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 int 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 if (rq_qos_id(q, rqos->id)) 102 goto ebusy; 103 rqos->next = q->rq_qos; 104 q->rq_qos = rqos; 105 spin_unlock_irq(&q->queue_lock); 106 107 blk_mq_unfreeze_queue(q); 108 109 if (rqos->ops->debugfs_attrs) { 110 mutex_lock(&q->debugfs_mutex); 111 blk_mq_debugfs_register_rqos(rqos); 112 mutex_unlock(&q->debugfs_mutex); 113 } 114 115 return 0; 116 ebusy: 117 spin_unlock_irq(&q->queue_lock); 118 blk_mq_unfreeze_queue(q); 119 return -EBUSY; 120 121 } 122 123 static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos) 124 { 125 struct rq_qos **cur; 126 127 /* 128 * See comment in rq_qos_add() about freezing queue & using 129 * ->queue_lock. 130 */ 131 blk_mq_freeze_queue(q); 132 133 spin_lock_irq(&q->queue_lock); 134 for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) { 135 if (*cur == rqos) { 136 *cur = rqos->next; 137 break; 138 } 139 } 140 spin_unlock_irq(&q->queue_lock); 141 142 blk_mq_unfreeze_queue(q); 143 144 mutex_lock(&q->debugfs_mutex); 145 blk_mq_debugfs_unregister_rqos(rqos); 146 mutex_unlock(&q->debugfs_mutex); 147 } 148 149 typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data); 150 typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data); 151 152 void rq_qos_wait(struct rq_wait *rqw, void *private_data, 153 acquire_inflight_cb_t *acquire_inflight_cb, 154 cleanup_cb_t *cleanup_cb); 155 bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit); 156 bool rq_depth_scale_up(struct rq_depth *rqd); 157 bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle); 158 bool rq_depth_calc_max_depth(struct rq_depth *rqd); 159 160 void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio); 161 void __rq_qos_done(struct rq_qos *rqos, struct request *rq); 162 void __rq_qos_issue(struct rq_qos *rqos, struct request *rq); 163 void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq); 164 void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio); 165 void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio); 166 void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio); 167 void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio); 168 void __rq_qos_queue_depth_changed(struct rq_qos *rqos); 169 170 static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio) 171 { 172 if (q->rq_qos) 173 __rq_qos_cleanup(q->rq_qos, bio); 174 } 175 176 static inline void rq_qos_done(struct request_queue *q, struct request *rq) 177 { 178 if (q->rq_qos) 179 __rq_qos_done(q->rq_qos, rq); 180 } 181 182 static inline void rq_qos_issue(struct request_queue *q, struct request *rq) 183 { 184 if (q->rq_qos) 185 __rq_qos_issue(q->rq_qos, rq); 186 } 187 188 static inline void rq_qos_requeue(struct request_queue *q, struct request *rq) 189 { 190 if (q->rq_qos) 191 __rq_qos_requeue(q->rq_qos, rq); 192 } 193 194 static inline void rq_qos_done_bio(struct bio *bio) 195 { 196 if (bio->bi_bdev && (bio_flagged(bio, BIO_QOS_THROTTLED) || 197 bio_flagged(bio, BIO_QOS_MERGED))) { 198 struct request_queue *q = bdev_get_queue(bio->bi_bdev); 199 if (q->rq_qos) 200 __rq_qos_done_bio(q->rq_qos, bio); 201 } 202 } 203 204 static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio) 205 { 206 if (q->rq_qos) { 207 bio_set_flag(bio, BIO_QOS_THROTTLED); 208 __rq_qos_throttle(q->rq_qos, bio); 209 } 210 } 211 212 static inline void rq_qos_track(struct request_queue *q, struct request *rq, 213 struct bio *bio) 214 { 215 if (q->rq_qos) 216 __rq_qos_track(q->rq_qos, rq, bio); 217 } 218 219 static inline void rq_qos_merge(struct request_queue *q, struct request *rq, 220 struct bio *bio) 221 { 222 if (q->rq_qos) { 223 bio_set_flag(bio, BIO_QOS_MERGED); 224 __rq_qos_merge(q->rq_qos, rq, bio); 225 } 226 } 227 228 static inline void rq_qos_queue_depth_changed(struct request_queue *q) 229 { 230 if (q->rq_qos) 231 __rq_qos_queue_depth_changed(q->rq_qos); 232 } 233 234 void rq_qos_exit(struct request_queue *); 235 236 #endif 237