fs:ext4:write: Add lldiv and do_div to perform 64-32 bits division

The ext4write code has been using direct calls to 64-32 division
(/ and %).

Officially supported u-boot toolchains (eldk-5.[12].x) generate calls
to __aeabi_uldivmod(), which is niether defined in the toolchain libs
nor u-boot source tree.

Due to that, when the ext4write command has been executed, "undefined
instruction" execption was generated (since the __aeabi_uldivmod()
is not provided).

To fix this error, lldiv() for division and do_div() for modulo have
been used.

Those two functions are recommended for performing 64-32 bit number
division in u-boot.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

diff --git a/fs/ext4/ext4fs.c b/fs/ext4/ext4fs.c
index 06536baf625b375e5843e8af08fb4e6d354857aa..80b3b90907d29b540c894b3c897519105a8747b5 100644 (file)
--- a/fs/ext4/ext4fs.c
+++ b/fs/ext4/ext4fs.c
@@ -40,6 +40,7 @@
 #include <linux/stat.h>
 #include <linux/time.h>
 #include <asm/byteorder.h>
+#include <div64.h>
 #include "ext4_common.h"
 
 int ext4fs_symlinknest;
@@ -1051,8 +1052,8 @@ int ext4fs_write(const char *fname, unsigned char *buffer,
        }
        /* calucalate how many blocks required */
        bytes_reqd_for_file = sizebytes;
-       blks_reqd_for_file = bytes_reqd_for_file / fs->blksz;
-       if (bytes_reqd_for_file % fs->blksz != 0) {
+       blks_reqd_for_file = lldiv(bytes_reqd_for_file, fs->blksz);
+       if (do_div(bytes_reqd_for_file, fs->blksz) != 0) {
                blks_reqd_for_file++;
                debug("total bytes for a file %u\n", blks_reqd_for_file);
        }