[PATCH v1] drm/xe/uapi: Bring back reset uevent

[Lucas De Marchi]

On Tue, Aug 06, 2024 at 10:02:31AM GMT, Raag Jadav wrote:
>From: Lucas De Marchi <lucas.demarchi at intel.com>
>
>Bring back uevent for gt reset failure with better uapi naming.
>With this in place we can receive failure event using udev.
>
>$ udevadm monitor --property --kernel
>monitor will print the received events for:
>KERNEL - the kernel uevent
>
>KERNEL[871.188570] change   /devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:01.0/0000:03:00.0 (pci)
>ACTION=change
>DEVPATH=/devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:01.0/0000:03:00.0
>SUBSYSTEM=pci
>DEVICE_STATUS=NEEDS_RESET
>REASON=GT_RESET_FAILED
>TILE_ID=0
>GT_ID=0
>DRIVER=xe
>PCI_CLASS=30000
>PCI_ID=8086:56B1
>PCI_SUBSYS_ID=8086:1210
>PCI_SLOT_NAME=0000:03:00.0
>MODALIAS=pci:v00008086d000056B1sv00008086sd00001210bc03sc00i00
>SEQNUM=6104
>
>Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>

please drop my s-o-b here and don't add me as the author of this patch,
which I certainly am not.

You need to point to the commit where it was reverted and *why* it's ok
to have this uapi now.

Lucas De Marchi


>Signed-off-by: Raag Jadav <raag.jadav at intel.com>
>---
> drivers/gpu/drm/xe/xe_gt.c | 27 +++++++++++++++++++++++++--
> include/uapi/drm/xe_drm.h  | 17 +++++++++++++++++
> 2 files changed, 42 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
>index b04e47186f5b..5ceef0059861 100644
>--- a/drivers/gpu/drm/xe/xe_gt.c
>+++ b/drivers/gpu/drm/xe/xe_gt.c
>@@ -740,6 +740,30 @@ static int do_gt_restart(struct xe_gt *gt)
> 	return 0;
> }
>
>+static void xe_uevent_gt_reset_failure(struct pci_dev *pdev, u8 tile_id, u8 gt_id)
>+{
>+	char *reset_event[5];
>+
>+	reset_event[0] = DRM_XE_RESET_REQUIRED_UEVENT;
>+	reset_event[1] = DRM_XE_RESET_REQUIRED_UEVENT_REASON_GT;
>+	reset_event[2] = kasprintf(GFP_KERNEL, "TILE_ID=%d", tile_id);
>+	reset_event[3] = kasprintf(GFP_KERNEL, "GT_ID=%d", gt_id);
>+	reset_event[4] = NULL;
>+	kobject_uevent_env(&pdev->dev.kobj, KOBJ_CHANGE, reset_event);
>+
>+	kfree(reset_event[2]);
>+	kfree(reset_event[3]);
>+}
>+
>+static void gt_reset_failed(struct xe_gt *gt, int err)
>+{
>+	xe_gt_err(gt, "reset failed (%pe)\n", ERR_PTR(err));
>+
>+	/* Notify userspace about gt reset failure */
>+	xe_uevent_gt_reset_failure(to_pci_dev(gt_to_xe(gt)->drm.dev),
>+				   gt_to_tile(gt)->id, gt->info.id);
>+}
>+
> static int gt_reset(struct xe_gt *gt)
> {
> 	int err;
>@@ -795,8 +819,7 @@ static int gt_reset(struct xe_gt *gt)
> 	XE_WARN_ON(xe_uc_start(&gt->uc));
> 	xe_pm_runtime_put(gt_to_xe(gt));
> err_fail:
>-	xe_gt_err(gt, "reset failed (%pe)\n", ERR_PTR(err));
>-
>+	gt_reset_failed(gt, err);
> 	xe_device_declare_wedged(gt_to_xe(gt));
>
> 	return err;
>diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
>index 19619d4952a8..9ea3be97535e 100644
>--- a/include/uapi/drm/xe_drm.h
>+++ b/include/uapi/drm/xe_drm.h
>@@ -20,6 +20,7 @@ extern "C" {
>  *   2. Extension definition and helper structs
>  *   3. IOCTL's Query structs in the order of the Query's entries.
>  *   4. The rest of IOCTL structs in the order of IOCTL declaration.
>+ *   5. uEvents
>  */
>
> /**
>@@ -1686,6 +1687,22 @@ struct drm_xe_oa_stream_info {
> 	__u64 reserved[3];
> };
>
>+/**
>+ * DOC: uevent generated by xe on it's pci node.
>+ *
>+ * DRM_XE_RESET_REQUIRED_UEVENT - Event is generated when device needs reset.
>+ * The REASON is provided along with the event for which reset is required.
>+ * On the basis of REASONS, additional information might be supplied.
>+ */
>+#define DRM_XE_RESET_REQUIRED_UEVENT "DEVICE_STATUS=NEEDS_RESET"
>+
>+/**
>+ * DRM_XE_RESET_REQUIRED_UEVENT_REASON_GT - Reason provided to DRM_XE_RESET_REQUIRED_UEVENT
>+ * incase of gt reset failure. The additional information supplied is tile id and
>+ * gt id of the gt unit for which reset has failed.
>+ */
>+#define DRM_XE_RESET_REQUIRED_UEVENT_REASON_GT "REASON=GT_RESET_FAILED"
>+
> #if defined(__cplusplus)
> }
> #endif
>-- 
>2.34.1
>