From b76321eab2ff7ba2a69eefd643a6c5e5dc917529 Mon Sep 17 00:00:00 2001
From: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Date: Mon, 17 Jun 2013 13:32:11 +0300
Subject: [PATCH] fbdev: add FBIOCOPYAREA ioctl

Based on the patch authored by Ali Gholami Rudi at
    https://lkml.org/lkml/2009/7/13/153

Provide an ioctl for userspace applications, but only if this operation
is hardware accelerated (otherwide it does not make any sense).

Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
---
 drivers/video/fbdev/core/fbmem.c | 30 ++++++++++++++++++++++++++++++
 include/uapi/linux/fb.h          |  5 +++++
 2 files changed, 35 insertions(+)

--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1091,6 +1091,25 @@ fb_blank(struct fb_info *info, int blank
 }
 EXPORT_SYMBOL(fb_blank);
 
+static int fb_copyarea_user(struct fb_info *info,
+			    struct fb_copyarea *copy)
+{
+	int ret = 0;
+	if (!lock_fb_info(info))
+		return -ENODEV;
+	if (copy->dx + copy->width > info->var.xres ||
+	    copy->sx + copy->width > info->var.xres ||
+	    copy->dy + copy->height > info->var.yres ||
+	    copy->sy + copy->height > info->var.yres) {
+		ret = -EINVAL;
+		goto out;
+	}
+	info->fbops->fb_copyarea(info, copy);
+out:
+	unlock_fb_info(info);
+	return ret;
+}
+
 static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
 			unsigned long arg)
 {
@@ -1101,6 +1120,7 @@ static long do_fb_ioctl(struct fb_info *
 	struct fb_cmap cmap_from;
 	struct fb_cmap_user cmap;
 	struct fb_event event;
+	struct fb_copyarea copy;
 	void __user *argp = (void __user *)arg;
 	long ret = 0;
 
@@ -1218,6 +1238,15 @@ static long do_fb_ioctl(struct fb_info *
 		unlock_fb_info(info);
 		console_unlock();
 		break;
+	case FBIOCOPYAREA:
+		if (info->flags & FBINFO_HWACCEL_COPYAREA) {
+			/* only provide this ioctl if it is accelerated */
+			if (copy_from_user(&copy, argp, sizeof(copy)))
+				return -EFAULT;
+			ret = fb_copyarea_user(info, &copy);
+			break;
+		}
+		/* fall through */
 	default:
 		if (!lock_fb_info(info))
 			return -ENODEV;
@@ -1372,6 +1401,7 @@ static long fb_compat_ioctl(struct file
 	case FBIOPAN_DISPLAY:
 	case FBIOGET_CON2FBMAP:
 	case FBIOPUT_CON2FBMAP:
+	case FBIOCOPYAREA:
 		arg = (unsigned long) compat_ptr(arg);
 	case FBIOBLANK:
 		ret = do_fb_ioctl(info, cmd, arg);
--- a/include/uapi/linux/fb.h
+++ b/include/uapi/linux/fb.h
@@ -34,6 +34,11 @@
 #define FBIOPUT_MODEINFO        0x4617
 #define FBIOGET_DISPINFO        0x4618
 #define FBIO_WAITFORVSYNC	_IOW('F', 0x20, __u32)
+/*
+ * HACK: use 'z' in order not to clash with any other ioctl numbers which might
+ * be concurrently added to the mainline kernel
+ */
+#define FBIOCOPYAREA		_IOW('z', 0x21, struct fb_copyarea)
 
 #define FB_TYPE_PACKED_PIXELS		0	/* Packed Pixels	*/
 #define FB_TYPE_PLANES			1	/* Non interleaved planes */
