Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / lib / mpi / mpicoder.c

diff --git a/kernel/lib/mpi/mpicoder.c b/kernel/lib/mpi/mpicoder.c
index 3db76b8..e37dbf5 100644 (file)
--- a/kernel/lib/mpi/mpicoder.c
+++ b/kernel/lib/mpi/mpicoder.c
@@ -128,6 +128,23 @@ leave:
 }
 EXPORT_SYMBOL_GPL(mpi_read_from_buffer);
 
+static int count_lzeros(MPI a)
+{
+       mpi_limb_t alimb;
+       int i, lzeros = 0;
+
+       for (i = a->nlimbs - 1; i >= 0; i--) {
+               alimb = a->d[i];
+               if (alimb == 0) {
+                       lzeros += sizeof(mpi_limb_t);
+               } else {
+                       lzeros += count_leading_zeros(alimb) / 8;
+                       break;
+               }
+       }
+       return lzeros;
+}
+
 /**
  * mpi_read_buffer() - read MPI to a bufer provided by user (msb first)
  *
@@ -146,7 +163,7 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes,
        uint8_t *p;
        mpi_limb_t alimb;
        unsigned int n = mpi_get_size(a);
-       int i, lzeros = 0;
+       int i, lzeros;
 
        if (buf_len < n || !buf || !nbytes)
                return -EINVAL;
@@ -154,14 +171,7 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes,
        if (sign)
                *sign = a->sign;
 
-       p = (void *)&a->d[a->nlimbs] - 1;
-
-       for (i = a->nlimbs * sizeof(alimb) - 1; i >= 0; i--, p--) {
-               if (!*p)
-                       lzeros++;
-               else
-                       break;
-       }
+       lzeros = count_lzeros(a);
 
        p = buf;
        *nbytes = n - lzeros;
@@ -343,7 +353,7 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes,
        u8 *p, *p2;
        mpi_limb_t alimb, alimb2;
        unsigned int n = mpi_get_size(a);
-       int i, x, y = 0, lzeros = 0, buf_len;
+       int i, x, y = 0, lzeros, buf_len;
 
        if (!nbytes || *nbytes < n)
                return -EINVAL;
@@ -351,20 +361,15 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes,
        if (sign)
                *sign = a->sign;
 
-       p = (void *)&a->d[a->nlimbs] - 1;
-
-       for (i = a->nlimbs * sizeof(alimb) - 1; i >= 0; i--, p--) {
-               if (!*p)
-                       lzeros++;
-               else
-                       break;
-       }
+       lzeros = count_lzeros(a);
 
        *nbytes = n - lzeros;
        buf_len = sgl->length;
        p2 = sg_virt(sgl);
 
-       for (i = a->nlimbs - 1; i >= 0; i--) {
+       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
@@ -385,17 +390,12 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes,
 #error please implement for this limb size.
 #endif
                if (lzeros > 0) {
-                       if (lzeros >= sizeof(alimb)) {
-                               p -= sizeof(alimb);
-                               continue;
-                       } else {
-                               mpi_limb_t *limb1 = (void *)p - sizeof(alimb);
-                               mpi_limb_t *limb2 = (void *)p - sizeof(alimb)
-                                                       + lzeros;
-                               *limb1 = *limb2;
-                               p -= lzeros;
-                               y = lzeros;
-                       }
+                       mpi_limb_t *limb1 = (void *)p - sizeof(alimb);
+                       mpi_limb_t *limb2 = (void *)p - sizeof(alimb)
+                               + lzeros;
+                       *limb1 = *limb2;
+                       p -= lzeros;
+                       y = lzeros;
                        lzeros -= sizeof(alimb);
                }