nvme: export nvme_configure_[sq|cq] to public

They have been used when creating admin queue and I/O queues in
nvme_configure_adminq() and nvme_create_io[sq|cq]() to create an
instance of SQ and CQ to be managed in libvfn with ``ctrl->sq[qid]`` and
``ctrl->cq[qid]``.

The problem happens when an application handles admin CQ only when an
interrupt (e.g., MSI-X) comes with its own CQ handling behavior on top
of it.  In this case, nvme_create_iosq() and nvme_create_iocq()
high-level APIs issue create I/O queue admin command by __admin() where
the command is handled in a sync way by reaping the CQ entry right after
the command submission.  It goes to collision of the CQ between
application CQ reaper class and libvfn __admin() callstack.

To solve this issue, export nvme_configure_[sq|cq]() to public to let
application manages admin command submission for creating queues.

Signed-off-by: Minwoo Im <[email protected]>

include/vfn/nvme/ctrl.h

@@ -215,6 +215,49 @@ int nvme_del_ctrl(struct nvme_ctrl *ctrl);
  */
 int nvme_reset(struct nvme_ctrl *ctrl);
 
+/**
+ * nvme_configure_sq - Configure a submission queue instance
+ * @ctrl: Controller to configure a submission queue instance
+ * @qid: Queue identifier
+ * @qsize: Queue size
+ * @cq: Corresponding completion queue instance
+ * @flags: Submission queue configuration flags
+ *
+ * Create a submission queue instance for the given @qid.  This allocates
+ * memory spaces for the submission queue and map it to IOMMU page table for
+ * the DMA operations.
+ *
+ * The newly created SQ instance can be referred by ``ctrl->sq[qid]``.
+ *
+ * **Note** This helper does not issue a Create I/O Submission Queue admin
+ * command to the admin submission queue.  Caller should prepare command
+ * submission with the instance to be configured.
+ *
+ * Return: ``0`` on success, ``-1`` on error and set ``errno``.
+ */
+int nvme_configure_sq(struct nvme_ctrl *ctrl, int qid, int qsize,
+		      struct nvme_cq *cq, unsigned long flags);
+
+/**
+ * nvme_configure_cq - Configure a completion queue instance
+ * @ctrl: Controller to configure a completion queue instance
+ * @qid: Queue identifier
+ * @qsize: Queue size
+ * @vector: interrupt vector
+ *
+ * Create a completion queue instance for the given @qid.  This allocates
+ * memory spaces for the completion queue and map it to IOMMU page table for
+ * the DMA operations.
+ *
+ * The newly created CQ instance can be referred by ``ctrl->cq[qid]``.
+ *
+ * **Note** This helper does not issue a Create I/O Completion Queue admin
+ * command to the admin submission queue.  Caller should prepare command
+ * submission with the instance to be configured.
+ *
+ * Return: ``0`` on success, ``-1`` on error and set ``errno``.
+ */
+int nvme_configure_cq(struct nvme_ctrl *ctrl, int qid, int qsize, int vector);
 
 /**
  * nvme_configure_adminq - Configure admin sq/cq pair

src/nvme/core.c

@@ -110,7 +110,7 @@ int nvme_del_ctrl(struct nvme_ctrl *ctrl)
 	return 0;
 }
 
-static int nvme_configure_cq(struct nvme_ctrl *ctrl, int qid, int qsize, int vector)
+int nvme_configure_cq(struct nvme_ctrl *ctrl, int qid, int qsize, int vector)
 {
 	struct nvme_cq *cq = &ctrl->cq[qid];
 	uint64_t cap;
@@ -181,8 +181,8 @@ void nvme_discard_cq(struct nvme_ctrl *ctrl, struct nvme_cq *cq)
 	memset(cq, 0x0, sizeof(*cq));
 }
 
-static int nvme_configure_sq(struct nvme_ctrl *ctrl, int qid, int qsize,
-			     struct nvme_cq *cq, unsigned long UNUSED flags)
+int nvme_configure_sq(struct nvme_ctrl *ctrl, int qid, int qsize,
+		      struct nvme_cq *cq, unsigned long UNUSED flags)
 {
 	struct nvme_sq *sq = &ctrl->sq[qid];
 	uint64_t cap;