Merge branch 'for-3.16/core' of git://git.kernel.dk/linux-block into next

Pull block core updates from Jens Axboe:
 "It's a big(ish) round this time, lots of development effort has gone
  into blk-mq in the last 3 months.  Generally we're heading to where
  3.16 will be a feature complete and performant blk-mq.  scsi-mq is
  progressing nicely and will hopefully be in 3.17.  A nvme port is in
  progress, and the Micron pci-e flash driver, mtip32xx, is converted
  and will be sent in with the driver pull request for 3.16.

  This pull request contains:

   - Lots of prep and support patches for scsi-mq have been integrated.
     All from Christoph.

   - API and code cleanups for blk-mq from Christoph.

   - Lots of good corner case and error handling cleanup fixes for
     blk-mq from Ming Lei.

   - A flew of blk-mq updates from me:

     * Provide strict mappings so that the driver can rely on the CPU
       to queue mapping.  This enables optimizations in the driver.

     * Provided a bitmap tagging instead of percpu_ida, which never
       really worked well for blk-mq.  percpu_ida relies on the fact
       that we have a lot more tags available than we really need, it
       fails miserably for cases where we exhaust (or are close to
       exhausting) the tag space.

     * Provide sane support for shared tag maps, as utilized by scsi-mq

     * Various fixes for IO timeouts.

     * API cleanups, and lots of perf tweaks and optimizations.

   - Remove 'buffer' from struct request.  This is ancient code, from
     when requests were always virtually mapped.  Kill it, to reclaim
     some space in struct request.  From me.

   - Remove 'magic' from blk_plug.  Since we store these on the stack
     and since we've never caught any actual bugs with this, lets just
     get rid of it.  From me.

   - Only call part_in_flight() once for IO completion, as includes two
     atomic reads.  Hopefully we'll get a better implementation soon, as
     the part IO stats are now one of the more expensive parts of doing
     IO on blk-mq.  From me.

   - File migration of block code from {mm,fs}/ to block/.  This
     includes bio.c, bio-integrity.c, bounce.c, and ioprio.c.  From me,
     from a discussion on lkml.

  That should describe the meat of the pull request.  Also has various
  little fixes and cleanups from Dave Jones, Shaohua Li, Duan Jiong,
  Fengguang Wu, Fabian Frederick, Randy Dunlap, Robert Elliott, and Sam
  Bradshaw"

* 'for-3.16/core' of git://git.kernel.dk/linux-block: (100 commits)
  blk-mq: push IPI or local end_io decision to __blk_mq_complete_request()
  blk-mq: remember to start timeout handler for direct queue
  block: ensure that the timer is always added
  blk-mq: blk_mq_unregister_hctx() can be static
  blk-mq: make the sysfs mq/ layout reflect current mappings
  blk-mq: blk_mq_tag_to_rq should handle flush request
  block: remove dead code in scsi_ioctl:blk_verify_command
  blk-mq: request initialization optimizations
  block: add queue flag for disabling SG merging
  block: remove 'magic' from struct blk_plug
  blk-mq: remove alloc_hctx and free_hctx methods
  blk-mq: add file comments and update copyright notices
  blk-mq: remove blk_mq_alloc_request_pinned
  blk-mq: do not use blk_mq_alloc_request_pinned in blk_mq_map_request
  blk-mq: remove blk_mq_wait_for_tags
  blk-mq: initialize request in __blk_mq_alloc_request
  blk-mq: merge blk_mq_alloc_reserved_request into blk_mq_alloc_request
  blk-mq: add helper to insert requests from irq context
  blk-mq: remove stale comment for blk_mq_complete_request()
  blk-mq: allow non-softirq completions
  ...

1 files changed, 66 insertions, 5 deletions

diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index 947ba2c..c959de5 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -1,17 +1,59 @@
 #ifndef INT_BLK_MQ_TAG_H
 #define INT_BLK_MQ_TAG_H
 
-struct blk_mq_tags;
+#include "blk-mq.h"
+
+enum {
+	BT_WAIT_QUEUES	= 8,
+	BT_WAIT_BATCH	= 8,
+};
+
+struct bt_wait_state {
+	atomic_t wait_cnt;
+	wait_queue_head_t wait;
+} ____cacheline_aligned_in_smp;
+
+#define TAG_TO_INDEX(bt, tag)	((tag) >> (bt)->bits_per_word)
+#define TAG_TO_BIT(bt, tag)	((tag) & ((1 << (bt)->bits_per_word) - 1))
+
+struct blk_mq_bitmap_tags {
+	unsigned int depth;
+	unsigned int wake_cnt;
+	unsigned int bits_per_word;
+
+	unsigned int map_nr;
+	struct blk_align_bitmap *map;
+
+	unsigned int wake_index;
+	struct bt_wait_state *bs;
+};
+
+/*
+ * Tag address space map.
+ */
+struct blk_mq_tags {
+	unsigned int nr_tags;
+	unsigned int nr_reserved_tags;
+
+	atomic_t active_queues;
+
+	struct blk_mq_bitmap_tags bitmap_tags;
+	struct blk_mq_bitmap_tags breserved_tags;
+
+	struct request **rqs;
+	struct list_head page_list;
+};
+
 
 extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node);
 extern void blk_mq_free_tags(struct blk_mq_tags *tags);
 
-extern unsigned int blk_mq_get_tag(struct blk_mq_tags *tags, gfp_t gfp, bool reserved);
-extern void blk_mq_wait_for_tags(struct blk_mq_tags *tags);
-extern void blk_mq_put_tag(struct blk_mq_tags *tags, unsigned int tag);
-extern void blk_mq_tag_busy_iter(struct blk_mq_tags *tags, void (*fn)(void *data, unsigned long *), void *data);
+extern unsigned int blk_mq_get_tag(struct blk_mq_hw_ctx *hctx, unsigned int *last_tag, gfp_t gfp, bool reserved);
+extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag, unsigned int *last_tag);
 extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);
 extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page);
+extern void blk_mq_tag_init_last_tag(struct blk_mq_tags *tags, unsigned int *last_tag);
+extern int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int depth);
 
 enum {
 	BLK_MQ_TAG_CACHE_MIN	= 1,
@@ -24,4 +66,23 @@ enum {
 	BLK_MQ_TAG_MAX		= BLK_MQ_TAG_FAIL - 1,
 };
 
+extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
+extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
+
+static inline bool blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
+{
+	if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
+		return false;
+
+	return __blk_mq_tag_busy(hctx);
+}
+
+static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
+{
+	if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
+		return;
+
+	__blk_mq_tag_idle(hctx);
+}
+
 #endif