[linux-block.git] / drivers / block / null_blk.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __BLK_NULL_BLK_H
#define __BLK_NULL_BLK_H

#undef pr_fmt
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/blk-mq.h>
#include <linux/hrtimer.h>
#include <linux/configfs.h>
#include <linux/badblocks.h>
#include <linux/fault-inject.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>

struct nullb_cmd {
	struct request *rq;
	struct bio *bio;
	unsigned int tag;
	blk_status_t error;
	struct nullb_queue *nq;
	struct hrtimer timer;
};

struct nullb_queue {
	unsigned long *tag_map;
	wait_queue_head_t wait;
	unsigned int queue_depth;
	struct nullb_device *dev;
	unsigned int requeue_selection;

	struct nullb_cmd *cmds;
};

struct nullb_zone {
	/*
	 * Zone lock to prevent concurrent modification of a zone write
	 * pointer position and condition: with memory backing, a write
	 * command execution may sleep on memory allocation. For this case,
	 * use mutex as the zone lock. Otherwise, use the spinlock for
	 * locking the zone.
	 */
	union {
		spinlock_t spinlock;
		struct mutex mutex;
	};
	enum blk_zone_type type;
	enum blk_zone_cond cond;
	sector_t start;
	sector_t wp;
	unsigned int len;
	unsigned int capacity;
};

struct nullb_device {
	struct nullb *nullb;
	struct config_item item;
	struct radix_tree_root data; /* data stored in the disk */
	struct radix_tree_root cache; /* disk cache data */
	unsigned long flags; /* device flags */
	unsigned int curr_cache;
	struct badblocks badblocks;

	unsigned int nr_zones;
	unsigned int nr_zones_imp_open;
	unsigned int nr_zones_exp_open;
	unsigned int nr_zones_closed;
	unsigned int imp_close_zone_no;
	struct nullb_zone *zones;
	sector_t zone_size_sects;
	bool need_zone_res_mgmt;
	spinlock_t zone_res_lock;

	unsigned long size; /* device size in MB */
	unsigned long completion_nsec; /* time in ns to complete a request */
	unsigned long cache_size; /* disk cache size in MB */
	unsigned long zone_size; /* zone size in MB if device is zoned */
	unsigned long zone_capacity; /* zone capacity in MB if device is zoned */
	unsigned int zone_nr_conv; /* number of conventional zones */
	unsigned int zone_max_open; /* max number of open zones */
	unsigned int zone_max_active; /* max number of active zones */
	unsigned int submit_queues; /* number of submission queues */
	unsigned int home_node; /* home node for the device */
	unsigned int queue_mode; /* block interface */
	unsigned int blocksize; /* block size */
	unsigned int max_sectors; /* Max sectors per command */
	unsigned int irqmode; /* IRQ completion handler */
	unsigned int hw_queue_depth; /* queue depth */
	unsigned int index; /* index of the disk, only valid with a disk */
	unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
	bool blocking; /* blocking blk-mq device */
	bool use_per_node_hctx; /* use per-node allocation for hardware context */
	bool power; /* power on/off the device */
	bool memory_backed; /* if data is stored in memory */
	bool discard; /* if support discard */
	bool zoned; /* if device is zoned */
};

struct nullb {
	struct nullb_device *dev;
	struct list_head list;
	unsigned int index;
	struct request_queue *q;
	struct gendisk *disk;
	struct blk_mq_tag_set *tag_set;
	struct blk_mq_tag_set __tag_set;
	unsigned int queue_depth;
	atomic_long_t cur_bytes;
	struct hrtimer bw_timer;
	unsigned long cache_flush_pos;
	spinlock_t lock;

	struct nullb_queue *queues;
	unsigned int nr_queues;
	char disk_name[DISK_NAME_LEN];
};

blk_status_t null_handle_discard(struct nullb_device *dev, sector_t sector,
				 sector_t nr_sectors);
blk_status_t null_process_cmd(struct nullb_cmd *cmd,
			      enum req_opf op, sector_t sector,
			      unsigned int nr_sectors);

#ifdef CONFIG_BLK_DEV_ZONED
int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q);
int null_register_zoned_dev(struct nullb *nullb);
void null_free_zoned_dev(struct nullb_device *dev);
int null_report_zones(struct gendisk *disk, sector_t sector,
		      unsigned int nr_zones, report_zones_cb cb, void *data);
blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
				    enum req_opf op, sector_t sector,
				    sector_t nr_sectors);
size_t null_zone_valid_read_len(struct nullb *nullb,
				sector_t sector, unsigned int len);
#else
static inline int null_init_zoned_dev(struct nullb_device *dev,
				      struct request_queue *q)
{
	pr_err("CONFIG_BLK_DEV_ZONED not enabled\n");
	return -EINVAL;
}
static inline int null_register_zoned_dev(struct nullb *nullb)
{
	return -ENODEV;
}
static inline void null_free_zoned_dev(struct nullb_device *dev) {}
static inline blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
			enum req_opf op, sector_t sector, sector_t nr_sectors)
{
	return BLK_STS_NOTSUPP;
}
static inline size_t null_zone_valid_read_len(struct nullb *nullb,
					      sector_t sector,
					      unsigned int len)
{
	return len;
}
#define null_report_zones	NULL
#endif /* CONFIG_BLK_DEV_ZONED */
#endif /* __NULL_BLK_H */
Commit	Line	Data
6dad38d3 MB	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef __BLK_NULL_BLK_H
	3	#define __BLK_NULL_BLK_H
	4
9c7eddf1 AA	5	#undef pr_fmt
	6	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	7
6dad38d3 MB	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>
2b8b7ed7 DLM	15	#include <linux/spinlock.h>
2b8b7ed7 DLM	16	#include <linux/mutex.h>
6dad38d3 MB	17
6dad38d3 MB	18	struct nullb_cmd {
6dad38d3 MB	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	};
	26
	27	struct nullb_queue {
	28	unsigned long *tag_map;
	29	wait_queue_head_t wait;
	30	unsigned int queue_depth;
	31	struct nullb_device *dev;
	32	unsigned int requeue_selection;
	33
	34	struct nullb_cmd *cmds;
	35	};
	36
2b8b7ed7 DLM	37	struct nullb_zone {
	38	/*
	39	* Zone lock to prevent concurrent modification of a zone write
	40	* pointer position and condition: with memory backing, a write
	41	* command execution may sleep on memory allocation. For this case,
	42	* use mutex as the zone lock. Otherwise, use the spinlock for
	43	* locking the zone.
	44	*/
	45	union {
	46	spinlock_t spinlock;
	47	struct mutex mutex;
	48	};
	49	enum blk_zone_type type;
	50	enum blk_zone_cond cond;
	51	sector_t start;
	52	sector_t wp;
	53	unsigned int len;
	54	unsigned int capacity;
	55	};
	56
6dad38d3 MB	57	struct nullb_device {
	58	struct nullb *nullb;
	59	struct config_item item;
	60	struct radix_tree_root data; /* data stored in the disk */
	61	struct radix_tree_root cache; /* disk cache data */
	62	unsigned long flags; /* device flags */
	63	unsigned int curr_cache;
	64	struct badblocks badblocks;
	65
ca4b2a01	66	unsigned int nr_zones;
dc4d137e NC	67	unsigned int nr_zones_imp_open;
	68	unsigned int nr_zones_exp_open;
	69	unsigned int nr_zones_closed;
2e8c6e0e	70	unsigned int imp_close_zone_no;
2b8b7ed7	71	struct nullb_zone *zones;
ca4b2a01	72	sector_t zone_size_sects;
2b8b7ed7 DLM	73	bool need_zone_res_mgmt;
2b8b7ed7 DLM	74	spinlock_t zone_res_lock;
ca4b2a01	75
6dad38d3 MB	76	unsigned long size; /* device size in MB */
	77	unsigned long completion_nsec; /* time in ns to complete a request */
	78	unsigned long cache_size; /* disk cache size in MB */
ca4b2a01	79	unsigned long zone_size; /* zone size in MB if device is zoned */
089565fb	80	unsigned long zone_capacity; /* zone capacity in MB if device is zoned */
ea2c18e1	81	unsigned int zone_nr_conv; /* number of conventional zones */
dc4d137e NC	82	unsigned int zone_max_open; /* max number of open zones */
dc4d137e NC	83	unsigned int zone_max_active; /* max number of active zones */
6dad38d3 MB	84	unsigned int submit_queues; /* number of submission queues */
	85	unsigned int home_node; /* home node for the device */
	86	unsigned int queue_mode; /* block interface */
	87	unsigned int blocksize; /* block size */
ea17fd35	88	unsigned int max_sectors; /* Max sectors per command */
6dad38d3 MB	89	unsigned int irqmode; /* IRQ completion handler */
	90	unsigned int hw_queue_depth; /* queue depth */
	91	unsigned int index; /* index of the disk, only valid with a disk */
	92	unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
	93	bool blocking; /* blocking blk-mq device */
	94	bool use_per_node_hctx; /* use per-node allocation for hardware context */
	95	bool power; /* power on/off the device */
	96	bool memory_backed; /* if data is stored in memory */
	97	bool discard; /* if support discard */
ca4b2a01	98	bool zoned; /* if device is zoned */
6dad38d3 MB	99	};
	100
	101	struct nullb {
	102	struct nullb_device *dev;
	103	struct list_head list;
	104	unsigned int index;
	105	struct request_queue *q;
	106	struct gendisk *disk;
	107	struct blk_mq_tag_set *tag_set;
	108	struct blk_mq_tag_set __tag_set;
	109	unsigned int queue_depth;
	110	atomic_long_t cur_bytes;
	111	struct hrtimer bw_timer;
	112	unsigned long cache_flush_pos;
	113	spinlock_t lock;
	114
	115	struct nullb_queue *queues;
	116	unsigned int nr_queues;
	117	char disk_name[DISK_NAME_LEN];
	118	};
ca4b2a01	119
0ec4d913 DLM	120	blk_status_t null_handle_discard(struct nullb_device *dev, sector_t sector,
0ec4d913 DLM	121	sector_t nr_sectors);
9dd44c7e DLM	122	blk_status_t null_process_cmd(struct nullb_cmd *cmd,
	123	enum req_opf op, sector_t sector,
	124	unsigned int nr_sectors);
	125
ca4b2a01	126	#ifdef CONFIG_BLK_DEV_ZONED
d205bde7 DLM	127	int null_init_zoned_dev(struct nullb_device dev, struct request_queue q);
	128	int null_register_zoned_dev(struct nullb *nullb);
	129	void null_free_zoned_dev(struct nullb_device *dev);
7fc8fb51	130	int null_report_zones(struct gendisk *disk, sector_t sector,
d4100351	131	unsigned int nr_zones, report_zones_cb cb, void *data);
9dd44c7e DLM	132	blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
	133	enum req_opf op, sector_t sector,
	134	sector_t nr_sectors);
dd85b492 AJ	135	size_t null_zone_valid_read_len(struct nullb *nullb,
dd85b492 AJ	136	sector_t sector, unsigned int len);
ca4b2a01	137	#else
d205bde7 DLM	138	static inline int null_init_zoned_dev(struct nullb_device *dev,
d205bde7 DLM	139	struct request_queue *q)
ca4b2a01	140	{
9c7eddf1	141	pr_err("CONFIG_BLK_DEV_ZONED not enabled\n");
ca4b2a01 MB	142	return -EINVAL;
ca4b2a01 MB	143	}
d205bde7 DLM	144	static inline int null_register_zoned_dev(struct nullb *nullb)
	145	{
	146	return -ENODEV;
	147	}
	148	static inline void null_free_zoned_dev(struct nullb_device *dev) {}
9dd44c7e DLM	149	static inline blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
9dd44c7e DLM	150	enum req_opf op, sector_t sector, sector_t nr_sectors)
b228ba1c	151	{
fceb5d1b	152	return BLK_STS_NOTSUPP;
b228ba1c	153	}
dd85b492 AJ	154	static inline size_t null_zone_valid_read_len(struct nullb *nullb,
	155	sector_t sector,
	156	unsigned int len)
	157	{
	158	return len;
	159	}
7fc8fb51	160	#define null_report_zones NULL
ca4b2a01	161	#endif /* CONFIG_BLK_DEV_ZONED */
6dad38d3	162	#endif /* __NULL_BLK_H */