nvme: Add APIs for managing nvme_ctrl instances

One might want for libvfn to manage nvme_ctrl instances which are
initialized by the application inside of the library.  This patch
introduces nvme_get_ctrl, nvme_add_ctrl and nvme_del_ctrl APIs for
application to request controller intance management.  Rather than
adding list_node to struct nvme_ctrl, it uses struct nvme_ctrl_handle
inside of the core.c and open APIs based on the struct nvme_ctrl.

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

include/vfn/nvme/ctrl.h

@@ -158,6 +158,38 @@ int nvme_init(struct nvme_ctrl *ctrl, const char *bdf, const struct nvme_ctrl_op
  */
 void nvme_close(struct nvme_ctrl *ctrl);
 
+/**
+ * nvme_get_ctrl - Get nvme_ctrl instance initialized
+ * @bdf: PCI device identifier ("bus:device:function")
+ *
+ * Return nvme_ctrl instance initialized by the application.
+ *
+ * Return: nvme_ctrl instance pointer on success, ``NULL`` on error.
+ */
+struct nvme_ctrl *nvme_get_ctrl(const char *bdf);
+
+/**
+ * nvme_add_ctrl - Add nvme_ctrl instance to library
+ * @ctrl: Controller to keep in the library
+ *
+ * Add initialized nvme_ctrl instance to library for application can
+ * ask to retrieve the controller instance back.  If application keeps the
+ * instance list, it's not required to call this function.
+ *
+ * Return: ``0`` on success, ``-1`` on error and set ``errno``.
+ */
+int nvme_add_ctrl(struct nvme_ctrl *ctrl);
+
+/**
+ * nvme_del_ctrl - Delete nvme_ctrl instance from library
+ * @ctrl: Controller to delete from the library
+ *
+ * Delete added nvme_ctrl instance from library.
+ *
+ * Return: ``0`` on success, ``-1`` on error and set ``errno``.
+ */
+int nvme_del_ctrl(struct nvme_ctrl *ctrl);
+
 /**
  * nvme_reset - Reset controller
  * @ctrl: Controller to reset

src/nvme/core.c

@@ -40,6 +40,7 @@
 #include "ccan/compiler/compiler.h"
 #include "ccan/minmax/minmax.h"
 #include "ccan/time/time.h"
+#include "ccan/list/list.h"
 
 #include "types.h"
 
@@ -49,6 +50,66 @@
 #define sqtdbl(doorbells, qid, dstrd) \
 	(doorbells + (2 * qid) * (4 << dstrd))
 
+struct nvme_ctrl_handle {
+	struct nvme_ctrl *ctrl;
+	struct list_node list;
+};
+
+static LIST_HEAD(nvme_ctrl_handles);
+
+static struct nvme_ctrl_handle *nvme_get_ctrl_handle(const char *bdf)
+{
+	struct nvme_ctrl_handle *handle;
+
+	list_for_each(&nvme_ctrl_handles, handle, list) {
+		if (streq(handle->ctrl->pci.bdf, bdf))
+			return handle;
+	}
+
+	return NULL;
+}
+
+
+struct nvme_ctrl *nvme_get_ctrl(const char *bdf)
+{
+	struct nvme_ctrl_handle *handle = nvme_get_ctrl_handle(bdf);
+
+	if (!handle)
+		return NULL;
+
+	return handle->ctrl;
+}
+
+int nvme_add_ctrl(struct nvme_ctrl *ctrl)
+{
+	struct nvme_ctrl_handle *handle;
+
+	if (nvme_get_ctrl(ctrl->pci.bdf)) {
+		errno = EEXIST;
+		return -1;
+	}
+
+	handle = znew_t(struct nvme_ctrl_handle, 1);
+	handle->ctrl = ctrl;
+	list_add_tail(&nvme_ctrl_handles, &handle->list);
+	return 0;
+}
+
+int nvme_del_ctrl(struct nvme_ctrl *ctrl)
+{
+	struct nvme_ctrl_handle *handle;
+
+	handle = nvme_get_ctrl_handle(ctrl->pci.bdf);
+	if (!handle) {
+		errno = ENODEV;
+		return -1;
+	}
+
+	list_del(&handle->list);
+	free(handle);
+	return 0;
+}
+
 static int nvme_configure_cq(struct nvme_ctrl *ctrl, int qid, int qsize, int vector)
 {
 	struct nvme_cq *cq = &ctrl->cq[qid];