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	blk_status_t error;
20	bool fake_timeout;
21	struct nullb_queue *nq;
22	struct hrtimer timer;
23};
24
25struct nullb_queue {
26	struct nullb_device *dev;
27	unsigned int requeue_selection;
28
29	struct list_head poll_list;
30	spinlock_t poll_lock;
31};
32
33struct nullb_zone {
34	/*
35	 * Zone lock to prevent concurrent modification of a zone write
36	 * pointer position and condition: with memory backing, a write
37	 * command execution may sleep on memory allocation. For this case,
38	 * use mutex as the zone lock. Otherwise, use the spinlock for
39	 * locking the zone.
40	 */
41	union {
42		spinlock_t spinlock;
43		struct mutex mutex;
44	};
45	enum blk_zone_type type;
46	enum blk_zone_cond cond;
47	sector_t start;
48	sector_t wp;
49	unsigned int len;
50	unsigned int capacity;
51};
52
53struct nullb_device {
54	struct nullb *nullb;
55	struct config_group group;
56#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
57	struct fault_config timeout_config;
58	struct fault_config requeue_config;
59	struct fault_config init_hctx_fault_config;
60#endif
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 prev_submit_queues; /* number of submission queues before change */
87	unsigned int poll_queues; /* number of IOPOLL submission queues */
88	unsigned int prev_poll_queues; /* number of IOPOLL submission queues before change */
89	unsigned int home_node; /* home node for the device */
90	unsigned int queue_mode; /* block interface */
91	unsigned int blocksize; /* block size */
92	unsigned int max_sectors; /* Max sectors per command */
93	unsigned int irqmode; /* IRQ completion handler */
94	unsigned int hw_queue_depth; /* queue depth */
95	unsigned int index; /* index of the disk, only valid with a disk */
96	unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
97	bool blocking; /* blocking blk-mq device */
98	bool use_per_node_hctx; /* use per-node allocation for hardware context */
99	bool power; /* power on/off the device */
100	bool memory_backed; /* if data is stored in memory */
101	bool discard; /* if support discard */
102	bool zoned; /* if device is zoned */
103	bool virt_boundary; /* virtual boundary on/off for the device */
104	bool no_sched; /* no IO scheduler for the device */
105	bool shared_tags; /* share tag set between devices for blk-mq */
106	bool shared_tag_bitmap; /* use hostwide shared tags */
107};
108
109struct nullb {
110	struct nullb_device *dev;
111	struct list_head list;
112	unsigned int index;
113	struct request_queue *q;
114	struct gendisk *disk;
115	struct blk_mq_tag_set *tag_set;
116	struct blk_mq_tag_set __tag_set;
117	atomic_long_t cur_bytes;
118	struct hrtimer bw_timer;
119	unsigned long cache_flush_pos;
120	spinlock_t lock;
121
122	struct nullb_queue *queues;
123	char disk_name[DISK_NAME_LEN];
124};
125
126blk_status_t null_handle_discard(struct nullb_device *dev, sector_t sector,
127				 sector_t nr_sectors);
128blk_status_t null_process_cmd(struct nullb_cmd *cmd, enum req_op op,
129			      sector_t sector, unsigned int nr_sectors);
130
131#ifdef CONFIG_BLK_DEV_ZONED
132int null_init_zoned_dev(struct nullb_device *dev, struct queue_limits *lim);
133int null_register_zoned_dev(struct nullb *nullb);
134void null_free_zoned_dev(struct nullb_device *dev);
135int null_report_zones(struct gendisk *disk, sector_t sector,
136		      unsigned int nr_zones, report_zones_cb cb, void *data);
137blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_op op,
138				    sector_t sector, sector_t nr_sectors);
139size_t null_zone_valid_read_len(struct nullb *nullb,
140				sector_t sector, unsigned int len);
141ssize_t zone_cond_store(struct nullb_device *dev, const char *page,
142			size_t count, enum blk_zone_cond cond);
143#else
144static inline int null_init_zoned_dev(struct nullb_device *dev,
145		struct queue_limits *lim)
146{
147	pr_err("CONFIG_BLK_DEV_ZONED not enabled\n");
148	return -EINVAL;
149}
150static inline int null_register_zoned_dev(struct nullb *nullb)
151{
152	return -ENODEV;
153}
154static inline void null_free_zoned_dev(struct nullb_device *dev) {}
155static inline blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
156			enum req_op op, sector_t sector, sector_t nr_sectors)
157{
158	return BLK_STS_NOTSUPP;
159}
160static inline size_t null_zone_valid_read_len(struct nullb *nullb,
161					      sector_t sector,
162					      unsigned int len)
163{
164	return len;
165}
166static inline ssize_t zone_cond_store(struct nullb_device *dev,
167				      const char *page, size_t count,
168				      enum blk_zone_cond cond)
169{
170	return -EOPNOTSUPP;
171}
172#define null_report_zones	NULL
173#endif /* CONFIG_BLK_DEV_ZONED */
174#endif /* __NULL_BLK_H */
175