block/blk-rq-qos.h

   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
  11 #include "blk-mq-debugfs.h"
  12
  13 struct blk_mq_debugfs_attr;
  14
  15 enum rq_qos_id {
  16         RQ_QOS_WBT,
  17         RQ_QOS_LATENCY,
  18         RQ_QOS_COST,
  19 };
  20
  21 struct rq_wait {
  22         wait_queue_head_t wait;
  23         atomic_t inflight;
  24 };
  25
  26 struct rq_qos {
  27         struct rq_qos_ops *ops;
  28         struct request_queue *q;
  29         enum rq_qos_id id;
  30         struct rq_qos *next;
  31 #ifdef CONFIG_BLK_DEBUG_FS
  32         struct dentry *debugfs_dir;
  33 #endif
  34 };
  35
  36 struct rq_qos_ops {
  37         void (*throttle)(struct rq_qos *, struct bio *);
  38         void (*track)(struct rq_qos *, struct request *, struct bio *);
  39         void (*merge)(struct rq_qos *, struct request *, struct bio *);
  40         void (*issue)(struct rq_qos *, struct request *);
  41         void (*requeue)(struct rq_qos *, struct request *);
  42         void (*done)(struct rq_qos *, struct request *);
  43         void (*done_bio)(struct rq_qos *, struct bio *);
  44         void (*cleanup)(struct rq_qos *, struct bio *);
  45         void (*queue_depth_changed)(struct rq_qos *);
  46         void (*exit)(struct rq_qos *);
  47         const struct blk_mq_debugfs_attr *debugfs_attrs;
  48 };
  49
  50 struct rq_depth {
  51         unsigned int max_depth;
  52
  53         int scale_step;
  54         bool scaled_max;
  55
  56         unsigned int queue_depth;
  57         unsigned int default_depth;
  58 };
  59
  60 static inline struct rq_qos *rq_qos_id(struct request_queue *q,
  61                                        enum rq_qos_id id)
  62 {
  63         struct rq_qos *rqos;
  64         for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
  65                 if (rqos->id == id)
  66                         break;
  67         }
  68         return rqos;
  69 }
  70
  71 static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
  72 {
  73         return rq_qos_id(q, RQ_QOS_WBT);
  74 }
  75
  76 static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
  77 {
  78         return rq_qos_id(q, RQ_QOS_LATENCY);
  79 }
  80
  81 static inline const char *rq_qos_id_to_name(enum rq_qos_id id)
  82 {
  83         switch (id) {
  84         case RQ_QOS_WBT:
  85                 return "wbt";
  86         case RQ_QOS_LATENCY:
  87                 return "latency";
  88         case RQ_QOS_COST:
  89                 return "cost";
  90         }
  91         return "unknown";
  92 }
  93
  94 static inline void rq_wait_init(struct rq_wait *rq_wait)
  95 {
  96         atomic_set(&rq_wait->inflight, 0);
  97         init_waitqueue_head(&rq_wait->wait);
  98 }
  99
 100 static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
 101 {
 102         rqos->next = q->rq_qos;
 103         q->rq_qos = rqos;
 104
 105         if (rqos->ops->debugfs_attrs)
 106                 blk_mq_debugfs_register_rqos(rqos);
 107 }
 108
 109 static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
 110 {
 111         struct rq_qos **cur;
 112
 113         for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) {
 114                 if (*cur == rqos) {
 115                         *cur = rqos->next;
 116                         break;
 117                 }
 118         }
 119
 120         blk_mq_debugfs_unregister_rqos(rqos);
 121 }
 122
 123 typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
 124 typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data);
 125
 126 void rq_qos_wait(struct rq_wait *rqw, void *private_data,
 127                  acquire_inflight_cb_t *acquire_inflight_cb,
 128                  cleanup_cb_t *cleanup_cb);
 129 bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
 130 bool rq_depth_scale_up(struct rq_depth *rqd);
 131 bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
 132 bool rq_depth_calc_max_depth(struct rq_depth *rqd);
 133
 134 void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio);
 135 void __rq_qos_done(struct rq_qos *rqos, struct request *rq);
 136 void __rq_qos_issue(struct rq_qos *rqos, struct request *rq);
 137 void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq);
 138 void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio);
 139 void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio);
 140 void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio);
 141 void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio);
 142 void __rq_qos_queue_depth_changed(struct rq_qos *rqos);
 143
 144 static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio)
 145 {
 146         if (q->rq_qos)
 147                 __rq_qos_cleanup(q->rq_qos, bio);
 148 }
 149
 150 static inline void rq_qos_done(struct request_queue *q, struct request *rq)
 151 {
 152         if (q->rq_qos)
 153                 __rq_qos_done(q->rq_qos, rq);
 154 }
 155
 156 static inline void rq_qos_issue(struct request_queue *q, struct request *rq)
 157 {
 158         if (q->rq_qos)
 159                 __rq_qos_issue(q->rq_qos, rq);
 160 }
 161
 162 static inline void rq_qos_requeue(struct request_queue *q, struct request *rq)
 163 {
 164         if (q->rq_qos)
 165                 __rq_qos_requeue(q->rq_qos, rq);
 166 }
 167
 168 static inline void rq_qos_done_bio(struct request_queue *q, struct bio *bio)
 169 {
 170         if (q->rq_qos)
 171                 __rq_qos_done_bio(q->rq_qos, bio);
 172 }
 173
 174 static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio)
 175 {
 176         /*
 177          * BIO_TRACKED lets controllers know that a bio went through the
 178          * normal rq_qos path.
 179          */
 180         bio_set_flag(bio, BIO_TRACKED);
 181         if (q->rq_qos)
 182                 __rq_qos_throttle(q->rq_qos, bio);
 183 }
 184
 185 static inline void rq_qos_track(struct request_queue *q, struct request *rq,
 186                                 struct bio *bio)
 187 {
 188         if (q->rq_qos)
 189                 __rq_qos_track(q->rq_qos, rq, bio);
 190 }
 191
 192 static inline void rq_qos_merge(struct request_queue *q, struct request *rq,
 193                                 struct bio *bio)
 194 {
 195         if (q->rq_qos)
 196                 __rq_qos_merge(q->rq_qos, rq, bio);
 197 }
 198
 199 static inline void rq_qos_queue_depth_changed(struct request_queue *q)
 200 {
 201         if (q->rq_qos)
 202                 __rq_qos_queue_depth_changed(q->rq_qos);
 203 }
 204
 205 void rq_qos_exit(struct request_queue *);
 206
 207 #endif