1 files changed, 266 insertions, 0 deletions
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
new file mode 100644
index 000000000..2056a99b9
--- /dev/null
+++ b/include/linux/blk-mq.h
@@ -0,0 +1,266 @@
+#ifndef BLK_MQ_H
+#define BLK_MQ_H
+
+#include <linux/blkdev.h>
+
+struct blk_mq_tags;
+struct blk_flush_queue;
+
+struct blk_mq_cpu_notifier {
+	struct list_head list;
+	void *data;
+	int (*notify)(void *data, unsigned long action, unsigned int cpu);
+};
+
+struct blk_mq_ctxmap {
+	unsigned int size;
+	unsigned int bits_per_word;
+	struct blk_align_bitmap *map;
+};
+
+struct blk_mq_hw_ctx {
+	struct {
+		spinlock_t		lock;
+		struct list_head	dispatch;
+	} ____cacheline_aligned_in_smp;
+
+	unsigned long		state;		/* BLK_MQ_S_* flags */
+	struct delayed_work	run_work;
+	struct delayed_work	delay_work;
+	cpumask_var_t		cpumask;
+	int			next_cpu;
+	int			next_cpu_batch;
+
+	unsigned long		flags;		/* BLK_MQ_F_* flags */
+
+	struct request_queue	*queue;
+	struct blk_flush_queue	*fq;
+
+	void			*driver_data;
+
+	struct blk_mq_ctxmap	ctx_map;
+
+	unsigned int		nr_ctx;
+	struct blk_mq_ctx	**ctxs;
+
+	atomic_t		wait_index;
+
+	struct blk_mq_tags	*tags;
+
+	unsigned long		queued;
+	unsigned long		run;
+#define BLK_MQ_MAX_DISPATCH_ORDER	10
+	unsigned long		dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
+
+	unsigned int		numa_node;
+	unsigned int		queue_num;
+
+	atomic_t		nr_active;
+
+	struct blk_mq_cpu_notifier	cpu_notifier;
+	struct kobject		kobj;
+};
+
+struct blk_mq_tag_set {
+	struct blk_mq_ops	*ops;
+	unsigned int		nr_hw_queues;
+	unsigned int		queue_depth;	/* max hw supported */
+	unsigned int		reserved_tags;
+	unsigned int		cmd_size;	/* per-request extra data */
+	int			numa_node;
+	unsigned int		timeout;
+	unsigned int		flags;		/* BLK_MQ_F_* */
+	void			*driver_data;
+
+	struct blk_mq_tags	**tags;
+
+	struct mutex		tag_list_lock;
+	struct list_head	tag_list;
+};
+
+struct blk_mq_queue_data {
+	struct request *rq;
+	struct list_head *list;
+	bool last;
+};
+
+typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, const struct blk_mq_queue_data *);
+typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
+typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool);
+typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
+typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
+typedef int (init_request_fn)(void *, struct request *, unsigned int,
+		unsigned int, unsigned int);
+typedef void (exit_request_fn)(void *, struct request *, unsigned int,
+		unsigned int);
+
+typedef void (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
+		bool);
+
+struct blk_mq_ops {
+	/*
+	 * Queue request
+	 */
+	queue_rq_fn		*queue_rq;
+
+	/*
+	 * Map to specific hardware queue
+	 */
+	map_queue_fn		*map_queue;
+
+	/*
+	 * Called on request timeout
+	 */
+	timeout_fn		*timeout;
+
+	softirq_done_fn		*complete;
+
+	/*
+	 * Called when the block layer side of a hardware queue has been
+	 * set up, allowing the driver to allocate/init matching structures.
+	 * Ditto for exit/teardown.
+	 */
+	init_hctx_fn		*init_hctx;
+	exit_hctx_fn		*exit_hctx;
+
+	/*
+	 * Called for every command allocated by the block layer to allow
+	 * the driver to set up driver specific data.
+	 *
+	 * Tag greater than or equal to queue_depth is for setting up
+	 * flush request.
+	 *
+	 * Ditto for exit/teardown.
+	 */
+	init_request_fn		*init_request;
+	exit_request_fn		*exit_request;
+};
+
+enum {
+	BLK_MQ_RQ_QUEUE_OK	= 0,	/* queued fine */
+	BLK_MQ_RQ_QUEUE_BUSY	= 1,	/* requeue IO for later */
+	BLK_MQ_RQ_QUEUE_ERROR	= 2,	/* end IO with error */
+
+	BLK_MQ_F_SHOULD_MERGE	= 1 << 0,
+	BLK_MQ_F_TAG_SHARED	= 1 << 1,
+	BLK_MQ_F_SG_MERGE	= 1 << 2,
+	BLK_MQ_F_SYSFS_UP	= 1 << 3,
+	BLK_MQ_F_DEFER_ISSUE	= 1 << 4,
+	BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
+	BLK_MQ_F_ALLOC_POLICY_BITS = 1,
+
+	BLK_MQ_S_STOPPED	= 0,
+	BLK_MQ_S_TAG_ACTIVE	= 1,
+
+	BLK_MQ_MAX_DEPTH	= 10240,
+
+	BLK_MQ_CPU_WORK_BATCH	= 8,
+};
+#define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \
+	((flags >> BLK_MQ_F_ALLOC_POLICY_START_BIT) & \
+		((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1))
+#define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \
+	((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \
+		<< BLK_MQ_F_ALLOC_POLICY_START_BIT)
+
+struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
+struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
+						  struct request_queue *q);
+void blk_mq_finish_init(struct request_queue *q);
+int blk_mq_register_disk(struct gendisk *);
+void blk_mq_unregister_disk(struct gendisk *);
+
+int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
+void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
+
+void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
+
+void blk_mq_insert_request(struct request *, bool, bool, bool);
+void blk_mq_free_request(struct request *rq);
+void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *, struct request *rq);
+bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
+struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
+		gfp_t gfp, bool reserved);
+struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
+
+enum {
+	BLK_MQ_UNIQUE_TAG_BITS = 16,
+	BLK_MQ_UNIQUE_TAG_MASK = (1 << BLK_MQ_UNIQUE_TAG_BITS) - 1,
+};
+
+u32 blk_mq_unique_tag(struct request *rq);
+
+static inline u16 blk_mq_unique_tag_to_hwq(u32 unique_tag)
+{
+	return unique_tag >> BLK_MQ_UNIQUE_TAG_BITS;
+}
+
+static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
+{
+	return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
+}
+
+struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
+struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int, int);
+
+int blk_mq_request_started(struct request *rq);
+void blk_mq_start_request(struct request *rq);
+void blk_mq_end_request(struct request *rq, int error);
+void __blk_mq_end_request(struct request *rq, int error);
+
+void blk_mq_requeue_request(struct request *rq);
+void blk_mq_add_to_requeue_list(struct request *rq, bool at_head);
+void blk_mq_cancel_requeue_work(struct request_queue *q);
+void blk_mq_kick_requeue_list(struct request_queue *q);
+void blk_mq_abort_requeue_list(struct request_queue *q);
+void blk_mq_complete_request(struct request *rq);
+
+void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
+void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
+void blk_mq_stop_hw_queues(struct request_queue *q);
+void blk_mq_start_hw_queues(struct request_queue *q);
+void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
+void blk_mq_run_hw_queues(struct request_queue *q, bool async);
+void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
+void blk_mq_tag_busy_iter(struct blk_mq_hw_ctx *hctx, busy_iter_fn *fn,
+		void *priv);
+void blk_mq_freeze_queue(struct request_queue *q);
+void blk_mq_unfreeze_queue(struct request_queue *q);
+void blk_mq_freeze_queue_start(struct request_queue *q);
+
+/*
+ * Driver command data is immediately after the request. So subtract request
+ * size to get back to the original request, add request size to get the PDU.
+ */
+static inline struct request *blk_mq_rq_from_pdu(void *pdu)
+{
+	return pdu - sizeof(struct request);
+}
+static inline void *blk_mq_rq_to_pdu(struct request *rq)
+{
+	return rq + 1;
+}
+
+#define queue_for_each_hw_ctx(q, hctx, i)				\
+	for ((i) = 0; (i) < (q)->nr_hw_queues &&			\
+	     ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
+
+#define queue_for_each_ctx(q, ctx, i)					\
+	for ((i) = 0; (i) < (q)->nr_queues &&				\
+	     ({ ctx = per_cpu_ptr((q)->queue_ctx, (i)); 1; }); (i)++)
+
+#define hctx_for_each_ctx(hctx, ctx, i)					\
+	for ((i) = 0; (i) < (hctx)->nr_ctx &&				\
+	     ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
+
+#define blk_ctx_sum(q, sum)						\
+({									\
+	struct blk_mq_ctx *__x;						\
+	unsigned int __ret = 0, __i;					\
+									\
+	queue_for_each_ctx((q), __x, __i)				\
+		__ret += sum;						\
+	__ret;								\
+})
+
+#endif