[PATCH 2/2] dmr/amdgpu: Add system auto reboot to RAS.

[Andrey Grodzovsky]

In case of RAS error allow user configure auto system
reboot through ras_ctrl.
This is also part of the temproray work around for the RAS
hang problem.

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 18 ++++++++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c    | 10 +++++++++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h    |  1 +
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 3ecee10..f1cff47 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3805,6 +3805,24 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
 	int i, r = 0;
 	bool in_ras_intr = amdgpu_ras_intr_triggered();
 
+	/*
+	 * Flush RAM to disk so that after reboot
+	 * the user can read log and see why the system rebooted.
+	 *
+	 * Using user mode app call instead of kernel APIs such as
+	 * ksys_sync_helper for backward comparability with earlier
+	 * kernels into which this is also intended.
+	 */
+	if (in_ras_intr && amdgpu_ras_get_context(adev)->reboot) {
+		char *envp[] = { "HOME=/", NULL };
+		char *argv[] = { "/bin/sync", NULL };
+
+		DRM_WARN("Emergency reboot.");
+
+		call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
+		emergency_restart();
+	}
+
 	need_full_reset = job_signaled = false;
 	INIT_LIST_HEAD(&device_list);
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
index 086e6df..423a1ba 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
@@ -30,6 +30,7 @@
 #include "amdgpu_ras.h"
 #include "amdgpu_atomfirmware.h"
 #include "ivsrcid/nbio/irqsrcs_nbif_7_4.h"
+#include <linux/kmod.h>
 
 const char *ras_error_string[] = {
 	"none",
@@ -154,6 +155,8 @@ static int amdgpu_ras_debugfs_ctrl_parse_data(struct file *f,
 		op = 1;
 	else if (sscanf(str, "inject %32s %8s", block_name, err) == 2)
 		op = 2;
+	else if (sscanf(str, "reboot %32s", block_name) == 1)
+		op = 3;
 	else if (str[0] && str[1] && str[2] && str[3])
 		/* ascii string, but commands are not matched. */
 		return -EINVAL;
@@ -287,6 +290,9 @@ static ssize_t amdgpu_ras_debugfs_ctrl_write(struct file *f, const char __user *
 		/* data.inject.address is offset instead of absolute gpu address */
 		ret = amdgpu_ras_error_inject(adev, &data.inject);
 		break;
+	case 3:
+		amdgpu_ras_get_context(adev)->reboot = true;
+		break;
 	default:
 		ret = -EINVAL;
 		break;
@@ -1733,6 +1739,8 @@ int amdgpu_ras_fini(struct amdgpu_device *adev)
 void amdgpu_ras_global_ras_isr(struct amdgpu_device *adev)
 {
 	if (atomic_cmpxchg(&amdgpu_ras_in_intr, 0, 1) == 0) {
-		DRM_WARN("RAS event of type ERREVENT_ATHUB_INTERRUPT detected! Stopping all GPU jobs.\n");
+		DRM_WARN("RAS event of type ERREVENT_ATHUB_INTERRUPT detected!\n");
+
+		amdgpu_ras_reset_gpu(adev, false);
 	}
 }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h
index c0e22af..e3f0764 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h
@@ -333,6 +333,7 @@ struct amdgpu_ras {
 	struct mutex recovery_lock;
 
 	uint32_t flags;
+	bool reboot;
 };
 
 struct ras_fs_data {
-- 
2.7.4