This patch makes mmapping the simple-framebuffer device work on a no-MMU
ARM target. The code is mostly taken from
arch/blackfin/kernel/sys_bfin.c.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
---
Hello,
note this is only tested on this no-MMU machine and I don't know enough
about framebuffers and mm to decide if this patch is sane. Also I'm
a bit unsure about the size check, I just believed Geert that
PAGE_ALIGN(info->fix.smem_len) is the right value to check against.
Best regards
Uwe
drivers/video/fbmem.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index 7309ac704e26..d0ccedafec8c 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1491,6 +1491,22 @@ __releases(&info->lock)
return 0;
}
+#ifdef HAVE_ARCH_FB_UNMAPPED_AREA
+#define fb_get_unmapped_area get_fb_unmapped_area
+#else
+unsigned long fb_get_unmapped_area(struct file *filp, unsigned long orig_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,
@@ -1502,9 +1518,7 @@ static const struct file_operations fb_fops = {
.mmap = fb_mmap,
.open = fb_open,
.release = fb_release,
-#ifdef HAVE_ARCH_FB_UNMAPPED_AREA
- .get_unmapped_area = get_fb_unmapped_area,
-#endif
+ .get_unmapped_area = fb_get_unmapped_area,
#ifdef CONFIG_FB_DEFERRED_IO
.fsync = fb_deferred_io_fsync,
#endif
--
1.8.5.2
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