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authorNicolai Stange <nicstange@gmail.com>2016-03-22 13:12:41 +0100
committerHerbert Xu <herbert@gondor.apana.org.au>2016-04-05 14:35:49 +0200
commit90f864e20029600a8dc33e27b1192af4636100d4 (patch)
tree73eba1689c2e633581f9fc84b2e1baf55d838d45 /lib
parentlib/mpi: mpi_read_buffer(): optimize skipping of leading zero limbs (diff)
downloadlinux-90f864e20029600a8dc33e27b1192af4636100d4.tar.xz
linux-90f864e20029600a8dc33e27b1192af4636100d4.zip
lib/mpi: mpi_read_buffer(): replace open coded endian conversion
Currently, the endian conversion from CPU order to BE is open coded in mpi_read_buffer(). Replace this by the centrally provided cpu_to_be*() macros. Copy from the temporary storage on stack to the destination buffer by means of memcpy(). Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'lib')
-rw-r--r--lib/mpi/mpicoder.c27
1 files changed, 12 insertions, 15 deletions
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
index 2fd8d418526c..a999ee1cddc5 100644
--- a/lib/mpi/mpicoder.c
+++ b/lib/mpi/mpicoder.c
@@ -21,6 +21,7 @@
#include <linux/bitops.h>
#include <linux/count_zeros.h>
#include <linux/byteorder/generic.h>
+#include <linux/string.h>
#include "mpi-internal.h"
#define MAX_EXTERN_MPI_BITS 16384
@@ -164,7 +165,13 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes,
int *sign)
{
uint8_t *p;
- mpi_limb_t alimb;
+#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, lzeros;
@@ -187,25 +194,15 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes,
for (i = a->nlimbs - 1 - lzeros / BYTES_PER_MPI_LIMB,
lzeros %= BYTES_PER_MPI_LIMB;
i >= 0; i--) {
- alimb = a->d[i];
#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
-
+ memcpy(p, &alimb, BYTES_PER_MPI_LIMB);
+ p += BYTES_PER_MPI_LIMB;
if (lzeros > 0) {
mpi_limb_t *limb1 = (void *)p - sizeof(alimb);
mpi_limb_t *limb2 = (void *)p - sizeof(alimb)