1/* mpiutil.ac  -  Utility functions for MPI
  2 * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
  3 *
  4 * This file is part of GnuPG.
  5 *
  6 * GnuPG is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License as published by
  8 * the Free Software Foundation; either version 2 of the License, or
  9 * (at your option) any later version.
 10 *
 11 * GnuPG is distributed in the hope that it will be useful,
 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 14 * GNU General Public License for more details.
 15 *
 16 * You should have received a copy of the GNU General Public License
 17 * along with this program; if not, write to the Free Software
 18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 19 */
 20
 21#include "mpi-internal.h"
 22
 23/****************
 24 * Note:  It was a bad idea to use the number of limbs to allocate
 25 *	  because on a alpha the limbs are large but we normally need
 26 *	  integers of n bits - So we should chnage this to bits (or bytes).
 27 *
 28 *	  But mpi_alloc is used in a lot of places :-)
 29 */
 30MPI mpi_alloc(unsigned nlimbs)
 31{
 32	MPI a;
 33
 34	a = kmalloc(sizeof *a, GFP_KERNEL);
 35	if (!a)
 36		return a;
 37
 38	if (nlimbs) {
 39		a->d = mpi_alloc_limb_space(nlimbs);
 40		if (!a->d) {
 41			kfree(a);
 42			return NULL;
 43		}
 44	} else {
 45		a->d = NULL;
 46	}
 47
 48	a->alloced = nlimbs;
 49	a->nlimbs = 0;
 50	a->sign = 0;
 51	a->flags = 0;
 52	a->nbits = 0;
 53	return a;
 54}
 55EXPORT_SYMBOL_GPL(mpi_alloc);
 56
 57mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs)
 58{
 59	size_t len = nlimbs * sizeof(mpi_limb_t);
 60
 61	if (!len)
 62		return NULL;
 63
 64	return kmalloc(len, GFP_KERNEL);
 65}
 66
 67void mpi_free_limb_space(mpi_ptr_t a)
 68{
 69	if (!a)
 70		return;
 71
 72	kfree(a);
 73}
 74
 75void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs)
 76{
 77	mpi_free_limb_space(a->d);
 78	a->d = ap;
 79	a->alloced = nlimbs;
 80}
 81
 82/****************
 83 * Resize the array of A to NLIMBS. the additional space is cleared
 84 * (set to 0) [done by m_realloc()]
 85 */
 86int mpi_resize(MPI a, unsigned nlimbs)
 87{
 88	void *p;
 89
 90	if (nlimbs <= a->alloced)
 91		return 0;	/* no need to do it */
 92
 93	if (a->d) {
 94		p = kmalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
 95		if (!p)
 96			return -ENOMEM;
 97		memcpy(p, a->d, a->alloced * sizeof(mpi_limb_t));
 98		kfree(a->d);
 99		a->d = p;
100	} else {
101		a->d = kzalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
102		if (!a->d)
103			return -ENOMEM;
104	}
105	a->alloced = nlimbs;
106	return 0;
107}
108
109void mpi_free(MPI a)
110{
111	if (!a)
112		return;
113
114	if (a->flags & 4)
115		kfree(a->d);
116	else
117		mpi_free_limb_space(a->d);
118
119	if (a->flags & ~7)
120		pr_info("invalid flag value in mpi\n");
121	kfree(a);
122}
123EXPORT_SYMBOL_GPL(mpi_free);
124
125MODULE_DESCRIPTION("Multiprecision maths library");
126MODULE_LICENSE("GPL");