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 map_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         unsigned int            queue_num;
  38         struct blk_flush_queue  *fq;
  39
  40         void                    *driver_data;
  41
  42         struct blk_mq_ctxmap    ctx_map;
  43
  44         unsigned int            nr_ctx;
  45         struct blk_mq_ctx       **ctxs;
  46
  47         atomic_t                wait_index;
  48
  49         struct blk_mq_tags      *tags;
  50
  51         unsigned long           queued;
  52         unsigned long           run;
  53 #define BLK_MQ_MAX_DISPATCH_ORDER       10
  54         unsigned long           dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
  55
  56         unsigned int            numa_node;
  57         unsigned int            cmd_size;       /* per-request extra data */
  58
  59         atomic_t                nr_active;
  60
  61         struct blk_mq_cpu_notifier      cpu_notifier;
  62         struct kobject          kobj;
  63 };
  64
  65 struct blk_mq_tag_set {
  66         struct blk_mq_ops       *ops;
  67         unsigned int            nr_hw_queues;
  68         unsigned int            queue_depth;    /* max hw supported */
  69         unsigned int            reserved_tags;
  70         unsigned int            cmd_size;       /* per-request extra data */
  71         int                     numa_node;
  72         unsigned int            timeout;
  73         unsigned int            flags;          /* BLK_MQ_F_* */
  74         void                    *driver_data;
  75
  76         struct blk_mq_tags      **tags;
  77
  78         struct mutex            tag_list_lock;
  79         struct list_head        tag_list;
  80 };
  81
  82 struct blk_mq_queue_data {
  83         struct request *rq;
  84         struct list_head *list;
  85         bool last;
  86 };
  87
  88 typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, const struct blk_mq_queue_data *);
  89 typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
  90 typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool);
  91 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
  92 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
  93 typedef int (init_request_fn)(void *, struct request *, unsigned int,
  94                 unsigned int, unsigned int);
  95 typedef void (exit_request_fn)(void *, struct request *, unsigned int,
  96                 unsigned int);
  97
  98 typedef void (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
  99                 bool);
 100
 101 struct blk_mq_ops {
 102         /*
 103          * Queue request
 104          */
 105         queue_rq_fn             *queue_rq;
 106
 107         /*
 108          * Map to specific hardware queue
 109          */
 110         map_queue_fn            *map_queue;
 111
 112         /*
 113          * Called on request timeout
 114          */
 115         timeout_fn              *timeout;
 116
 117         softirq_done_fn         *complete;
 118
 119         /*
 120          * Called when the block layer side of a hardware queue has been
 121          * set up, allowing the driver to allocate/init matching structures.
 122          * Ditto for exit/teardown.
 123          */
 124         init_hctx_fn            *init_hctx;
 125         exit_hctx_fn            *exit_hctx;
 126
 127         /*
 128          * Called for every command allocated by the block layer to allow
 129          * the driver to set up driver specific data.
 130          *
 131          * Tag greater than or equal to queue_depth is for setting up
 132          * flush request.
 133          *
 134          * Ditto for exit/teardown.
 135          */
 136         init_request_fn         *init_request;
 137         exit_request_fn         *exit_request;
 138 };
 139
 140 enum {
 141         BLK_MQ_RQ_QUEUE_OK      = 0,    /* queued fine */
 142         BLK_MQ_RQ_QUEUE_BUSY    = 1,    /* requeue IO for later */
 143         BLK_MQ_RQ_QUEUE_ERROR   = 2,    /* end IO with error */
 144
 145         BLK_MQ_F_SHOULD_MERGE   = 1 << 0,
 146         BLK_MQ_F_TAG_SHARED     = 1 << 1,
 147         BLK_MQ_F_SG_MERGE       = 1 << 2,
 148         BLK_MQ_F_SYSFS_UP       = 1 << 3,
 149         BLK_MQ_F_DEFER_ISSUE    = 1 << 4,
 150
 151         BLK_MQ_S_STOPPED        = 0,
 152         BLK_MQ_S_TAG_ACTIVE     = 1,
 153
 154         BLK_MQ_MAX_DEPTH        = 10240,
 155
 156         BLK_MQ_CPU_WORK_BATCH   = 8,
 157 };
 158
 159 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
 160 void blk_mq_finish_init(struct request_queue *q);
 161 int blk_mq_register_disk(struct gendisk *);
 162 void blk_mq_unregister_disk(struct gendisk *);
 163
 164 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
 165 void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
 166
 167 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
 168
 169 void blk_mq_insert_request(struct request *, bool, bool, bool);
 170 void blk_mq_run_queues(struct request_queue *q, bool async);
 171 void blk_mq_free_request(struct request *rq);
 172 void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *, struct request *rq);
 173 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
 174 struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
 175                 gfp_t gfp, bool reserved);
 176 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
 177
 178 enum {
 179         BLK_MQ_UNIQUE_TAG_BITS = 16,
 180         BLK_MQ_UNIQUE_TAG_MASK = (1 << BLK_MQ_UNIQUE_TAG_BITS) - 1,
 181 };
 182
 183 u32 blk_mq_unique_tag(struct request *rq);
 184
 185 static inline u16 blk_mq_unique_tag_to_hwq(u32 unique_tag)
 186 {
 187         return unique_tag >> BLK_MQ_UNIQUE_TAG_BITS;
 188 }
 189
 190 static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
 191 {
 192         return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
 193 }
 194
 195 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
 196 struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int, int);
 197
 198 void blk_mq_start_request(struct request *rq);
 199 void blk_mq_end_request(struct request *rq, int error);
 200 void __blk_mq_end_request(struct request *rq, int error);
 201
 202 void blk_mq_requeue_request(struct request *rq);
 203 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head);
 204 void blk_mq_kick_requeue_list(struct request_queue *q);
 205 void blk_mq_complete_request(struct request *rq);
 206
 207 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
 208 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
 209 void blk_mq_stop_hw_queues(struct request_queue *q);
 210 void blk_mq_start_hw_queues(struct request_queue *q);
 211 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
 212 void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
 213 void blk_mq_tag_busy_iter(struct blk_mq_hw_ctx *hctx, busy_iter_fn *fn,
 214                 void *priv);
 215 void blk_mq_unfreeze_queue(struct request_queue *q);
 216 void blk_mq_freeze_queue_start(struct request_queue *q);
 217
 218 /*
 219  * Driver command data is immediately after the request. So subtract request
 220  * size to get back to the original request.
 221  */
 222 static inline struct request *blk_mq_rq_from_pdu(void *pdu)
 223 {
 224         return pdu - sizeof(struct request);
 225 }
 226 static inline void *blk_mq_rq_to_pdu(struct request *rq)
 227 {
 228         return (void *) rq + sizeof(*rq);
 229 }
 230
 231 #define queue_for_each_hw_ctx(q, hctx, i)                               \
 232         for ((i) = 0; (i) < (q)->nr_hw_queues &&                        \
 233              ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
 234
 235 #define queue_for_each_ctx(q, ctx, i)                                   \
 236         for ((i) = 0; (i) < (q)->nr_queues &&                           \
 237              ({ ctx = per_cpu_ptr((q)->queue_ctx, (i)); 1; }); (i)++)
 238
 239 #define hctx_for_each_ctx(hctx, ctx, i)                                 \
 240         for ((i) = 0; (i) < (hctx)->nr_ctx &&                           \
 241              ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
 242
 243 #define blk_ctx_sum(q, sum)                                             \
 244 ({                                                                      \
 245         struct blk_mq_ctx *__x;                                         \
 246         unsigned int __ret = 0, __i;                                    \
 247                                                                         \
 248         queue_for_each_ctx((q), __x, __i)                               \
 249                 __ret += sum;                                           \
 250         __ret;                                                          \
 251 })
 252
 253 #endif