fbdev: add drawing functions for framebuffers in system RAM

The generic drawing functions (cfbimgblt, cfbcopyarea, cfbfillrect) assume
that the framebuffer is in IO memory.  However, we have 3 drivers (hecubafb,
arcfb, and vfb) where the framebuffer is allocated from system RAM (via
vmalloc). Using _raw_read/write and family for these drivers (as used in
the cfb* functions) is illegal, especially in other platforms.

Create 3 new drawing functions, based almost entirely from the original
except that the framebuffer memory is assumed to be in system RAM.
These are named as sysimgblt, syscopyarea, and sysfillrect.

Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 0de4260..c4e1b3d 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -895,6 +895,12 @@
 extern void cfb_fillrect(struct fb_info *info, const struct fb_fillrect *rect); 
 extern void cfb_copyarea(struct fb_info *info, const struct fb_copyarea *area); 
 extern void cfb_imageblit(struct fb_info *info, const struct fb_image *image);
+/*
+ * Drawing operations where framebuffer is in system RAM
+ */
+extern void sys_fillrect(struct fb_info *info, const struct fb_fillrect *rect);
+extern void sys_copyarea(struct fb_info *info, const struct fb_copyarea *area);
+extern void sys_imageblit(struct fb_info *info, const struct fb_image *image);
 
 /* drivers/video/fbmem.c */
 extern int register_framebuffer(struct fb_info *fb_info);