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authorDaniel Vetter <daniel.vetter@ffwll.ch>2012-02-10 16:52:55 +0100
committerDaniel Vetter <daniel.vetter@ffwll.ch>2012-02-10 17:14:49 +0100
commit9edd576d89a5b6d3e136d7dcab654d887c0d25b7 (patch)
treed19670de2256f8187321de3a41fa4a10d3c8e402 /lib/mpi/mpi-bit.c
parente21af88d39796c907c38648c824be3d646ffbe35 (diff)
parent28a4d5675857f6386930a324317281cb8ed1e5d0 (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-bit.c')
-rw-r--r--lib/mpi/mpi-bit.c217
1 files changed, 217 insertions, 0 deletions
diff --git a/lib/mpi/mpi-bit.c b/lib/mpi/mpi-bit.c
new file mode 100644
index 00000000000..2f526627e4f
--- /dev/null
+++ b/lib/mpi/mpi-bit.c
@@ -0,0 +1,217 @@
+/* mpi-bit.c - MPI bit level fucntions
+ * Copyright (C) 1998, 1999 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
+ */
+
+#include "mpi-internal.h"
+#include "longlong.h"
+
+#define A_LIMB_1 ((mpi_limb_t) 1)
+
+/****************
+ * Sometimes we have MSL (most significant limbs) which are 0;
+ * this is for some reasons not good, so this function removes them.
+ */
+void mpi_normalize(MPI a)
+{
+ for (; a->nlimbs && !a->d[a->nlimbs - 1]; a->nlimbs--)
+ ;
+}
+
+/****************
+ * Return the number of bits in A.
+ */
+unsigned mpi_get_nbits(MPI a)
+{
+ unsigned n;
+
+ mpi_normalize(a);
+
+ if (a->nlimbs) {
+ mpi_limb_t alimb = a->d[a->nlimbs - 1];
+ if (alimb)
+ count_leading_zeros(n, alimb);
+ else
+ n = BITS_PER_MPI_LIMB;
+ n = BITS_PER_MPI_LIMB - n + (a->nlimbs - 1) * BITS_PER_MPI_LIMB;
+ } else
+ n = 0;
+ return n;
+}
+EXPORT_SYMBOL_GPL(mpi_get_nbits);
+
+/****************
+ * Test whether bit N is set.
+ */
+int mpi_test_bit(MPI a, unsigned n)
+{
+ unsigned limbno, bitno;
+ mpi_limb_t limb;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs)
+ return 0; /* too far left: this is a 0 */
+ limb = a->d[limbno];
+ return (limb & (A_LIMB_1 << bitno)) ? 1 : 0;
+}
+
+/****************
+ * Set bit N of A.
+ */
+int mpi_set_bit(MPI a, unsigned n)
+{
+ unsigned limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs) { /* resize */
+ if (a->alloced >= limbno)
+ if (mpi_resize(a, limbno + 1) < 0)
+ return -ENOMEM;
+ a->nlimbs = limbno + 1;
+ }
+ a->d[limbno] |= (A_LIMB_1 << bitno);
+ return 0;
+}
+
+/****************
+ * Set bit N of A. and clear all bits above
+ */
+int mpi_set_highbit(MPI a, unsigned n)
+{
+ unsigned limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs) { /* resize */
+ if (a->alloced >= limbno)
+ if (mpi_resize(a, limbno + 1) < 0)
+ return -ENOMEM;
+ a->nlimbs = limbno + 1;
+ }
+ a->d[limbno] |= (A_LIMB_1 << bitno);
+ for (bitno++; bitno < BITS_PER_MPI_LIMB; bitno++)
+ a->d[limbno] &= ~(A_LIMB_1 << bitno);
+ a->nlimbs = limbno + 1;
+ return 0;
+}
+
+/****************
+ * clear bit N of A and all bits above
+ */
+void mpi_clear_highbit(MPI a, unsigned n)
+{
+ unsigned limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs)
+ return; /* not allocated, so need to clear bits :-) */
+
+ for (; bitno < BITS_PER_MPI_LIMB; bitno++)
+ a->d[limbno] &= ~(A_LIMB_1 << bitno);
+ a->nlimbs = limbno + 1;
+}
+
+/****************
+ * Clear bit N of A.
+ */
+void mpi_clear_bit(MPI a, unsigned n)
+{
+ unsigned limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs)
+ return; /* don't need to clear this bit, it's to far to left */
+ a->d[limbno] &= ~(A_LIMB_1 << bitno);
+}
+
+/****************
+ * Shift A by N bits to the right
+ * FIXME: should use alloc_limb if X and A are same.
+ */
+int mpi_rshift(MPI x, MPI a, unsigned n)
+{
+ mpi_ptr_t xp;
+ mpi_size_t xsize;
+
+ xsize = a->nlimbs;
+ x->sign = a->sign;
+ if (RESIZE_IF_NEEDED(x, (size_t) xsize) < 0)
+ return -ENOMEM;
+ xp = x->d;
+
+ if (xsize) {
+ mpihelp_rshift(xp, a->d, xsize, n);
+ MPN_NORMALIZE(xp, xsize);
+ }
+ x->nlimbs = xsize;
+ return 0;
+}
+
+/****************
+ * Shift A by COUNT limbs to the left
+ * This is used only within the MPI library
+ */
+int mpi_lshift_limbs(MPI a, unsigned int count)
+{
+ mpi_ptr_t ap = a->d;
+ int n = a->nlimbs;
+ int i;
+
+ if (!count || !n)
+ return 0;
+
+ if (RESIZE_IF_NEEDED(a, n + count) < 0)
+ return -ENOMEM;
+
+ for (i = n - 1; i >= 0; i--)
+ ap[i + count] = ap[i];
+ for (i = 0; i < count; i++)
+ ap[i] = 0;
+ a->nlimbs += count;
+ return 0;
+}
+
+/****************
+ * Shift A by COUNT limbs to the right
+ * This is used only within the MPI library
+ */
+void mpi_rshift_limbs(MPI a, unsigned int count)
+{
+ mpi_ptr_t ap = a->d;
+ mpi_size_t n = a->nlimbs;
+ unsigned int i;
+
+ if (count >= n) {
+ a->nlimbs = 0;
+ return;
+ }
+
+ for (i = 0; i < n - count; i++)
+ ap[i] = ap[i + count];
+ ap[i] = 0;
+ a->nlimbs -= count;
+}