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         unsigned int            last_tag ____cacheline_aligned_in_smp;
  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_complete_request(struct request *rq);
  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 void blk_mq_clone_flush_request(struct request *flush_rq,
  33                 struct request *orig_rq);
  34 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
  35
  36 /*
  37  * CPU hotplug helpers
  38  */
  39 struct blk_mq_cpu_notifier;
  40 void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier,
  41                               int (*fn)(void *, unsigned long, unsigned int),
  42                               void *data);
  43 void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
  44 void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
  45 void blk_mq_cpu_init(void);
  46 void blk_mq_enable_hotplug(void);
  47 void blk_mq_disable_hotplug(void);
  48
  49 /*
  50  * CPU -> queue mappings
  51  */
  52 extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set);
  53 extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues);
  54 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
  55
  56 /*
  57  * sysfs helpers
  58  */
  59 extern int blk_mq_sysfs_register(struct request_queue *q);
  60 extern void blk_mq_sysfs_unregister(struct request_queue *q);
  61
  62 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
  63
  64 /*
  65  * Basic implementation of sparser bitmap, allowing the user to spread
  66  * the bits over more cachelines.
  67  */
  68 struct blk_align_bitmap {
  69         unsigned long word;
  70         unsigned long depth;
  71 } ____cacheline_aligned_in_smp;
  72
  73 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
  74                                            unsigned int cpu)
  75 {
  76         return per_cpu_ptr(q->queue_ctx, cpu);
  77 }
  78
  79 /*
  80  * This assumes per-cpu software queueing queues. They could be per-node
  81  * as well, for instance. For now this is hardcoded as-is. Note that we don't
  82  * care about preemption, since we know the ctx's are persistent. This does
  83  * mean that we can't rely on ctx always matching the currently running CPU.
  84  */
  85 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
  86 {
  87         return __blk_mq_get_ctx(q, get_cpu());
  88 }
  89
  90 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
  91 {
  92         put_cpu();
  93 }
  94
  95 struct blk_mq_alloc_data {
  96         /* input parameter */
  97         struct request_queue *q;
  98         gfp_t gfp;
  99         bool reserved;
 100
 101         /* input & output parameter */
 102         struct blk_mq_ctx *ctx;
 103         struct blk_mq_hw_ctx *hctx;
 104 };
 105
 106 static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
 107                 struct request_queue *q, gfp_t gfp, bool reserved,
 108                 struct blk_mq_ctx *ctx,
 109                 struct blk_mq_hw_ctx *hctx)
 110 {
 111         data->q = q;
 112         data->gfp = gfp;
 113         data->reserved = reserved;
 114         data->ctx = ctx;
 115         data->hctx = hctx;
 116 }
 117
 118 #endif