include/linux/blk-mq.h

   1 #ifndef BLK_MQ_H
   2 #define BLK_MQ_H
   3
   4 #include <linux/blkdev.h>
   5 #include <linux/sbitmap.h>
   6 #include <linux/srcu.h>
   7
   8 struct blk_mq_tags;
   9 struct blk_flush_queue;
  10
  11 struct blk_mq_hw_ctx {
  12         struct {
  13                 spinlock_t              lock;
  14                 struct list_head        dispatch;
  15                 unsigned long           state;          /* BLK_MQ_S_* flags */
  16         } ____cacheline_aligned_in_smp;
  17
  18         struct delayed_work     run_work;
  19         cpumask_var_t           cpumask;
  20         int                     next_cpu;
  21         int                     next_cpu_batch;
  22
  23         unsigned long           flags;          /* BLK_MQ_F_* flags */
  24
  25         void                    *sched_data;
  26         struct request_queue    *queue;
  27         struct blk_flush_queue  *fq;
  28
  29         void                    *driver_data;
  30
  31         struct sbitmap          ctx_map;
  32
  33         struct blk_mq_ctx       **ctxs;
  34         unsigned int            nr_ctx;
  35
  36         wait_queue_t            dispatch_wait;
  37         atomic_t                wait_index;
  38
  39         struct blk_mq_tags      *tags;
  40         struct blk_mq_tags      *sched_tags;
  41
  42         struct srcu_struct      queue_rq_srcu;
  43
  44         unsigned long           queued;
  45         unsigned long           run;
  46 #define BLK_MQ_MAX_DISPATCH_ORDER       7
  47         unsigned long           dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
  48
  49         unsigned int            numa_node;
  50         unsigned int            queue_num;
  51
  52         atomic_t                nr_active;
  53
  54         struct hlist_node       cpuhp_dead;
  55         struct kobject          kobj;
  56
  57         unsigned long           poll_considered;
  58         unsigned long           poll_invoked;
  59         unsigned long           poll_success;
  60
  61 #ifdef CONFIG_BLK_DEBUG_FS
  62         struct dentry           *debugfs_dir;
  63         struct dentry           *sched_debugfs_dir;
  64 #endif
  65 };
  66
  67 struct blk_mq_tag_set {
  68         unsigned int            *mq_map;
  69         const struct blk_mq_ops *ops;
  70         unsigned int            nr_hw_queues;
  71         unsigned int            queue_depth;    /* max hw supported */
  72         unsigned int            reserved_tags;
  73         unsigned int            cmd_size;       /* per-request extra data */
  74         int                     numa_node;
  75         unsigned int            timeout;
  76         unsigned int            flags;          /* BLK_MQ_F_* */
  77         void                    *driver_data;
  78
  79         struct blk_mq_tags      **tags;
  80
  81         struct mutex            tag_list_lock;
  82         struct list_head        tag_list;
  83 };
  84
  85 struct blk_mq_queue_data {
  86         struct request *rq;
  87         bool last;
  88 };
  89
  90 typedef blk_status_t (queue_rq_fn)(struct blk_mq_hw_ctx *,
  91                 const struct blk_mq_queue_data *);
  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)(struct blk_mq_tag_set *set, struct request *,
  96                 unsigned int, unsigned int);
  97 typedef void (exit_request_fn)(struct blk_mq_tag_set *set, struct request *,
  98                 unsigned int);
  99 typedef int (reinit_request_fn)(void *, struct request *);
 100
 101 typedef void (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
 102                 bool);
 103 typedef void (busy_tag_iter_fn)(struct request *, void *, bool);
 104 typedef int (poll_fn)(struct blk_mq_hw_ctx *, unsigned int);
 105 typedef int (map_queues_fn)(struct blk_mq_tag_set *set);
 106
 107
 108 struct blk_mq_ops {
 109         /*
 110          * Queue request
 111          */
 112         queue_rq_fn             *queue_rq;
 113
 114         /*
 115          * Called on request timeout
 116          */
 117         timeout_fn              *timeout;
 118
 119         /*
 120          * Called to poll for completion of a specific tag.
 121          */
 122         poll_fn                 *poll;
 123
 124         softirq_done_fn         *complete;
 125
 126         /*
 127          * Called when the block layer side of a hardware queue has been
 128          * set up, allowing the driver to allocate/init matching structures.
 129          * Ditto for exit/teardown.
 130          */
 131         init_hctx_fn            *init_hctx;
 132         exit_hctx_fn            *exit_hctx;
 133
 134         /*
 135          * Called for every command allocated by the block layer to allow
 136          * the driver to set up driver specific data.
 137          *
 138          * Tag greater than or equal to queue_depth is for setting up
 139          * flush request.
 140          *
 141          * Ditto for exit/teardown.
 142          */
 143         init_request_fn         *init_request;
 144         exit_request_fn         *exit_request;
 145         reinit_request_fn       *reinit_request;
 146
 147         map_queues_fn           *map_queues;
 148
 149 #ifdef CONFIG_BLK_DEBUG_FS
 150         /*
 151          * Used by the debugfs implementation to show driver-specific
 152          * information about a request.
 153          */
 154         void (*show_rq)(struct seq_file *m, struct request *rq);
 155 #endif
 156 };
 157
 158 enum {
 159         BLK_MQ_F_SHOULD_MERGE   = 1 << 0,
 160         BLK_MQ_F_TAG_SHARED     = 1 << 1,
 161         BLK_MQ_F_SG_MERGE       = 1 << 2,
 162         BLK_MQ_F_BLOCKING       = 1 << 5,
 163         BLK_MQ_F_NO_SCHED       = 1 << 6,
 164         BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
 165         BLK_MQ_F_ALLOC_POLICY_BITS = 1,
 166
 167         BLK_MQ_S_STOPPED        = 0,
 168         BLK_MQ_S_TAG_ACTIVE     = 1,
 169         BLK_MQ_S_SCHED_RESTART  = 2,
 170         BLK_MQ_S_TAG_WAITING    = 3,
 171         BLK_MQ_S_START_ON_RUN   = 4,
 172
 173         BLK_MQ_MAX_DEPTH        = 10240,
 174
 175         BLK_MQ_CPU_WORK_BATCH   = 8,
 176 };
 177 #define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \
 178         ((flags >> BLK_MQ_F_ALLOC_POLICY_START_BIT) & \
 179                 ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1))
 180 #define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \
 181         ((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \
 182                 << BLK_MQ_F_ALLOC_POLICY_START_BIT)
 183
 184 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
 185 struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
 186                                                   struct request_queue *q);
 187 int blk_mq_register_dev(struct device *, struct request_queue *);
 188 void blk_mq_unregister_dev(struct device *, struct request_queue *);
 189
 190 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
 191 void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
 192
 193 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
 194
 195 void blk_mq_free_request(struct request *rq);
 196 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
 197
 198 enum {
 199         BLK_MQ_REQ_NOWAIT       = (1 << 0), /* return when out of requests */
 200         BLK_MQ_REQ_RESERVED     = (1 << 1), /* allocate from reserved pool */
 201         BLK_MQ_REQ_INTERNAL     = (1 << 2), /* allocate internal/sched tag */
 202 };
 203
 204 struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
 205                 unsigned int flags);
 206 struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int op,
 207                 unsigned int flags, unsigned int hctx_idx);
 208 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
 209
 210 enum {
 211         BLK_MQ_UNIQUE_TAG_BITS = 16,
 212         BLK_MQ_UNIQUE_TAG_MASK = (1 << BLK_MQ_UNIQUE_TAG_BITS) - 1,
 213 };
 214
 215 u32 blk_mq_unique_tag(struct request *rq);
 216
 217 static inline u16 blk_mq_unique_tag_to_hwq(u32 unique_tag)
 218 {
 219         return unique_tag >> BLK_MQ_UNIQUE_TAG_BITS;
 220 }
 221
 222 static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
 223 {
 224         return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
 225 }
 226
 227
 228 int blk_mq_request_started(struct request *rq);
 229 void blk_mq_start_request(struct request *rq);
 230 void blk_mq_end_request(struct request *rq, blk_status_t error);
 231 void __blk_mq_end_request(struct request *rq, blk_status_t error);
 232
 233 void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list);
 234 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
 235                                 bool kick_requeue_list);
 236 void blk_mq_kick_requeue_list(struct request_queue *q);
 237 void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
 238 void blk_mq_complete_request(struct request *rq);
 239
 240 bool blk_mq_queue_stopped(struct request_queue *q);
 241 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
 242 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
 243 void blk_mq_stop_hw_queues(struct request_queue *q);
 244 void blk_mq_start_hw_queues(struct request_queue *q);
 245 void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
 246 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
 247 void blk_mq_quiesce_queue(struct request_queue *q);
 248 void blk_mq_unquiesce_queue(struct request_queue *q);
 249 void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
 250 void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
 251 void blk_mq_run_hw_queues(struct request_queue *q, bool async);
 252 void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
 253 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
 254                 busy_tag_iter_fn *fn, void *priv);
 255 void blk_mq_freeze_queue(struct request_queue *q);
 256 void blk_mq_unfreeze_queue(struct request_queue *q);
 257 void blk_freeze_queue_start(struct request_queue *q);
 258 void blk_mq_freeze_queue_wait(struct request_queue *q);
 259 int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
 260                                      unsigned long timeout);
 261 int blk_mq_reinit_tagset(struct blk_mq_tag_set *set);
 262
 263 int blk_mq_map_queues(struct blk_mq_tag_set *set);
 264 void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues);
 265
 266 /*
 267  * FIXME: this helper is just for working around mpt3sas.
 268  */
 269 static inline void blk_mq_quiesce_queue_nowait(struct request_queue *q)
 270 {
 271         spin_lock_irq(q->queue_lock);
 272         queue_flag_set(QUEUE_FLAG_QUIESCED, q);
 273         spin_unlock_irq(q->queue_lock);
 274
 275         blk_mq_stop_hw_queues(q);
 276 }
 277
 278 /*
 279  * Driver command data is immediately after the request. So subtract request
 280  * size to get back to the original request, add request size to get the PDU.
 281  */
 282 static inline struct request *blk_mq_rq_from_pdu(void *pdu)
 283 {
 284         return pdu - sizeof(struct request);
 285 }
 286 static inline void *blk_mq_rq_to_pdu(struct request *rq)
 287 {
 288         return rq + 1;
 289 }
 290
 291 #define queue_for_each_hw_ctx(q, hctx, i)                               \
 292         for ((i) = 0; (i) < (q)->nr_hw_queues &&                        \
 293              ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
 294
 295 #define hctx_for_each_ctx(hctx, ctx, i)                                 \
 296         for ((i) = 0; (i) < (hctx)->nr_ctx &&                           \
 297              ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
 298
 299 #endif