lib/mpi: Do not do sg_virt

[cascardo/linux.git] / lib / mpi / mpicoder.c

diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
index 7150e5c..c6272ae 100644 (file)
--- 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);