diff options
Diffstat (limited to 'lib/mpi/mpicoder.c')
-rw-r--r-- | lib/mpi/mpicoder.c | 122 |
1 files changed, 43 insertions, 79 deletions
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c index eb15e7dc7b65..747606f9e4a3 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -20,6 +20,8 @@ #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 @@ -163,7 +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; @@ -183,38 +191,19 @@ int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, p = buf; *nbytes = n - lzeros; - for (i = a->nlimbs - 1; i >= 0; i--) { - alimb = a->d[i]; + for (i = a->nlimbs - 1 - lzeros / BYTES_PER_MPI_LIMB, + lzeros %= BYTES_PER_MPI_LIMB; + i >= 0; 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 - - if (lzeros > 0) { - if (lzeros >= sizeof(alimb)) { - p -= sizeof(alimb); - } else { - mpi_limb_t *limb1 = (void *)p - sizeof(alimb); - mpi_limb_t *limb2 = (void *)p - sizeof(alimb) - + lzeros; - *limb1 = *limb2; - p -= lzeros; - } - lzeros -= sizeof(alimb); - } + memcpy(p, (u8 *)&alimb + lzeros, BYTES_PER_MPI_LIMB - lzeros); + p += BYTES_PER_MPI_LIMB - lzeros; + lzeros = 0; } return 0; } @@ -359,7 +348,13 @@ 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; @@ -380,42 +375,22 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes, buf_len = sgl->length; p2 = sg_virt(sgl); - for (i = a->nlimbs - 1; i >= 0; i--) { - alimb = a->d[i]; - p = (u8 *)&alimb2; + for (i = a->nlimbs - 1 - lzeros / BYTES_PER_MPI_LIMB, + lzeros %= BYTES_PER_MPI_LIMB; + i >= 0; 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 - 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; - } - lzeros -= sizeof(alimb); + if (lzeros) { + y = lzeros; + lzeros = 0; } - p = p - (sizeof(alimb) - y); + p = (u8 *)&alimb + y; for (x = 0; x < sizeof(alimb) - y; x++) { if (!buf_len) { @@ -443,15 +418,15 @@ EXPORT_SYMBOL_GPL(mpi_write_to_sgl); * a new MPI and reads the content of the sgl to the MPI. * * @sgl: scatterlist to read from - * @len: number of bytes to read + * @nbytes: number of bytes to read * * Return: Pointer to a new MPI or NULL on error */ -MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len) +MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes) { struct scatterlist *sg; int x, i, j, z, lzeros, ents; - unsigned int nbits, nlimbs, nbytes; + unsigned int nbits, nlimbs; mpi_limb_t a; MPI val = NULL; @@ -472,16 +447,12 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len) break; ents--; + nbytes -= lzeros; lzeros = 0; } sgl = sg; - - if (!ents) - nbytes = 0; - else - nbytes = len - lzeros; - + nbytes -= lzeros; nbits = nbytes * 8; if (nbits > MAX_EXTERN_MPI_BITS) { pr_info("MPI: mpi too large (%u bits)\n", nbits); @@ -489,9 +460,8 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len) } if (nbytes > 0) - nbits -= count_leading_zeros(*(u8 *)(sg_virt(sgl) + lzeros)); - else - nbits = 0; + nbits -= count_leading_zeros(*(u8 *)(sg_virt(sgl) + lzeros)) - + (BITS_PER_LONG - 8); nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB); val = mpi_alloc(nlimbs); @@ -507,19 +477,14 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len) j = nlimbs - 1; a = 0; - z = 0; - x = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB; - x %= BYTES_PER_MPI_LIMB; + 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; - int buf_shift = x; - - if (sg_is_last(sg) && (len % BYTES_PER_MPI_LIMB)) - len += BYTES_PER_MPI_LIMB - (len % BYTES_PER_MPI_LIMB); - for (; x < len + buf_shift; x++) { + for (x = 0; x < len; x++) { a <<= 8; a |= *buffer++; if (((z + x + 1) % BYTES_PER_MPI_LIMB) == 0) { @@ -528,7 +493,6 @@ MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int len) } } z += x; - x = 0; lzeros = 0; } return val; |