Merge branch 'for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata

[sfrench/cifs-2.6.git] / block / blk-mq.h

diff --git a/block/blk-mq.h b/block/blk-mq.h
index 6c7c3ff5bf627d3e36a8e1bf1feca66ff00ac74d..88c558f718190f88e123bba0444b0c50b296e572 100644 (file)
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -27,6 +27,20 @@ struct blk_mq_ctx {
        struct kobject          kobj;
 } ____cacheline_aligned_in_smp;
 
+/*
+ * Bits for request->gstate.  The lower two bits carry MQ_RQ_* state value
+ * and the upper bits the generation number.
+ */
+enum mq_rq_state {
+       MQ_RQ_IDLE              = 0,
+       MQ_RQ_IN_FLIGHT         = 1,
+       MQ_RQ_COMPLETE          = 2,
+
+       MQ_RQ_STATE_BITS        = 2,
+       MQ_RQ_STATE_MASK        = (1 << MQ_RQ_STATE_BITS) - 1,
+       MQ_RQ_GEN_INC           = 1 << MQ_RQ_STATE_BITS,
+};
+
 void blk_mq_freeze_queue(struct request_queue *q);
 void blk_mq_free_queue(struct request_queue *q);
 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
@@ -60,6 +74,9 @@ void blk_mq_request_bypass_insert(struct request *rq, bool run_queue);
 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
                                struct list_head *list);
 
+/* Used by blk_insert_cloned_request() to issue request directly */
+blk_status_t blk_mq_request_issue_directly(struct request *rq);
+
 /*
  * CPU -> queue mappings
  */
@@ -81,10 +98,41 @@ extern int blk_mq_sysfs_register(struct request_queue *q);
 extern void blk_mq_sysfs_unregister(struct request_queue *q);
 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
 
-extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
-
 void blk_mq_release(struct request_queue *q);
 
+/**
+ * blk_mq_rq_state() - read the current MQ_RQ_* state of a request
+ * @rq: target request.
+ */
+static inline int blk_mq_rq_state(struct request *rq)
+{
+       return READ_ONCE(rq->gstate) & MQ_RQ_STATE_MASK;
+}
+
+/**
+ * blk_mq_rq_update_state() - set the current MQ_RQ_* state of a request
+ * @rq: target request.
+ * @state: new state to set.
+ *
+ * Set @rq's state to @state.  The caller is responsible for ensuring that
+ * there are no other updaters.  A request can transition into IN_FLIGHT
+ * only from IDLE and doing so increments the generation number.
+ */
+static inline void blk_mq_rq_update_state(struct request *rq,
+                                         enum mq_rq_state state)
+{
+       u64 old_val = READ_ONCE(rq->gstate);
+       u64 new_val = (old_val & ~MQ_RQ_STATE_MASK) | state;
+
+       if (state == MQ_RQ_IN_FLIGHT) {
+               WARN_ON_ONCE((old_val & MQ_RQ_STATE_MASK) != MQ_RQ_IDLE);
+               new_val += MQ_RQ_GEN_INC;
+       }
+
+       /* avoid exposing interim values */
+       WRITE_ONCE(rq->gstate, new_val);
+}
+
 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
                                           unsigned int cpu)
 {