1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __BLK_NULL_BLK_H
3 #define __BLK_NULL_BLK_H
4
5 #undef pr_fmt
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8 #include <linux/blkdev.h>
9 #include <linux/slab.h>
10 #include <linux/blk-mq.h>
11 #include <linux/hrtimer.h>
12 #include <linux/configfs.h>
13 #include <linux/badblocks.h>
14 #include <linux/fault-inject.h>
15 #include <linux/spinlock.h>
16 #include <linux/mutex.h>
17
18 struct nullb_cmd {
19 struct request *rq;
20 struct bio *bio;
21 unsigned int tag;
22 blk_status_t error;
23 struct nullb_queue *nq;
24 struct hrtimer timer;
25 bool fake_timeout;
26 };
27
28 struct nullb_queue {
29 unsigned long *tag_map;
30 wait_queue_head_t wait;
31 unsigned int queue_depth;
32 struct nullb_device *dev;
33 unsigned int requeue_selection;
34
35 struct nullb_cmd *cmds;
36 };
37
38 struct nullb_zone {
39 /*
40 * Zone lock to prevent concurrent modification of a zone write
41 * pointer position and condition: with memory backing, a write
42 * command execution may sleep on memory allocation. For this case,
43 * use mutex as the zone lock. Otherwise, use the spinlock for
44 * locking the zone.
45 */
46 union {
47 spinlock_t spinlock;
48 struct mutex mutex;
49 };
50 enum blk_zone_type type;
51 enum blk_zone_cond cond;
52 sector_t start;
53 sector_t wp;
54 unsigned int len;
55 unsigned int capacity;
56 };
57
58 struct nullb_device {
59 struct nullb *nullb;
60 struct config_item item;
61 struct radix_tree_root data; /* data stored in the disk */
62 struct radix_tree_root cache; /* disk cache data */
63 unsigned long flags; /* device flags */
64 unsigned int curr_cache;
65 struct badblocks badblocks;
66
67 unsigned int nr_zones;
68 unsigned int nr_zones_imp_open;
69 unsigned int nr_zones_exp_open;
70 unsigned int nr_zones_closed;
71 unsigned int imp_close_zone_no;
72 struct nullb_zone *zones;
73 sector_t zone_size_sects;
74 bool need_zone_res_mgmt;
75 spinlock_t zone_res_lock;
76
77 unsigned long size; /* device size in MB */
78 unsigned long completion_nsec; /* time in ns to complete a request */
79 unsigned long cache_size; /* disk cache size in MB */
80 unsigned long zone_size; /* zone size in MB if device is zoned */
81 unsigned long zone_capacity; /* zone capacity in MB if device is zoned */
82 unsigned int zone_nr_conv; /* number of conventional zones */
83 unsigned int zone_max_open; /* max number of open zones */
84 unsigned int zone_max_active; /* max number of active zones */
85 unsigned int submit_queues; /* number of submission queues */
86 unsigned int home_node; /* home node for the device */
87 unsigned int queue_mode; /* block interface */
88 unsigned int blocksize; /* block size */
89 unsigned int max_sectors; /* Max sectors per command */
90 unsigned int irqmode; /* IRQ completion handler */
91 unsigned int hw_queue_depth; /* queue depth */
92 unsigned int index; /* index of the disk, only valid with a disk */
93 unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
94 bool blocking; /* blocking blk-mq device */
95 bool use_per_node_hctx; /* use per-node allocation for hardware context */
96 bool power; /* power on/off the device */
97 bool memory_backed; /* if data is stored in memory */
98 bool discard; /* if support discard */
99 bool zoned; /* if device is zoned */
100 bool virt_boundary; /* virtual boundary on/off for the device */
101 };
102
103 struct nullb {
104 struct nullb_device *dev;
105 struct list_head list;
106 unsigned int index;
107 struct request_queue *q;
108 struct gendisk *disk;
109 struct blk_mq_tag_set *tag_set;
110 struct blk_mq_tag_set __tag_set;
111 unsigned int queue_depth;
112 atomic_long_t cur_bytes;
113 struct hrtimer bw_timer;
114 unsigned long cache_flush_pos;
115 spinlock_t lock;
116
117 struct nullb_queue *queues;
118 unsigned int nr_queues;
119 char disk_name[DISK_NAME_LEN];
120 };
121
122 blk_status_t null_handle_discard(struct nullb_device *dev, sector_t sector,
123 sector_t nr_sectors);
124 blk_status_t null_process_cmd(struct nullb_cmd *cmd,
125 enum req_opf op, sector_t sector,
126 unsigned int nr_sectors);
127
128 #ifdef CONFIG_BLK_DEV_ZONED
129 int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q);
130 int null_register_zoned_dev(struct nullb *nullb);
131 void null_free_zoned_dev(struct nullb_device *dev);
132 int null_report_zones(struct gendisk *disk, sector_t sector,
133 unsigned int nr_zones, report_zones_cb cb, void *data);
134 blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
135 enum req_opf op, sector_t sector,
136 sector_t nr_sectors);
137 size_t null_zone_valid_read_len(struct nullb *nullb,
138 sector_t sector, unsigned int len);
139 #else
null_init_zoned_dev(struct nullb_device * dev,struct request_queue * q)140 static inline int null_init_zoned_dev(struct nullb_device *dev,
141 struct request_queue *q)
142 {
143 pr_err("CONFIG_BLK_DEV_ZONED not enabled\n");
144 return -EINVAL;
145 }
null_register_zoned_dev(struct nullb * nullb)146 static inline int null_register_zoned_dev(struct nullb *nullb)
147 {
148 return -ENODEV;
149 }
null_free_zoned_dev(struct nullb_device * dev)150 static inline void null_free_zoned_dev(struct nullb_device *dev) {}
null_process_zoned_cmd(struct nullb_cmd * cmd,enum req_opf op,sector_t sector,sector_t nr_sectors)151 static inline blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
152 enum req_opf op, sector_t sector, sector_t nr_sectors)
153 {
154 return BLK_STS_NOTSUPP;
155 }
null_zone_valid_read_len(struct nullb * nullb,sector_t sector,unsigned int len)156 static inline size_t null_zone_valid_read_len(struct nullb *nullb,
157 sector_t sector,
158 unsigned int len)
159 {
160 return len;
161 }
162 #define null_report_zones NULL
163 #endif /* CONFIG_BLK_DEV_ZONED */
164 #endif /* __NULL_BLK_H */
165
