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         struct blk_rq_stat      stat[2];
  24
  25         struct request_queue    *queue;
  26         struct kobject          kobj;
  27 } ____cacheline_aligned_in_smp;
  28
  29 void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
  30 void blk_mq_freeze_queue(struct request_queue *q);
  31 void blk_mq_free_queue(struct request_queue *q);
  32 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
  33 void blk_mq_wake_waiters(struct request_queue *q);
  34 bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *, struct list_head *);
  35
  36 /*
  37  * CPU hotplug helpers
  38  */
  39 void blk_mq_enable_hotplug(void);
  40 void blk_mq_disable_hotplug(void);
  41
  42 /*
  43  * CPU -> queue mappings
  44  */
  45 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
  46
  47 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  48                 int cpu)
  49 {
  50         return q->queue_hw_ctx[q->mq_map[cpu]];
  51 }
  52
  53 /*
  54  * sysfs helpers
  55  */
  56 extern int blk_mq_sysfs_register(struct request_queue *q);
  57 extern void blk_mq_sysfs_unregister(struct request_queue *q);
  58 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
  59
  60 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
  61
  62 void blk_mq_release(struct request_queue *q);
  63
  64 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
  65                                            unsigned int cpu)
  66 {
  67         return per_cpu_ptr(q->queue_ctx, cpu);
  68 }
  69
  70 /*
  71  * This assumes per-cpu software queueing queues. They could be per-node
  72  * as well, for instance. For now this is hardcoded as-is. Note that we don't
  73  * care about preemption, since we know the ctx's are persistent. This does
  74  * mean that we can't rely on ctx always matching the currently running CPU.
  75  */
  76 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
  77 {
  78         return __blk_mq_get_ctx(q, get_cpu());
  79 }
  80
  81 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
  82 {
  83         put_cpu();
  84 }
  85
  86 struct blk_mq_alloc_data {
  87         /* input parameter */
  88         struct request_queue *q;
  89         unsigned int flags;
  90
  91         /* input & output parameter */
  92         struct blk_mq_ctx *ctx;
  93         struct blk_mq_hw_ctx *hctx;
  94 };
  95
  96 static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
  97                 struct request_queue *q, unsigned int flags,
  98                 struct blk_mq_ctx *ctx, struct blk_mq_hw_ctx *hctx)
  99 {
 100         data->q = q;
 101         data->flags = flags;
 102         data->ctx = ctx;
 103         data->hctx = hctx;
 104 }
 105
 106 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
 107 {
 108         return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
 109 }
 110
 111 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 112 {
 113         return hctx->nr_ctx && hctx->tags;
 114 }
 115
 116 #endif