LXR linux/block/blk-mq.h

   1#ifndef INT_BLK_MQ_H
   2#define INT_BLK_MQ_H
   3
   4struct blk_mq_tag_set;
   5
   6struct 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
  28void __blk_mq_complete_request(struct request *rq);
  29void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
  30void blk_mq_freeze_queue(struct request_queue *q);
  31void blk_mq_free_queue(struct request_queue *q);
  32void blk_mq_clone_flush_request(struct request *flush_rq,
  33                struct request *orig_rq);
  34int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
  35void blk_mq_wake_waiters(struct request_queue *q);
  36
  37/*
  38 * CPU hotplug helpers
  39 */
  40struct blk_mq_cpu_notifier;
  41void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier,
  42                              int (*fn)(void *, unsigned long, unsigned int),
  43                              void *data);
  44void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
  45void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
  46void blk_mq_cpu_init(void);
  47void blk_mq_enable_hotplug(void);
  48void blk_mq_disable_hotplug(void);
  49
  50/*
  51 * CPU -> queue mappings
  52 */
  53extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set);
  54extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues);
  55extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
  56
  57/*
  58 * sysfs helpers
  59 */
  60extern int blk_mq_sysfs_register(struct request_queue *q);
  61extern void blk_mq_sysfs_unregister(struct request_queue *q);
  62
  63extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
  64
  65void blk_mq_release(struct request_queue *q);
  66
  67/*
  68 * Basic implementation of sparser bitmap, allowing the user to spread
  69 * the bits over more cachelines.
  70 */
  71struct blk_align_bitmap {
  72        unsigned long word;
  73        unsigned long depth;
  74} ____cacheline_aligned_in_smp;
  75
  76static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
  77                                           unsigned int cpu)
  78{
  79        return per_cpu_ptr(q->queue_ctx, cpu);
  80}
  81
  82/*
  83 * This assumes per-cpu software queueing queues. They could be per-node
  84 * as well, for instance. For now this is hardcoded as-is. Note that we don't
  85 * care about preemption, since we know the ctx's are persistent. This does
  86 * mean that we can't rely on ctx always matching the currently running CPU.
  87 */
  88static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
  89{
  90        return __blk_mq_get_ctx(q, get_cpu());
  91}
  92
  93static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
  94{
  95        put_cpu();
  96}
  97
  98struct blk_mq_alloc_data {
  99        /* input parameter */
 100        struct request_queue *q;
 101        gfp_t gfp;
 102        bool reserved;
 103
 104        /* input & output parameter */
 105        struct blk_mq_ctx *ctx;
 106        struct blk_mq_hw_ctx *hctx;
 107};
 108
 109static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
 110                struct request_queue *q, gfp_t gfp, bool reserved,
 111                struct blk_mq_ctx *ctx,
 112                struct blk_mq_hw_ctx *hctx)
 113{
 114        data->q = q;
 115        data->gfp = gfp;
 116        data->reserved = reserved;
 117        data->ctx = ctx;
 118        data->hctx = hctx;
 119}
 120
 121static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 122{
 123        return hctx->nr_ctx && hctx->tags;
 124}
 125
 126#endif
 127