblock_t cblock)
49 {
50 	p->set_dirty(p, cblock);
51 }
52 
53 static inline void policy_clear_dirty(struct dm_cache_policy *p, dm_cblock_t cblock)
54 {
55 	p->clear_dirty(p, cblock);
56 }
57 
58 static inline int policy_load_mapping(struct dm_cache_policy *p,
59 				      dm_oblock_t oblock, dm_cblock_t cblock,
60 				      bool dirty, uint32_t hint, bool hint_valid)
61 {
62 	return p->load_mapping(p, oblock, cblock, dirty, hint, hint_valid);
63 }
64 
65 static inline int policy_invalidate_mapping(struct dm_cache_policy *p,
66 					    dm_cblock_t cblock)
67 {
68 	return p->invalidate_mapping(p, cblock);
69 }
70 
71 static inline uint32_t policy_get_hint(struct dm_cache_policy *p,
72 				       dm_cblock_t cblock)
73 {
74 	return p->get_hint ? p->get_hint(p, cblock) : 0;
75 }
76 
77 static inline dm_cblock_t policy_residency(struct dm_cache_policy *p)
78 {
79 	return p->residency(p);
80 }
81 
82 static inline void policy_tick(struct dm_cache_policy *p, bool can_block)
83 {
84 	if (p->tick)
85 		return p->tick(p, can_block);
86 }
87 
88 static inline int policy_emit_config_values(struct dm_cache_policy *p, char *result,
89 					    unsigned int maxlen, ssize_t *sz_ptr)
90 {
91 	ssize_t sz = *sz_ptr;
92 
93 	if (p->emit_config_values)
94 		return p->emit_config_values(p, result, maxlen, sz_ptr);
95 
96 	DMEMIT("0 ");
97 	*sz_ptr = sz;
98 	return 0;
99 }
100 
101 static inline int policy_set_config_value(struct dm_cache_policy *p,
102 					  const char *key, const char *value)
103 {
104 	return p->set_config_value ? p->set_config_value(p, key, value) : -EINVAL;
105 }
106 
107 static inline void policy_allow_migrations(struct dm_cache_policy *p, bool allow)
108 {
109 	return p->allow_migrations(p, allow);
110 }
111 
112 /*----------------------------------------------------------------*/
113 
114 /*
115  * Some utility functions commonly used by policies and the core target.
116  */
117 static inline size_t bitset_size_in_bytes(unsigned int nr_entries)
118 {
119 	return sizeof(unsigned long) * dm_div_up(nr_entries, BITS_PER_LONG);
120 }
121 
122 static inline unsigned long *alloc_bitset(unsigned int nr_entries)
123 {
124 	size_t s = bitset_size_in_bytes(nr_entries);
125 
126 	return vzalloc(s);
127 }
128 
129 static inline void clear_bitset(void *bitset, unsigned int nr_entries)
130 {
131 	size_t s = bitset_size_in_bytes(nr_entries);
132 
133 	memset(bitset, 0, s);
134 }
135 
136 static inline void free_bitset(unsigned long *bits)
137 {
138 	vfree(bits);
139 }
140 
141 /*----------------------------------------------------------------*/
142 
143 /*
144  * Creates a new cache policy given a policy name, a cache size, an origin size and the block size.
145  */
146 struct dm_cache_policy *dm_cache_policy_create(const char *name, dm_cblock_t cache_size,
147 					       sector_t origin_size, sector_t block_size);
148 
149 /*
150  * Destroys the policy.  This drops references to the policy module as well
151  * as calling it's destroy method.  So always use this rather than calling
152  * the policy->destroy method directly.
153  */
154 void dm_cache_policy_destroy(struct dm_cache_policy *p);
155 
156 /*
157  * In case we've forgotten.
158  */
159 const char *dm_cache_policy_get_name(struct dm_cache_policy *p);
160 
161 const unsigned int *dm_cache_policy_get_version(struct dm_cache_policy *p);
162 
163 size_t dm_cache_policy_get_hint_size(struct dm_cache_policy *p);
164 
165 /*----------------------------------------------------------------*/
166 
167 #endif /* DM_CACHE_POLICY_INTERNAL_H */
168