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