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 14struct blk_mq_debugfs_attr; 15 16enum rq_qos_id { 17 RQ_QOS_WBT, 18 RQ_QOS_LATENCY, 19 RQ_QOS_COST, 20}; 21 22struct rq_wait { 23 wait_queue_head_t wait; 24 atomic_t inflight; 25}; 26 27struct 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 37struct 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 51struct 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 61static 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 72static inline struct rq_qos *wbt_rq_qos(struct request_queue *q) 73{ 74 return rq_qos_id(q, RQ_QOS_WBT); 75} 76 77static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q) 78{ 79 return rq_qos_id(q, RQ_QOS_LATENCY); 80} 81 82static inline const char *rq_qos_id_to_name(enum rq_qos_id id) 83{ 84 switch (id) { 85 case RQ_QOS_WBT: 86 return "wbt"; 87 case RQ_QOS_LATENCY: 88 return "latency"; 89 case RQ_QOS_COST: 90 return "cost"; 91 } 92 return "unknown"; 93} 94 95static inline void rq_wait_init(struct rq_wait *rq_wait) 96{ 97 atomic_set(&rq_wait->inflight, 0); 98 init_waitqueue_head(&rq_wait->wait); 99} 100 101static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos) 102{ 103 /* 104 * No IO can be in-flight when adding rqos, so freeze queue, which 105 * is fine since we only support rq_qos for blk-mq queue. 106 * 107 * Reuse ->queue_lock for protecting against other concurrent 108 * rq_qos adding/deleting 109 */ 110 blk_mq_freeze_queue(q); 111 112 spin_lock_irq(&q->queue_lock); 113 rqos->next = q->rq_qos; 114 q->rq_qos = rqos; 115 spin_unlock_irq(&q->queue_lock); 116 117 blk_mq_unfreeze_queue(q); 118 119 if (rqos->ops->debugfs_attrs) 120 blk_mq_debugfs_register_rqos(rqos); 121} 122 123static 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 blk_mq_debugfs_unregister_rqos(rqos); 145} 146 147typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data); 148typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data); 149 150void rq_qos_wait(struct rq_wait *rqw, void *private_data, 151 acquire_inflight_cb_t *acquire_inflight_cb, 152 cleanup_cb_t *cleanup_cb); 153bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit); 154bool rq_depth_scale_up(struct rq_depth *rqd); 155bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle); 156bool rq_depth_calc_max_depth(struct rq_depth *rqd); 157 158void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio); 159void __rq_qos_done(struct rq_qos *rqos, struct request *rq); 160void __rq_qos_issue(struct rq_qos *rqos, struct request *rq); 161void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq); 162void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio); 163void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio); 164void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio); 165void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio); 166void __rq_qos_queue_depth_changed(struct rq_qos *rqos); 167 168static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio) 169{ 170 if (q->rq_qos) 171 __rq_qos_cleanup(q->rq_qos, bio); 172} 173 174static inline void rq_qos_done(struct request_queue *q, struct request *rq) 175{ 176 if (q->rq_qos) 177 __rq_qos_done(q->rq_qos, rq); 178} 179 180static inline void rq_qos_issue(struct request_queue *q, struct request *rq) 181{ 182 if (q->rq_qos) 183 __rq_qos_issue(q->rq_qos, rq); 184} 185 186static inline void rq_qos_requeue(struct request_queue *q, struct request *rq) 187{ 188 if (q->rq_qos) 189 __rq_qos_requeue(q->rq_qos, rq); 190} 191 192static inline void rq_qos_done_bio(struct request_queue *q, struct bio *bio) 193{ 194 if (q->rq_qos) 195 __rq_qos_done_bio(q->rq_qos, bio); 196} 197 198static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio) 199{ 200 /* 201 * BIO_TRACKED lets controllers know that a bio went through the 202 * normal rq_qos path. 203 */ 204 bio_set_flag(bio, BIO_TRACKED); 205 if (q->rq_qos) 206 __rq_qos_throttle(q->rq_qos, bio); 207} 208 209static inline void rq_qos_track(struct request_queue *q, struct request *rq, 210 struct bio *bio) 211{ 212 if (q->rq_qos) 213 __rq_qos_track(q->rq_qos, rq, bio); 214} 215 216static inline void rq_qos_merge(struct request_queue *q, struct request *rq, 217 struct bio *bio) 218{ 219 if (q->rq_qos) 220 __rq_qos_merge(q->rq_qos, rq, bio); 221} 222 223static inline void rq_qos_queue_depth_changed(struct request_queue *q) 224{ 225 if (q->rq_qos) 226 __rq_qos_queue_depth_changed(q->rq_qos); 227} 228 229void rq_qos_exit(struct request_queue *); 230 231#endif 232