drm/xe: Introduce GuC PC debugfs

Allows the visualization of the current GuC power conservation
status and policies.

v2: Fix DCC msg (Vinay)
v3: Simplify pc_get_state_string (Jonathan)

Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250115145053.1142023-1-rodrigo.vivi@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Author: rodrigovivi

drivers/gpu/drm/xe/xe_guc_debugfs.c

@@ -13,6 +13,7 @@
 #include "xe_guc.h"
 #include "xe_guc_ct.h"
 #include "xe_guc_log.h"
+#include "xe_guc_pc.h"
 #include "xe_macros.h"
 #include "xe_pm.h"
 
@@ -60,10 +61,24 @@ static int guc_ctb(struct seq_file *m, void *data)
 	return 0;
 }
 
+static int guc_pc(struct seq_file *m, void *data)
+{
+	struct xe_guc *guc = node_to_guc(m->private);
+	struct xe_device *xe = guc_to_xe(guc);
+	struct drm_printer p = drm_seq_file_printer(m);
+
+	xe_pm_runtime_get(xe);
+	xe_guc_pc_print(&guc->pc, &p);
+	xe_pm_runtime_put(xe);
+
+	return 0;
+}
+
 static const struct drm_info_list debugfs_list[] = {
 	{"guc_info", guc_info, 0},
 	{"guc_log", guc_log, 0},
 	{"guc_ctb", guc_ctb, 0},
+	{"guc_pc", guc_pc, 0},
 };
 
 void xe_guc_debugfs_register(struct xe_guc *guc, struct dentry *parent)

drivers/gpu/drm/xe/xe_guc_pc.c

@@ -8,6 +8,7 @@
 #include <linux/delay.h>
 
 #include <drm/drm_managed.h>
+#include <drm/drm_print.h>
 #include <generated/xe_wa_oob.h>
 
 #include "abi/guc_actions_slpc_abi.h"
@@ -1131,3 +1132,61 @@ int xe_guc_pc_init(struct xe_guc_pc *pc)
 
 	return devm_add_action_or_reset(xe->drm.dev, xe_guc_pc_fini_hw, pc);
 }
+
+static const char *pc_get_state_string(struct xe_guc_pc *pc)
+{
+	switch (slpc_shared_data_read(pc, header.global_state)) {
+	case SLPC_GLOBAL_STATE_NOT_RUNNING:
+		return "not running";
+	case SLPC_GLOBAL_STATE_INITIALIZING:
+		return "initializing";
+	case SLPC_GLOBAL_STATE_RESETTING:
+		return "resetting";
+	case SLPC_GLOBAL_STATE_RUNNING:
+		return "running";
+	case SLPC_GLOBAL_STATE_SHUTTING_DOWN:
+		return "shutting down";
+	case SLPC_GLOBAL_STATE_ERROR:
+		return "error";
+	default:
+		return "unknown";
+	}
+}
+
+/**
+ * xe_guc_pc_print - Print GuC's Power Conservation information for debug
+ * @pc: Xe_GuC_PC instance
+ * @p: drm_printer
+ */
+void xe_guc_pc_print(struct xe_guc_pc *pc, struct drm_printer *p)
+{
+	drm_printf(p, "SLPC Shared Data Header:\n");
+	drm_printf(p, "\tSize: %x\n", slpc_shared_data_read(pc, header.size));
+	drm_printf(p, "\tGlobal State: %s\n", pc_get_state_string(pc));
+
+	if (pc_action_query_task_state(pc))
+		return;
+
+	drm_printf(p, "\nSLPC Tasks Status:\n");
+	drm_printf(p, "\tGTPERF enabled: %s\n",
+		   str_yes_no(slpc_shared_data_read(pc, task_state_data.status) &
+			      SLPC_GTPERF_TASK_ENABLED));
+	drm_printf(p, "\tDCC enabled: %s\n",
+		   str_yes_no(slpc_shared_data_read(pc, task_state_data.status) &
+			      SLPC_DCC_TASK_ENABLED));
+	drm_printf(p, "\tDCC in use: %s\n",
+		   str_yes_no(slpc_shared_data_read(pc, task_state_data.status) &
+			      SLPC_IN_DCC));
+	drm_printf(p, "\tBalancer enabled: %s\n",
+		   str_yes_no(slpc_shared_data_read(pc, task_state_data.status) &
+			      SLPC_BALANCER_ENABLED));
+	drm_printf(p, "\tIBC enabled: %s\n",
+		   str_yes_no(slpc_shared_data_read(pc, task_state_data.status) &
+			      SLPC_IBC_TASK_ENABLED));
+	drm_printf(p, "\tBalancer IA LMT enabled: %s\n",
+		   str_yes_no(slpc_shared_data_read(pc, task_state_data.status) &
+			      SLPC_BALANCER_IA_LMT_ENABLED));
+	drm_printf(p, "\tBalancer IA LMT active: %s\n",
+		   str_yes_no(slpc_shared_data_read(pc, task_state_data.status) &
+			      SLPC_BALANCER_IA_LMT_ACTIVE));
+}

drivers/gpu/drm/xe/xe_guc_pc.h

@@ -10,13 +10,15 @@
 
 struct xe_guc_pc;
 enum slpc_gucrc_mode;
+struct drm_printer;
 
 int xe_guc_pc_init(struct xe_guc_pc *pc);
 int xe_guc_pc_start(struct xe_guc_pc *pc);
 int xe_guc_pc_stop(struct xe_guc_pc *pc);
 int xe_guc_pc_gucrc_disable(struct xe_guc_pc *pc);
 int xe_guc_pc_override_gucrc_mode(struct xe_guc_pc *pc, enum slpc_gucrc_mode mode);
 int xe_guc_pc_unset_gucrc_mode(struct xe_guc_pc *pc);
+void xe_guc_pc_print(struct xe_guc_pc *pc, struct drm_printer *p);
 
 u32 xe_guc_pc_get_act_freq(struct xe_guc_pc *pc);
 int xe_guc_pc_get_cur_freq(struct xe_guc_pc *pc, u32 *freq);