drm/cma: add debugfs helpers

Add helper to display fb's which can be used directly in drm_info_list:

static struct drm_info_list foo_debugfs_list[] = {
		...
		{ "fb",   drm_fb_cma_debugfs_show, 0 },
};

to display information about CMA fb objects, as well as a
drm_gem_cma_describe() which can be used if the driver bothers to keep
a list of CMA GEM objects.
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/drm_fb_cma_helper.c

@@ -180,6 +180,59 @@ struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer *fb,
 }
 EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_obj);
 
+#ifdef CONFIG_DEBUG_FS
+/**
+ * drm_fb_cma_describe() - Helper to dump information about a single
+ * CMA framebuffer object
+ */
+void drm_fb_cma_describe(struct drm_framebuffer *fb, struct seq_file *m)
+{
+	struct drm_fb_cma *fb_cma = to_fb_cma(fb);
+	int i, n = drm_format_num_planes(fb->pixel_format);
+
+	seq_printf(m, "fb: %dx%d@%4.4s\n", fb->width, fb->height,
+			(char *)&fb->pixel_format);
+
+	for (i = 0; i < n; i++) {
+		seq_printf(m, "   %d: offset=%d pitch=%d, obj: ",
+				i, fb->offsets[i], fb->pitches[i]);
+		drm_gem_cma_describe(fb_cma->obj[i], m);
+	}
+}
+EXPORT_SYMBOL_GPL(drm_fb_cma_describe);
+
+/**
+ * drm_fb_cma_debugfs_show() - Helper to list CMA framebuffer objects
+ * in debugfs.
+ */
+int drm_fb_cma_debugfs_show(struct seq_file *m, void *arg)
+{
+	struct drm_info_node *node = (struct drm_info_node *) m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct drm_framebuffer *fb;
+	int ret;
+
+	ret = mutex_lock_interruptible(&dev->mode_config.mutex);
+	if (ret)
+		return ret;
+
+	ret = mutex_lock_interruptible(&dev->struct_mutex);
+	if (ret) {
+		mutex_unlock(&dev->mode_config.mutex);
+		return ret;
+	}
+
+	list_for_each_entry(fb, &dev->mode_config.fb_list, head)
+		drm_fb_cma_describe(fb, m);
+
+	mutex_unlock(&dev->struct_mutex);
+	mutex_unlock(&dev->mode_config.mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drm_fb_cma_debugfs_show);
+#endif
+
 static struct fb_ops drm_fbdev_cma_ops = {
 	.owner		= THIS_MODULE,
 	.fb_fillrect	= sys_fillrect,

drivers/gpu/drm/drm_gem_cma_helper.c

@@ -249,3 +249,24 @@ int drm_gem_cma_dumb_destroy(struct drm_file *file_priv,
 	return drm_gem_handle_delete(file_priv, handle);
 }
 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_destroy);
+
+#ifdef CONFIG_DEBUG_FS
+void drm_gem_cma_describe(struct drm_gem_cma_object *cma_obj, struct seq_file *m)
+{
+	struct drm_gem_object *obj = &cma_obj->base;
+	struct drm_device *dev = obj->dev;
+	uint64_t off = 0;
+
+	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+
+	if (obj->map_list.map)
+		off = (uint64_t)obj->map_list.hash.key;
+
+	seq_printf(m, "%2d (%2d) %08llx %08Zx %p %d",
+			obj->name, obj->refcount.refcount.counter,
+			off, cma_obj->paddr, cma_obj->vaddr, obj->size);
+
+	seq_printf(m, "\n");
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_describe);
+#endif

include/drm/drm_fb_cma_helper.h

@@ -23,5 +23,10 @@ struct drm_framebuffer *drm_fb_cma_create(struct drm_device *dev,
 struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer *fb,
 	unsigned int plane);
 
+#ifdef CONFIG_DEBUG_FS
+void drm_fb_cma_describe(struct drm_framebuffer *fb, struct seq_file *m);
+int drm_fb_cma_debugfs_show(struct seq_file *m, void *arg);
+#endif
+
 #endif
 

include/drm/drm_gem_cma_helper.h

@@ -41,4 +41,8 @@ struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
 
 extern const struct vm_operations_struct drm_gem_cma_vm_ops;
 
+#ifdef CONFIG_DEBUG_FS
+void drm_gem_cma_describe(struct drm_gem_cma_object *obj, struct seq_file *m);
+#endif
+
 #endif /* __DRM_GEM_CMA_HELPER_H__ */