[RFC v3 1/3] fbmem: add default get_fb_unmapped_area function

[Benjamin Gaignard]

If HAVE_ARCH_FB_UNMAPPED_AREA is set and get_fb_unmapped_area
function not defined in platform architecture let use a default function.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard at linaro.org>
---
 drivers/video/fbdev/core/fbmem.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 76c1ad9..54488ee 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1492,6 +1492,21 @@ static long fb_compat_ioctl(struct file *file, unsigned int cmd,
 	return 0;
 }
 
+#if defined(HAVE_ARCH_FB_UNMAPPED_AREA) && !defined(get_fb_unmapped_area)
+unsigned long get_fb_unmapped_area(struct file *filp,
+				   unsigned long addr, unsigned long len,
+				   unsigned long pgoff, unsigned long flags)
+{
+	struct fb_info * const info = filp->private_data;
+	unsigned long fb_size = PAGE_ALIGN(info->fix.smem_len);
+
+	if (pgoff > fb_size || len > fb_size - pgoff)
+		return -EINVAL;
+
+	return (unsigned long)info->screen_base + pgoff;
+}
+#endif
+
 static const struct file_operations fb_fops = {
 	.owner =	THIS_MODULE,
 	.read =		fb_read,
-- 
1.9.1