drm/i915: Debugfs interface to read GuC load status

The new node provides access to the status of the GuC-specific loader;
also the scratch registers used for communication between the i915
driver and the GuC firmware.

v2:
    Changes to output formats per Chris Wilson's suggestions

v6:
    Rebased

Issue: VIZ-4884
Signed-off-by: NAlex Dai <yu.dai@intel.com>
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTom O'Rourke <Tom.O'Rourke@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -2374,6 +2374,44 @@ static int i915_llc(struct seq_file *m, void *data)
 	return 0;
 }
 
+static int i915_guc_load_status_info(struct seq_file *m, void *data)
+{
+	struct drm_info_node *node = m->private;
+	struct drm_i915_private *dev_priv = node->minor->dev->dev_private;
+	struct intel_guc_fw *guc_fw = &dev_priv->guc.guc_fw;
+	u32 tmp, i;
+
+	if (!HAS_GUC_UCODE(dev_priv->dev))
+		return 0;
+
+	seq_printf(m, "GuC firmware status:\n");
+	seq_printf(m, "\tpath: %s\n",
+		guc_fw->guc_fw_path);
+	seq_printf(m, "\tfetch: %s\n",
+		intel_guc_fw_status_repr(guc_fw->guc_fw_fetch_status));
+	seq_printf(m, "\tload: %s\n",
+		intel_guc_fw_status_repr(guc_fw->guc_fw_load_status));
+	seq_printf(m, "\tversion wanted: %d.%d\n",
+		guc_fw->guc_fw_major_wanted, guc_fw->guc_fw_minor_wanted);
+	seq_printf(m, "\tversion found: %d.%d\n",
+		guc_fw->guc_fw_major_found, guc_fw->guc_fw_minor_found);
+
+	tmp = I915_READ(GUC_STATUS);
+
+	seq_printf(m, "\nGuC status 0x%08x:\n", tmp);
+	seq_printf(m, "\tBootrom status = 0x%x\n",
+		(tmp & GS_BOOTROM_MASK) >> GS_BOOTROM_SHIFT);
+	seq_printf(m, "\tuKernel status = 0x%x\n",
+		(tmp & GS_UKERNEL_MASK) >> GS_UKERNEL_SHIFT);
+	seq_printf(m, "\tMIA Core status = 0x%x\n",
+		(tmp & GS_MIA_MASK) >> GS_MIA_SHIFT);
+	seq_puts(m, "\nScratch registers:\n");
+	for (i = 0; i < 16; i++)
+		seq_printf(m, "\t%2d: \t0x%x\n", i, I915_READ(SOFT_SCRATCH(i)));
+
+	return 0;
+}
+
 static int i915_edp_psr_status(struct seq_file *m, void *data)
 {
 	struct drm_info_node *node = m->private;
@@ -5033,6 +5071,7 @@ static const struct drm_info_list i915_debugfs_list[] = {
 	{"i915_gem_hws_bsd", i915_hws_info, 0, (void *)VCS},
 	{"i915_gem_hws_vebox", i915_hws_info, 0, (void *)VECS},
 	{"i915_gem_batch_pool", i915_gem_batch_pool_info, 0},
+	{"i915_guc_load_status", i915_guc_load_status_info, 0},
 	{"i915_frequency_info", i915_frequency_info, 0},
 	{"i915_hangcheck_info", i915_hangcheck_info, 0},
 	{"i915_drpc_info", i915_drpc_info, 0},