[PATCH v3 2/2] drm/i915: debugfs for register write taint

[Ben Widawsky <ben@bwidawsk.net>]

Provide an interface to see which register ranges have been tainted by
the user's interaction.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_debugfs.c |   20 ++++++++++++++++++++
 1 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 87c8e29..7142a0c 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1186,6 +1186,25 @@ static int i915_gem_framebuffer_info(struct seq_file *m, void *data)
 	return 0;
 }
 
+static int i915_user_tainted_info(struct seq_file *m, void *unused)
+{
+	struct drm_info_node *node = (struct drm_info_node *) m->private;
+	struct drm_device *dev = node->minor->dev;
+	drm_i915_private_t *dev_priv = dev->dev_private;
+	struct i915_register_range *range = dev_priv->register_map.map;
+	u32 range_count = dev_priv->register_map.length;
+
+	while(range_count--) {
+		if (range->user_tainted) {
+			seq_printf(m, "tainted register range 0x%08x->0x%08x\n",
+				   range->base, range->size);
+		}
+		range++;
+	}
+
+	return 0;
+}
+
 static int
 i915_wedged_open(struct inode *inode,
 		 struct file *filp)
@@ -1324,6 +1343,7 @@ static struct drm_info_list i915_debugfs_list[] = {
 	{"i915_sr_status", i915_sr_status, 0},
 	{"i915_opregion", i915_opregion, 0},
 	{"i915_gem_framebuffer", i915_gem_framebuffer_info, 0},
+	{"i915_user_tainted", i915_user_tainted_info, 0},
 };
 #define I915_DEBUGFS_ENTRIES ARRAY_SIZE(i915_debugfs_list)
 
-- 
1.7.3.4