LXR linux/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
  13struct blk_mq_debugfs_attr;
  14
  15enum rq_qos_id {
  16        RQ_QOS_WBT,
  17        RQ_QOS_CGROUP,
  18};
  19
  20struct rq_wait {
  21        wait_queue_head_t wait;
  22        atomic_t inflight;
  23};
  24
  25struct 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
  35struct 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
  47struct 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
  57static 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
  68static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
  69{
  70        return rq_qos_id(q, RQ_QOS_WBT);
  71}
  72
  73static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
  74{
  75        return rq_qos_id(q, RQ_QOS_CGROUP);
  76}
  77
  78static 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
  89static 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
  95static 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
 104static 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
 121typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
 122typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data);
 123
 124void rq_qos_wait(struct rq_wait *rqw, void *private_data,
 125                 acquire_inflight_cb_t *acquire_inflight_cb,
 126                 cleanup_cb_t *cleanup_cb);
 127bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
 128void rq_depth_scale_up(struct rq_depth *rqd);
 129void rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
 130bool rq_depth_calc_max_depth(struct rq_depth *rqd);
 131
 132void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio);
 133void __rq_qos_done(struct rq_qos *rqos, struct request *rq);
 134void __rq_qos_issue(struct rq_qos *rqos, struct request *rq);
 135void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq);
 136void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio);
 137void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio);
 138void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio);
 139
 140static 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
 146static 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
 152static 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
 158static 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
 164static 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
 170static 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
 181static 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
 188void rq_qos_exit(struct request_queue *);
 189
 190#endif
 191