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         int                     next_cpu;
  25         int                     next_cpu_batch;
  26
  27         unsigned long           flags;          /* BLK_MQ_F_* flags */
  28
  29         struct request_queue    *queue;
  30         unsigned int            queue_num;
  31
  32         void                    *driver_data;
  33
  34         unsigned int            nr_ctx_map;
  35         unsigned long           *ctx_map;
  36         unsigned int            nr_ctx;
  37         struct blk_mq_ctx       **ctxs;
  38
  39         unsigned int            wait_index;
  40
  41         struct blk_mq_tags      *tags;
  42
  43         unsigned long           queued;
  44         unsigned long           run;
  45 #define BLK_MQ_MAX_DISPATCH_ORDER       10
  46         unsigned long           dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
  47
  48         unsigned int            numa_node;
  49         unsigned int            cmd_size;       /* per-request extra data */
  50
  51         struct blk_mq_cpu_notifier      cpu_notifier;
  52         struct kobject          kobj;
  53 };
  54
  55 struct blk_mq_tag_set {
  56         struct blk_mq_ops       *ops;
  57         unsigned int            nr_hw_queues;
  58         unsigned int            queue_depth;
  59         unsigned int            reserved_tags;
  60         unsigned int            cmd_size;       /* per-request extra data */
  61         int                     numa_node;
  62         unsigned int            timeout;
  63         unsigned int            flags;          /* BLK_MQ_F_* */
  64         void                    *driver_data;
  65
  66         struct blk_mq_tags      **tags;
  67 };
  68
  69 typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *);
  70 typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
  71 typedef struct blk_mq_hw_ctx *(alloc_hctx_fn)(struct blk_mq_tag_set *,
  72                 unsigned int);
  73 typedef void (free_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
  74 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
  75 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
  76 typedef int (init_request_fn)(void *, struct request *, unsigned int,
  77                 unsigned int, unsigned int);
  78 typedef void (exit_request_fn)(void *, struct request *, unsigned int,
  79                 unsigned int);
  80
  81 struct blk_mq_ops {
  82         /*
  83          * Queue request
  84          */
  85         queue_rq_fn             *queue_rq;
  86
  87         /*
  88          * Map to specific hardware queue
  89          */
  90         map_queue_fn            *map_queue;
  91
  92         /*
  93          * Called on request timeout
  94          */
  95         rq_timed_out_fn         *timeout;
  96
  97         softirq_done_fn         *complete;
  98
  99         /*
 100          * Override for hctx allocations (should probably go)
 101          */
 102         alloc_hctx_fn           *alloc_hctx;
 103         free_hctx_fn            *free_hctx;
 104
 105         /*
 106          * Called when the block layer side of a hardware queue has been
 107          * set up, allowing the driver to allocate/init matching structures.
 108          * Ditto for exit/teardown.
 109          */
 110         init_hctx_fn            *init_hctx;
 111         exit_hctx_fn            *exit_hctx;
 112
 113         /*
 114          * Called for every command allocated by the block layer to allow
 115          * the driver to set up driver specific data.
 116          * Ditto for exit/teardown.
 117          */
 118         init_request_fn         *init_request;
 119         exit_request_fn         *exit_request;
 120 };
 121
 122 enum {
 123         BLK_MQ_RQ_QUEUE_OK      = 0,    /* queued fine */
 124         BLK_MQ_RQ_QUEUE_BUSY    = 1,    /* requeue IO for later */
 125         BLK_MQ_RQ_QUEUE_ERROR   = 2,    /* end IO with error */
 126
 127         BLK_MQ_F_SHOULD_MERGE   = 1 << 0,
 128         BLK_MQ_F_SHOULD_SORT    = 1 << 1,
 129
 130         BLK_MQ_S_STOPPED        = 0,
 131
 132         BLK_MQ_MAX_DEPTH        = 2048,
 133
 134         BLK_MQ_CPU_WORK_BATCH   = 8,
 135 };
 136
 137 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
 138 int blk_mq_register_disk(struct gendisk *);
 139 void blk_mq_unregister_disk(struct gendisk *);
 140
 141 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
 142 void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
 143
 144 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
 145
 146 void blk_mq_insert_request(struct request *, bool, bool, bool);
 147 void blk_mq_run_queues(struct request_queue *q, bool async);
 148 void blk_mq_free_request(struct request *rq);
 149 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
 150 struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp);
 151 struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, gfp_t gfp);
 152 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
 153
 154 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
 155 struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int);
 156 void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *, unsigned int);
 157
 158 void blk_mq_end_io(struct request *rq, int error);
 159 void __blk_mq_end_io(struct request *rq, int error);
 160
 161 void blk_mq_requeue_request(struct request *rq);
 162
 163 void blk_mq_complete_request(struct request *rq);
 164
 165 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
 166 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
 167 void blk_mq_stop_hw_queues(struct request_queue *q);
 168 void blk_mq_start_hw_queues(struct request_queue *q);
 169 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
 170 void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
 171
 172 /*
 173  * Driver command data is immediately after the request. So subtract request
 174  * size to get back to the original request.
 175  */
 176 static inline struct request *blk_mq_rq_from_pdu(void *pdu)
 177 {
 178         return pdu - sizeof(struct request);
 179 }
 180 static inline void *blk_mq_rq_to_pdu(struct request *rq)
 181 {
 182         return (void *) rq + sizeof(*rq);
 183 }
 184
 185 #define queue_for_each_hw_ctx(q, hctx, i)                               \
 186         for ((i) = 0; (i) < (q)->nr_hw_queues &&                        \
 187              ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
 188
 189 #define queue_for_each_ctx(q, ctx, i)                                   \
 190         for ((i) = 0; (i) < (q)->nr_queues &&                           \
 191              ({ ctx = per_cpu_ptr((q)->queue_ctx, (i)); 1; }); (i)++)
 192
 193 #define hctx_for_each_ctx(hctx, ctx, i)                                 \
 194         for ((i) = 0; (i) < (hctx)->nr_ctx &&                           \
 195              ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
 196
 197 #define blk_ctx_sum(q, sum)                                             \
 198 ({                                                                      \
 199         struct blk_mq_ctx *__x;                                         \
 200         unsigned int __ret = 0, __i;                                    \
 201                                                                         \
 202         queue_for_each_ctx((q), __x, __i)                               \
 203                 __ret += sum;                                           \
 204         __ret;                                                          \
 205 })
 206
 207 #endif