block/blk-mq.h

   1 #ifndef INT_BLK_MQ_H
   2 #define INT_BLK_MQ_H
   3
   4 struct blk_mq_tag_set;
   5
   6 struct blk_mq_ctx {
   7         struct {
   8                 spinlock_t              lock;
   9                 struct list_head        rq_list;
  10         }  ____cacheline_aligned_in_smp;
  11
  12         unsigned int            cpu;
  13         unsigned int            index_hw;
  14
  15         /* incremented at dispatch time */
  16         unsigned long           rq_dispatched[2];
  17         unsigned long           rq_merged;
  18
  19         /* incremented at completion time */
  20         unsigned long           ____cacheline_aligned_in_smp rq_completed[2];
  21
  22         struct request_queue    *queue;
  23         struct kobject          kobj;
  24 } ____cacheline_aligned_in_smp;
  25
  26 void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
  27 void blk_mq_freeze_queue(struct request_queue *q);
  28 void blk_mq_free_queue(struct request_queue *q);
  29 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
  30 void blk_mq_wake_waiters(struct request_queue *q);
  31
  32 /*
  33  * CPU hotplug helpers
  34  */
  35 void blk_mq_enable_hotplug(void);
  36 void blk_mq_disable_hotplug(void);
  37
  38 /*
  39  * CPU -> queue mappings
  40  */
  41 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
  42
  43 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  44                 int cpu)
  45 {
  46         return q->queue_hw_ctx[q->mq_map[cpu]];
  47 }
  48
  49 /*
  50  * sysfs helpers
  51  */
  52 extern int blk_mq_sysfs_register(struct request_queue *q);
  53 extern void blk_mq_sysfs_unregister(struct request_queue *q);
  54 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
  55
  56 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
  57
  58 void blk_mq_release(struct request_queue *q);
  59
  60 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
  61                                            unsigned int cpu)
  62 {
  63         return per_cpu_ptr(q->queue_ctx, cpu);
  64 }
  65
  66 /*
  67  * This assumes per-cpu software queueing queues. They could be per-node
  68  * as well, for instance. For now this is hardcoded as-is. Note that we don't
  69  * care about preemption, since we know the ctx's are persistent. This does
  70  * mean that we can't rely on ctx always matching the currently running CPU.
  71  */
  72 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
  73 {
  74         return __blk_mq_get_ctx(q, get_cpu());
  75 }
  76
  77 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
  78 {
  79         put_cpu();
  80 }
  81
  82 struct blk_mq_alloc_data {
  83         /* input parameter */
  84         struct request_queue *q;
  85         unsigned int flags;
  86
  87         /* input & output parameter */
  88         struct blk_mq_ctx *ctx;
  89         struct blk_mq_hw_ctx *hctx;
  90 };
  91
  92 static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
  93                 struct request_queue *q, unsigned int flags,
  94                 struct blk_mq_ctx *ctx, struct blk_mq_hw_ctx *hctx)
  95 {
  96         data->q = q;
  97         data->flags = flags;
  98         data->ctx = ctx;
  99         data->hctx = hctx;
 100 }
 101
 102 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 103 {
 104         return hctx->nr_ctx && hctx->tags;
 105 }
 106
 107 #endif