include/linux/blk-mq.h

   1 #ifndef BLK_MQ_H
   2 #define BLK_MQ_H
   3
   4 #include <linux/blkdev.h>
   5
   6 struct blk_mq_tags;
   7
   8 struct blk_mq_cpu_notifier {
   9         struct list_head list;
  10         void *data;
  11         void (*notify)(void *data, unsigned long action, unsigned int cpu);
  12 };
  13
  14 struct blk_mq_hw_ctx {
  15         struct {
  16                 spinlock_t              lock;
  17                 struct list_head        dispatch;
  18         } ____cacheline_aligned_in_smp;
  19
  20         unsigned long           state;          /* BLK_MQ_S_* flags */
  21         struct delayed_work     run_work;
  22         struct delayed_work     delay_work;
  23         cpumask_var_t           cpumask;
  24
  25         unsigned long           flags;          /* BLK_MQ_F_* flags */
  26
  27         struct request_queue    *queue;
  28         unsigned int            queue_num;
  29
  30         void                    *driver_data;
  31
  32         unsigned int            nr_ctx;
  33         struct blk_mq_ctx       **ctxs;
  34         unsigned int            nr_ctx_map;
  35         unsigned long           *ctx_map;
  36
  37         struct blk_mq_tags      *tags;
  38
  39         unsigned long           queued;
  40         unsigned long           run;
  41 #define BLK_MQ_MAX_DISPATCH_ORDER       10
  42         unsigned long           dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
  43
  44         unsigned int            numa_node;
  45         unsigned int            cmd_size;       /* per-request extra data */
  46
  47         struct blk_mq_cpu_notifier      cpu_notifier;
  48         struct kobject          kobj;
  49 };
  50
  51 struct blk_mq_tag_set {
  52         struct blk_mq_ops       *ops;
  53         unsigned int            nr_hw_queues;
  54         unsigned int            queue_depth;
  55         unsigned int            reserved_tags;
  56         unsigned int            cmd_size;       /* per-request extra data */
  57         int                     numa_node;
  58         unsigned int            timeout;
  59         unsigned int            flags;          /* BLK_MQ_F_* */
  60         void                    *driver_data;
  61
  62         struct blk_mq_tags      **tags;
  63 };
  64
  65 typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *);
  66 typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
  67 typedef struct blk_mq_hw_ctx *(alloc_hctx_fn)(struct blk_mq_tag_set *,
  68                 unsigned int);
  69 typedef void (free_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
  70 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
  71 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
  72 typedef int (init_request_fn)(void *, struct request *, unsigned int,
  73                 unsigned int, unsigned int);
  74 typedef void (exit_request_fn)(void *, struct request *, unsigned int,
  75                 unsigned int);
  76
  77 struct blk_mq_ops {
  78         /*
  79          * Queue request
  80          */
  81         queue_rq_fn             *queue_rq;
  82
  83         /*
  84          * Map to specific hardware queue
  85          */
  86         map_queue_fn            *map_queue;
  87
  88         /*
  89          * Called on request timeout
  90          */
  91         rq_timed_out_fn         *timeout;
  92
  93         softirq_done_fn         *complete;
  94
  95         /*
  96          * Override for hctx allocations (should probably go)
  97          */
  98         alloc_hctx_fn           *alloc_hctx;
  99         free_hctx_fn            *free_hctx;
 100
 101         /*
 102          * Called when the block layer side of a hardware queue has been
 103          * set up, allowing the driver to allocate/init matching structures.
 104          * Ditto for exit/teardown.
 105          */
 106         init_hctx_fn            *init_hctx;
 107         exit_hctx_fn            *exit_hctx;
 108
 109         /*
 110          * Called for every command allocated by the block layer to allow
 111          * the driver to set up driver specific data.
 112          * Ditto for exit/teardown.
 113          */
 114         init_request_fn         *init_request;
 115         exit_request_fn         *exit_request;
 116 };
 117
 118 enum {
 119         BLK_MQ_RQ_QUEUE_OK      = 0,    /* queued fine */
 120         BLK_MQ_RQ_QUEUE_BUSY    = 1,    /* requeue IO for later */
 121         BLK_MQ_RQ_QUEUE_ERROR   = 2,    /* end IO with error */
 122
 123         BLK_MQ_F_SHOULD_MERGE   = 1 << 0,
 124         BLK_MQ_F_SHOULD_SORT    = 1 << 1,
 125         BLK_MQ_F_SHOULD_IPI     = 1 << 2,
 126
 127         BLK_MQ_S_STOPPED        = 0,
 128
 129         BLK_MQ_MAX_DEPTH        = 2048,
 130 };
 131
 132 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
 133 int blk_mq_register_disk(struct gendisk *);
 134 void blk_mq_unregister_disk(struct gendisk *);
 135
 136 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
 137 void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
 138
 139 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
 140
 141 void blk_mq_insert_request(struct request *, bool, bool, bool);
 142 void blk_mq_run_queues(struct request_queue *q, bool async);
 143 void blk_mq_free_request(struct request *rq);
 144 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
 145 struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp);
 146 struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, gfp_t gfp);
 147 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
 148
 149 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
 150 struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int);
 151 void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *, unsigned int);
 152
 153 void blk_mq_end_io(struct request *rq, int error);
 154 void __blk_mq_end_io(struct request *rq, int error);
 155
 156 void blk_mq_complete_request(struct request *rq);
 157
 158 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
 159 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
 160 void blk_mq_stop_hw_queues(struct request_queue *q);
 161 void blk_mq_start_hw_queues(struct request_queue *q);
 162 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
 163 void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
 164
 165 /*
 166  * Driver command data is immediately after the request. So subtract request
 167  * size to get back to the original request.
 168  */
 169 static inline struct request *blk_mq_rq_from_pdu(void *pdu)
 170 {
 171         return pdu - sizeof(struct request);
 172 }
 173 static inline void *blk_mq_rq_to_pdu(struct request *rq)
 174 {
 175         return (void *) rq + sizeof(*rq);
 176 }
 177
 178 #define queue_for_each_hw_ctx(q, hctx, i)                               \
 179         for ((i) = 0; (i) < (q)->nr_hw_queues &&                        \
 180              ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
 181
 182 #define queue_for_each_ctx(q, ctx, i)                                   \
 183         for ((i) = 0; (i) < (q)->nr_queues &&                           \
 184              ({ ctx = per_cpu_ptr((q)->queue_ctx, (i)); 1; }); (i)++)
 185
 186 #define hctx_for_each_ctx(hctx, ctx, i)                                 \
 187         for ((i) = 0; (i) < (hctx)->nr_ctx &&                           \
 188              ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
 189
 190 #define blk_ctx_sum(q, sum)                                             \
 191 ({                                                                      \
 192         struct blk_mq_ctx *__x;                                         \
 193         unsigned int __ret = 0, __i;                                    \
 194                                                                         \
 195         queue_for_each_ctx((q), __x, __i)                               \
 196                 __ret += sum;                                           \
 197         __ret;                                                          \
 198 })
 199
 200 #endif