4 files changed, 233 insertions, 7 deletions

diff --git a/include/linux/bio.h b/include/linux/bio.h
index ec48bac5b039..4c2775443dcf 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -419,6 +419,8 @@ static inline void bio_list_init(struct bio_list *bl)
         bl->head = bl->tail = NULL;
 }
 
+#define BIO_EMPTY_LIST  { NULL, NULL }
+
 #define bio_list_for_each(bio, bl) \
         for (bio = (bl)->head; bio; bio = bio->bi_next)
 
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
new file mode 100644
index 000000000000..746042ff321a
--- /dev/null
+++ b/include/linux/blk-mq.h
@@ -0,0 +1,182 @@
+#ifndef BLK_MQ_H
+#define BLK_MQ_H
+
+#include <linux/blkdev.h>
+
+struct blk_mq_tags;
+
+struct blk_mq_cpu_notifier {
+        struct list_head list;
+        void *data;
+        void (*notify)(void *data, unsigned long action, unsigned int cpu);
+};
+
+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     delayed_work;
+
+        unsigned long           flags;          /* BLK_MQ_F_* flags */
+
+        struct request_queue    *queue;
+        unsigned int            queue_num;
+
+        void                    *driver_data;
+
+        unsigned int            nr_ctx;
+        struct blk_mq_ctx       **ctxs;
+        unsigned int            nr_ctx_map;
+        unsigned long           *ctx_map;
+
+        struct request          **rqs;
+        struct list_head        page_list;
+        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            queue_depth;
+        unsigned int            numa_node;
+        unsigned int            cmd_size;       /* per-request extra data */
+
+        struct blk_mq_cpu_notifier      cpu_notifier;
+        struct kobject          kobj;
+};
+
+struct blk_mq_reg {
+        struct blk_mq_ops       *ops;
+        unsigned int            nr_hw_queues;
+        unsigned int            queue_depth;
+        unsigned int            reserved_tags;
+        unsigned int            cmd_size;       /* per-request extra data */
+        int                     numa_node;
+        unsigned int            timeout;
+        unsigned int            flags;          /* BLK_MQ_F_* */
+};
+
+typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *);
+typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
+typedef struct blk_mq_hw_ctx *(alloc_hctx_fn)(struct blk_mq_reg *,unsigned int);
+typedef void (free_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
+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);
+
+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
+         */
+        rq_timed_out_fn         *timeout;
+
+        /*
+         * Override for hctx allocations (should probably go)
+         */
+        alloc_hctx_fn           *alloc_hctx;
+        free_hctx_fn            *free_hctx;
+
+        /*
+         * 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;
+};
+
+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_SHOULD_SORT    = 1 << 1,
+        BLK_MQ_F_SHOULD_IPI     = 1 << 2,
+
+        BLK_MQ_S_STOPPED        = 1 << 0,
+
+        BLK_MQ_MAX_DEPTH        = 2048,
+};
+
+struct request_queue *blk_mq_init_queue(struct blk_mq_reg *, void *);
+void blk_mq_free_queue(struct request_queue *);
+int blk_mq_register_disk(struct gendisk *);
+void blk_mq_unregister_disk(struct gendisk *);
+void blk_mq_init_commands(struct request_queue *, void (*init)(void *data, struct blk_mq_hw_ctx *, struct request *, unsigned int), void *data);
+
+void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
+
+void blk_mq_insert_request(struct request_queue *, struct request *, bool);
+void blk_mq_run_queues(struct request_queue *q, bool async);
+void blk_mq_free_request(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);
+struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, gfp_t gfp);
+struct request *blk_mq_rq_from_tag(struct request_queue *q, unsigned int tag);
+
+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_reg *, unsigned int);
+void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *, unsigned int);
+
+void blk_mq_end_io(struct request *rq, int error);
+
+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_start_stopped_hw_queues(struct request_queue *q);
+
+/*
+ * Driver command data is immediately after the request. So subtract request
+ * size to get back to the original request.
+ */
+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 (void *) rq + sizeof(*rq);
+}
+
+static inline struct request *blk_mq_tag_to_rq(struct blk_mq_hw_ctx *hctx,
+                                               unsigned int tag)
+{
+        return hctx->rqs[tag];
+}
+
+#define queue_for_each_hw_ctx(q, hctx, i)                               \
+        for ((i) = 0, hctx = (q)->queue_hw_ctx[0];                      \
+             (i) < (q)->nr_hw_queues; (i)++, hctx = (q)->queue_hw_ctx[i])
+
+#define queue_for_each_ctx(q, ctx, i)                                   \
+        for ((i) = 0, ctx = per_cpu_ptr((q)->queue_ctx, 0);             \
+             (i) < (q)->nr_queues; (i)++, ctx = per_cpu_ptr(q->queue_ctx, (i)))
+
+#define hctx_for_each_ctx(hctx, ctx, i)                                 \
+        for ((i) = 0, ctx = (hctx)->ctxs[0];                            \
+             (i) < (hctx)->nr_ctx; (i)++, ctx = (hctx)->ctxs[(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
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index c26801e14788..238ef0ed62f8 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -178,6 +178,7 @@ enum rq_flag_bits {
         __REQ_MIXED_MERGE,      /* merge of different types, fail separately */
         __REQ_KERNEL,           /* direct IO to kernel pages */
         __REQ_PM,               /* runtime pm request */
+        __REQ_END,              /* last of chain of requests */
         __REQ_NR_BITS,          /* stops here */
 };
 
@@ -229,5 +230,6 @@ enum rq_flag_bits {
 #define REQ_SECURE              (1ULL << __REQ_SECURE)
 #define REQ_KERNEL              (1ULL << __REQ_KERNEL)
 #define REQ_PM                  (1ULL << __REQ_PM)
+#define REQ_END                 (1ULL << __REQ_END)
 
 #endif /* __LINUX_BLK_TYPES_H */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 0a8da96274c3..f26ec20f6354 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -8,6 +8,7 @@
 #include <linux/major.h>
 #include <linux/genhd.h>
 #include <linux/list.h>
+#include <linux/llist.h>
 #include <linux/timer.h>
 #include <linux/workqueue.h>
 #include <linux/pagemap.h>
@@ -94,10 +95,17 @@ enum rq_cmd_type_bits {
  * as well!
  */
 struct request {
-        struct list_head queuelist;
-        struct call_single_data csd;
+        union {
+                struct list_head queuelist;
+                struct llist_node ll_list;
+        };
+        union {
+                struct call_single_data csd;
+                struct work_struct mq_flush_data;
+        };
 
         struct request_queue *q;
+        struct blk_mq_ctx *mq_ctx;
 
         u64 cmd_flags;
         enum rq_cmd_type_bits cmd_type;
@@ -213,6 +221,8 @@ struct request_pm_state
 
 #include <linux/elevator.h>
 
+struct blk_queue_ctx;
+
 typedef void (request_fn_proc) (struct request_queue *q);
 typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
@@ -311,6 +321,18 @@ struct request_queue {
         dma_drain_needed_fn     *dma_drain_needed;
         lld_busy_fn             *lld_busy_fn;
 
+        struct blk_mq_ops       *mq_ops;
+
+        unsigned int            *mq_map;
+
+        /* sw queues */
+        struct blk_mq_ctx       *queue_ctx;
+        unsigned int            nr_queues;
+
+        /* hw dispatch queues */
+        struct blk_mq_hw_ctx    **queue_hw_ctx;
+        unsigned int            nr_hw_queues;
+
         /*
          * Dispatch queue sorting
          */
@@ -359,6 +381,11 @@ struct request_queue {
          */
         struct kobject kobj;
 
+        /*
+         * mq queue kobject
+         */
+        struct kobject mq_kobj;
+
 #ifdef CONFIG_PM_RUNTIME
         struct device           *dev;
         int                     rpm_status;
@@ -423,7 +450,13 @@ struct request_queue {
         unsigned long           flush_pending_since;
         struct list_head        flush_queue[2];
         struct list_head        flush_data_in_flight;
-        struct request          flush_rq;
+        union {
+                struct request  flush_rq;
+                struct {
+                        spinlock_t mq_flush_lock;
+                        struct work_struct mq_flush_work;
+                };
+        };
 
         struct mutex            sysfs_lock;
 
@@ -435,14 +468,14 @@ struct request_queue {
         struct bsg_class_device bsg_dev;
 #endif
 
-#ifdef CONFIG_BLK_CGROUP
-        struct list_head        all_q_node;
-#endif
 #ifdef CONFIG_BLK_DEV_THROTTLING
         /* Throttle data */
         struct throtl_data *td;
 #endif
         struct rcu_head         rcu_head;
+        wait_queue_head_t       mq_freeze_wq;
+        struct percpu_counter   mq_usage_counter;
+        struct list_head        all_q_node;
 };
 
 #define QUEUE_FLAG_QUEUED       1       /* uses generic tag queueing */
@@ -465,6 +498,7 @@ struct request_queue {
 #define QUEUE_FLAG_SECDISCARD  17       /* supports SECDISCARD */
 #define QUEUE_FLAG_SAME_FORCE  18       /* force complete on same CPU */
 #define QUEUE_FLAG_DEAD        19       /* queue tear-down finished */
+#define QUEUE_FLAG_INIT_DONE   20       /* queue is initialized */
 
 #define QUEUE_FLAG_DEFAULT      ((1 << QUEUE_FLAG_IO_STAT) |            \
                                  (1 << QUEUE_FLAG_STACKABLE)    |       \
@@ -537,6 +571,7 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 #define blk_queue_dying(q)      test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
 #define blk_queue_dead(q)       test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
 #define blk_queue_bypass(q)     test_bit(QUEUE_FLAG_BYPASS, &(q)->queue_flags)
+#define blk_queue_init_done(q)  test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags)
 #define blk_queue_nomerges(q)   test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
 #define blk_queue_noxmerges(q)  \
         test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
@@ -1011,6 +1046,7 @@ static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
 struct blk_plug {
         unsigned long magic; /* detect uninitialized use-cases */
         struct list_head list; /* requests */
+        struct list_head mq_list; /* blk-mq requests */
         struct list_head cb_list; /* md requires an unplug callback */
 };
 #define BLK_MAX_REQUEST_COUNT 16
@@ -1048,7 +1084,10 @@ static inline bool blk_needs_flush_plug(struct task_struct *tsk)
 {
         struct blk_plug *plug = tsk->plug;
 
-        return plug && (!list_empty(&plug->list) || !list_empty(&plug->cb_list));
+        return plug &&
+                (!list_empty(&plug->list) ||
+                 !list_empty(&plug->mq_list) ||
+                 !list_empty(&plug->cb_list));
 }
 
 /*
@@ -1323,6 +1362,7 @@ static inline void put_dev_sector(Sector p)
 
 struct work_struct;
 int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
+int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay);
 
 #ifdef CONFIG_BLK_CGROUP
 /*