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 }; 21 22 struct rq_wait { 23 wait_queue_head_t wait; 24 atomic_t inflight; 25 }; 26 27 struct rq_qos { 28 struct rq_qos_ops *ops; 29 struct request_queue *q; 30 enum rq_qos_id id; 31 struct rq_qos *next; 32 #ifdef CONFIG_BLK_DEBUG_FS 33 struct dentry *debugfs_dir; 34 #endif 35 }; 36 37 struct rq_qos_ops { 38 void (*throttle)(struct rq_qos *, struct bio *); 39 void (*track)(struct rq_qos *, struct request *, struct bio *); 40 void (*merge)(struct rq_qos *, struct request *, struct bio *); 41 void (*issue)(struct rq_qos *, struct request *); 42 void (*requeue)(struct rq_qos *, struct request *); 43 void (*done)(struct rq_qos *, struct request *); 44 void (*done_bio)(struct rq_qos *, struct bio *); 45 void (*cleanup)(struct rq_qos *, struct bio *); 46 void (*queue_depth_changed)(struct rq_qos *); 47 void (*exit)(struct rq_qos *); 48 const struct blk_mq_debugfs_attr *debugfs_attrs; 49 }; 50 51 struct rq_depth { 52 unsigned int max_depth; 53 54 int scale_step; 55 bool scaled_max; 56 57 unsigned int queue_depth; 58 unsigned int default_depth; 59 }; 60 61 static inline struct rq_qos *rq_qos_id(struct request_queue *q, 62 enum rq_qos_id id) 63 { 64 struct rq_qos *rqos; 65 for (rqos = q->rq_qos; rqos; rqos = rqos->next) { 66 if (rqos->id == id) 67 break; 68 } 69 return rqos; 70 } 71 72 static inline struct rq_qos *wbt_rq_qos(struct request_queue *q) 73 { 74 return rq_qos_id(q, RQ_QOS_WBT); 75 } 76 77 static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q) 78 { 79 return rq_qos_id(q, RQ_QOS_LATENCY); 80 } 81 82 static inline void rq_wait_init(struct rq_wait *rq_wait) 83 { 84 atomic_set(&rq_wait->inflight, 0); 85 init_waitqueue_head(&rq_wait->wait); 86 } 87 88 static inline int rq_qos_add(struct request_queue *q, struct rq_qos *rqos) 89 { 90 /* 91 * No IO can be in-flight when adding rqos, so freeze queue, which 92 * is fine since we only support rq_qos for blk-mq queue. 93 * 94 * Reuse ->queue_lock for protecting against other concurrent 95 * rq_qos adding/deleting 96 */ 97 blk_mq_freeze_queue(q); 98 99 spin_lock_irq(&q->queue_lock); 100 if (rq_qos_id(q, rqos->id)) 101 goto ebusy; 102 rqos->next = q->rq_qos; 103 q->rq_qos = rqos; 104 spin_unlock_irq(&q->queue_lock); 105 106 blk_mq_unfreeze_queue(q); 107 108 if (rqos->ops->debugfs_attrs) { 109 mutex_lock(&q->debugfs_mutex); 110 blk_mq_debugfs_register_rqos(rqos); 111 mutex_unlock(&q->debugfs_mutex); 112 } 113 114 return 0; 115 ebusy: 116 spin_unlock_irq(&q->queue_lock); 117 blk_mq_unfreeze_queue(q); 118 return -EBUSY; 119 120 } 121 122 static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos) 123 { 124 struct rq_qos **cur; 125 126 /* 127 * See comment in rq_qos_add() about freezing queue & using 128 * ->queue_lock. 129 */ 130 blk_mq_freeze_queue(q); 131 132 spin_lock_irq(&q->queue_lock); 133 for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) { 134 if (*cur == rqos) { 135 *cur = rqos->next; 136 break; 137 } 138 } 139 spin_unlock_irq(&q->queue_lock); 140 141 blk_mq_unfreeze_queue(q); 142 143 mutex_lock(&q->debugfs_mutex); 144 blk_mq_debugfs_unregister_rqos(rqos); 145 mutex_unlock(&q->debugfs_mutex); 146 } 147 148 typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data); 149 typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data); 150 151 void rq_qos_wait(struct rq_wait *rqw, void *private_data, 152 acquire_inflight_cb_t *acquire_inflight_cb, 153 cleanup_cb_t *cleanup_cb); 154 bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit); 155 bool rq_depth_scale_up(struct rq_depth *rqd); 156 bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle); 157 bool rq_depth_calc_max_depth(struct rq_depth *rqd); 158 159 void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio); 160 void __rq_qos_done(struct rq_qos *rqos, struct request *rq); 161 void __rq_qos_issue(struct rq_qos *rqos, struct request *rq); 162 void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq); 163 void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio); 164 void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio); 165 void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio); 166 void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio); 167 void __rq_qos_queue_depth_changed(struct rq_qos *rqos); 168 169 static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio) 170 { 171 if (q->rq_qos) 172 __rq_qos_cleanup(q->rq_qos, bio); 173 } 174 175 static inline void rq_qos_done(struct request_queue *q, struct request *rq) 176 { 177 if (q->rq_qos) 178 __rq_qos_done(q->rq_qos, rq); 179 } 180 181 static inline void rq_qos_issue(struct request_queue *q, struct request *rq) 182 { 183 if (q->rq_qos) 184 __rq_qos_issue(q->rq_qos, rq); 185 } 186 187 static inline void rq_qos_requeue(struct request_queue *q, struct request *rq) 188 { 189 if (q->rq_qos) 190 __rq_qos_requeue(q->rq_qos, rq); 191 } 192 193 static inline void rq_qos_done_bio(struct bio *bio) 194 { 195 if (bio->bi_bdev && (bio_flagged(bio, BIO_QOS_THROTTLED) || 196 bio_flagged(bio, BIO_QOS_MERGED))) { 197 struct request_queue *q = bdev_get_queue(bio->bi_bdev); 198 if (q->rq_qos) 199 __rq_qos_done_bio(q->rq_qos, bio); 200 } 201 } 202 203 static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio) 204 { 205 if (q->rq_qos) { 206 bio_set_flag(bio, BIO_QOS_THROTTLED); 207 __rq_qos_throttle(q->rq_qos, bio); 208 } 209 } 210 211 static inline void rq_qos_track(struct request_queue *q, struct request *rq, 212 struct bio *bio) 213 { 214 if (q->rq_qos) 215 __rq_qos_track(q->rq_qos, rq, bio); 216 } 217 218 static inline void rq_qos_merge(struct request_queue *q, struct request *rq, 219 struct bio *bio) 220 { 221 if (q->rq_qos) { 222 bio_set_flag(bio, BIO_QOS_MERGED); 223 __rq_qos_merge(q->rq_qos, rq, bio); 224 } 225 } 226 227 static inline void rq_qos_queue_depth_changed(struct request_queue *q) 228 { 229 if (q->rq_qos) 230 __rq_qos_queue_depth_changed(q->rq_qos); 231 } 232 233 void rq_qos_exit(struct request_queue *); 234 235 #endif 236