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 const struct rq_qos_ops *ops; 29 struct gendisk *disk; 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 *iolat_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 int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id, 89 const struct rq_qos_ops *ops); 90 void rq_qos_del(struct rq_qos *rqos); 91 92 typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data); 93 typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data); 94 95 void rq_qos_wait(struct rq_wait *rqw, void *private_data, 96 acquire_inflight_cb_t *acquire_inflight_cb, 97 cleanup_cb_t *cleanup_cb); 98 bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit); 99 bool rq_depth_scale_up(struct rq_depth *rqd); 100 bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle); 101 bool rq_depth_calc_max_depth(struct rq_depth *rqd); 102 103 void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio); 104 void __rq_qos_done(struct rq_qos *rqos, struct request *rq); 105 void __rq_qos_issue(struct rq_qos *rqos, struct request *rq); 106 void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq); 107 void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio); 108 void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio); 109 void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio); 110 void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio); 111 void __rq_qos_queue_depth_changed(struct rq_qos *rqos); 112 113 static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio) 114 { 115 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && 116 q->rq_qos) 117 __rq_qos_cleanup(q->rq_qos, bio); 118 } 119 120 static inline void rq_qos_done(struct request_queue *q, struct request *rq) 121 { 122 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && 123 q->rq_qos && !blk_rq_is_passthrough(rq)) 124 __rq_qos_done(q->rq_qos, rq); 125 } 126 127 static inline void rq_qos_issue(struct request_queue *q, struct request *rq) 128 { 129 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && 130 q->rq_qos) 131 __rq_qos_issue(q->rq_qos, rq); 132 } 133 134 static inline void rq_qos_requeue(struct request_queue *q, struct request *rq) 135 { 136 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && 137 q->rq_qos) 138 __rq_qos_requeue(q->rq_qos, rq); 139 } 140 141 static inline void rq_qos_done_bio(struct bio *bio) 142 { 143 struct request_queue *q; 144 145 if (!bio->bi_bdev || (!bio_flagged(bio, BIO_QOS_THROTTLED) && 146 !bio_flagged(bio, BIO_QOS_MERGED))) 147 return; 148 149 q = bdev_get_queue(bio->bi_bdev); 150 151 /* 152 * A BIO may carry BIO_QOS_* flags even if the associated request_queue 153 * does not have rq_qos enabled. This can happen with stacked block 154 * devices — for example, NVMe multipath, where it's possible that the 155 * bottom device has QoS enabled but the top device does not. Therefore, 156 * always verify that q->rq_qos is present and QoS is enabled before 157 * calling __rq_qos_done_bio(). 158 */ 159 if (test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags) && q->rq_qos) 160 __rq_qos_done_bio(q->rq_qos, bio); 161 } 162 163 static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio) 164 { 165 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && 166 q->rq_qos) { 167 bio_set_flag(bio, BIO_QOS_THROTTLED); 168 __rq_qos_throttle(q->rq_qos, bio); 169 } 170 } 171 172 static inline void rq_qos_track(struct request_queue *q, struct request *rq, 173 struct bio *bio) 174 { 175 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && 176 q->rq_qos) 177 __rq_qos_track(q->rq_qos, rq, bio); 178 } 179 180 static inline void rq_qos_merge(struct request_queue *q, struct request *rq, 181 struct bio *bio) 182 { 183 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && 184 q->rq_qos) { 185 bio_set_flag(bio, BIO_QOS_MERGED); 186 __rq_qos_merge(q->rq_qos, rq, bio); 187 } 188 } 189 190 static inline void rq_qos_queue_depth_changed(struct request_queue *q) 191 { 192 if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && 193 q->rq_qos) 194 __rq_qos_queue_depth_changed(q->rq_qos); 195 } 196 197 void rq_qos_exit(struct request_queue *); 198 199 #endif 200