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 bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx);
  37 bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
  38                                 bool wait);
  39
  40 /*
  41  * Internal helpers for allocating/freeing the request map
  42  */
  43 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  44                      unsigned int hctx_idx);
  45 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
  46 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
  47                                         unsigned int hctx_idx,
  48                                         unsigned int nr_tags,
  49                                         unsigned int reserved_tags);
  50 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  51                      unsigned int hctx_idx, unsigned int depth);
  52
  53 /*
  54  * Internal helpers for request insertion into sw queues
  55  */
  56 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
  57                                 bool at_head);
  58 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
  59                                 struct list_head *list);
  60 /*
  61  * CPU hotplug helpers
  62  */
  63 void blk_mq_enable_hotplug(void);
  64 void blk_mq_disable_hotplug(void);
  65
  66 /*
  67  * CPU -> queue mappings
  68  */
  69 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
  70
  71 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  72                 int cpu)
  73 {
  74         return q->queue_hw_ctx[q->mq_map[cpu]];
  75 }
  76
  77 /*
  78  * sysfs helpers
  79  */
  80 extern int blk_mq_sysfs_register(struct request_queue *q);
  81 extern void blk_mq_sysfs_unregister(struct request_queue *q);
  82 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
  83
  84 /*
  85  * debugfs helpers
  86  */
  87 #ifdef CONFIG_DEBUG_FS
  88 void blk_mq_debugfs_init(void);
  89 int blk_mq_debugfs_register(struct request_queue *q, const char *name);
  90 void blk_mq_debugfs_unregister(struct request_queue *q);
  91 int blk_mq_debugfs_register_hctxs(struct request_queue *q);
  92 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q);
  93 #else
  94 static inline void blk_mq_debugfs_init(void)
  95 {
  96 }
  97
  98 int blk_mq_debugfs_register(struct request_queue *q, const char *name);
  99 {
 100         return 0;
 101 }
 102
 103 void blk_mq_debugfs_unregister(struct request_queue *q)
 104 {
 105 }
 106
 107 int blk_mq_debugfs_register_hctxs(struct request_queue *q)
 108 {
 109         return 0;
 110 }
 111
 112 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
 113 {
 114 }
 115 #endif
 116
 117 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
 118
 119 void blk_mq_release(struct request_queue *q);
 120
 121 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
 122                                            unsigned int cpu)
 123 {
 124         return per_cpu_ptr(q->queue_ctx, cpu);
 125 }
 126
 127 /*
 128  * This assumes per-cpu software queueing queues. They could be per-node
 129  * as well, for instance. For now this is hardcoded as-is. Note that we don't
 130  * care about preemption, since we know the ctx's are persistent. This does
 131  * mean that we can't rely on ctx always matching the currently running CPU.
 132  */
 133 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 134 {
 135         return __blk_mq_get_ctx(q, get_cpu());
 136 }
 137
 138 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 139 {
 140         put_cpu();
 141 }
 142
 143 struct blk_mq_alloc_data {
 144         /* input parameter */
 145         struct request_queue *q;
 146         unsigned int flags;
 147
 148         /* input & output parameter */
 149         struct blk_mq_ctx *ctx;
 150         struct blk_mq_hw_ctx *hctx;
 151 };
 152
 153 static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
 154                 struct request_queue *q, unsigned int flags,
 155                 struct blk_mq_ctx *ctx, struct blk_mq_hw_ctx *hctx)
 156 {
 157         data->q = q;
 158         data->flags = flags;
 159         data->ctx = ctx;
 160         data->hctx = hctx;
 161 }
 162
 163 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
 164 {
 165         if (data->flags & BLK_MQ_REQ_INTERNAL)
 166                 return data->hctx->sched_tags;
 167
 168         return data->hctx->tags;
 169 }
 170
 171 /*
 172  * Internal helpers for request allocation/init/free
 173  */
 174 void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
 175                         struct request *rq, unsigned int op);
 176 void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
 177                                 struct request *rq);
 178 void blk_mq_finish_request(struct request *rq);
 179 struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data,
 180                                         unsigned int op);
 181
 182 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
 183 {
 184         return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
 185 }
 186
 187 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
 188 {
 189         return hctx->nr_ctx && hctx->tags;
 190 }
 191
 192 #endif