drm/framebuffer: Add framebuffer debugfs file

Add debugfs file that dumps info about the framebuffers and its planes.
Also dump info about any connected gem object(s).
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107191348.17555-5-noralf@tronnes.org

drivers/gpu/drm/drm_debugfs.c

@@ -158,6 +158,12 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
 		}
 	}
 
+	ret = drm_framebuffer_debugfs_init(minor);
+	if (ret) {
+		DRM_ERROR("Failed to create framebuffer debugfs file\n");
+		return ret;
+	}
+
 	if (dev->driver->debugfs_init) {
 		ret = dev->driver->debugfs_init(minor);
 		if (ret) {

drivers/gpu/drm/drm_framebuffer.c

@@ -25,7 +25,9 @@
 #include <drm/drm_auth.h>
 #include <drm/drm_framebuffer.h>
 #include <drm/drm_atomic.h>
+#include <drm/drm_print.h>
 
+#include "drm_internal.h"
 #include "drm_crtc_internal.h"
 
 /**
@@ -967,3 +969,60 @@ int drm_framebuffer_plane_height(int height,
 	return fb_plane_height(height, fb->format, plane);
 }
 EXPORT_SYMBOL(drm_framebuffer_plane_height);
+
+void drm_framebuffer_print_info(struct drm_printer *p, unsigned int indent,
+				const struct drm_framebuffer *fb)
+{
+	struct drm_format_name_buf format_name;
+	unsigned int i;
+
+	drm_printf_indent(p, indent, "refcount=%u\n",
+			  drm_framebuffer_read_refcount(fb));
+	drm_printf_indent(p, indent, "format=%s\n",
+			  drm_get_format_name(fb->format->format, &format_name));
+	drm_printf_indent(p, indent, "modifier=0x%llx\n", fb->modifier);
+	drm_printf_indent(p, indent, "size=%ux%u\n", fb->width, fb->height);
+	drm_printf_indent(p, indent, "layers:\n");
+
+	for (i = 0; i < fb->format->num_planes; i++) {
+		drm_printf_indent(p, indent + 1, "size[%u]=%dx%d\n", i,
+				  drm_framebuffer_plane_width(fb->width, fb, i),
+				  drm_framebuffer_plane_height(fb->height, fb, i));
+		drm_printf_indent(p, indent + 1, "pitch[%u]=%u\n", i, fb->pitches[i]);
+		drm_printf_indent(p, indent + 1, "offset[%u]=%u\n", i, fb->offsets[i]);
+		drm_printf_indent(p, indent + 1, "obj[%u]:%s\n", i,
+				  fb->obj[i] ? "" : "(null)");
+		if (fb->obj[i])
+			drm_gem_print_info(p, indent + 2, fb->obj[i]);
+	}
+}
+
+#ifdef CONFIG_DEBUG_FS
+static int drm_framebuffer_info(struct seq_file *m, void *data)
+{
+	struct drm_info_node *node = m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct drm_printer p = drm_seq_file_printer(m);
+	struct drm_framebuffer *fb;
+
+	mutex_lock(&dev->mode_config.fb_lock);
+	drm_for_each_fb(fb, dev) {
+		drm_printf(&p, "framebuffer[%u]:\n", fb->base.id);
+		drm_framebuffer_print_info(&p, 1, fb);
+	}
+	mutex_unlock(&dev->mode_config.fb_lock);
+
+	return 0;
+}
+
+static const struct drm_info_list drm_framebuffer_debugfs_list[] = {
+	{ "framebuffer", drm_framebuffer_info, 0 },
+};
+
+int drm_framebuffer_debugfs_init(struct drm_minor *minor)
+{
+	return drm_debugfs_create_files(drm_framebuffer_debugfs_list,
+				ARRAY_SIZE(drm_framebuffer_debugfs_list),
+				minor->debugfs_root, minor);
+}
+#endif

drivers/gpu/drm/drm_gem.c

@@ -40,6 +40,7 @@
 #include <drm/drmP.h>
 #include <drm/drm_vma_manager.h>
 #include <drm/drm_gem.h>
+#include <drm/drm_print.h>
 #include "drm_internal.h"
 
 /** @file drm_gem.c
@@ -1040,3 +1041,19 @@ int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 	return ret;
 }
 EXPORT_SYMBOL(drm_gem_mmap);
+
+void drm_gem_print_info(struct drm_printer *p, unsigned int indent,
+			const struct drm_gem_object *obj)
+{
+	drm_printf_indent(p, indent, "name=%d\n", obj->name);
+	drm_printf_indent(p, indent, "refcount=%u\n",
+			  kref_read(&obj->refcount));
+	drm_printf_indent(p, indent, "start=%08lx\n",
+			  drm_vma_node_start(&obj->vma_node));
+	drm_printf_indent(p, indent, "size=%zu\n", obj->size);
+	drm_printf_indent(p, indent, "imported=%s\n",
+			  obj->import_attach ? "yes" : "no");
+
+	if (obj->dev->driver->gem_print_info)
+		obj->dev->driver->gem_print_info(p, indent, obj);
+}

drivers/gpu/drm/drm_internal.h

@@ -106,6 +106,8 @@ int drm_gem_open_ioctl(struct drm_device *dev, void *data,
 		       struct drm_file *file_priv);
 void drm_gem_open(struct drm_device *dev, struct drm_file *file_private);
 void drm_gem_release(struct drm_device *dev, struct drm_file *file_private);
+void drm_gem_print_info(struct drm_printer *p, unsigned int indent,
+			const struct drm_gem_object *obj);
 
 /* drm_debugfs.c drm_debugfs_crc.c */
 #if defined(CONFIG_DEBUG_FS)
@@ -173,3 +175,8 @@ int drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
 			    struct drm_file *file_private);
 int drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
 			     struct drm_file *file_private);
+
+/* drm_framebuffer.c */
+void drm_framebuffer_print_info(struct drm_printer *p, unsigned int indent,
+				const struct drm_framebuffer *fb);
+int drm_framebuffer_debugfs_init(struct drm_minor *minor);

include/drm/drm_drv.h

@@ -39,6 +39,7 @@ struct drm_minor;
 struct dma_buf_attachment;
 struct drm_display_mode;
 struct drm_mode_create_dumb;
+struct drm_printer;
 
 /* driver capabilities and requirements mask */
 #define DRIVER_USE_AGP			0x1
@@ -428,6 +429,20 @@ struct drm_driver {
 	 */
 	void (*gem_close_object) (struct drm_gem_object *, struct drm_file *);
 
+	/**
+	 * @gem_print_info:
+	 *
+	 * If driver subclasses struct &drm_gem_object, it can implement this
+	 * optional hook for printing additional driver specific info.
+	 *
+	 * drm_printf_indent() should be used in the callback passing it the
+	 * indent argument.
+	 *
+	 * This callback is called from drm_gem_print_info().
+	 */
+	void (*gem_print_info)(struct drm_printer *p, unsigned int indent,
+			       const struct drm_gem_object *obj);
+
 	/**
 	 * @gem_create_object: constructor for gem objects
 	 *