LXR linux/drivers/block/null_blk/null

   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        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        bool fake_timeout;
  26};
  27
  28struct nullb_queue {
  29        unsigned long *tag_map;
  30        wait_queue_head_t wait;
  31        unsigned int queue_depth;
  32        struct nullb_device *dev;
  33        unsigned int requeue_selection;
  34
  35        struct nullb_cmd *cmds;
  36};
  37
  38struct nullb_zone {
  39        /*
  40         * Zone lock to prevent concurrent modification of a zone write
  41         * pointer position and condition: with memory backing, a write
  42         * command execution may sleep on memory allocation. For this case,
  43         * use mutex as the zone lock. Otherwise, use the spinlock for
  44         * locking the zone.
  45         */
  46        union {
  47                spinlock_t spinlock;
  48                struct mutex mutex;
  49        };
  50        enum blk_zone_type type;
  51        enum blk_zone_cond cond;
  52        sector_t start;
  53        sector_t wp;
  54        unsigned int len;
  55        unsigned int capacity;
  56};
  57
  58struct nullb_device {
  59        struct nullb *nullb;
  60        struct config_item item;
  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 home_node; /* home node for the device */
  87        unsigned int queue_mode; /* block interface */
  88        unsigned int blocksize; /* block size */
  89        unsigned int max_sectors; /* Max sectors per command */
  90        unsigned int irqmode; /* IRQ completion handler */
  91        unsigned int hw_queue_depth; /* queue depth */
  92        unsigned int index; /* index of the disk, only valid with a disk */
  93        unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
  94        bool blocking; /* blocking blk-mq device */
  95        bool use_per_node_hctx; /* use per-node allocation for hardware context */
  96        bool power; /* power on/off the device */
  97        bool memory_backed; /* if data is stored in memory */
  98        bool discard; /* if support discard */
  99        bool zoned; /* if device is zoned */
 100        bool virt_boundary; /* virtual boundary on/off for the device */
 101};
 102
 103struct nullb {
 104        struct nullb_device *dev;
 105        struct list_head list;
 106        unsigned int index;
 107        struct request_queue *q;
 108        struct gendisk *disk;
 109        struct blk_mq_tag_set *tag_set;
 110        struct blk_mq_tag_set __tag_set;
 111        unsigned int queue_depth;
 112        atomic_long_t cur_bytes;
 113        struct hrtimer bw_timer;
 114        unsigned long cache_flush_pos;
 115        spinlock_t lock;
 116
 117        struct nullb_queue *queues;
 118        unsigned int nr_queues;
 119        char disk_name[DISK_NAME_LEN];
 120};
 121
 122blk_status_t null_handle_discard(struct nullb_device *dev, sector_t sector,
 123                                 sector_t nr_sectors);
 124blk_status_t null_process_cmd(struct nullb_cmd *cmd,
 125                              enum req_opf op, sector_t sector,
 126                              unsigned int nr_sectors);
 127
 128#ifdef CONFIG_BLK_DEV_ZONED
 129int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q);
 130int null_register_zoned_dev(struct nullb *nullb);
 131void null_free_zoned_dev(struct nullb_device *dev);
 132int null_report_zones(struct gendisk *disk, sector_t sector,
 133                      unsigned int nr_zones, report_zones_cb cb, void *data);
 134blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
 135                                    enum req_opf op, sector_t sector,
 136                                    sector_t nr_sectors);
 137size_t null_zone_valid_read_len(struct nullb *nullb,
 138                                sector_t sector, unsigned int len);
 139#else
 140static inline int null_init_zoned_dev(struct nullb_device *dev,
 141                                      struct request_queue *q)
 142{
 143        pr_err("CONFIG_BLK_DEV_ZONED not enabled\n");
 144        return -EINVAL;
 145}
 146static inline int null_register_zoned_dev(struct nullb *nullb)
 147{
 148        return -ENODEV;
 149}
 150static inline void null_free_zoned_dev(struct nullb_device *dev) {}
 151static inline blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
 152                        enum req_opf op, sector_t sector, sector_t nr_sectors)
 153{
 154        return BLK_STS_NOTSUPP;
 155}
 156static inline size_t null_zone_valid_read_len(struct nullb *nullb,
 157                                              sector_t sector,
 158                                              unsigned int len)
 159{
 160        return len;
 161}
 162#define null_report_zones       NULL
 163#endif /* CONFIG_BLK_DEV_ZONED */
 164#endif /* __NULL_BLK_H */
 165