LXR linux/drivers/block/null

   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
  13struct 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
  25struct 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
  35struct 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
  69struct 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
  89int null_zone_init(struct nullb_device *dev);
  90void null_zone_exit(struct nullb_device *dev);
  91int null_zone_report(struct gendisk *disk, sector_t sector,
  92                     struct blk_zone *zones, unsigned int *nr_zones);
  93void null_zone_write(struct nullb_cmd *cmd, sector_t sector,
  94                        unsigned int nr_sectors);
  95void null_zone_reset(struct nullb_cmd *cmd, sector_t sector);
  96#else
  97static 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}
 102static inline void null_zone_exit(struct nullb_device *dev) {}
 103static 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}
 109static inline void null_zone_write(struct nullb_cmd *cmd, sector_t sector,
 110                                   unsigned int nr_sectors)
 111{
 112}
 113static inline void null_zone_reset(struct nullb_cmd *cmd, sector_t sector) {}
 114#endif /* CONFIG_BLK_DEV_ZONED */
 115#endif /* __NULL_BLK_H */
 116