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
18struct nullb_cmd {
19	union {
20		struct request *rq;
21		struct bio *bio;
22	};
23	unsigned int tag;
24	blk_status_t error;
25	bool fake_timeout;
26	struct nullb_queue *nq;
27	struct hrtimer timer;
28};
29
30struct nullb_queue {
31	unsigned long *tag_map;
32	wait_queue_head_t wait;
33	unsigned int queue_depth;
34	struct nullb_device *dev;
35	unsigned int requeue_selection;
36
37	struct list_head poll_list;
38	spinlock_t poll_lock;
39
40	struct nullb_cmd *cmds;
41};
42
43struct nullb_zone {
44	/*
45	 * Zone lock to prevent concurrent modification of a zone write
46	 * pointer position and condition: with memory backing, a write
47	 * command execution may sleep on memory allocation. For this case,
48	 * use mutex as the zone lock. Otherwise, use the spinlock for
49	 * locking the zone.
50	 */
51	union {
52		spinlock_t spinlock;
53		struct mutex mutex;
54	};
55	enum blk_zone_type type;
56	enum blk_zone_cond cond;
57	sector_t start;
58	sector_t wp;
59	unsigned int len;
60	unsigned int capacity;
61};
62
63/* Queue modes */
64enum {
65	NULL_Q_BIO	= 0,
66	NULL_Q_RQ	= 1,
67	NULL_Q_MQ	= 2,
68};
69
70struct nullb_device {
71	struct nullb *nullb;
72	struct config_group group;
73#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
74	struct fault_config timeout_config;
75	struct fault_config requeue_config;
76	struct fault_config init_hctx_fault_config;
77#endif
78	struct radix_tree_root data; /* data stored in the disk */
79	struct radix_tree_root cache; /* disk cache data */
80	unsigned long flags; /* device flags */
81	unsigned int curr_cache;
82	struct badblocks badblocks;
83
84	unsigned int nr_zones;
85	unsigned int nr_zones_imp_open;
86	unsigned int nr_zones_exp_open;
87	unsigned int nr_zones_closed;
88	unsigned int imp_close_zone_no;
89	struct nullb_zone *zones;
90	sector_t zone_size_sects;
91	bool need_zone_res_mgmt;
92	spinlock_t zone_res_lock;
93
94	unsigned long size; /* device size in MB */
95	unsigned long completion_nsec; /* time in ns to complete a request */
96	unsigned long cache_size; /* disk cache size in MB */
97	unsigned long zone_size; /* zone size in MB if device is zoned */
98	unsigned long zone_capacity; /* zone capacity in MB if device is zoned */
99	unsigned int zone_nr_conv; /* number of conventional zones */
100	unsigned int zone_max_open; /* max number of open zones */
101	unsigned int zone_max_active; /* max number of active zones */
102	unsigned int submit_queues; /* number of submission queues */
103	unsigned int prev_submit_queues; /* number of submission queues before change */
104	unsigned int poll_queues; /* number of IOPOLL submission queues */
105	unsigned int prev_poll_queues; /* number of IOPOLL submission queues before change */
106	unsigned int home_node; /* home node for the device */
107	unsigned int queue_mode; /* block interface */
108	unsigned int blocksize; /* block size */
109	unsigned int max_sectors; /* Max sectors per command */
110	unsigned int irqmode; /* IRQ completion handler */
111	unsigned int hw_queue_depth; /* queue depth */
112	unsigned int index; /* index of the disk, only valid with a disk */
113	unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
114	bool blocking; /* blocking blk-mq device */
115	bool use_per_node_hctx; /* use per-node allocation for hardware context */
116	bool power; /* power on/off the device */
117	bool memory_backed; /* if data is stored in memory */
118	bool discard; /* if support discard */
119	bool zoned; /* if device is zoned */
120	bool virt_boundary; /* virtual boundary on/off for the device */
121	bool no_sched; /* no IO scheduler for the device */
122	bool shared_tag_bitmap; /* use hostwide shared tags */
123};
124
125struct nullb {
126	struct nullb_device *dev;
127	struct list_head list;
128	unsigned int index;
129	struct request_queue *q;
130	struct gendisk *disk;
131	struct blk_mq_tag_set *tag_set;
132	struct blk_mq_tag_set __tag_set;
133	unsigned int queue_depth;
134	atomic_long_t cur_bytes;
135	struct hrtimer bw_timer;
136	unsigned long cache_flush_pos;
137	spinlock_t lock;
138
139	struct nullb_queue *queues;
140	unsigned int nr_queues;
141	char disk_name[DISK_NAME_LEN];
142};
143
144blk_status_t null_handle_discard(struct nullb_device *dev, sector_t sector,
145				 sector_t nr_sectors);
146blk_status_t null_process_cmd(struct nullb_cmd *cmd, enum req_op op,
147			      sector_t sector, unsigned int nr_sectors);
148
149#ifdef CONFIG_BLK_DEV_ZONED
150int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q);
151int null_register_zoned_dev(struct nullb *nullb);
152void null_free_zoned_dev(struct nullb_device *dev);
153int null_report_zones(struct gendisk *disk, sector_t sector,
154		      unsigned int nr_zones, report_zones_cb cb, void *data);
155blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_op op,
156				    sector_t sector, sector_t nr_sectors);
157size_t null_zone_valid_read_len(struct nullb *nullb,
158				sector_t sector, unsigned int len);
159ssize_t zone_cond_store(struct nullb_device *dev, const char *page,
160			size_t count, enum blk_zone_cond cond);
161#else
162static inline int null_init_zoned_dev(struct nullb_device *dev,
163				      struct request_queue *q)
164{
165	pr_err("CONFIG_BLK_DEV_ZONED not enabled\n");
166	return -EINVAL;
167}
168static inline int null_register_zoned_dev(struct nullb *nullb)
169{
170	return -ENODEV;
171}
172static inline void null_free_zoned_dev(struct nullb_device *dev) {}
173static inline blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
174			enum req_op op, sector_t sector, sector_t nr_sectors)
175{
176	return BLK_STS_NOTSUPP;
177}
178static inline size_t null_zone_valid_read_len(struct nullb *nullb,
179					      sector_t sector,
180					      unsigned int len)
181{
182	return len;
183}
184static inline ssize_t zone_cond_store(struct nullb_device *dev,
185				      const char *page, size_t count,
186				      enum blk_zone_cond cond)
187{
188	return -EOPNOTSUPP;
189}
190#define null_report_zones	NULL
191#endif /* CONFIG_BLK_DEV_ZONED */
192#endif /* __NULL_BLK_H */
193