drivers/block/null_blk/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 #include <linux/spinlock.h>
  16 #include <linux/mutex.h>
  17
  18 struct 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 };
  26
  27 struct nullb_queue {
  28         unsigned long *tag_map;
  29         wait_queue_head_t wait;
  30         unsigned int queue_depth;
  31         struct nullb_device *dev;
  32         unsigned int requeue_selection;
  33
  34         struct nullb_cmd *cmds;
  35 };
  36
  37 struct nullb_zone {
  38         /*
  39          * Zone lock to prevent concurrent modification of a zone write
  40          * pointer position and condition: with memory backing, a write
  41          * command execution may sleep on memory allocation. For this case,
  42          * use mutex as the zone lock. Otherwise, use the spinlock for
  43          * locking the zone.
  44          */
  45         union {
  46                 spinlock_t spinlock;
  47                 struct mutex mutex;
  48         };
  49         enum blk_zone_type type;
  50         enum blk_zone_cond cond;
  51         sector_t start;
  52         sector_t wp;
  53         unsigned int len;
  54         unsigned int capacity;
  55 };
  56
  57 struct nullb_device {
  58         struct nullb *nullb;
  59         struct config_item item;
  60         struct radix_tree_root data; /* data stored in the disk */
  61         struct radix_tree_root cache; /* disk cache data */
  62         unsigned long flags; /* device flags */
  63         unsigned int curr_cache;
  64         struct badblocks badblocks;
  65
  66         unsigned int nr_zones;
  67         unsigned int nr_zones_imp_open;
  68         unsigned int nr_zones_exp_open;
  69         unsigned int nr_zones_closed;
  70         unsigned int imp_close_zone_no;
  71         struct nullb_zone *zones;
  72         sector_t zone_size_sects;
  73         bool need_zone_res_mgmt;
  74         spinlock_t zone_res_lock;
  75
  76         unsigned long size; /* device size in MB */
  77         unsigned long completion_nsec; /* time in ns to complete a request */
  78         unsigned long cache_size; /* disk cache size in MB */
  79         unsigned long zone_size; /* zone size in MB if device is zoned */
  80         unsigned long zone_capacity; /* zone capacity in MB if device is zoned */
  81         unsigned int zone_nr_conv; /* number of conventional zones */
  82         unsigned int zone_max_open; /* max number of open zones */
  83         unsigned int zone_max_active; /* max number of active zones */
  84         unsigned int submit_queues; /* number of submission queues */
  85         unsigned int home_node; /* home node for the device */
  86         unsigned int queue_mode; /* block interface */
  87         unsigned int blocksize; /* block size */
  88         unsigned int max_sectors; /* Max sectors per command */
  89         unsigned int irqmode; /* IRQ completion handler */
  90         unsigned int hw_queue_depth; /* queue depth */
  91         unsigned int index; /* index of the disk, only valid with a disk */
  92         unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
  93         bool blocking; /* blocking blk-mq device */
  94         bool use_per_node_hctx; /* use per-node allocation for hardware context */
  95         bool power; /* power on/off the device */
  96         bool memory_backed; /* if data is stored in memory */
  97         bool discard; /* if support discard */
  98         bool zoned; /* if device is zoned */
  99 };
 100
 101 struct nullb {
 102         struct nullb_device *dev;
 103         struct list_head list;
 104         unsigned int index;
 105         struct request_queue *q;
 106         struct gendisk *disk;
 107         struct blk_mq_tag_set *tag_set;
 108         struct blk_mq_tag_set __tag_set;
 109         unsigned int queue_depth;
 110         atomic_long_t cur_bytes;
 111         struct hrtimer bw_timer;
 112         unsigned long cache_flush_pos;
 113         spinlock_t lock;
 114
 115         struct nullb_queue *queues;
 116         unsigned int nr_queues;
 117         char disk_name[DISK_NAME_LEN];
 118 };
 119
 120 blk_status_t null_handle_discard(struct nullb_device *dev, sector_t sector,
 121                                  sector_t nr_sectors);
 122 blk_status_t null_process_cmd(struct nullb_cmd *cmd,
 123                               enum req_opf op, sector_t sector,
 124                               unsigned int nr_sectors);
 125
 126 #ifdef CONFIG_BLK_DEV_ZONED
 127 int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q);
 128 int null_register_zoned_dev(struct nullb *nullb);
 129 void null_free_zoned_dev(struct nullb_device *dev);
 130 int null_report_zones(struct gendisk *disk, sector_t sector,
 131                       unsigned int nr_zones, report_zones_cb cb, void *data);
 132 blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
 133                                     enum req_opf op, sector_t sector,
 134                                     sector_t nr_sectors);
 135 size_t null_zone_valid_read_len(struct nullb *nullb,
 136                                 sector_t sector, unsigned int len);
 137 #else
 138 static inline int null_init_zoned_dev(struct nullb_device *dev,
 139                                       struct request_queue *q)
 140 {
 141         pr_err("CONFIG_BLK_DEV_ZONED not enabled\n");
 142         return -EINVAL;
 143 }
 144 static inline int null_register_zoned_dev(struct nullb *nullb)
 145 {
 146         return -ENODEV;
 147 }
 148 static inline void null_free_zoned_dev(struct nullb_device *dev) {}
 149 static inline blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd,
 150                         enum req_opf op, sector_t sector, sector_t nr_sectors)
 151 {
 152         return BLK_STS_NOTSUPP;
 153 }
 154 static inline size_t null_zone_valid_read_len(struct nullb *nullb,
 155                                               sector_t sector,
 156                                               unsigned int len)
 157 {
 158         return len;
 159 }
 160 #define null_report_zones       NULL
 161 #endif /* CONFIG_BLK_DEV_ZONED */
 162 #endif /* __NULL_BLK_H */