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 struct blk_flush_queue;
   8
   9 struct blk_mq_cpu_notifier {
  10         struct list_head list;
  11         void *data;
  12         int (*notify)(void *data, unsigned long action, unsigned int cpu);
  13 };
  14
  15 struct blk_mq_ctxmap {
  16         unsigned int size;
  17         unsigned int bits_per_word;
  18         struct blk_align_bitmap *map;
  19 };
  20
  21 struct blk_mq_hw_ctx {
  22         struct {
  23                 spinlock_t              lock;
  24                 struct list_head        dispatch;
  25         } ____cacheline_aligned_in_smp;
  26
  27         unsigned long           state;          /* BLK_MQ_S_* flags */
  28         struct delayed_work     run_work;
  29         struct delayed_work     delay_work;
  30         cpumask_var_t           cpumask;
  31         int                     next_cpu;
  32         int                     next_cpu_batch;
  33
  34         unsigned long           flags;          /* BLK_MQ_F_* flags */
  35
  36         struct request_queue    *queue;
  37         struct blk_flush_queue  *fq;
  38
  39         void                    *driver_data;
  40
  41         struct blk_mq_ctxmap    ctx_map;
  42
  43         unsigned int            nr_ctx;
  44         struct blk_mq_ctx       **ctxs;
  45
  46         atomic_t                wait_index;
  47
  48         struct blk_mq_tags      *tags;
  49
  50         unsigned long           queued;
  51         unsigned long           run;
  52 #define BLK_MQ_MAX_DISPATCH_ORDER       10
  53         unsigned long           dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
  54
  55         unsigned int            numa_node;
  56         unsigned int            queue_num;
  57
  58         atomic_t                nr_active;
  59
  60         struct blk_mq_cpu_notifier      cpu_notifier;
  61         struct kobject          kobj;
  62
  63         unsigned long           poll_invoked;
  64         unsigned long           poll_success;
  65 };
  66
  67 struct blk_mq_tag_set {
  68         struct blk_mq_ops       *ops;
  69         unsigned int            nr_hw_queues;
  70         unsigned int            queue_depth;    /* max hw supported */
  71         unsigned int            reserved_tags;
  72         unsigned int            cmd_size;       /* per-request extra data */
  73         int                     numa_node;
  74         unsigned int            timeout;
  75         unsigned int            flags;          /* BLK_MQ_F_* */
  76         void                    *driver_data;
  77
  78         struct blk_mq_tags      **tags;
  79
  80         struct mutex            tag_list_lock;
  81         struct list_head        tag_list;
  82 };
  83
  84 struct blk_mq_queue_data {
  85         struct request *rq;
  86         struct list_head *list;
  87         bool last;
  88 };
  89
  90 typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, const struct blk_mq_queue_data *);
  91 typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
  92 typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool);
  93 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
  94 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
  95 typedef int (init_request_fn)(void *, struct request *, unsigned int,
  96                 unsigned int, unsigned int);
  97 typedef void (exit_request_fn)(void *, struct request *, unsigned int,
  98                 unsigned int);
  99
 100 typedef void (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
 101                 bool);
 102 typedef void (busy_tag_iter_fn)(struct request *, void *, bool);
 103 typedef int (poll_fn)(struct blk_mq_hw_ctx *, unsigned int);
 104
 105
 106 struct blk_mq_ops {
 107         /*
 108          * Queue request
 109          */
 110         queue_rq_fn             *queue_rq;
 111
 112         /*
 113          * Map to specific hardware queue
 114          */
 115         map_queue_fn            *map_queue;
 116
 117         /*
 118          * Called on request timeout
 119          */
 120         timeout_fn              *timeout;
 121
 122         /*
 123          * Called to poll for completion of a specific tag.
 124          */
 125         poll_fn                 *poll;
 126
 127         softirq_done_fn         *complete;
 128
 129         /*
 130          * Called when the block layer side of a hardware queue has been
 131          * set up, allowing the driver to allocate/init matching structures.
 132          * Ditto for exit/teardown.
 133          */
 134         init_hctx_fn            *init_hctx;
 135         exit_hctx_fn            *exit_hctx;
 136
 137         /*
 138          * Called for every command allocated by the block layer to allow
 139          * the driver to set up driver specific data.
 140          *
 141          * Tag greater than or equal to queue_depth is for setting up
 142          * flush request.
 143          *
 144          * Ditto for exit/teardown.
 145          */
 146         init_request_fn         *init_request;
 147         exit_request_fn         *exit_request;
 148 };
 149
 150 enum {
 151         BLK_MQ_RQ_QUEUE_OK      = 0,    /* queued fine */
 152         BLK_MQ_RQ_QUEUE_BUSY    = 1,    /* requeue IO for later */
 153         BLK_MQ_RQ_QUEUE_ERROR   = 2,    /* end IO with error */
 154
 155         BLK_MQ_F_SHOULD_MERGE   = 1 << 0,
 156         BLK_MQ_F_TAG_SHARED     = 1 << 1,
 157         BLK_MQ_F_SG_MERGE       = 1 << 2,
 158         BLK_MQ_F_DEFER_ISSUE    = 1 << 4,
 159         BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
 160         BLK_MQ_F_ALLOC_POLICY_BITS = 1,
 161
 162         BLK_MQ_S_STOPPED        = 0,
 163         BLK_MQ_S_TAG_ACTIVE     = 1,
 164
 165         BLK_MQ_MAX_DEPTH        = 10240,
 166
 167         BLK_MQ_CPU_WORK_BATCH   = 8,
 168 };
 169 #define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \
 170         ((flags >> BLK_MQ_F_ALLOC_POLICY_START_BIT) & \
 171                 ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1))
 172 #define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \
 173         ((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \
 174                 << BLK_MQ_F_ALLOC_POLICY_START_BIT)
 175
 176 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
 177 struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
 178                                                   struct request_queue *q);
 179 int blk_mq_register_disk(struct gendisk *);
 180 void blk_mq_unregister_disk(struct gendisk *);
 181
 182 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
 183 void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
 184
 185 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
 186
 187 void blk_mq_insert_request(struct request *, bool, bool, bool);
 188 void blk_mq_free_request(struct request *rq);
 189 void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *, struct request *rq);
 190 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
 191
 192 enum {
 193         BLK_MQ_REQ_NOWAIT       = (1 << 0), /* return when out of requests */
 194         BLK_MQ_REQ_RESERVED     = (1 << 1), /* allocate from reserved pool */
 195 };
 196
 197 struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
 198                 unsigned int flags);
 199 struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int op,
 200                 unsigned int flags, unsigned int hctx_idx);
 201 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
 202 struct cpumask *blk_mq_tags_cpumask(struct blk_mq_tags *tags);
 203
 204 enum {
 205         BLK_MQ_UNIQUE_TAG_BITS = 16,
 206         BLK_MQ_UNIQUE_TAG_MASK = (1 << BLK_MQ_UNIQUE_TAG_BITS) - 1,
 207 };
 208
 209 u32 blk_mq_unique_tag(struct request *rq);
 210
 211 static inline u16 blk_mq_unique_tag_to_hwq(u32 unique_tag)
 212 {
 213         return unique_tag >> BLK_MQ_UNIQUE_TAG_BITS;
 214 }
 215
 216 static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
 217 {
 218         return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
 219 }
 220
 221 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
 222 struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int, int);
 223
 224 int blk_mq_request_started(struct request *rq);
 225 void blk_mq_start_request(struct request *rq);
 226 void blk_mq_end_request(struct request *rq, int error);
 227 void __blk_mq_end_request(struct request *rq, int error);
 228
 229 void blk_mq_requeue_request(struct request *rq);
 230 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head);
 231 void blk_mq_cancel_requeue_work(struct request_queue *q);
 232 void blk_mq_kick_requeue_list(struct request_queue *q);
 233 void blk_mq_abort_requeue_list(struct request_queue *q);
 234 void blk_mq_complete_request(struct request *rq, int error);
 235
 236 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
 237 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
 238 void blk_mq_stop_hw_queues(struct request_queue *q);
 239 void blk_mq_start_hw_queues(struct request_queue *q);
 240 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
 241 void blk_mq_run_hw_queues(struct request_queue *q, bool async);
 242 void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
 243 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
 244                 busy_tag_iter_fn *fn, void *priv);
 245 void blk_mq_freeze_queue(struct request_queue *q);
 246 void blk_mq_unfreeze_queue(struct request_queue *q);
 247 void blk_mq_freeze_queue_start(struct request_queue *q);
 248
 249 void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues);
 250
 251 /*
 252  * Driver command data is immediately after the request. So subtract request
 253  * size to get back to the original request, add request size to get the PDU.
 254  */
 255 static inline struct request *blk_mq_rq_from_pdu(void *pdu)
 256 {
 257         return pdu - sizeof(struct request);
 258 }
 259 static inline void *blk_mq_rq_to_pdu(struct request *rq)
 260 {
 261         return rq + 1;
 262 }
 263
 264 #define queue_for_each_hw_ctx(q, hctx, i)                               \
 265         for ((i) = 0; (i) < (q)->nr_hw_queues &&                        \
 266              ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
 267
 268 #define hctx_for_each_ctx(hctx, ctx, i)                                 \
 269         for ((i) = 0; (i) < (hctx)->nr_ctx &&                           \
 270              ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
 271
 272 #endif