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-rw-r--r--lib/mpi/mpicoder.c86
1 files changed, 50 insertions, 36 deletions
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
index 7150e5c23604..c6272ae2015e 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/scatterlist.h>
#include <linux/string.h>
#include "mpi-internal.h"
@@ -255,7 +256,9 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned nbytes,
#error please implement for this limb size.
#endif
unsigned int n = mpi_get_size(a);
+ struct sg_mapping_iter miter;
int i, x, buf_len;
+ int nents;
if (sign)
*sign = a->sign;
@@ -263,23 +266,27 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned nbytes,
if (nbytes < n)
return -EOVERFLOW;
- buf_len = sgl->length;
- p2 = sg_virt(sgl);
+ nents = sg_nents_for_len(sgl, nbytes);
+ if (nents < 0)
+ return -EINVAL;
- while (nbytes > n) {
- if (!buf_len) {
- sgl = sg_next(sgl);
- if (!sgl)
- return -EINVAL;
- buf_len = sgl->length;
- p2 = sg_virt(sgl);
- }
+ sg_miter_start(&miter, sgl, nents, SG_MITER_ATOMIC | SG_MITER_TO_SG);
+ sg_miter_next(&miter);
+ buf_len = miter.length;
+ p2 = miter.addr;
+ while (nbytes > n) {
i = min_t(unsigned, nbytes - n, buf_len);
memset(p2, 0, i);
p2 += i;
- buf_len -= i;
nbytes -= i;
+
+ buf_len -= i;
+ if (!buf_len) {
+ sg_miter_next(&miter);
+ buf_len = miter.length;
+ p2 = miter.addr;
+ }
}
for (i = a->nlimbs - 1; i >= 0; i--) {
@@ -293,17 +300,16 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned nbytes,
p = (u8 *)&alimb;
for (x = 0; x < sizeof(alimb); x++) {
- if (!buf_len) {
- sgl = sg_next(sgl);
- if (!sgl)
- return -EINVAL;
- buf_len = sgl->length;
- p2 = sg_virt(sgl);
- }
*p2++ = *p++;
- buf_len--;
+ if (!--buf_len) {
+ sg_miter_next(&miter);
+ buf_len = miter.length;
+ p2 = miter.addr;
+ }
}
}
+
+ sg_miter_stop(&miter);
return 0;
}
EXPORT_SYMBOL_GPL(mpi_write_to_sgl);
@@ -323,19 +329,23 @@ EXPORT_SYMBOL_GPL(mpi_write_to_sgl);
*/
MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes)
{
- struct scatterlist *sg;
- int x, i, j, z, lzeros, ents;
+ struct sg_mapping_iter miter;
unsigned int nbits, nlimbs;
+ int x, j, z, lzeros, ents;
+ unsigned int len;
+ const u8 *buff;
mpi_limb_t a;
MPI val = NULL;
- lzeros = 0;
- ents = sg_nents(sgl);
+ ents = sg_nents_for_len(sgl, nbytes);
+ if (ents < 0)
+ return NULL;
- for_each_sg(sgl, sg, ents, i) {
- const u8 *buff = sg_virt(sg);
- int len = sg->length;
+ sg_miter_start(&miter, sgl, ents, SG_MITER_ATOMIC | SG_MITER_FROM_SG);
+ lzeros = 0;
+ len = 0;
+ while (nbytes > 0) {
while (len && !*buff) {
lzeros++;
len--;
@@ -345,12 +355,14 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes)
if (len && *buff)
break;
- ents--;
+ sg_miter_next(&miter);
+ buff = miter.addr;
+ len = miter.length;
+
nbytes -= lzeros;
lzeros = 0;
}
- sgl = sg;
nbytes -= lzeros;
nbits = nbytes * 8;
if (nbits > MAX_EXTERN_MPI_BITS) {
@@ -359,8 +371,7 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes)
}
if (nbytes > 0)
- nbits -= count_leading_zeros(*(u8 *)(sg_virt(sgl) + lzeros)) -
- (BITS_PER_LONG - 8);
+ nbits -= count_leading_zeros(*buff) - (BITS_PER_LONG - 8);
nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB);
val = mpi_alloc(nlimbs);
@@ -379,21 +390,24 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes)
z = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;
z %= BYTES_PER_MPI_LIMB;
- for_each_sg(sgl, sg, ents, i) {
- const u8 *buffer = sg_virt(sg) + lzeros;
- int len = sg->length - lzeros;
-
+ for (;;) {
for (x = 0; x < len; x++) {
a <<= 8;
- a |= *buffer++;
+ a |= *buff++;
if (((z + x + 1) % BYTES_PER_MPI_LIMB) == 0) {
val->d[j--] = a;
a = 0;
}
}
z += x;
- lzeros = 0;
+
+ if (!sg_miter_next(&miter))
+ break;
+
+ buff = miter.addr;
+ len = miter.length;
}
+
return val;
}
EXPORT_SYMBOL_GPL(mpi_read_raw_from_sgl);