diff options
| -rw-r--r-- | lib/mpi/mpicoder.c | 86 |
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); |