1 files changed, 196 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_devcoredump.c b/drivers/gpu/drm/xe/xe_devcoredump.c
new file mode 100644
index 000000000..68abc0b19
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_devcoredump.c
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#include "xe_devcoredump.h"
+#include "xe_devcoredump_types.h"
+
+#include <linux/devcoredump.h>
+#include <generated/utsrelease.h>
+
+#include "xe_device.h"
+#include "xe_exec_queue.h"
+#include "xe_force_wake.h"
+#include "xe_gt.h"
+#include "xe_guc_ct.h"
+#include "xe_guc_submit.h"
+#include "xe_hw_engine.h"
+
+/**
+ * DOC: Xe device coredump
+ *
+ * Devices overview:
+ * Xe uses dev_coredump infrastructure for exposing the crash errors in a
+ * standardized way.
+ * devcoredump exposes a temporary device under /sys/class/devcoredump/
+ * which is linked with our card device directly.
+ * The core dump can be accessed either from
+ * /sys/class/drm/card<n>/device/devcoredump/ or from
+ * /sys/class/devcoredump/devcd<m> where
+ * /sys/class/devcoredump/devcd<m>/failing_device is a link to
+ * /sys/class/drm/card<n>/device/.
+ *
+ * Snapshot at hang:
+ * The 'data' file is printed with a drm_printer pointer at devcoredump read
+ * time. For this reason, we need to take snapshots from when the hang has
+ * happened, and not only when the user is reading the file. Otherwise the
+ * information is outdated since the resets might have happened in between.
+ *
+ * 'First' failure snapshot:
+ * In general, the first hang is the most critical one since the following hangs
+ * can be a consequence of the initial hang. For this reason we only take the
+ * snapshot of the 'first' failure and ignore subsequent calls of this function,
+ * at least while the coredump device is alive. Dev_coredump has a delayed work
+ * queue that will eventually delete the device and free all the dump
+ * information.
+ */
+
+#ifdef CONFIG_DEV_COREDUMP
+
+static struct xe_device *coredump_to_xe(const struct xe_devcoredump *coredump)
+{
+	return container_of(coredump, struct xe_device, devcoredump);
+}
+
+static struct xe_guc *exec_queue_to_guc(struct xe_exec_queue *q)
+{
+	return &q->gt->uc.guc;
+}
+
+static ssize_t xe_devcoredump_read(char *buffer, loff_t offset,
+				   size_t count, void *data, size_t datalen)
+{
+	struct xe_devcoredump *coredump = data;
+	struct xe_devcoredump_snapshot *ss;
+	struct drm_printer p;
+	struct drm_print_iterator iter;
+	struct timespec64 ts;
+	int i;
+
+	/* Our device is gone already... */
+	if (!data || !coredump_to_xe(coredump))
+		return -ENODEV;
+
+	iter.data = buffer;
+	iter.offset = 0;
+	iter.start = offset;
+	iter.remain = count;
+
+	ss = &coredump->snapshot;
+	p = drm_coredump_printer(&iter);
+
+	drm_printf(&p, "**** Xe Device Coredump ****\n");
+	drm_printf(&p, "kernel: " UTS_RELEASE "\n");
+	drm_printf(&p, "module: " KBUILD_MODNAME "\n");
+
+	ts = ktime_to_timespec64(ss->snapshot_time);
+	drm_printf(&p, "Snapshot time: %lld.%09ld\n", ts.tv_sec, ts.tv_nsec);
+	ts = ktime_to_timespec64(ss->boot_time);
+	drm_printf(&p, "Uptime: %lld.%09ld\n", ts.tv_sec, ts.tv_nsec);
+
+	drm_printf(&p, "\n**** GuC CT ****\n");
+	xe_guc_ct_snapshot_print(coredump->snapshot.ct, &p);
+	xe_guc_exec_queue_snapshot_print(coredump->snapshot.ge, &p);
+
+	drm_printf(&p, "\n**** HW Engines ****\n");
+	for (i = 0; i < XE_NUM_HW_ENGINES; i++)
+		if (coredump->snapshot.hwe[i])
+			xe_hw_engine_snapshot_print(coredump->snapshot.hwe[i],
+						    &p);
+
+	return count - iter.remain;
+}
+
+static void xe_devcoredump_free(void *data)
+{
+	struct xe_devcoredump *coredump = data;
+	int i;
+
+	/* Our device is gone. Nothing to do... */
+	if (!data || !coredump_to_xe(coredump))
+		return;
+
+	xe_guc_ct_snapshot_free(coredump->snapshot.ct);
+	xe_guc_exec_queue_snapshot_free(coredump->snapshot.ge);
+	for (i = 0; i < XE_NUM_HW_ENGINES; i++)
+		if (coredump->snapshot.hwe[i])
+			xe_hw_engine_snapshot_free(coredump->snapshot.hwe[i]);
+
+	coredump->captured = false;
+	drm_info(&coredump_to_xe(coredump)->drm,
+		 "Xe device coredump has been deleted.\n");
+}
+
+static void devcoredump_snapshot(struct xe_devcoredump *coredump,
+				 struct xe_exec_queue *q)
+{
+	struct xe_devcoredump_snapshot *ss = &coredump->snapshot;
+	struct xe_guc *guc = exec_queue_to_guc(q);
+	struct xe_hw_engine *hwe;
+	enum xe_hw_engine_id id;
+	u32 adj_logical_mask = q->logical_mask;
+	u32 width_mask = (0x1 << q->width) - 1;
+	int i;
+	bool cookie;
+
+	ss->snapshot_time = ktime_get_real();
+	ss->boot_time = ktime_get_boottime();
+
+	cookie = dma_fence_begin_signalling();
+	for (i = 0; q->width > 1 && i < XE_HW_ENGINE_MAX_INSTANCE;) {
+		if (adj_logical_mask & BIT(i)) {
+			adj_logical_mask |= width_mask << i;
+			i += q->width;
+		} else {
+			++i;
+		}
+	}
+
+	xe_force_wake_get(gt_to_fw(q->gt), XE_FORCEWAKE_ALL);
+
+	coredump->snapshot.ct = xe_guc_ct_snapshot_capture(&guc->ct, true);
+	coredump->snapshot.ge = xe_guc_exec_queue_snapshot_capture(q);
+
+	for_each_hw_engine(hwe, q->gt, id) {
+		if (hwe->class != q->hwe->class ||
+		    !(BIT(hwe->logical_instance) & adj_logical_mask)) {
+			coredump->snapshot.hwe[id] = NULL;
+			continue;
+		}
+		coredump->snapshot.hwe[id] = xe_hw_engine_snapshot_capture(hwe);
+	}
+
+	xe_force_wake_put(gt_to_fw(q->gt), XE_FORCEWAKE_ALL);
+	dma_fence_end_signalling(cookie);
+}
+
+/**
+ * xe_devcoredump - Take the required snapshots and initialize coredump device.
+ * @q: The faulty xe_exec_queue, where the issue was detected.
+ *
+ * This function should be called at the crash time within the serialized
+ * gt_reset. It is skipped if we still have the core dump device available
+ * with the information of the 'first' snapshot.
+ */
+void xe_devcoredump(struct xe_exec_queue *q)
+{
+	struct xe_device *xe = gt_to_xe(q->gt);
+	struct xe_devcoredump *coredump = &xe->devcoredump;
+
+	if (coredump->captured) {
+		drm_dbg(&xe->drm, "Multiple hangs are occurring, but only the first snapshot was taken\n");
+		return;
+	}
+
+	coredump->captured = true;
+	devcoredump_snapshot(coredump, q);
+
+	drm_info(&xe->drm, "Xe device coredump has been created\n");
+	drm_info(&xe->drm, "Check your /sys/class/drm/card%d/device/devcoredump/data\n",
+		 xe->drm.primary->index);
+
+	dev_coredumpm(xe->drm.dev, THIS_MODULE, coredump, 0, GFP_KERNEL,
+		      xe_devcoredump_read, xe_devcoredump_free);
+}
+#endif