drm/xe/vf: Fix guc_info debugfs for VFs

The guc_info debugfs attempts to read a bunch of registers that the VFs
doesn't have access to, so fix it by skipping the reads.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4775
Signed-off-by: Daniele Ceraolo Spurio <[email protected]>
Cc: Michal Wajdeczko <[email protected]>
Cc: Lukasz Laguna <[email protected]>
Reviewed-by: Lukasz Laguna <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: dceraolo

drivers/gpu/drm/xe/xe_guc.c

@@ -1510,30 +1510,32 @@ void xe_guc_print_info(struct xe_guc *guc, struct drm_printer *p)
 
 	xe_uc_fw_print(&guc->fw, p);
 
-	fw_ref = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
-	if (!fw_ref)
-		return;
+	if (!IS_SRIOV_VF(gt_to_xe(gt))) {
+		fw_ref = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
+		if (!fw_ref)
+			return;
+
+		status = xe_mmio_read32(&gt->mmio, GUC_STATUS);
+
+		drm_printf(p, "\nGuC status 0x%08x:\n", status);
+		drm_printf(p, "\tBootrom status = 0x%x\n",
+			   REG_FIELD_GET(GS_BOOTROM_MASK, status));
+		drm_printf(p, "\tuKernel status = 0x%x\n",
+			   REG_FIELD_GET(GS_UKERNEL_MASK, status));
+		drm_printf(p, "\tMIA Core status = 0x%x\n",
+			   REG_FIELD_GET(GS_MIA_MASK, status));
+		drm_printf(p, "\tLog level = %d\n",
+			   xe_guc_log_get_level(&guc->log));
+
+		drm_puts(p, "\nScratch registers:\n");
+		for (i = 0; i < SOFT_SCRATCH_COUNT; i++) {
+			drm_printf(p, "\t%2d: \t0x%x\n",
+				   i, xe_mmio_read32(&gt->mmio, SOFT_SCRATCH(i)));
+		}
 
-	status = xe_mmio_read32(&gt->mmio, GUC_STATUS);
-
-	drm_printf(p, "\nGuC status 0x%08x:\n", status);
-	drm_printf(p, "\tBootrom status = 0x%x\n",
-		   REG_FIELD_GET(GS_BOOTROM_MASK, status));
-	drm_printf(p, "\tuKernel status = 0x%x\n",
-		   REG_FIELD_GET(GS_UKERNEL_MASK, status));
-	drm_printf(p, "\tMIA Core status = 0x%x\n",
-		   REG_FIELD_GET(GS_MIA_MASK, status));
-	drm_printf(p, "\tLog level = %d\n",
-		   xe_guc_log_get_level(&guc->log));
-
-	drm_puts(p, "\nScratch registers:\n");
-	for (i = 0; i < SOFT_SCRATCH_COUNT; i++) {
-		drm_printf(p, "\t%2d: \t0x%x\n",
-			   i, xe_mmio_read32(&gt->mmio, SOFT_SCRATCH(i)));
+		xe_force_wake_put(gt_to_fw(gt), fw_ref);
 	}
 
-	xe_force_wake_put(gt_to_fw(gt), fw_ref);
-
 	drm_puts(p, "\n");
 	xe_guc_ct_print(&guc->ct, p, false);