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");
127