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         softirq_done_fn         *complete;
  87
  88         /*
  89          * Override for hctx allocations (should probably go)
  90          */
  91         alloc_hctx_fn           *alloc_hctx;
  92         free_hctx_fn            *free_hctx;
  93
  94         /*
  95          * Called when the block layer side of a hardware queue has been
  96          * set up, allowing the driver to allocate/init matching structures.
  97          * Ditto for exit/teardown.
  98          */
  99         init_hctx_fn            *init_hctx;
 100         exit_hctx_fn            *exit_hctx;
 101 };
 102
 103 enum {
 104         BLK_MQ_RQ_QUEUE_OK      = 0,    /* queued fine */
 105         BLK_MQ_RQ_QUEUE_BUSY    = 1,    /* requeue IO for later */
 106         BLK_MQ_RQ_QUEUE_ERROR   = 2,    /* end IO with error */
 107
 108         BLK_MQ_F_SHOULD_MERGE   = 1 << 0,
 109         BLK_MQ_F_SHOULD_SORT    = 1 << 1,
 110         BLK_MQ_F_SHOULD_IPI     = 1 << 2,
 111
 112         BLK_MQ_S_STOPPED        = 1 << 0,
 113
 114         BLK_MQ_MAX_DEPTH        = 2048,
 115 };
 116
 117 struct request_queue *blk_mq_init_queue(struct blk_mq_reg *, void *);
 118 int blk_mq_register_disk(struct gendisk *);
 119 void blk_mq_unregister_disk(struct gendisk *);
 120 void blk_mq_init_commands(struct request_queue *, void (*init)(void *data, struct blk_mq_hw_ctx *, struct request *, unsigned int), void *data);
 121
 122 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
 123
 124 void blk_mq_insert_request(struct request *, bool, bool, bool);
 125 void blk_mq_run_queues(struct request_queue *q, bool async);
 126 void blk_mq_free_request(struct request *rq);
 127 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
 128 struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp);
 129 struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, gfp_t gfp);
 130 struct request *blk_mq_rq_from_tag(struct request_queue *q, unsigned int tag);
 131
 132 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
 133 struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_reg *, unsigned int);
 134 void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *, unsigned int);
 135
 136 bool blk_mq_end_io_partial(struct request *rq, int error,
 137                 unsigned int nr_bytes);
 138 static inline void blk_mq_end_io(struct request *rq, int error)
 139 {
 140         bool done = !blk_mq_end_io_partial(rq, error, blk_rq_bytes(rq));
 141         BUG_ON(!done);
 142 }
 143
 144 void blk_mq_complete_request(struct request *rq);
 145
 146 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
 147 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
 148 void blk_mq_stop_hw_queues(struct request_queue *q);
 149 void blk_mq_start_stopped_hw_queues(struct request_queue *q);
 150
 151 /*
 152  * Driver command data is immediately after the request. So subtract request
 153  * size to get back to the original request.
 154  */
 155 static inline struct request *blk_mq_rq_from_pdu(void *pdu)
 156 {
 157         return pdu - sizeof(struct request);
 158 }
 159 static inline void *blk_mq_rq_to_pdu(struct request *rq)
 160 {
 161         return (void *) rq + sizeof(*rq);
 162 }
 163
 164 static inline struct request *blk_mq_tag_to_rq(struct blk_mq_hw_ctx *hctx,
 165                                                unsigned int tag)
 166 {
 167         return hctx->rqs[tag];
 168 }
 169
 170 #define queue_for_each_hw_ctx(q, hctx, i)                               \
 171         for ((i) = 0; (i) < (q)->nr_hw_queues &&                        \
 172              ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
 173
 174 #define queue_for_each_ctx(q, ctx, i)                                   \
 175         for ((i) = 0; (i) < (q)->nr_queues &&                           \
 176              ({ ctx = per_cpu_ptr((q)->queue_ctx, (i)); 1; }); (i)++)
 177
 178 #define hctx_for_each_ctx(hctx, ctx, i)                                 \
 179         for ((i) = 0; (i) < (hctx)->nr_ctx &&                           \
 180              ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
 181
 182 #define blk_ctx_sum(q, sum)                                             \
 183 ({                                                                      \
 184         struct blk_mq_ctx *__x;                                         \
 185         unsigned int __ret = 0, __i;                                    \
 186                                                                         \
 187         queue_for_each_ctx((q), __x, __i)                               \
 188                 __ret += sum;                                           \
 189         __ret;                                                          \
 190 })
 191
 192 #endif