blk-mq: move blk_mq_get_ctx/blk_mq_put_ctx to mq private header

The blk-mq tag code need these helpers.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/block/blk-mq.h b/block/blk-mq.h
index de7b3bb..57a7968 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -69,4 +69,26 @@ struct blk_align_bitmap {
 	unsigned long depth;
 } ____cacheline_aligned_in_smp;
 
+static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
+					   unsigned int cpu)
+{
+	return per_cpu_ptr(q->queue_ctx, cpu);
+}
+
+/*
+ * This assumes per-cpu software queueing queues. They could be per-node
+ * as well, for instance. For now this is hardcoded as-is. Note that we don't
+ * care about preemption, since we know the ctx's are persistent. This does
+ * mean that we can't rely on ctx always matching the currently running CPU.
+ */
+static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
+{
+	return __blk_mq_get_ctx(q, get_cpu());
+}
+
+static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
+{
+	put_cpu();
+}
+
 #endif