xref: /openbmc/linux/drivers/md/dm-zoned.h (revision 5e012745)
1 /*
2  * Copyright (C) 2017 Western Digital Corporation or its affiliates.
3  *
4  * This file is released under the GPL.
5  */
6 
7 #ifndef DM_ZONED_H
8 #define DM_ZONED_H
9 
10 #include <linux/types.h>
11 #include <linux/blkdev.h>
12 #include <linux/device-mapper.h>
13 #include <linux/dm-kcopyd.h>
14 #include <linux/list.h>
15 #include <linux/spinlock.h>
16 #include <linux/mutex.h>
17 #include <linux/workqueue.h>
18 #include <linux/rwsem.h>
19 #include <linux/rbtree.h>
20 #include <linux/radix-tree.h>
21 #include <linux/shrinker.h>
22 
23 /*
24  * dm-zoned creates block devices with 4KB blocks, always.
25  */
26 #define DMZ_BLOCK_SHIFT		12
27 #define DMZ_BLOCK_SIZE		(1 << DMZ_BLOCK_SHIFT)
28 #define DMZ_BLOCK_MASK		(DMZ_BLOCK_SIZE - 1)
29 
30 #define DMZ_BLOCK_SHIFT_BITS	(DMZ_BLOCK_SHIFT + 3)
31 #define DMZ_BLOCK_SIZE_BITS	(1 << DMZ_BLOCK_SHIFT_BITS)
32 #define DMZ_BLOCK_MASK_BITS	(DMZ_BLOCK_SIZE_BITS - 1)
33 
34 #define DMZ_BLOCK_SECTORS_SHIFT	(DMZ_BLOCK_SHIFT - SECTOR_SHIFT)
35 #define DMZ_BLOCK_SECTORS	(DMZ_BLOCK_SIZE >> SECTOR_SHIFT)
36 #define DMZ_BLOCK_SECTORS_MASK	(DMZ_BLOCK_SECTORS - 1)
37 
38 /*
39  * 4KB block <-> 512B sector conversion.
40  */
41 #define dmz_blk2sect(b)		((sector_t)(b) << DMZ_BLOCK_SECTORS_SHIFT)
42 #define dmz_sect2blk(s)		((sector_t)(s) >> DMZ_BLOCK_SECTORS_SHIFT)
43 
44 #define dmz_bio_block(bio)	dmz_sect2blk((bio)->bi_iter.bi_sector)
45 #define dmz_bio_blocks(bio)	dmz_sect2blk(bio_sectors(bio))
46 
47 /*
48  * Zoned block device information.
49  */
50 struct dmz_dev {
51 	struct block_device	*bdev;
52 
53 	char			name[BDEVNAME_SIZE];
54 
55 	sector_t		capacity;
56 
57 	unsigned int		nr_zones;
58 
59 	sector_t		zone_nr_sectors;
60 	unsigned int		zone_nr_sectors_shift;
61 
62 	sector_t		zone_nr_blocks;
63 	sector_t		zone_nr_blocks_shift;
64 };
65 
66 #define dmz_bio_chunk(dev, bio)	((bio)->bi_iter.bi_sector >> \
67 				 (dev)->zone_nr_sectors_shift)
68 #define dmz_chunk_block(dev, b)	((b) & ((dev)->zone_nr_blocks - 1))
69 
70 /*
71  * Zone descriptor.
72  */
73 struct dm_zone {
74 	/* For listing the zone depending on its state */
75 	struct list_head	link;
76 
77 	/* Zone type and state */
78 	unsigned long		flags;
79 
80 	/* Zone activation reference count */
81 	atomic_t		refcount;
82 
83 	/* Zone write pointer block (relative to the zone start block) */
84 	unsigned int		wp_block;
85 
86 	/* Zone weight (number of valid blocks in the zone) */
87 	unsigned int		weight;
88 
89 	/* The chunk that the zone maps */
90 	unsigned int		chunk;
91 
92 	/*
93 	 * For a sequential data zone, pointer to the random zone
94 	 * used as a buffer for processing unaligned writes.
95 	 * For a buffer zone, this points back to the data zone.
96 	 */
97 	struct dm_zone		*bzone;
98 };
99 
100 /*
101  * Zone flags.
102  */
103 enum {
104 	/* Zone write type */
105 	DMZ_RND,
106 	DMZ_SEQ,
107 
108 	/* Zone critical condition */
109 	DMZ_OFFLINE,
110 	DMZ_READ_ONLY,
111 
112 	/* How the zone is being used */
113 	DMZ_META,
114 	DMZ_DATA,
115 	DMZ_BUF,
116 
117 	/* Zone internal state */
118 	DMZ_RECLAIM,
119 	DMZ_SEQ_WRITE_ERR,
120 };
121 
122 /*
123  * Zone data accessors.
124  */
125 #define dmz_is_rnd(z)		test_bit(DMZ_RND, &(z)->flags)
126 #define dmz_is_seq(z)		test_bit(DMZ_SEQ, &(z)->flags)
127 #define dmz_is_empty(z)		((z)->wp_block == 0)
128 #define dmz_is_offline(z)	test_bit(DMZ_OFFLINE, &(z)->flags)
129 #define dmz_is_readonly(z)	test_bit(DMZ_READ_ONLY, &(z)->flags)
130 #define dmz_in_reclaim(z)	test_bit(DMZ_RECLAIM, &(z)->flags)
131 #define dmz_seq_write_err(z)	test_bit(DMZ_SEQ_WRITE_ERR, &(z)->flags)
132 
133 #define dmz_is_meta(z)		test_bit(DMZ_META, &(z)->flags)
134 #define dmz_is_buf(z)		test_bit(DMZ_BUF, &(z)->flags)
135 #define dmz_is_data(z)		test_bit(DMZ_DATA, &(z)->flags)
136 
137 #define dmz_weight(z)		((z)->weight)
138 
139 /*
140  * Message functions.
141  */
142 #define dmz_dev_info(dev, format, args...)	\
143 	DMINFO("(%s): " format, (dev)->name, ## args)
144 
145 #define dmz_dev_err(dev, format, args...)	\
146 	DMERR("(%s): " format, (dev)->name, ## args)
147 
148 #define dmz_dev_warn(dev, format, args...)	\
149 	DMWARN("(%s): " format, (dev)->name, ## args)
150 
151 #define dmz_dev_debug(dev, format, args...)	\
152 	DMDEBUG("(%s): " format, (dev)->name, ## args)
153 
154 struct dmz_metadata;
155 struct dmz_reclaim;
156 
157 /*
158  * Functions defined in dm-zoned-metadata.c
159  */
160 int dmz_ctr_metadata(struct dmz_dev *dev, struct dmz_metadata **zmd);
161 void dmz_dtr_metadata(struct dmz_metadata *zmd);
162 int dmz_resume_metadata(struct dmz_metadata *zmd);
163 
164 void dmz_lock_map(struct dmz_metadata *zmd);
165 void dmz_unlock_map(struct dmz_metadata *zmd);
166 void dmz_lock_metadata(struct dmz_metadata *zmd);
167 void dmz_unlock_metadata(struct dmz_metadata *zmd);
168 void dmz_lock_flush(struct dmz_metadata *zmd);
169 void dmz_unlock_flush(struct dmz_metadata *zmd);
170 int dmz_flush_metadata(struct dmz_metadata *zmd);
171 
172 unsigned int dmz_id(struct dmz_metadata *zmd, struct dm_zone *zone);
173 sector_t dmz_start_sect(struct dmz_metadata *zmd, struct dm_zone *zone);
174 sector_t dmz_start_block(struct dmz_metadata *zmd, struct dm_zone *zone);
175 unsigned int dmz_nr_chunks(struct dmz_metadata *zmd);
176 
177 #define DMZ_ALLOC_RND		0x01
178 #define DMZ_ALLOC_RECLAIM	0x02
179 
180 struct dm_zone *dmz_alloc_zone(struct dmz_metadata *zmd, unsigned long flags);
181 void dmz_free_zone(struct dmz_metadata *zmd, struct dm_zone *zone);
182 
183 void dmz_map_zone(struct dmz_metadata *zmd, struct dm_zone *zone,
184 		  unsigned int chunk);
185 void dmz_unmap_zone(struct dmz_metadata *zmd, struct dm_zone *zone);
186 unsigned int dmz_nr_rnd_zones(struct dmz_metadata *zmd);
187 unsigned int dmz_nr_unmap_rnd_zones(struct dmz_metadata *zmd);
188 
189 /*
190  * Activate a zone (increment its reference count).
191  */
192 static inline void dmz_activate_zone(struct dm_zone *zone)
193 {
194 	atomic_inc(&zone->refcount);
195 }
196 
197 /*
198  * Deactivate a zone. This decrement the zone reference counter
199  * indicating that all BIOs to the zone have completed when the count is 0.
200  */
201 static inline void dmz_deactivate_zone(struct dm_zone *zone)
202 {
203 	atomic_dec(&zone->refcount);
204 }
205 
206 /*
207  * Test if a zone is active, that is, has a refcount > 0.
208  */
209 static inline bool dmz_is_active(struct dm_zone *zone)
210 {
211 	return atomic_read(&zone->refcount);
212 }
213 
214 int dmz_lock_zone_reclaim(struct dm_zone *zone);
215 void dmz_unlock_zone_reclaim(struct dm_zone *zone);
216 struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd);
217 
218 struct dm_zone *dmz_get_chunk_mapping(struct dmz_metadata *zmd,
219 				      unsigned int chunk, int op);
220 void dmz_put_chunk_mapping(struct dmz_metadata *zmd, struct dm_zone *zone);
221 struct dm_zone *dmz_get_chunk_buffer(struct dmz_metadata *zmd,
222 				     struct dm_zone *dzone);
223 
224 int dmz_validate_blocks(struct dmz_metadata *zmd, struct dm_zone *zone,
225 			sector_t chunk_block, unsigned int nr_blocks);
226 int dmz_invalidate_blocks(struct dmz_metadata *zmd, struct dm_zone *zone,
227 			  sector_t chunk_block, unsigned int nr_blocks);
228 int dmz_block_valid(struct dmz_metadata *zmd, struct dm_zone *zone,
229 		    sector_t chunk_block);
230 int dmz_first_valid_block(struct dmz_metadata *zmd, struct dm_zone *zone,
231 			  sector_t *chunk_block);
232 int dmz_copy_valid_blocks(struct dmz_metadata *zmd, struct dm_zone *from_zone,
233 			  struct dm_zone *to_zone);
234 int dmz_merge_valid_blocks(struct dmz_metadata *zmd, struct dm_zone *from_zone,
235 			   struct dm_zone *to_zone, sector_t chunk_block);
236 
237 /*
238  * Functions defined in dm-zoned-reclaim.c
239  */
240 int dmz_ctr_reclaim(struct dmz_dev *dev, struct dmz_metadata *zmd,
241 		    struct dmz_reclaim **zrc);
242 void dmz_dtr_reclaim(struct dmz_reclaim *zrc);
243 void dmz_suspend_reclaim(struct dmz_reclaim *zrc);
244 void dmz_resume_reclaim(struct dmz_reclaim *zrc);
245 void dmz_reclaim_bio_acc(struct dmz_reclaim *zrc);
246 void dmz_schedule_reclaim(struct dmz_reclaim *zrc);
247 
248 #endif /* DM_ZONED_H */
249