drm/msm: add rd logging debugfs

To ease debugging, add debugfs file which can be cat/tail'd to log
submits, along with fence #.  If GPU hangs, you can look at 'gpu'
debugfs file to find last completed fence and current register state,
and compare with logged rd file to narrow down the DRAW_INDX which
triggered the GPU hang.

Signed-off-by: Rob Clark <robdclark@gmail.com>
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index 588c427..c9c71a0 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -55,6 +55,8 @@
 struct msm_kms;
 struct msm_gpu;
 struct msm_mmu;
+struct msm_rd_state;
+struct msm_gem_submit;
 
 #define NUM_DOMAINS 2    /* one for KMS, then one per gpu core (?) */
 
@@ -82,6 +84,8 @@
 	uint32_t next_fence, completed_fence;
 	wait_queue_head_t fence_event;
 
+	struct msm_rd_state *rd;
+
 	/* list of GEM objects: */
 	struct list_head inactive_list;
 
@@ -204,6 +208,13 @@
 void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m);
 void msm_gem_describe_objects(struct list_head *list, struct seq_file *m);
 void msm_framebuffer_describe(struct drm_framebuffer *fb, struct seq_file *m);
+int msm_debugfs_late_init(struct drm_device *dev);
+int msm_rd_debugfs_init(struct drm_minor *minor);
+void msm_rd_debugfs_cleanup(struct drm_minor *minor);
+void msm_rd_dump_submit(struct msm_gem_submit *submit);
+#else
+static inline int msm_debugfs_late_init(struct drm_device *dev) { return 0; }
+static inline void msm_rd_dump_submit(struct msm_gem_submit *submit) {}
 #endif
 
 void __iomem *msm_ioremap(struct platform_device *pdev, const char *name,