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 #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
  16 struct nullb_cmd {
  17         struct list_head list;
  18         struct llist_node ll_list;
  19         struct __call_single_data csd;
  20         struct request *rq;
  21         struct bio *bio;
  22         unsigned int tag;
  23         blk_status_t error;
  24         struct nullb_queue *nq;
  25         struct hrtimer timer;
  26 };
  27
  28 struct 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
  38 struct nullb_device {
  39         struct nullb *nullb;
  40         struct config_item item;
  41         struct radix_tree_root data; /* data stored in the disk */
  42         struct radix_tree_root cache; /* disk cache data */
  43         unsigned long flags; /* device flags */
  44         unsigned int curr_cache;
  45         struct badblocks badblocks;
  46
  47         unsigned int nr_zones;
  48         struct blk_zone *zones;
  49         sector_t zone_size_sects;
  50
  51         unsigned long size; /* device size in MB */
  52         unsigned long completion_nsec; /* time in ns to complete a request */
  53         unsigned long cache_size; /* disk cache size in MB */
  54         unsigned long zone_size; /* zone size in MB if device is zoned */
  55         unsigned int zone_nr_conv; /* number of conventional zones */
  56         unsigned int submit_queues; /* number of submission queues */
  57         unsigned int home_node; /* home node for the device */
  58         unsigned int queue_mode; /* block interface */
  59         unsigned int blocksize; /* block size */
  60         unsigned int irqmode; /* IRQ completion handler */
  61         unsigned int hw_queue_depth; /* queue depth */
  62         unsigned int index; /* index of the disk, only valid with a disk */
  63         unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
  64         bool blocking; /* blocking blk-mq device */
  65         bool use_per_node_hctx; /* use per-node allocation for hardware context */
  66         bool power; /* power on/off the device */
  67         bool memory_backed; /* if data is stored in memory */
  68         bool discard; /* if support discard */
  69         bool zoned; /* if device is zoned */
  70 };
  71
  72 struct nullb {
  73         struct nullb_device *dev;
  74         struct list_head list;
  75         unsigned int index;
  76         struct request_queue *q;
  77         struct gendisk *disk;
  78         struct blk_mq_tag_set *tag_set;
  79         struct blk_mq_tag_set __tag_set;
  80         unsigned int queue_depth;
  81         atomic_long_t cur_bytes;
  82         struct hrtimer bw_timer;
  83         unsigned long cache_flush_pos;
  84         spinlock_t lock;
  85
  86         struct nullb_queue *queues;
  87         unsigned int nr_queues;
  88         char disk_name[DISK_NAME_LEN];
  89 };
  90
  91 #ifdef CONFIG_BLK_DEV_ZONED
  92 int null_zone_init(struct nullb_device *dev);
  93 void null_zone_exit(struct nullb_device *dev);
  94 int null_zone_report(struct gendisk *disk, sector_t sector,
  95                      struct blk_zone *zones, unsigned int *nr_zones);
  96 blk_status_t null_handle_zoned(struct nullb_cmd *cmd,
  97                                 enum req_opf op, sector_t sector,
  98                                 sector_t nr_sectors);
  99 #else
 100 static inline int null_zone_init(struct nullb_device *dev)
 101 {
 102         pr_err("CONFIG_BLK_DEV_ZONED not enabled\n");
 103         return -EINVAL;
 104 }
 105 static inline void null_zone_exit(struct nullb_device *dev) {}
 106 static inline int null_zone_report(struct gendisk *disk, sector_t sector,
 107                                    struct blk_zone *zones,
 108                                    unsigned int *nr_zones)
 109 {
 110         return -EOPNOTSUPP;
 111 }
 112 static inline blk_status_t null_handle_zoned(struct nullb_cmd *cmd,
 113                                              enum req_opf op, sector_t sector,
 114                                              sector_t nr_sectors)
 115 {
 116         return BLK_STS_NOTSUPP;
 117 }
 118 #endif /* CONFIG_BLK_DEV_ZONED */
 119 #endif /* __NULL_BLK_H */