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
 16struct nullb_cmd {
 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
 25struct 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
 35struct 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 long zone_capacity; /* zone capacity in MB if device is zoned */
 53	unsigned int zone_nr_conv; /* number of conventional zones */
 54	unsigned int submit_queues; /* number of submission queues */
 55	unsigned int home_node; /* home node for the device */
 56	unsigned int queue_mode; /* block interface */
 57	unsigned int blocksize; /* block size */
 58	unsigned int irqmode; /* IRQ completion handler */
 59	unsigned int hw_queue_depth; /* queue depth */
 60	unsigned int index; /* index of the disk, only valid with a disk */
 61	unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
 62	bool blocking; /* blocking blk-mq device */
 63	bool use_per_node_hctx; /* use per-node allocation for hardware context */
 64	bool power; /* power on/off the device */
 65	bool memory_backed; /* if data is stored in memory */
 66	bool discard; /* if support discard */
 67	bool zoned; /* if device is zoned */
 68};
 69
 70struct nullb {
 71	struct nullb_device *dev;
 72	struct list_head list;
 73	unsigned int index;
 74	struct request_queue *q;
 75	struct gendisk *disk;
 76	struct blk_mq_tag_set *tag_set;
 77	struct blk_mq_tag_set __tag_set;
 78	unsigned int queue_depth;
 79	atomic_long_t cur_bytes;
 80	struct hrtimer bw_timer;
 81	unsigned long cache_flush_pos;
 82	spinlock_t lock;
 83
 84	struct nullb_queue *queues;
 85	unsigned int nr_queues;
 86	char disk_name[DISK_NAME_LEN];
 87};
 88
 89blk_status_t null_process_cmd(struct nullb_cmd *cmd,
 90			      enum req_opf op, sector_t sector,
 91			      unsigned int nr_sectors);
 92
 93#ifdef CONFIG_BLK_DEV_ZONED
 94int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q);
 95int null_register_zoned_dev(struct nullb *nullb);
 96void null_free_zoned_dev(struct nullb_device *dev);
 97int null_report_zones(struct gendisk *disk, sector_t sector,
 98		      unsigned int nr_zones, report_zones_cb cb, void *data);
 99blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
100				    enum req_opf op, sector_t sector,
101				    sector_t nr_sectors);
102size_t null_zone_valid_read_len(struct nullb *nullb,
103				sector_t sector, unsigned int len);
104#else
105static inline int null_init_zoned_dev(struct nullb_device *dev,
106				      struct request_queue *q)
107{
108	pr_err("CONFIG_BLK_DEV_ZONED not enabled\n");
109	return -EINVAL;
110}
111static inline int null_register_zoned_dev(struct nullb *nullb)
112{
113	return -ENODEV;
114}
115static inline void null_free_zoned_dev(struct nullb_device *dev) {}
116static inline blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
117			enum req_opf op, sector_t sector, sector_t nr_sectors)
118{
119	return BLK_STS_NOTSUPP;
120}
121static inline size_t null_zone_valid_read_len(struct nullb *nullb,
122					      sector_t sector,
123					      unsigned int len)
124{
125	return len;
126}
127#define null_report_zones	NULL
128#endif /* CONFIG_BLK_DEV_ZONED */
129#endif /* __NULL_BLK_H */