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_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
  34 /*
  35  * CPU hotplug helpers
  36  */
  37 struct blk_mq_cpu_notifier;
  38 void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier,
  39                               int (*fn)(void *, unsigned long, unsigned int),
  40                               void *data);
  41 void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
  42 void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
  43 void blk_mq_cpu_init(void);
  44 void blk_mq_enable_hotplug(void);
  45 void blk_mq_disable_hotplug(void);
  46
  47 /*
  48  * CPU -> queue mappings
  49  */
  50 extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set);
  51 extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues,
  52                                    const struct cpumask *online_mask);
  53 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
  54
  55 /*
  56  * sysfs helpers
  57  */
  58 extern int blk_mq_sysfs_register(struct request_queue *q);
  59 extern void blk_mq_sysfs_unregister(struct request_queue *q);
  60
  61 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
  62
  63 void blk_mq_release(struct request_queue *q);
  64
  65 /*
  66  * Basic implementation of sparser bitmap, allowing the user to spread
  67  * the bits over more cachelines.
  68  */
  69 struct blk_align_bitmap {
  70         unsigned long word;
  71         unsigned long depth;
  72 } ____cacheline_aligned_in_smp;
  73
  74 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
  75                                            unsigned int cpu)
  76 {
  77         return per_cpu_ptr(q->queue_ctx, cpu);
  78 }
  79
  80 /*
  81  * This assumes per-cpu software queueing queues. They could be per-node
  82  * as well, for instance. For now this is hardcoded as-is. Note that we don't
  83  * care about preemption, since we know the ctx's are persistent. This does
  84  * mean that we can't rely on ctx always matching the currently running CPU.
  85  */
  86 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
  87 {
  88         return __blk_mq_get_ctx(q, get_cpu());
  89 }
  90
  91 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
  92 {
  93         put_cpu();
  94 }
  95
  96 struct blk_mq_alloc_data {
  97         /* input parameter */
  98         struct request_queue *q;
  99         unsigned int flags;
 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, unsigned int flags,
 108                 struct blk_mq_ctx *ctx, struct blk_mq_hw_ctx *hctx)
 109 {
 110         data->q = q;
 111         data->flags = flags;
 112         data->ctx = ctx;
 113         data->hctx = hctx;
 114 }
 115
 116 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 117 {
 118         return hctx->nr_ctx && hctx->tags;
 119 }
 120
 121 #endif