drivers/block/null_blk.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __BLK_NULL_BLK_H
   3 #define __BLK_NULL_BLK_H
   4
   5 #include <linux/blkdev.h>
   6 #include <linux/slab.h>
   7 #include <linux/blk-mq.h>
   8 #include <linux/hrtimer.h>
   9 #include <linux/configfs.h>
  10 #include <linux/badblocks.h>
  11 #include <linux/fault-inject.h>
  12
  13 struct nullb_cmd {
  14         struct list_head list;
  15         struct llist_node ll_list;
  16         struct __call_single_data csd;
  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
  25 struct 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
  35 struct 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 int zone_nr_conv; /* number of conventional zones */
  53         unsigned int submit_queues; /* number of submission queues */
  54         unsigned int home_node; /* home node for the device */
  55         unsigned int queue_mode; /* block interface */
  56         unsigned int blocksize; /* block size */
  57         unsigned int irqmode; /* IRQ completion handler */
  58         unsigned int hw_queue_depth; /* queue depth */
  59         unsigned int index; /* index of the disk, only valid with a disk */
  60         unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
  61         bool blocking; /* blocking blk-mq device */
  62         bool use_per_node_hctx; /* use per-node allocation for hardware context */
  63         bool power; /* power on/off the device */
  64         bool memory_backed; /* if data is stored in memory */
  65         bool discard; /* if support discard */
  66         bool zoned; /* if device is zoned */
  67 };
  68
  69 struct nullb {
  70         struct nullb_device *dev;
  71         struct list_head list;
  72         unsigned int index;
  73         struct request_queue *q;
  74         struct gendisk *disk;
  75         struct blk_mq_tag_set *tag_set;
  76         struct blk_mq_tag_set __tag_set;
  77         unsigned int queue_depth;
  78         atomic_long_t cur_bytes;
  79         struct hrtimer bw_timer;
  80         unsigned long cache_flush_pos;
  81         spinlock_t lock;
  82
  83         struct nullb_queue *queues;
  84         unsigned int nr_queues;
  85         char disk_name[DISK_NAME_LEN];
  86 };
  87
  88 #ifdef CONFIG_BLK_DEV_ZONED
  89 int null_zone_init(struct nullb_device *dev);
  90 void null_zone_exit(struct nullb_device *dev);
  91 int null_zone_report(struct gendisk *disk, sector_t sector,
  92                      struct blk_zone *zones, unsigned int *nr_zones);
  93 blk_status_t null_handle_zoned(struct nullb_cmd *cmd,
  94                                 enum req_opf op, sector_t sector,
  95                                 sector_t nr_sectors);
  96 #else
  97 static inline int null_zone_init(struct nullb_device *dev)
  98 {
  99         pr_err("null_blk: CONFIG_BLK_DEV_ZONED not enabled\n");
 100         return -EINVAL;
 101 }
 102 static inline void null_zone_exit(struct nullb_device *dev) {}
 103 static inline int null_zone_report(struct gendisk *disk, sector_t sector,
 104                                    struct blk_zone *zones,
 105                                    unsigned int *nr_zones)
 106 {
 107         return -EOPNOTSUPP;
 108 }
 109 static inline blk_status_t null_handle_zoned(struct nullb_cmd *cmd,
 110                                              enum req_opf op, sector_t sector,
 111                                              sector_t nr_sectors)
 112 {
 113         return BLK_STS_NOTSUPP;
 114 }
 115 #endif /* CONFIG_BLK_DEV_ZONED */
 116 #endif /* __NULL_BLK_H */