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 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
  36
  37 /*
  38  * Internal helpers for allocating/freeing the request map
  39  */
  40 void blk_mq_free_rq_map(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  41                         unsigned int hctx_idx);
  42 struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
  43                                         unsigned int hctx_idx);
  44
  45 /*
  46  * Internal helpers for request insertion into sw queues
  47  */
  48 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
  49                                 bool at_head);
  50
  51 /*
  52  * CPU hotplug helpers
  53  */
  54 void blk_mq_enable_hotplug(void);
  55 void blk_mq_disable_hotplug(void);
  56
  57 /*
  58  * CPU -> queue mappings
  59  */
  60 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
  61
  62 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  63                 int cpu)
  64 {
  65         return q->queue_hw_ctx[q->mq_map[cpu]];
  66 }
  67
  68 /*
  69  * sysfs helpers
  70  */
  71 extern int blk_mq_sysfs_register(struct request_queue *q);
  72 extern void blk_mq_sysfs_unregister(struct request_queue *q);
  73 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
  74
  75 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
  76
  77 void blk_mq_release(struct request_queue *q);
  78
  79 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
  80                                            unsigned int cpu)
  81 {
  82         return per_cpu_ptr(q->queue_ctx, cpu);
  83 }
  84
  85 /*
  86  * This assumes per-cpu software queueing queues. They could be per-node
  87  * as well, for instance. For now this is hardcoded as-is. Note that we don't
  88  * care about preemption, since we know the ctx's are persistent. This does
  89  * mean that we can't rely on ctx always matching the currently running CPU.
  90  */
  91 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
  92 {
  93         return __blk_mq_get_ctx(q, get_cpu());
  94 }
  95
  96 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
  97 {
  98         put_cpu();
  99 }
 100
 101 struct blk_mq_alloc_data {
 102         /* input parameter */
 103         struct request_queue *q;
 104         unsigned int flags;
 105
 106         /* input & output parameter */
 107         struct blk_mq_ctx *ctx;
 108         struct blk_mq_hw_ctx *hctx;
 109 };
 110
 111 static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
 112                 struct request_queue *q, unsigned int flags,
 113                 struct blk_mq_ctx *ctx, struct blk_mq_hw_ctx *hctx)
 114 {
 115         data->q = q;
 116         data->flags = flags;
 117         data->ctx = ctx;
 118         data->hctx = hctx;
 119 }
 120
 121 /*
 122  * Internal helpers for request allocation/init/free
 123  */
 124 void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
 125                         struct request *rq, unsigned int op);
 126 void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
 127                                 struct request *rq);
 128 struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data,
 129                                         unsigned int op);
 130
 131 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
 132 {
 133         return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
 134 }
 135
 136 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 137 {
 138         return hctx->nr_ctx && hctx->tags;
 139 }
 140
 141 #endif