fbmem: fix fb_read, fb_write unaligned accesses
fb_{read,write} access the framebuffer using lots of fb_{read,write}l's
but don't check that the file position is aligned which can cause problems
on some architectures which do not support unaligned accesses.
Since the operations are essentially memcpy_{from,to}io, new
fb_memcpy_{from,to}fb macros have been defined and these are used instead.
For Sparc, fb_{read,write} macros use sbus_{read,write}, so this defines
new sbus_memcpy_{from,to}io functions the same as memcpy_{from,to}io but
using sbus_{read,write}b instead of {read,write}b.
Signed-off-by: James Hogan <james@albanarts.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index a434423..0e6aa3d 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -697,9 +697,9 @@
struct inode *inode = file->f_path.dentry->d_inode;
int fbidx = iminor(inode);
struct fb_info *info = registered_fb[fbidx];
- u32 *buffer, *dst;
- u32 __iomem *src;
- int c, i, cnt = 0, err = 0;
+ u8 *buffer, *dst;
+ u8 __iomem *src;
+ int c, cnt = 0, err = 0;
unsigned long total_size;
if (!info || ! info->screen_base)
@@ -730,7 +730,7 @@
if (!buffer)
return -ENOMEM;
- src = (u32 __iomem *) (info->screen_base + p);
+ src = (u8 __iomem *) (info->screen_base + p);
if (info->fbops->fb_sync)
info->fbops->fb_sync(info);
@@ -738,17 +738,9 @@
while (count) {
c = (count > PAGE_SIZE) ? PAGE_SIZE : count;
dst = buffer;
- for (i = c >> 2; i--; )
- *dst++ = fb_readl(src++);
- if (c & 3) {
- u8 *dst8 = (u8 *) dst;
- u8 __iomem *src8 = (u8 __iomem *) src;
-
- for (i = c & 3; i--;)
- *dst8++ = fb_readb(src8++);
-
- src = (u32 __iomem *) src8;
- }
+ fb_memcpy_fromfb(dst, src, c);
+ dst += c;
+ src += c;
if (copy_to_user(buf, buffer, c)) {
err = -EFAULT;
@@ -772,9 +764,9 @@
struct inode *inode = file->f_path.dentry->d_inode;
int fbidx = iminor(inode);
struct fb_info *info = registered_fb[fbidx];
- u32 *buffer, *src;
- u32 __iomem *dst;
- int c, i, cnt = 0, err = 0;
+ u8 *buffer, *src;
+ u8 __iomem *dst;
+ int c, cnt = 0, err = 0;
unsigned long total_size;
if (!info || !info->screen_base)
@@ -811,7 +803,7 @@
if (!buffer)
return -ENOMEM;
- dst = (u32 __iomem *) (info->screen_base + p);
+ dst = (u8 __iomem *) (info->screen_base + p);
if (info->fbops->fb_sync)
info->fbops->fb_sync(info);
@@ -825,19 +817,9 @@
break;
}
- for (i = c >> 2; i--; )
- fb_writel(*src++, dst++);
-
- if (c & 3) {
- u8 *src8 = (u8 *) src;
- u8 __iomem *dst8 = (u8 __iomem *) dst;
-
- for (i = c & 3; i--; )
- fb_writeb(*src8++, dst8++);
-
- dst = (u32 __iomem *) dst8;
- }
-
+ fb_memcpy_tofb(dst, src, c);
+ dst += c;
+ src += c;
*ppos += c;
buf += c;
cnt += c;