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         int (*notify)(void *data, unsigned long action, unsigned int cpu);
  12 };
  13
  14 struct blk_mq_ctxmap {
  15         unsigned int map_size;
  16         unsigned int bits_per_word;
  17         struct blk_align_bitmap *map;
  18 };
  19
  20 struct blk_mq_hw_ctx {
  21         struct {
  22                 spinlock_t              lock;
  23                 struct list_head        dispatch;
  24         } ____cacheline_aligned_in_smp;
  25
  26         unsigned long           state;          /* BLK_MQ_S_* flags */
  27         struct delayed_work     run_work;
  28         struct delayed_work     delay_work;
  29         cpumask_var_t           cpumask;
  30         int                     next_cpu;
  31         int                     next_cpu_batch;
  32
  33         unsigned long           flags;          /* BLK_MQ_F_* flags */
  34
  35         struct request_queue    *queue;
  36         unsigned int            queue_num;
  37
  38         void                    *driver_data;
  39
  40         struct blk_mq_ctxmap    ctx_map;
  41
  42         unsigned int            nr_ctx;
  43         struct blk_mq_ctx       **ctxs;
  44
  45         atomic_t                wait_index;
  46
  47         struct blk_mq_tags      *tags;
  48
  49         unsigned long           queued;
  50         unsigned long           run;
  51 #define BLK_MQ_MAX_DISPATCH_ORDER       10
  52         unsigned long           dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
  53
  54         unsigned int            numa_node;
  55         unsigned int            cmd_size;       /* per-request extra data */
  56
  57         atomic_t                nr_active;
  58
  59         struct blk_mq_cpu_notifier      cpu_notifier;
  60         struct kobject          kobj;
  61 };
  62
  63 struct blk_mq_tag_set {
  64         struct blk_mq_ops       *ops;
  65         unsigned int            nr_hw_queues;
  66         unsigned int            queue_depth;    /* max hw supported */
  67         unsigned int            reserved_tags;
  68         unsigned int            cmd_size;       /* per-request extra data */
  69         int                     numa_node;
  70         unsigned int            timeout;
  71         unsigned int            flags;          /* BLK_MQ_F_* */
  72         void                    *driver_data;
  73
  74         struct blk_mq_tags      **tags;
  75
  76         struct mutex            tag_list_lock;
  77         struct list_head        tag_list;
  78 };
  79
  80 typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *, bool);
  81 typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
  82 typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool);
  83 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
  84 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
  85 typedef int (init_request_fn)(void *, struct request *, unsigned int,
  86                 unsigned int, unsigned int);
  87 typedef void (exit_request_fn)(void *, struct request *, unsigned int,
  88                 unsigned int);
  89
  90 typedef void (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
  91                 bool);
  92
  93 struct blk_mq_ops {
  94         /*
  95          * Queue request
  96          */
  97         queue_rq_fn             *queue_rq;
  98
  99         /*
 100          * Map to specific hardware queue
 101          */
 102         map_queue_fn            *map_queue;
 103
 104         /*
 105          * Called on request timeout
 106          */
 107         timeout_fn              *timeout;
 108
 109         softirq_done_fn         *complete;
 110
 111         /*
 112          * Called when the block layer side of a hardware queue has been
 113          * set up, allowing the driver to allocate/init matching structures.
 114          * Ditto for exit/teardown.
 115          */
 116         init_hctx_fn            *init_hctx;
 117         exit_hctx_fn            *exit_hctx;
 118
 119         /*
 120          * Called for every command allocated by the block layer to allow
 121          * the driver to set up driver specific data.
 122          * Ditto for exit/teardown.
 123          */
 124         init_request_fn         *init_request;
 125         exit_request_fn         *exit_request;
 126 };
 127
 128 enum {
 129         BLK_MQ_RQ_QUEUE_OK      = 0,    /* queued fine */
 130         BLK_MQ_RQ_QUEUE_BUSY    = 1,    /* requeue IO for later */
 131         BLK_MQ_RQ_QUEUE_ERROR   = 2,    /* end IO with error */
 132
 133         BLK_MQ_F_SHOULD_MERGE   = 1 << 0,
 134         BLK_MQ_F_TAG_SHARED     = 1 << 1,
 135         BLK_MQ_F_SG_MERGE       = 1 << 2,
 136         BLK_MQ_F_SYSFS_UP       = 1 << 3,
 137
 138         BLK_MQ_S_STOPPED        = 0,
 139         BLK_MQ_S_TAG_ACTIVE     = 1,
 140
 141         BLK_MQ_MAX_DEPTH        = 10240,
 142
 143         BLK_MQ_CPU_WORK_BATCH   = 8,
 144 };
 145
 146 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
 147 int blk_mq_register_disk(struct gendisk *);
 148 void blk_mq_unregister_disk(struct gendisk *);
 149
 150 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
 151 void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
 152
 153 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
 154
 155 void blk_mq_insert_request(struct request *, bool, bool, bool);
 156 void blk_mq_run_queues(struct request_queue *q, bool async);
 157 void blk_mq_free_request(struct request *rq);
 158 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
 159 struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
 160                 gfp_t gfp, bool reserved);
 161 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
 162
 163 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
 164 struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int, int);
 165
 166 void blk_mq_start_request(struct request *rq);
 167 void blk_mq_end_request(struct request *rq, int error);
 168 void __blk_mq_end_request(struct request *rq, int error);
 169
 170 void blk_mq_requeue_request(struct request *rq);
 171 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head);
 172 void blk_mq_kick_requeue_list(struct request_queue *q);
 173 void blk_mq_complete_request(struct request *rq);
 174
 175 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
 176 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
 177 void blk_mq_stop_hw_queues(struct request_queue *q);
 178 void blk_mq_start_hw_queues(struct request_queue *q);
 179 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
 180 void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
 181 void blk_mq_tag_busy_iter(struct blk_mq_hw_ctx *hctx, busy_iter_fn *fn,
 182                 void *priv);
 183
 184 /*
 185  * Driver command data is immediately after the request. So subtract request
 186  * size to get back to the original request.
 187  */
 188 static inline struct request *blk_mq_rq_from_pdu(void *pdu)
 189 {
 190         return pdu - sizeof(struct request);
 191 }
 192 static inline void *blk_mq_rq_to_pdu(struct request *rq)
 193 {
 194         return (void *) rq + sizeof(*rq);
 195 }
 196
 197 #define queue_for_each_hw_ctx(q, hctx, i)                               \
 198         for ((i) = 0; (i) < (q)->nr_hw_queues &&                        \
 199              ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
 200
 201 #define queue_for_each_ctx(q, ctx, i)                                   \
 202         for ((i) = 0; (i) < (q)->nr_queues &&                           \
 203              ({ ctx = per_cpu_ptr((q)->queue_ctx, (i)); 1; }); (i)++)
 204
 205 #define hctx_for_each_ctx(hctx, ctx, i)                                 \
 206         for ((i) = 0; (i) < (hctx)->nr_ctx &&                           \
 207              ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
 208
 209 #define blk_ctx_sum(q, sum)                                             \
 210 ({                                                                      \
 211         struct blk_mq_ctx *__x;                                         \
 212         unsigned int __ret = 0, __i;                                    \
 213                                                                         \
 214         queue_for_each_ctx((q), __x, __i)                               \
 215                 __ret += sum;                                           \
 216         __ret;                                                          \
 217 })
 218
 219 #endif