[PATCH 4/5] nvme: Add a new exported function nvme_ctrl_shutdown_start()

[Jeremy Allison <jallison@ciq.com>]

Sets the shutdown bit but doesn't wait for ready.
Use from nvme_disable_ctrl(). Export nvme_wait_ready()
so we can call it from drivers/nvme/host/pci.c.

Signed-off-by: Jeremy Allison <jallison@ciq.com>
---
 drivers/nvme/host/core.c | 22 ++++++++++++++++------
 drivers/nvme/host/nvme.h |  3 +++
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 60537c9224bf..b7695f472fab 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2260,7 +2260,7 @@ const struct block_device_operations nvme_bdev_ops = {
 	.pr_ops		= &nvme_pr_ops,
 };
 
-static int nvme_wait_ready(struct nvme_ctrl *ctrl, u32 mask, u32 val,
+int nvme_wait_ready(struct nvme_ctrl *ctrl, u32 mask, u32 val,
 		u32 timeout, const char *op)
 {
 	unsigned long timeout_jiffies = jiffies + timeout * HZ;
@@ -2286,18 +2286,28 @@ static int nvme_wait_ready(struct nvme_ctrl *ctrl, u32 mask, u32 val,
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(nvme_wait_ready);
+
+int nvme_ctrl_shutdown_start(struct nvme_ctrl *ctrl)
+{
+	ctrl->ctrl_config &= ~NVME_CC_SHN_MASK;
+	ctrl->ctrl_config |= NVME_CC_SHN_NORMAL;
+	return ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
+}
+EXPORT_SYMBOL_GPL(nvme_ctrl_shutdown_start);
 
 int nvme_disable_ctrl(struct nvme_ctrl *ctrl, bool shutdown)
 {
 	int ret;
 
-	ctrl->ctrl_config &= ~NVME_CC_SHN_MASK;
-	if (shutdown)
-		ctrl->ctrl_config |= NVME_CC_SHN_NORMAL;
-	else
+	if (shutdown) {
+		ret = nvme_ctrl_shutdown_start(ctrl);
+	} else {
+		ctrl->ctrl_config &= ~NVME_CC_SHN_MASK;
 		ctrl->ctrl_config &= ~NVME_CC_ENABLE;
+		ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
+	}
 
-	ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
 	if (ret)
 		return ret;
 
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 7b87763e2f8a..f52cb3d1d9c7 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -759,6 +759,9 @@ blk_status_t nvme_host_path_error(struct request *req);
 bool nvme_cancel_request(struct request *req, void *data);
 void nvme_cancel_tagset(struct nvme_ctrl *ctrl);
 void nvme_cancel_admin_tagset(struct nvme_ctrl *ctrl);
+int nvme_wait_ready(struct nvme_ctrl *ctrl, u32 mask, u32 val,
+		u32 timeout, const char *op);
+int nvme_ctrl_shutdown_start(struct nvme_ctrl *ctrl);
 bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
 		enum nvme_ctrl_state new_state);
 int nvme_disable_ctrl(struct nvme_ctrl *ctrl, bool shutdown);
-- 
2.39.3