[PATCH v2 2/2] nvme: Add abrupt shutdown support

[shiva.linuxworks@gmail.com]

From: Shivamurthy Shastri <sshivamurthy@micron.com>

Enabling the abrupt shutdown support. In this shutdown type, the 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 | 7 ++++++-
 drivers/nvme/host/pci.c  | 6 ++++--
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 11779be42186..760ffb071c1b 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -20,6 +20,7 @@
 #include <linux/ptrace.h>
 #include <linux/nvme_ioctl.h>
 #include <linux/pm_qos.h>
+#include <linux/suspend.h>
 #include <asm/unaligned.h>
 
 #include "nvme.h"
@@ -2159,7 +2160,11 @@ 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 (pm_power_loss_imminent())
+		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/pci.c b/drivers/nvme/host/pci.c
index 320051f5a3dd..07be319f63d9 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -14,6 +14,7 @@
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/suspend.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -2524,13 +2525,14 @@ 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 && !pm_power_loss_imminent() && 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 (!pm_power_loss_imminent())
+			nvme_disable_io_queues(dev);
 		nvme_disable_admin_queue(dev, shutdown);
 	}
 	nvme_suspend_io_queues(dev);
-- 
2.25.1