drm/i915/bdw: Export workaround data to debugfs

The workarounds that are applied are exported to a debugfs file;
this is used to verify their state after the test case (reset or
suspend/resume etc). This patch is only required to support i-g-t.
Signed-off-by: Arun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -2628,6 +2628,45 @@ static int i915_shared_dplls_info(struct seq_file *m, void *unused)
 	return 0;
 }
 
+static int intel_wa_registers(struct seq_file *m, void *unused)
+{
+	int i;
+	int ret;
+	struct drm_info_node *node = (struct drm_info_node *) m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (!IS_BROADWELL(dev)) {
+		DRM_DEBUG_DRIVER("Workaround table not available !!\n");
+		return -EINVAL;
+	}
+
+	ret = mutex_lock_interruptible(&dev->struct_mutex);
+	if (ret)
+		return ret;
+
+	intel_runtime_pm_get(dev_priv);
+
+	seq_printf(m, "Workarounds applied: %d\n", dev_priv->num_wa_regs);
+	for (i = 0; i < dev_priv->num_wa_regs; ++i) {
+		u32 addr, mask;
+
+		addr = dev_priv->intel_wa_regs[i].addr;
+		mask = dev_priv->intel_wa_regs[i].mask;
+		dev_priv->intel_wa_regs[i].value = I915_READ(addr) | mask;
+		if (dev_priv->intel_wa_regs[i].addr)
+			seq_printf(m, "0x%X: 0x%08X, mask: 0x%08X\n",
+				   dev_priv->intel_wa_regs[i].addr,
+				   dev_priv->intel_wa_regs[i].value,
+				   dev_priv->intel_wa_regs[i].mask);
+	}
+
+	intel_runtime_pm_put(dev_priv);
+	mutex_unlock(&dev->struct_mutex);
+
+	return 0;
+}
+
 struct pipe_crc_info {
 	const char *name;
 	struct drm_device *dev;
@@ -4159,6 +4198,7 @@ static const struct drm_info_list i915_debugfs_list[] = {
 	{"i915_semaphore_status", i915_semaphore_status, 0},
 	{"i915_shared_dplls_info", i915_shared_dplls_info, 0},
 	{"i915_dp_mst_info", i915_dp_mst_info, 0},
+	{"intel_wa_registers", intel_wa_registers, 0}
 };
 #define I915_DEBUGFS_ENTRIES ARRAY_SIZE(i915_debugfs_list)
 

drivers/gpu/drm/i915/i915_drv.h

@@ -1556,6 +1556,20 @@ struct drm_i915_private {
 	struct intel_shared_dpll shared_dplls[I915_NUM_PLLS];
 	int dpio_phy_iosf_port[I915_NUM_PHYS_VLV];
 
+	/*
+	 * workarounds are currently applied at different places and
+	 * changes are being done to consolidate them so exact count is
+	 * not clear at this point, use a max value for now.
+	 */
+#define I915_MAX_WA_REGS  16
+	struct {
+		u32 addr;
+		u32 value;
+		/* bitmask representing WA bits */
+		u32 mask;
+	} intel_wa_regs[I915_MAX_WA_REGS];
+	u32 num_wa_regs;
+
 	/* Reclocking support */
 	bool render_reclock_avail;
 	bool lvds_downclock_avail;

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -660,20 +660,40 @@ intel_init_pipe_control(struct intel_engine_cs *ring)
 static inline void intel_ring_emit_wa(struct intel_engine_cs *ring,
 				       u32 addr, u32 value)
 {
+	struct drm_device *dev = ring->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (dev_priv->num_wa_regs > I915_MAX_WA_REGS)
+		return;
+
 	intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
 	intel_ring_emit(ring, addr);
 	intel_ring_emit(ring, value);
+
+	dev_priv->intel_wa_regs[dev_priv->num_wa_regs].addr = addr;
+	dev_priv->intel_wa_regs[dev_priv->num_wa_regs].mask = (value) & 0xFFFF;
+	/* value is updated with the status of remaining bits of this
+	 * register when it is read from debugfs file
+	 */
+	dev_priv->intel_wa_regs[dev_priv->num_wa_regs].value = value;
+	dev_priv->num_wa_regs++;
+
+	return;
 }
 
 static int gen8_init_workarounds(struct intel_engine_cs *ring)
 {
 	int ret;
+	struct drm_device *dev = ring->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
 
 	/*
 	 * workarounds applied in this fn are part of register state context,
 	 * they need to be re-initialized followed by gpu reset, suspend/resume,
 	 * module reload.
 	 */
+	dev_priv->num_wa_regs = 0;
+	memset(dev_priv->intel_wa_regs, 0, sizeof(dev_priv->intel_wa_regs));
 
 	/*
 	 * update the number of dwords required based on the
@@ -732,6 +752,9 @@ static int gen8_init_workarounds(struct intel_engine_cs *ring)
 
 	intel_ring_advance(ring);
 
+	DRM_DEBUG_DRIVER("Number of Workarounds applied: %d\n",
+			 dev_priv->num_wa_regs);
+
 	return 0;
 }