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 union { 20 struct request *rq; 21 struct bio *bio; 22 }; 23 unsigned int tag; 24 blk_status_t error; 25 bool fake_timeout; 26 struct nullb_queue *nq; 27 struct hrtimer timer; 28 }; 29 30 struct nullb_queue { 31 unsigned long *tag_map; 32 wait_queue_head_t wait; 33 unsigned int queue_depth; 34 struct nullb_device *dev; 35 unsigned int requeue_selection; 36 37 struct list_head poll_list; 38 spinlock_t poll_lock; 39 40 struct nullb_cmd *cmds; 41 }; 42 43 struct nullb_zone { 44 /* 45 * Zone lock to prevent concurrent modification of a zone write 46 * pointer position and condition: with memory backing, a write 47 * command execution may sleep on memory allocation. For this case, 48 * use mutex as the zone lock. Otherwise, use the spinlock for 49 * locking the zone. 50 */ 51 union { 52 spinlock_t spinlock; 53 struct mutex mutex; 54 }; 55 enum blk_zone_type type; 56 enum blk_zone_cond cond; 57 sector_t start; 58 sector_t wp; 59 unsigned int len; 60 unsigned int capacity; 61 }; 62 63 /* Queue modes */ 64 enum { 65 NULL_Q_BIO = 0, 66 NULL_Q_RQ = 1, 67 NULL_Q_MQ = 2, 68 }; 69 70 struct nullb_device { 71 struct nullb *nullb; 72 struct config_group group; 73 #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION 74 struct fault_config timeout_config; 75 struct fault_config requeue_config; 76 struct fault_config init_hctx_fault_config; 77 #endif 78 struct radix_tree_root data; /* data stored in the disk */ 79 struct radix_tree_root cache; /* disk cache data */ 80 unsigned long flags; /* device flags */ 81 unsigned int curr_cache; 82 struct badblocks badblocks; 83 84 unsigned int nr_zones; 85 unsigned int nr_zones_imp_open; 86 unsigned int nr_zones_exp_open; 87 unsigned int nr_zones_closed; 88 unsigned int imp_close_zone_no; 89 struct nullb_zone *zones; 90 sector_t zone_size_sects; 91 bool need_zone_res_mgmt; 92 spinlock_t zone_res_lock; 93 94 unsigned long size; /* device size in MB */ 95 unsigned long completion_nsec; /* time in ns to complete a request */ 96 unsigned long cache_size; /* disk cache size in MB */ 97 unsigned long zone_size; /* zone size in MB if device is zoned */ 98 unsigned long zone_capacity; /* zone capacity in MB if device is zoned */ 99 unsigned int zone_nr_conv; /* number of conventional zones */ 100 unsigned int zone_max_open; /* max number of open zones */ 101 unsigned int zone_max_active; /* max number of active zones */ 102 unsigned int submit_queues; /* number of submission queues */ 103 unsigned int prev_submit_queues; /* number of submission queues before change */ 104 unsigned int poll_queues; /* number of IOPOLL submission queues */ 105 unsigned int prev_poll_queues; /* number of IOPOLL submission queues before change */ 106 unsigned int home_node; /* home node for the device */ 107 unsigned int queue_mode; /* block interface */ 108 unsigned int blocksize; /* block size */ 109 unsigned int max_sectors; /* Max sectors per command */ 110 unsigned int irqmode; /* IRQ completion handler */ 111 unsigned int hw_queue_depth; /* queue depth */ 112 unsigned int index; /* index of the disk, only valid with a disk */ 113 unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */ 114 bool blocking; /* blocking blk-mq device */ 115 bool use_per_node_hctx; /* use per-node allocation for hardware context */ 116 bool power; /* power on/off the device */ 117 bool memory_backed; /* if data is stored in memory */ 118 bool discard; /* if support discard */ 119 bool zoned; /* if device is zoned */ 120 bool virt_boundary; /* virtual boundary on/off for the device */ 121 bool no_sched; /* no IO scheduler for the device */ 122 bool shared_tag_bitmap; /* use hostwide shared tags */ 123 }; 124 125 struct nullb { 126 struct nullb_device *dev; 127 struct list_head list; 128 unsigned int index; 129 struct request_queue *q; 130 struct gendisk *disk; 131 struct blk_mq_tag_set *tag_set; 132 struct blk_mq_tag_set __tag_set; 133 unsigned int queue_depth; 134 atomic_long_t cur_bytes; 135 struct hrtimer bw_timer; 136 unsigned long cache_flush_pos; 137 spinlock_t lock; 138 139 struct nullb_queue *queues; 140 unsigned int nr_queues; 141 char disk_name[DISK_NAME_LEN]; 142 }; 143 144 blk_status_t null_handle_discard(struct nullb_device *dev, sector_t sector, 145 sector_t nr_sectors); 146 blk_status_t null_process_cmd(struct nullb_cmd *cmd, enum req_op op, 147 sector_t sector, unsigned int nr_sectors); 148 149 #ifdef CONFIG_BLK_DEV_ZONED 150 int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q); 151 int null_register_zoned_dev(struct nullb *nullb); 152 void null_free_zoned_dev(struct nullb_device *dev); 153 int null_report_zones(struct gendisk *disk, sector_t sector, 154 unsigned int nr_zones, report_zones_cb cb, void *data); 155 blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, enum req_op op, 156 sector_t sector, sector_t nr_sectors); 157 size_t null_zone_valid_read_len(struct nullb *nullb, 158 sector_t sector, unsigned int len); 159 ssize_t zone_cond_store(struct nullb_device *dev, const char *page, 160 size_t count, enum blk_zone_cond cond); 161 #else 162 static inline int null_init_zoned_dev(struct nullb_device *dev, 163 struct request_queue *q) 164 { 165 pr_err("CONFIG_BLK_DEV_ZONED not enabled\n"); 166 return -EINVAL; 167 } 168 static inline int null_register_zoned_dev(struct nullb *nullb) 169 { 170 return -ENODEV; 171 } 172 static inline void null_free_zoned_dev(struct nullb_device *dev) {} 173 static inline blk_status_t null_process_zoned_cmd(struct nullb_cmd *cmd, 174 enum req_op op, sector_t sector, sector_t nr_sectors) 175 { 176 return BLK_STS_NOTSUPP; 177 } 178 static inline size_t null_zone_valid_read_len(struct nullb *nullb, 179 sector_t sector, 180 unsigned int len) 181 { 182 return len; 183 } 184 static inline ssize_t zone_cond_store(struct nullb_device *dev, 185 const char *page, size_t count, 186 enum blk_zone_cond cond) 187 { 188 return -EOPNOTSUPP; 189 } 190 #define null_report_zones NULL 191 #endif /* CONFIG_BLK_DEV_ZONED */ 192 #endif /* __NULL_BLK_H */ 193