[PATCH v2 05/14] lib/mpi: mpi_write_sgl(): replace open coded endian conversion

Nicolai Stange
2016-03-20T12:33:33Z

Currently, the endian conversion from CPU order to BE is open coded in
mpi_write_sgl().

Replace this by the centrally provided cpu_to_be*() macros.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
---
lib/mpi/mpicoder.c | 27 +++++++++++----------------
1 file changed, 11 insertions(+), 16 deletions(-)

diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
index b05d390..623439e 100644
--- a/lib/mpi/mpicoder.c
+++ b/lib/mpi/mpicoder.c
@@ -20,6 +20,7 @@

#include <linux/bitops.h>
#include <linux/count_zeros.h>
+#include <linux/byteorder/generic.h>
#include "mpi-internal.h"

#define MAX_EXTERN_MPI_BITS 16384
@@ -359,7 +360,13 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes,
int *sign)
{
u8 *p, *p2;
- mpi_limb_t alimb, alimb2;
+#if BYTES_PER_MPI_LIMB == 4
+ __be32 alimb;
+#elif BYTES_PER_MPI_LIMB == 8
+ __be64 alimb;
+#else
+#error please implement for this limb size.
+#endif
unsigned int n = mpi_get_size(a);
int i, x, y = 0, lzeros, buf_len;

@@ -383,22 +390,10 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes,
for (i = a->nlimbs - 1 - lzeros / BYTES_PER_MPI_LIMB,
lzeros %= BYTES_PER_MPI_LIMB;
i >= 0; i--) {
- alimb = a->d[i];
- p = (u8 *)&alimb2;
#if BYTES_PER_MPI_LIMB == 4
- *p++ = alimb >> 24;
- *p++ = alimb >> 16;
- *p++ = alimb >> 8;
- *p++ = alimb;
+ alimb = cpu_to_be32(a->d[i]);
#elif BYTES_PER_MPI_LIMB == 8
- *p++ = alimb >> 56;
- *p++ = alimb >> 48;
- *p++ = alimb >> 40;
- *p++ = alimb >> 32;
- *p++ = alimb >> 24;
- *p++ = alimb >> 16;
- *p++ = alimb >> 8;
- *p++ = alimb;
+ alimb = cpu_to_be64(a->d[i]);
#else
#error please implement for this limb size.
#endif
@@ -407,7 +402,7 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes,
lzeros = 0;
}

- p = p - sizeof(alimb) + y;
+ p = (u8 *)&alimb + y;

for (x = 0; x < sizeof(alimb) - y; x++) {
if (!buf_len) {
--
2.7.3