[PATCH v5 2/3] drm/xe/xe_ras: Report correctable error events to userspace

[Riana Tauro <riana.tauro@intel.com>]

When an interrupt is received indicating that error counter has crossed
its threshold, read the current counter value and deliver a drm_ras error
event to userspace for each affected component.

To avoid sending duplicate events when the same component appears multiple
times in the response. Send the error-event once per component.

Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Riana Tauro <riana.tauro@intel.com>
---
v2: add warns for unexpected values from system controller (Michal)
    send an event at most once per component for each interrupt (Raag)
    use correct parameters for get_counter (Sashiko)

v3: move unsupported logs to drm_ras layer
    use get_counter directly
    use BITS_PER_TYPE
    move the checks before detected log (Raag)
---
 drivers/gpu/drm/xe/xe_drm_ras.c | 42 +++++++++++++++++++++
 drivers/gpu/drm/xe/xe_drm_ras.h |  3 ++
 drivers/gpu/drm/xe/xe_ras.c     | 67 +++++++++++++++++++++++++++++++++
 3 files changed, 112 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_drm_ras.c b/drivers/gpu/drm/xe/xe_drm_ras.c
index 7937d8ba0ed9..0287594e1026 100644
--- a/drivers/gpu/drm/xe/xe_drm_ras.c
+++ b/drivers/gpu/drm/xe/xe_drm_ras.c
@@ -185,6 +185,48 @@ static int register_nodes(struct xe_device *xe)
 	return ret;
 }
 
+/**
+ * xe_drm_ras_event() - Report drm_ras error event to userspace
+ * @xe: xe device structure
+ * @component: error component (see &enum drm_xe_ras_error_component)
+ * @severity: error severity (see &enum drm_xe_ras_error_severity)
+ * @value: value of error counter
+ *
+ * Report an error-event to userspace.
+ */
+void xe_drm_ras_event(struct xe_device *xe, u8 component, u8 severity, u32 value)
+{
+	struct xe_drm_ras *ras = &xe->ras;
+	struct xe_drm_ras_counter *info;
+	struct drm_ras_node *node;
+	int ret;
+
+	/* Event is supported only if drm_ras is enabled */
+	if (!xe->info.has_drm_ras)
+		return;
+
+	if (component >= DRM_XE_RAS_ERR_COMP_MAX) {
+		drm_warn(&xe->drm, "unsupported component %u\n", component);
+		return;
+	}
+
+	if (severity >= DRM_XE_RAS_ERR_SEV_MAX) {
+		drm_warn(&xe->drm, "unsupported severity %u\n", severity);
+		return;
+	}
+
+	node = &ras->node[severity];
+	info = ras->info[severity];
+
+	if (!info || !info[component].name)
+		return;
+
+	ret = drm_ras_nl_error_event(node, component, info[component].name, value);
+	if (ret)
+		drm_err_ratelimited(&xe->drm, "drm_ras error-event failed: %d for %s %s\n", ret,
+				    info[component].name, error_severity[severity]);
+}
+
 /**
  * xe_drm_ras_init() - Initialize DRM RAS
  * @xe: xe device instance
diff --git a/drivers/gpu/drm/xe/xe_drm_ras.h b/drivers/gpu/drm/xe/xe_drm_ras.h
index 365c70e93e82..add96bf1a7ab 100644
--- a/drivers/gpu/drm/xe/xe_drm_ras.h
+++ b/drivers/gpu/drm/xe/xe_drm_ras.h
@@ -5,11 +5,14 @@
 #ifndef _XE_DRM_RAS_H_
 #define _XE_DRM_RAS_H_
 
+#include <linux/types.h>
+
 struct xe_device;
 
 #define for_each_error_severity(i)	\
 	for (i = 0; i < DRM_XE_RAS_ERR_SEV_MAX; i++)
 
 int xe_drm_ras_init(struct xe_device *xe);
+void xe_drm_ras_event(struct xe_device *xe, u8 component, u8 severity, u32 value);
 
 #endif
diff --git a/drivers/gpu/drm/xe/xe_ras.c b/drivers/gpu/drm/xe/xe_ras.c
index a31e06b8aa67..b08c664778ff 100644
--- a/drivers/gpu/drm/xe/xe_ras.c
+++ b/drivers/gpu/drm/xe/xe_ras.c
@@ -90,6 +90,8 @@ static const char * const gpu_health_states[] = {
 };
 static_assert(ARRAY_SIZE(gpu_health_states) == XE_RAS_HEALTH_MAX);
 
+static int get_counter(struct xe_device *xe, struct xe_ras_error_class *counter, u32 *value);
+
 static u8 drm_to_xe_ras_severity(u8 severity)
 {
 	switch (severity) {
@@ -102,6 +104,18 @@ static u8 drm_to_xe_ras_severity(u8 severity)
 	}
 }
 
+static u8 xe_to_drm_ras_severity(u8 severity)
+{
+	switch (severity) {
+	case XE_RAS_SEV_CORRECTABLE:
+		return DRM_XE_RAS_ERR_SEV_CORRECTABLE;
+	case XE_RAS_SEV_UNCORRECTABLE:
+		return DRM_XE_RAS_ERR_SEV_UNCORRECTABLE;
+	default:
+		return DRM_XE_RAS_ERR_SEV_MAX;
+	}
+}
+
 static u8 drm_to_xe_ras_component(u8 component)
 {
 	switch (component) {
@@ -120,6 +134,24 @@ static u8 drm_to_xe_ras_component(u8 component)
 	}
 }
 
+static u8 xe_to_drm_ras_component(u8 component)
+{
+	switch (component) {
+	case XE_RAS_COMP_DEVICE_MEMORY:
+		return DRM_XE_RAS_ERR_COMP_DEVICE_MEMORY;
+	case XE_RAS_COMP_CORE_COMPUTE:
+		return DRM_XE_RAS_ERR_COMP_CORE_COMPUTE;
+	case XE_RAS_COMP_PCIE:
+		return DRM_XE_RAS_ERR_COMP_PCIE;
+	case XE_RAS_COMP_FABRIC:
+		return DRM_XE_RAS_ERR_COMP_FABRIC;
+	case XE_RAS_COMP_SOC_INTERNAL:
+		return DRM_XE_RAS_ERR_COMP_SOC_INTERNAL;
+	default:
+		return DRM_XE_RAS_ERR_COMP_MAX;
+	}
+}
+
 static int ras_status_to_errno(u32 status)
 {
 	switch (status) {
@@ -218,6 +250,26 @@ static void ras_usp_aer_init(struct xe_device *xe)
 	dev_dbg(&usp->dev, "Uncorrectable Internal Errors downgraded and unmasked\n");
 }
 
+static void ras_send_error_event(struct xe_device *xe, u8 severity, u8 component)
+{
+	struct xe_ras_error_class counter = {0};
+	u8 drm_severity, drm_component;
+	u32 value;
+	int ret;
+
+	counter.common.severity = severity;
+	counter.common.component = component;
+
+	ret = get_counter(xe, &counter, &value);
+	if (ret)
+		return;
+
+	drm_severity = xe_to_drm_ras_severity(severity);
+	drm_component = xe_to_drm_ras_component(component);
+
+	xe_drm_ras_event(xe, drm_component, drm_severity, value);
+}
+
 static u8 handle_core_compute_errors(struct xe_ras_error_array *arr)
 {
 	struct xe_ras_compute_error *error_info = (void *)arr->details;
@@ -312,8 +364,10 @@ void xe_ras_counter_threshold_crossed(struct xe_device *xe,
 	struct xe_ras_threshold_crossed *pending = (void *)&response->data;
 	struct xe_ras_error_class *errors = pending->counters;
 	u32 id, ncounters = pending->ncounters;
+	u8 sent = 0;
 
 	BUILD_BUG_ON(sizeof(response->data) < sizeof(*pending));
+	BUILD_BUG_ON(BITS_PER_TYPE(sent) < XE_RAS_COMP_MAX);
 	xe_device_assert_mem_access(xe);
 
 	if (!ncounters || ncounters > XE_RAS_NUM_COUNTERS)
@@ -327,8 +381,21 @@ void xe_ras_counter_threshold_crossed(struct xe_device *xe,
 		severity = errors[id].common.severity;
 		component = errors[id].common.component;
 
+		if (severity != XE_RAS_SEV_CORRECTABLE) {
+			xe_warn(xe, "sysctrl: unexpected severity %s (%u)\n", sev_to_str(severity),
+				severity);
+			continue;
+		}
+
 		xe_warn(xe, "[RAS]: %s %s detected\n",
 			comp_to_str(component), sev_to_str(severity));
+
+		/* Send event once per component */
+		if (sent & BIT(component))
+			continue;
+		sent |= BIT(component);
+
+		ras_send_error_event(xe, severity, component);
 	}
 }
 
-- 
2.47.1