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 submit_queues; /* number of submission queues */
  53         unsigned int home_node; /* home node for the device */
  54         unsigned int queue_mode; /* block interface */
  55         unsigned int blocksize; /* block size */
  56         unsigned int irqmode; /* IRQ completion handler */
  57         unsigned int hw_queue_depth; /* queue depth */
  58         unsigned int index; /* index of the disk, only valid with a disk */
  59         unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
  60         bool blocking; /* blocking blk-mq device */
  61         bool use_per_node_hctx; /* use per-node allocation for hardware context */
  62         bool power; /* power on/off the device */
  63         bool memory_backed; /* if data is stored in memory */
  64         bool discard; /* if support discard */
  65         bool zoned; /* if device is zoned */
  66 };
  67
  68 struct nullb {
  69         struct nullb_device *dev;
  70         struct list_head list;
  71         unsigned int index;
  72         struct request_queue *q;
  73         struct gendisk *disk;
  74         struct blk_mq_tag_set *tag_set;
  75         struct blk_mq_tag_set __tag_set;
  76         unsigned int queue_depth;
  77         atomic_long_t cur_bytes;
  78         struct hrtimer bw_timer;
  79         unsigned long cache_flush_pos;
  80         spinlock_t lock;
  81
  82         struct nullb_queue *queues;
  83         unsigned int nr_queues;
  84         char disk_name[DISK_NAME_LEN];
  85 };
  86
  87 #ifdef CONFIG_BLK_DEV_ZONED
  88 int null_zone_init(struct nullb_device *dev);
  89 void null_zone_exit(struct nullb_device *dev);
  90 int null_zone_report(struct gendisk *disk, sector_t sector,
  91                      struct blk_zone *zones, unsigned int *nr_zones,
  92                      gfp_t gfp_mask);
  93 void null_zone_write(struct nullb_cmd *cmd, sector_t sector,
  94                         unsigned int nr_sectors);
  95 void null_zone_reset(struct nullb_cmd *cmd, sector_t sector);
  96 #else
  97 static inline int null_zone_init(struct nullb_device *dev)
  98 {
  99         return -EINVAL;
 100 }
 101 static inline void null_zone_exit(struct nullb_device *dev) {}
 102 static inline int null_zone_report(struct gendisk *disk, sector_t sector,
 103                                    struct blk_zone *zones,
 104                                    unsigned int *nr_zones, gfp_t gfp_mask)
 105 {
 106         return -EOPNOTSUPP;
 107 }
 108 static inline void null_zone_write(struct nullb_cmd *cmd, sector_t sector,
 109                                    unsigned int nr_sectors)
 110 {
 111 }
 112 static inline void null_zone_reset(struct nullb_cmd *cmd, sector_t sector) {}
 113 #endif /* CONFIG_BLK_DEV_ZONED */
 114 #endif /* __NULL_BLK_H */