diff options
| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-02-10 16:52:55 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-02-10 17:14:49 +0100 |
| commit | 9edd576d89a5b6d3e136d7dcab654d887c0d25b7 (patch) | |
| tree | d19670de2256f8187321de3a41fa4a10d3c8e402 /lib/mpi/mpi-mul.c | |
| parent | e21af88d39796c907c38648c824be3d646ffbe35 (diff) | |
| parent | 28a4d5675857f6386930a324317281cb8ed1e5d0 (diff) | |
Merge remote-tracking branch 'airlied/drm-fixes' into drm-intel-next-queued
Back-merge from drm-fixes into drm-intel-next to sort out two things:
- interlaced support: -fixes contains a bugfix to correctly clear
interlaced configuration bits in case the bios sets up an interlaced
mode and we want to set up the progressive mode (current kernels
don't support interlaced). The actual feature work to support
interlaced depends upon (and conflicts with) this bugfix.
- forcewake voodoo to workaround missed IRQ issues: -fixes only enabled
this for ivybridge, but some recent bug reports indicate that we
need this on Sandybridge, too. But in a slightly different flavour
and with other fixes and reworks on top. Additionally there are some
forcewake cleanup patches heading to -next that would conflict with
currrent -fixes.
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'lib/mpi/mpi-mul.c')
| -rw-r--r-- | lib/mpi/mpi-mul.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/lib/mpi/mpi-mul.c b/lib/mpi/mpi-mul.c new file mode 100644 index 00000000000..1f3219e2729 --- /dev/null +++ b/lib/mpi/mpi-mul.c @@ -0,0 +1,194 @@ +/* mpi-mul.c - MPI functions + * Copyright (C) 1994, 1996 Free Software Foundation, Inc. + * Copyright (C) 1998, 2001 Free Software Foundation, Inc. + * + * This file is part of GnuPG. + * + * GnuPG is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * GnuPG is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + * + * Note: This code is heavily based on the GNU MP Library. + * Actually it's the same code with only minor changes in the + * way the data is stored; this is to support the abstraction + * of an optional secure memory allocation which may be used + * to avoid revealing of sensitive data due to paging etc. + * The GNU MP Library itself is published under the LGPL; + * however I decided to publish this code under the plain GPL. + */ + +#include "mpi-internal.h" + +int mpi_mul_ui(MPI prod, MPI mult, unsigned long small_mult) +{ + mpi_size_t size, prod_size; + mpi_ptr_t prod_ptr; + mpi_limb_t cy; + int sign; + + size = mult->nlimbs; + sign = mult->sign; + + if (!size || !small_mult) { + prod->nlimbs = 0; + prod->sign = 0; + return 0; + } + + prod_size = size + 1; + if (prod->alloced < prod_size) + if (mpi_resize(prod, prod_size) < 0) + return -ENOMEM; + prod_ptr = prod->d; + + cy = mpihelp_mul_1(prod_ptr, mult->d, size, (mpi_limb_t) small_mult); + if (cy) + prod_ptr[size++] = cy; + prod->nlimbs = size; + prod->sign = sign; + return 0; +} + +int mpi_mul_2exp(MPI w, MPI u, unsigned long cnt) +{ + mpi_size_t usize, wsize, limb_cnt; + mpi_ptr_t wp; + mpi_limb_t wlimb; + int usign, wsign; + + usize = u->nlimbs; + usign = u->sign; + + if (!usize) { + w->nlimbs = 0; + w->sign = 0; + return 0; + } + + limb_cnt = cnt / BITS_PER_MPI_LIMB; + wsize = usize + limb_cnt + 1; + if (w->alloced < wsize) + if (mpi_resize(w, wsize) < 0) + return -ENOMEM; + wp = w->d; + wsize = usize + limb_cnt; + wsign = usign; + + cnt %= BITS_PER_MPI_LIMB; + if (cnt) { + wlimb = mpihelp_lshift(wp + limb_cnt, u->d, usize, cnt); + if (wlimb) { + wp[wsize] = wlimb; + wsize++; + } + } else { + MPN_COPY_DECR(wp + limb_cnt, u->d, usize); + } + + /* Zero all whole limbs at low end. Do it here and not before calling + * mpn_lshift, not to lose for U == W. */ + MPN_ZERO(wp, limb_cnt); + + w->nlimbs = wsize; + w->sign = wsign; + return 0; +} + +int mpi_mul(MPI w, MPI u, MPI v) +{ + int rc = -ENOMEM; + mpi_size_t usize, vsize, wsize; + mpi_ptr_t up, vp, wp; + mpi_limb_t cy; + int usign, vsign, sign_product; + int assign_wp = 0; + mpi_ptr_t tmp_limb = NULL; + + if (u->nlimbs < v->nlimbs) { /* Swap U and V. */ + usize = v->nlimbs; + usign = v->sign; + up = v->d; + vsize = u->nlimbs; + vsign = u->sign; + vp = u->d; + } else { + usize = u->nlimbs; + usign = u->sign; + up = u->d; + vsize = v->nlimbs; + vsign = v->sign; + vp = v->d; + } + sign_product = usign ^ vsign; + wp = w->d; + + /* Ensure W has space enough to store the result. */ + wsize = usize + vsize; + if (w->alloced < (size_t) wsize) { + if (wp == up || wp == vp) { + wp = mpi_alloc_limb_space(wsize); + if (!wp) + goto nomem; + assign_wp = 1; + } else { + if (mpi_resize(w, wsize) < 0) + goto nomem; + wp = w->d; + } + } else { /* Make U and V not overlap with W. */ + if (wp == up) { + /* W and U are identical. Allocate temporary space for U. */ + up = tmp_limb = mpi_alloc_limb_space(usize); + if (!up) + goto nomem; + /* Is V identical too? Keep it identical with U. */ + if (wp == vp) + vp = up; + /* Copy to the temporary space. */ + MPN_COPY(up, wp, usize); + } else if (wp == vp) { + /* W and V are identical. Allocate temporary space for V. */ + vp = tmp_limb = mpi_alloc_limb_space(vsize); + if (!vp) + goto nomem; + /* Copy to the temporary space. */ + MPN_COPY(vp, wp, vsize); + } + } + + if (!vsize) + wsize = 0; + else { + if (mpihelp_mul(wp, up, usize, vp, vsize, &cy) < 0) + goto nomem; + wsize -= cy ? 0 : 1; + } + + if (assign_wp) + mpi_assign_limb_space(w, wp, wsize); + + w->nlimbs = wsize; + w->sign = sign_product; + rc = 0; +nomem: + if (tmp_limb) + mpi_free_limb_space(tmp_limb); + return rc; +} + +int mpi_mulm(MPI w, MPI u, MPI v, MPI m) +{ + if (mpi_mul(w, u, v) < 0) + return -ENOMEM; + return mpi_fdiv_r(w, w, m); +} |
