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     delayed_work;
  22
  23         unsigned long           flags;          /* BLK_MQ_F_* flags */
  24
  25         struct request_queue    *queue;
  26         unsigned int            queue_num;
  27
  28         void                    *driver_data;
  29
  30         unsigned int            nr_ctx;
  31         struct blk_mq_ctx       **ctxs;
  32         unsigned int            nr_ctx_map;
  33         unsigned long           *ctx_map;
  34
  35         struct request          **rqs;
  36         struct list_head        page_list;
  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            queue_depth;
  45         unsigned int            numa_node;
  46         unsigned int            cmd_size;       /* per-request extra data */
  47
  48         struct blk_mq_cpu_notifier      cpu_notifier;
  49         struct kobject          kobj;
  50 };
  51
  52 struct blk_mq_reg {
  53         struct blk_mq_ops       *ops;
  54         unsigned int            nr_hw_queues;
  55         unsigned int            queue_depth;
  56         unsigned int            reserved_tags;
  57         unsigned int            cmd_size;       /* per-request extra data */
  58         int                     numa_node;
  59         unsigned int            timeout;
  60         unsigned int            flags;          /* BLK_MQ_F_* */
  61 };
  62
  63 typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *);
  64 typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
  65 typedef struct blk_mq_hw_ctx *(alloc_hctx_fn)(struct blk_mq_reg *,unsigned int);
  66 typedef void (free_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
  67 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
  68 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
  69
  70 struct blk_mq_ops {
  71         /*
  72          * Queue request
  73          */
  74         queue_rq_fn             *queue_rq;
  75
  76         /*
  77          * Map to specific hardware queue
  78          */
  79         map_queue_fn            *map_queue;
  80
  81         /*
  82          * Called on request timeout
  83          */
  84         rq_timed_out_fn         *timeout;
  85
  86         /*
  87          * Override for hctx allocations (should probably go)
  88          */
  89         alloc_hctx_fn           *alloc_hctx;
  90         free_hctx_fn            *free_hctx;
  91
  92         /*
  93          * Called when the block layer side of a hardware queue has been
  94          * set up, allowing the driver to allocate/init matching structures.
  95          * Ditto for exit/teardown.
  96          */
  97         init_hctx_fn            *init_hctx;
  98         exit_hctx_fn            *exit_hctx;
  99 };
 100
 101 enum {
 102         BLK_MQ_RQ_QUEUE_OK      = 0,    /* queued fine */
 103         BLK_MQ_RQ_QUEUE_BUSY    = 1,    /* requeue IO for later */
 104         BLK_MQ_RQ_QUEUE_ERROR   = 2,    /* end IO with error */
 105
 106         BLK_MQ_F_SHOULD_MERGE   = 1 << 0,
 107         BLK_MQ_F_SHOULD_SORT    = 1 << 1,
 108         BLK_MQ_F_SHOULD_IPI     = 1 << 2,
 109
 110         BLK_MQ_S_STOPPED        = 1 << 0,
 111
 112         BLK_MQ_MAX_DEPTH        = 2048,
 113 };
 114
 115 struct request_queue *blk_mq_init_queue(struct blk_mq_reg *, void *);
 116 void blk_mq_free_queue(struct request_queue *);
 117 int blk_mq_register_disk(struct gendisk *);
 118 void blk_mq_unregister_disk(struct gendisk *);
 119 void blk_mq_init_commands(struct request_queue *, void (*init)(void *data, struct blk_mq_hw_ctx *, struct request *, unsigned int), void *data);
 120
 121 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
 122
 123 void blk_mq_insert_request(struct request_queue *, struct request *, bool);
 124 void blk_mq_run_queues(struct request_queue *q, bool async);
 125 void blk_mq_free_request(struct request *rq);
 126 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
 127 struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp, bool reserved);
 128 struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, gfp_t gfp);
 129 struct request *blk_mq_rq_from_tag(struct request_queue *q, unsigned int tag);
 130
 131 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
 132 struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_reg *, unsigned int);
 133 void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *, unsigned int);
 134
 135 void blk_mq_end_io(struct request *rq, int error);
 136
 137 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
 138 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
 139 void blk_mq_stop_hw_queues(struct request_queue *q);
 140 void blk_mq_start_stopped_hw_queues(struct request_queue *q);
 141
 142 /*
 143  * Driver command data is immediately after the request. So subtract request
 144  * size to get back to the original request.
 145  */
 146 static inline struct request *blk_mq_rq_from_pdu(void *pdu)
 147 {
 148         return pdu - sizeof(struct request);
 149 }
 150 static inline void *blk_mq_rq_to_pdu(struct request *rq)
 151 {
 152         return (void *) rq + sizeof(*rq);
 153 }
 154
 155 static inline struct request *blk_mq_tag_to_rq(struct blk_mq_hw_ctx *hctx,
 156                                                unsigned int tag)
 157 {
 158         return hctx->rqs[tag];
 159 }
 160
 161 #define queue_for_each_hw_ctx(q, hctx, i)                               \
 162         for ((i) = 0, hctx = (q)->queue_hw_ctx[0];                      \
 163              (i) < (q)->nr_hw_queues; (i)++, hctx = (q)->queue_hw_ctx[i])
 164
 165 #define queue_for_each_ctx(q, ctx, i)                                   \
 166         for ((i) = 0, ctx = per_cpu_ptr((q)->queue_ctx, 0);             \
 167              (i) < (q)->nr_queues; (i)++, ctx = per_cpu_ptr(q->queue_ctx, (i)))
 168
 169 #define hctx_for_each_ctx(hctx, ctx, i)                                 \
 170         for ((i) = 0, ctx = (hctx)->ctxs[0];                            \
 171              (i) < (hctx)->nr_ctx; (i)++, ctx = (hctx)->ctxs[(i)])
 172
 173 #define blk_ctx_sum(q, sum)                                             \
 174 ({                                                                      \
 175         struct blk_mq_ctx *__x;                                         \
 176         unsigned int __ret = 0, __i;                                    \
 177                                                                         \
 178         queue_for_each_ctx((q), __x, __i)                               \
 179                 __ret += sum;                                           \
 180         __ret;                                                          \
 181 })
 182
 183 #endif