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