drm/xe/guc: Add a helper function for dumping GuC log to dmesg

Create a helper function that can be used to dump the GuC log to dmesg
in a manner that is reliable for extraction and decode. The intention
is that calls to this can be added by developers when debugging
specific issues that require a GuC log but do not allow easy capture
of the log - e.g. failures in selftests and failues that lead to
kernel hangs.

Also note that this is really a temporary stop-gap. The aim is to
allow on demand creation and dumping of devcoredump captures (which
includes the GuC log and much more). Currently this is not possible as
much of the devcoredump code requires a 'struct xe_sched_job' and
those are not available at many places that might want to do the dump.

v2: Add kerneldoc - review feedback from Michal W.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Julia Filipchuk <julia.filipchuk@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241003004611.2323493-12-John.C.Harrison@Intel.com

2 files changed, 19 insertions, 0 deletions

diff --git a/drivers/gpu/drm/xe/xe_guc_log.c b/drivers/gpu/drm/xe/xe_guc_log.c
index 79e01d724509..7fbc56cceaba 100644
--- a/drivers/gpu/drm/xe/xe_guc_log.c
+++ b/drivers/gpu/drm/xe/xe_guc_log.c
@@ -217,6 +217,24 @@ void xe_guc_log_snapshot_print(struct xe_guc_log_snapshot *snapshot, struct drm_
 }
 
 /**
+ * xe_guc_log_print_dmesg - dump a copy of the GuC log to dmesg
+ * @log: GuC log structure
+ */
+void xe_guc_log_print_dmesg(struct xe_guc_log *log)
+{
+	struct xe_gt *gt = log_to_gt(log);
+	static int g_count;
+	struct drm_printer ip = xe_gt_info_printer(gt);
+	struct drm_printer lp = drm_line_printer(&ip, "Capture", ++g_count);
+
+	drm_printf(&lp, "Dumping GuC log for %ps...\n", __builtin_return_address(0));
+
+	xe_guc_log_print(log, &lp);
+
+	drm_printf(&lp, "Done.\n");
+}
+
+/**
  * xe_guc_log_print - dump a copy of the GuC log to some useful location
  * @log: GuC log structure
  * @p: the printer object to output to
diff --git a/drivers/gpu/drm/xe/xe_guc_log.h b/drivers/gpu/drm/xe/xe_guc_log.h
index 949d2c98343d..1fb2fae1f4e1 100644
--- a/drivers/gpu/drm/xe/xe_guc_log.h
+++ b/drivers/gpu/drm/xe/xe_guc_log.h
@@ -39,6 +39,7 @@ struct xe_device;
 
 int xe_guc_log_init(struct xe_guc_log *log);
 void xe_guc_log_print(struct xe_guc_log *log, struct drm_printer *p);
+void xe_guc_log_print_dmesg(struct xe_guc_log *log);
 struct xe_guc_log_snapshot *xe_guc_log_snapshot_capture(struct xe_guc_log *log, bool atomic);
 void xe_guc_log_snapshot_print(struct xe_guc_log_snapshot *snapshot, struct drm_printer *p);
 void xe_guc_log_snapshot_free(struct xe_guc_log_snapshot *snapshot);