1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef RQ_QOS_H 3 #define RQ_QOS_H 4 5 #include <linux/kernel.h> 6 #include <linux/blkdev.h> 7 #include <linux/blk_types.h> 8 #include <linux/atomic.h> 9 #include <linux/wait.h> 10 #include <linux/blk-mq.h> 11 12 #include "blk-mq-debugfs.h" 13 14 struct blk_mq_debugfs_attr; 15 16 enum rq_qos_id { 17 RQ_QOS_WBT, 18 RQ_QOS_LATENCY, 19 RQ_QOS_COST, 20 RQ_QOS_IOPRIO, 21 }; 22 23 struct rq_wait { 24 wait_queue_head_t wait; 25 atomic_t inflight; 26 }; 27 28 struct rq_qos { 29 struct rq_qos_ops *ops; 30 struct request_queue *q; 31 enum rq_qos_id id; 32 struct rq_qos *next; 33 #ifdef CONFIG_BLK_DEBUG_FS 34 struct dentry *debugfs_dir; 35 #endif 36 }; 37 38 struct rq_qos_ops { 39 void (*throttle)(struct rq_qos *, struct bio *); 40 void (*track)(struct rq_qos *, struct request *, struct bio *); 41 void (*merge)(struct rq_qos *, struct request *, struct bio *); 42 void (*issue)(struct rq_qos *, struct request *); 43 void (*requeue)(struct rq_qos *, struct request *); 44 void (*done)(struct rq_qos *, struct request *); 45 void (*done_bio)(struct rq_qos *, struct bio *); 46 void (*cleanup)(struct rq_qos *, struct bio *); 47 void (*queue_depth_changed)(struct rq_qos *); 48 void (*exit)(struct rq_qos *); 49 const struct blk_mq_debugfs_attr *debugfs_attrs; 50 }; 51 52 struct rq_depth { 53 unsigned int max_depth; 54 55 int scale_step; 56 bool scaled_max; 57 58 unsigned int queue_depth; 59 unsigned int default_depth; 60 }; 61 62 static inline struct rq_qos *rq_qos_id(struct request_queue *q, 63 enum rq_qos_id id) 64 { 65 struct rq_qos *rqos; 66 for (rqos = q->rq_qos; rqos; rqos = rqos->next) { 67 if (rqos->id == id) 68 break; 69 } 70 return rqos; 71 } 72 73 static inline struct rq_qos *wbt_rq_qos(struct request_queue *q) 74 { 75 return rq_qos_id(q, RQ_QOS_WBT); 76 } 77 78 static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q) 79 { 80 return rq_qos_id(q, RQ_QOS_LATENCY); 81 } 82 83 static inline void rq_wait_init(struct rq_wait *rq_wait) 84 { 85 atomic_set(&rq_wait->inflight, 0); 86 init_waitqueue_head(&rq_wait->wait); 87 } 88 89 static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos) 90 { 91 /* 92 * No IO can be in-flight when adding rqos, so freeze queue, which 93 * is fine since we only support rq_qos for blk-mq queue. 94 * 95 * Reuse ->queue_lock for protecting against other concurrent 96 * rq_qos adding/deleting 97 */ 98 blk_mq_freeze_queue(q); 99 100 spin_lock_irq(&q->queue_lock); 101 rqos->next = q->rq_qos; 102 q->rq_qos = rqos; 103 spin_unlock_irq(&q->queue_lock); 104 105 blk_mq_unfreeze_queue(q); 106 107 if (rqos->ops->debugfs_attrs) 108 blk_mq_debugfs_register_rqos(rqos); 109 } 110 111 static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos) 112 { 113 struct rq_qos **cur; 114 115 /* 116 * See comment in rq_qos_add() about freezing queue & using 117 * ->queue_lock. 118 */ 119 blk_mq_freeze_queue(q); 120 121 spin_lock_irq(&q->queue_lock); 122 for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) { 123 if (*cur == rqos) { 124 *cur = rqos->next; 125 break; 126 } 127 } 128 spin_unlock_irq(&q->queue_lock); 129 130 blk_mq_unfreeze_queue(q); 131 132 blk_mq_debugfs_unregister_rqos(rqos); 133 } 134 135 typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data); 136 typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data); 137 138 void rq_qos_wait(struct rq_wait *rqw, void *private_data, 139 acquire_inflight_cb_t *acquire_inflight_cb, 140 cleanup_cb_t *cleanup_cb); 141 bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit); 142 bool rq_depth_scale_up(struct rq_depth *rqd); 143 bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle); 144 bool rq_depth_calc_max_depth(struct rq_depth *rqd); 145 146 void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio); 147 void __rq_qos_done(struct rq_qos *rqos, struct request *rq); 148 void __rq_qos_issue(struct rq_qos *rqos, struct request *rq); 149 void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq); 150 void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio); 151 void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio); 152 void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio); 153 void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio); 154 void __rq_qos_queue_depth_changed(struct rq_qos *rqos); 155 156 static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio) 157 { 158 if (q->rq_qos) 159 __rq_qos_cleanup(q->rq_qos, bio); 160 } 161 162 static inline void rq_qos_done(struct request_queue *q, struct request *rq) 163 { 164 if (q->rq_qos) 165 __rq_qos_done(q->rq_qos, rq); 166 } 167 168 static inline void rq_qos_issue(struct request_queue *q, struct request *rq) 169 { 170 if (q->rq_qos) 171 __rq_qos_issue(q->rq_qos, rq); 172 } 173 174 static inline void rq_qos_requeue(struct request_queue *q, struct request *rq) 175 { 176 if (q->rq_qos) 177 __rq_qos_requeue(q->rq_qos, rq); 178 } 179 180 static inline void rq_qos_done_bio(struct bio *bio) 181 { 182 if (bio->bi_bdev && (bio_flagged(bio, BIO_QOS_THROTTLED) || 183 bio_flagged(bio, BIO_QOS_MERGED))) { 184 struct request_queue *q = bdev_get_queue(bio->bi_bdev); 185 if (q->rq_qos) 186 __rq_qos_done_bio(q->rq_qos, bio); 187 } 188 } 189 190 static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio) 191 { 192 if (q->rq_qos) { 193 bio_set_flag(bio, BIO_QOS_THROTTLED); 194 __rq_qos_throttle(q->rq_qos, bio); 195 } 196 } 197 198 static inline void rq_qos_track(struct request_queue *q, struct request *rq, 199 struct bio *bio) 200 { 201 if (q->rq_qos) 202 __rq_qos_track(q->rq_qos, rq, bio); 203 } 204 205 static inline void rq_qos_merge(struct request_queue *q, struct request *rq, 206 struct bio *bio) 207 { 208 if (q->rq_qos) { 209 bio_set_flag(bio, BIO_QOS_MERGED); 210 __rq_qos_merge(q->rq_qos, rq, bio); 211 } 212 } 213 214 static inline void rq_qos_queue_depth_changed(struct request_queue *q) 215 { 216 if (q->rq_qos) 217 __rq_qos_queue_depth_changed(q->rq_qos); 218 } 219 220 void rq_qos_exit(struct request_queue *); 221 222 #endif 223