Line data    Source code

       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             :         RQ_QOS_IOPRIO,
      21             : };
      22             : 
      23             : struct rq_wait {
      24             :         wait_queue_head_t wait;
      25             :         atomic_t inflight;
      26             : };
      27             : 
      28             : struct rq_qos {
      29             :         struct rq_qos_ops *ops;
      30             :         struct request_queue *q;
      31             :         enum rq_qos_id id;
      32             :         struct rq_qos *next;
      33             : #ifdef CONFIG_BLK_DEBUG_FS
      34             :         struct dentry *debugfs_dir;
      35             : #endif
      36             : };
      37             : 
      38             : struct rq_qos_ops {
      39             :         void (*throttle)(struct rq_qos *, struct bio *);
      40             :         void (*track)(struct rq_qos *, struct request *, struct bio *);
      41             :         void (*merge)(struct rq_qos *, struct request *, struct bio *);
      42             :         void (*issue)(struct rq_qos *, struct request *);
      43             :         void (*requeue)(struct rq_qos *, struct request *);
      44             :         void (*done)(struct rq_qos *, struct request *);
      45             :         void (*done_bio)(struct rq_qos *, struct bio *);
      46             :         void (*cleanup)(struct rq_qos *, struct bio *);
      47             :         void (*queue_depth_changed)(struct rq_qos *);
      48             :         void (*exit)(struct rq_qos *);
      49             :         const struct blk_mq_debugfs_attr *debugfs_attrs;
      50             : };
      51             : 
      52             : struct rq_depth {
      53             :         unsigned int max_depth;
      54             : 
      55             :         int scale_step;
      56             :         bool scaled_max;
      57             : 
      58             :         unsigned int queue_depth;
      59             :         unsigned int default_depth;
      60             : };
      61             : 
      62             : static inline struct rq_qos *rq_qos_id(struct request_queue *q,
      63             :                                        enum rq_qos_id id)
      64             : {
      65             :         struct rq_qos *rqos;
      66           0 :         for (rqos = q->rq_qos; rqos; rqos = rqos->next) {
      67           0 :                 if (rqos->id == id)
      68             :                         break;
      69             :         }
      70             :         return rqos;
      71             : }
      72             : 
      73             : static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
      74             : {
      75           0 :         return rq_qos_id(q, RQ_QOS_WBT);
      76             : }
      77             : 
      78             : static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
      79             : {
      80             :         return rq_qos_id(q, RQ_QOS_LATENCY);
      81             : }
      82             : 
      83             : static inline void rq_wait_init(struct rq_wait *rq_wait)
      84             : {
      85             :         atomic_set(&rq_wait->inflight, 0);
      86             :         init_waitqueue_head(&rq_wait->wait);
      87             : }
      88             : 
      89             : static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
      90             : {
      91             :         /*
      92             :          * No IO can be in-flight when adding rqos, so freeze queue, which
      93             :          * is fine since we only support rq_qos for blk-mq queue.
      94             :          *
      95             :          * Reuse ->queue_lock for protecting against other concurrent
      96             :          * rq_qos adding/deleting
      97             :          */
      98             :         blk_mq_freeze_queue(q);
      99             : 
     100             :         spin_lock_irq(&q->queue_lock);
     101             :         rqos->next = q->rq_qos;
     102             :         q->rq_qos = rqos;
     103             :         spin_unlock_irq(&q->queue_lock);
     104             : 
     105             :         blk_mq_unfreeze_queue(q);
     106             : 
     107             :         if (rqos->ops->debugfs_attrs)
     108             :                 blk_mq_debugfs_register_rqos(rqos);
     109             : }
     110             : 
     111             : static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
     112             : {
     113             :         struct rq_qos **cur;
     114             : 
     115             :         /*
     116             :          * See comment in rq_qos_add() about freezing queue & using
     117             :          * ->queue_lock.
     118             :          */
     119             :         blk_mq_freeze_queue(q);
     120             : 
     121             :         spin_lock_irq(&q->queue_lock);
     122             :         for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) {
     123             :                 if (*cur == rqos) {
     124             :                         *cur = rqos->next;
     125             :                         break;
     126             :                 }
     127             :         }
     128             :         spin_unlock_irq(&q->queue_lock);
     129             : 
     130             :         blk_mq_unfreeze_queue(q);
     131             : 
     132             :         blk_mq_debugfs_unregister_rqos(rqos);
     133             : }
     134             : 
     135             : typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
     136             : typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data);
     137             : 
     138             : void rq_qos_wait(struct rq_wait *rqw, void *private_data,
     139             :                  acquire_inflight_cb_t *acquire_inflight_cb,
     140             :                  cleanup_cb_t *cleanup_cb);
     141             : bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
     142             : bool rq_depth_scale_up(struct rq_depth *rqd);
     143             : bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
     144             : bool rq_depth_calc_max_depth(struct rq_depth *rqd);
     145             : 
     146             : void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio);
     147             : void __rq_qos_done(struct rq_qos *rqos, struct request *rq);
     148             : void __rq_qos_issue(struct rq_qos *rqos, struct request *rq);
     149             : void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq);
     150             : void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio);
     151             : void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio);
     152             : void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio);
     153             : void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio);
     154             : void __rq_qos_queue_depth_changed(struct rq_qos *rqos);
     155             : 
     156             : static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio)
     157             : {
     158           0 :         if (q->rq_qos)
     159           0 :                 __rq_qos_cleanup(q->rq_qos, bio);
     160             : }
     161             : 
     162             : static inline void rq_qos_done(struct request_queue *q, struct request *rq)
     163             : {
     164           0 :         if (q->rq_qos)
     165           0 :                 __rq_qos_done(q->rq_qos, rq);
     166             : }
     167             : 
     168             : static inline void rq_qos_issue(struct request_queue *q, struct request *rq)
     169             : {
     170           0 :         if (q->rq_qos)
     171           0 :                 __rq_qos_issue(q->rq_qos, rq);
     172             : }
     173             : 
     174             : static inline void rq_qos_requeue(struct request_queue *q, struct request *rq)
     175             : {
     176           0 :         if (q->rq_qos)
     177           0 :                 __rq_qos_requeue(q->rq_qos, rq);
     178             : }
     179             : 
     180           0 : static inline void rq_qos_done_bio(struct bio *bio)
     181             : {
     182           0 :         if (bio->bi_bdev && (bio_flagged(bio, BIO_QOS_THROTTLED) ||
     183           0 :                              bio_flagged(bio, BIO_QOS_MERGED))) {
     184           0 :                 struct request_queue *q = bdev_get_queue(bio->bi_bdev);
     185           0 :                 if (q->rq_qos)
     186           0 :                         __rq_qos_done_bio(q->rq_qos, bio);
     187             :         }
     188           0 : }
     189             : 
     190             : static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio)
     191             : {
     192           0 :         if (q->rq_qos) {
     193           0 :                 bio_set_flag(bio, BIO_QOS_THROTTLED);
     194           0 :                 __rq_qos_throttle(q->rq_qos, bio);
     195             :         }
     196             : }
     197             : 
     198             : static inline void rq_qos_track(struct request_queue *q, struct request *rq,
     199             :                                 struct bio *bio)
     200             : {
     201           0 :         if (q->rq_qos)
     202           0 :                 __rq_qos_track(q->rq_qos, rq, bio);
     203             : }
     204             : 
     205             : static inline void rq_qos_merge(struct request_queue *q, struct request *rq,
     206             :                                 struct bio *bio)
     207             : {
     208           0 :         if (q->rq_qos) {
     209           0 :                 bio_set_flag(bio, BIO_QOS_MERGED);
     210           0 :                 __rq_qos_merge(q->rq_qos, rq, bio);
     211             :         }
     212             : }
     213             : 
     214             : static inline void rq_qos_queue_depth_changed(struct request_queue *q)
     215             : {
     216           0 :         if (q->rq_qos)
     217           0 :                 __rq_qos_queue_depth_changed(q->rq_qos);
     218             : }
     219             : 
     220             : void rq_qos_exit(struct request_queue *);
     221             : 
     222             : #endif