[PATCH] nvme: Add abrupt shutdown support

[shiva.linuxworks@gmail.com]

From: Shivamurthy Shastri <sshivamurthy@micron.com>

Enabling the abrupt shutdown support. In this shutdown type host does
not need to send Delete I/O Submission Queue and Delete I/O Completion
queue commands to the device.

Signed-off-by: Shivamurthy Shastri <sshivamurthy@micron.com>
---
 drivers/nvme/host/core.c | 11 ++++++++++-
 drivers/nvme/host/nvme.h |  2 ++
 drivers/nvme/host/pci.c  |  5 +++--
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 80c656dcbbac..c1d1bd6a03af 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -40,6 +40,11 @@ module_param_named(io_timeout, nvme_io_timeout, uint, 0644);
 MODULE_PARM_DESC(io_timeout, "timeout in seconds for I/O");
 EXPORT_SYMBOL_GPL(nvme_io_timeout);
 
+bool shutdown_type;
+EXPORT_SYMBOL_GPL(shutdown_type);
+module_param(shutdown_type, bool, 0644);
+MODULE_PARM_DESC(shutdown_type, "Type of controller shutdown");
+
 static unsigned char shutdown_timeout = 5;
 module_param(shutdown_timeout, byte, 0644);
 MODULE_PARM_DESC(shutdown_timeout, "timeout in seconds for controller shutdown");
@@ -2166,7 +2171,11 @@ int nvme_shutdown_ctrl(struct nvme_ctrl *ctrl)
 	int ret;
 
 	ctrl->ctrl_config &= ~NVME_CC_SHN_MASK;
-	ctrl->ctrl_config |= NVME_CC_SHN_NORMAL;
+
+	if (shutdown_type)
+		ctrl->ctrl_config |= NVME_CC_SHN_ABRUPT;
+	else
+		ctrl->ctrl_config |= NVME_CC_SHN_NORMAL;
 
 	ret = ctrl->ops->reg_write32(ctrl, NVME_REG_CC, ctrl->ctrl_config);
 	if (ret)
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 75420ceacc10..af14ee1cd7d8 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -23,6 +23,8 @@
 extern unsigned int nvme_io_timeout;
 #define NVME_IO_TIMEOUT	(nvme_io_timeout * HZ)
 
+extern bool shutdown_type;
+
 extern unsigned int admin_timeout;
 #define NVME_ADMIN_TIMEOUT	(admin_timeout * HZ)
 
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index d3c5086673bc..6a78233d9645 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2474,13 +2474,14 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
 	 * Give the controller a chance to complete all entered requests if
 	 * doing a safe shutdown.
 	 */
-	if (!dead && shutdown && freeze)
+	if (!dead && shutdown && !shutdown_type && freeze)
 		nvme_wait_freeze_timeout(&dev->ctrl, NVME_IO_TIMEOUT);
 
 	nvme_stop_queues(&dev->ctrl);
 
 	if (!dead && dev->ctrl.queue_count > 0) {
-		nvme_disable_io_queues(dev);
+		if (!shutdown_type)
+			nvme_disable_io_queues(dev);
 		nvme_disable_admin_queue(dev, shutdown);
 	}
 	nvme_suspend_io_queues(dev);
-- 
2.25.1