1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __BLK_NULL_BLK_H
3 #define __BLK_NULL_BLK_H
4 
5 #include <linux/blkdev.h>
6 #include <linux/slab.h>
7 #include <linux/blk-mq.h>
8 #include <linux/hrtimer.h>
9 #include <linux/configfs.h>
10 #include <linux/badblocks.h>
11 #include <linux/fault-inject.h>
12 
13 struct nullb_cmd {
14 	struct list_head list;
15 	struct llist_node ll_list;
16 	struct __call_single_data csd;
17 	struct request *rq;
18 	struct bio *bio;
19 	unsigned int tag;
20 	blk_status_t error;
21 	struct nullb_queue *nq;
22 	struct hrtimer timer;
23 };
24 
25 struct nullb_queue {
26 	unsigned long *tag_map;
27 	wait_queue_head_t wait;
28 	unsigned int queue_depth;
29 	struct nullb_device *dev;
30 	unsigned int requeue_selection;
31 
32 	struct nullb_cmd *cmds;
33 };
34 
35 struct nullb_device {
36 	struct nullb *nullb;
37 	struct config_item item;
38 	struct radix_tree_root data; /* data stored in the disk */
39 	struct radix_tree_root cache; /* disk cache data */
40 	unsigned long flags; /* device flags */
41 	unsigned int curr_cache;
42 	struct badblocks badblocks;
43 
44 	unsigned int nr_zones;
45 	struct blk_zone *zones;
46 	sector_t zone_size_sects;
47 
48 	unsigned long size; /* device size in MB */
49 	unsigned long completion_nsec; /* time in ns to complete a request */
50 	unsigned long cache_size; /* disk cache size in MB */
51 	unsigned long zone_size; /* zone size in MB if device is zoned */
52 	unsigned int submit_queues; /* number of submission queues */
53 	unsigned int home_node; /* home node for the device */
54 	unsigned int queue_mode; /* block interface */
55 	unsigned int blocksize; /* block size */
56 	unsigned int irqmode; /* IRQ completion handler */
57 	unsigned int hw_queue_depth; /* queue depth */
58 	unsigned int index; /* index of the disk, only valid with a disk */
59 	unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
60 	bool blocking; /* blocking blk-mq device */
61 	bool use_per_node_hctx; /* use per-node allocation for hardware context */
62 	bool power; /* power on/off the device */
63 	bool memory_backed; /* if data is stored in memory */
64 	bool discard; /* if support discard */
65 	bool zoned; /* if device is zoned */
66 };
67 
68 struct nullb {
69 	struct nullb_device *dev;
70 	struct list_head list;
71 	unsigned int index;
72 	struct request_queue *q;
73 	struct gendisk *disk;
74 	struct blk_mq_tag_set *tag_set;
75 	struct blk_mq_tag_set __tag_set;
76 	unsigned int queue_depth;
77 	atomic_long_t cur_bytes;
78 	struct hrtimer bw_timer;
79 	unsigned long cache_flush_pos;
80 	spinlock_t lock;
81 
82 	struct nullb_queue *queues;
83 	unsigned int nr_queues;
84 	char disk_name[DISK_NAME_LEN];
85 };
86 
87 #ifdef CONFIG_BLK_DEV_ZONED
88 int null_zone_init(struct nullb_device *dev);
89 void null_zone_exit(struct nullb_device *dev);
90 blk_status_t null_zone_report(struct nullb *nullb, struct bio *bio);
91 void null_zone_write(struct nullb_cmd *cmd, sector_t sector,
92 			unsigned int nr_sectors);
93 void null_zone_reset(struct nullb_cmd *cmd, sector_t sector);
94 #else
null_zone_init(struct nullb_device * dev)95 static inline int null_zone_init(struct nullb_device *dev)
96 {
97 	return -EINVAL;
98 }
null_zone_exit(struct nullb_device * dev)99 static inline void null_zone_exit(struct nullb_device *dev) {}
null_zone_report(struct nullb * nullb,struct bio * bio)100 static inline blk_status_t null_zone_report(struct nullb *nullb,
101 					    struct bio *bio)
102 {
103 	return BLK_STS_NOTSUPP;
104 }
null_zone_write(struct nullb_cmd * cmd,sector_t sector,unsigned int nr_sectors)105 static inline void null_zone_write(struct nullb_cmd *cmd, sector_t sector,
106 				   unsigned int nr_sectors)
107 {
108 }
null_zone_reset(struct nullb_cmd * cmd,sector_t sector)109 static inline void null_zone_reset(struct nullb_cmd *cmd, sector_t sector) {}
110 #endif /* CONFIG_BLK_DEV_ZONED */
111 #endif /* __NULL_BLK_H */
112