block/blk-mq.h

   1 #ifndef INT_BLK_MQ_H
   2 #define INT_BLK_MQ_H
   3
   4 #include "blk-stat.h"
   5
   6 struct blk_mq_tag_set;
   7
   8 struct blk_mq_ctx {
   9         struct {
  10                 spinlock_t              lock;
  11                 struct list_head        rq_list;
  12         }  ____cacheline_aligned_in_smp;
  13
  14         unsigned int            cpu;
  15         unsigned int            index_hw;
  16
  17         /* incremented at dispatch time */
  18         unsigned long           rq_dispatched[2];
  19         unsigned long           rq_merged;
  20
  21         /* incremented at completion time */
  22         unsigned long           ____cacheline_aligned_in_smp rq_completed[2];
  23
  24         struct request_queue    *queue;
  25         struct kobject          kobj;
  26 } ____cacheline_aligned_in_smp;
  27
  28 void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
  29 void blk_mq_freeze_queue(struct request_queue *q);
  30 void blk_mq_free_queue(struct request_queue *q);
  31 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
  32 void blk_mq_wake_waiters(struct request_queue *q);
  33 bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *);
  34 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
  35 bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx);
  36 bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
  37                                 bool wait);
  38
  39 /*
  40  * Internal helpers for allocating/freeing the request map
  41  */
  42 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  43                      unsigned int hctx_idx);
  44 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
  45 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
  46                                         unsigned int hctx_idx,
  47                                         unsigned int nr_tags,
  48                                         unsigned int reserved_tags);
  49 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  50                      unsigned int hctx_idx, unsigned int depth);
  51
  52 /*
  53  * Internal helpers for request insertion into sw queues
  54  */
  55 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
  56                                 bool at_head);
  57 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
  58                                 struct list_head *list);
  59 /*
  60  * CPU hotplug helpers
  61  */
  62 void blk_mq_enable_hotplug(void);
  63 void blk_mq_disable_hotplug(void);
  64
  65 /*
  66  * CPU -> queue mappings
  67  */
  68 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
  69
  70 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  71                 int cpu)
  72 {
  73         return q->queue_hw_ctx[q->mq_map[cpu]];
  74 }
  75
  76 /*
  77  * sysfs helpers
  78  */
  79 extern void blk_mq_sysfs_init(struct request_queue *q);
  80 extern void blk_mq_sysfs_deinit(struct request_queue *q);
  81 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
  82 extern int blk_mq_sysfs_register(struct request_queue *q);
  83 extern void blk_mq_sysfs_unregister(struct request_queue *q);
  84 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
  85
  86 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
  87
  88 void blk_mq_release(struct request_queue *q);
  89
  90 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
  91                                            unsigned int cpu)
  92 {
  93         return per_cpu_ptr(q->queue_ctx, cpu);
  94 }
  95
  96 /*
  97  * This assumes per-cpu software queueing queues. They could be per-node
  98  * as well, for instance. For now this is hardcoded as-is. Note that we don't
  99  * care about preemption, since we know the ctx's are persistent. This does
 100  * mean that we can't rely on ctx always matching the currently running CPU.
 101  */
 102 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 103 {
 104         return __blk_mq_get_ctx(q, get_cpu());
 105 }
 106
 107 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 108 {
 109         put_cpu();
 110 }
 111
 112 struct blk_mq_alloc_data {
 113         /* input parameter */
 114         struct request_queue *q;
 115         unsigned int flags;
 116         unsigned int shallow_depth;
 117
 118         /* input & output parameter */
 119         struct blk_mq_ctx *ctx;
 120         struct blk_mq_hw_ctx *hctx;
 121 };
 122
 123 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
 124 {
 125         if (data->flags & BLK_MQ_REQ_INTERNAL)
 126                 return data->hctx->sched_tags;
 127
 128         return data->hctx->tags;
 129 }
 130
 131 /*
 132  * Internal helpers for request allocation/init/free
 133  */
 134 void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
 135                         struct request *rq, unsigned int op);
 136 void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
 137                                 struct request *rq);
 138 void blk_mq_finish_request(struct request *rq);
 139 struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data,
 140                                         unsigned int op);
 141
 142 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
 143 {
 144         return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
 145 }
 146
 147 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 148 {
 149         return hctx->nr_ctx && hctx->tags;
 150 }
 151
 152 #endif