summaryrefslogtreecommitdiffstats
path: root/arch/mips/include/asm/war.h
blob: 21443f0962389e5b26c60d8edb9d607ec02e3ea6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2002, 2004, 2007 by Ralf Baechle
 * Copyright (C) 2007  Maciej W. Rozycki
 */
#ifndef _ASM_WAR_H
#define _ASM_WAR_H

/*
 * Work around certain R4000 CPU errata (as implemented by GCC):
 *
 * - A double-word or a variable shift may give an incorrect result
 *   if executed immediately after starting an integer division:
 *   "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0",
 *   erratum #28
 *   "MIPS R4000MC Errata, Processor Revision 2.2 and 3.0", erratum
 *   #19
 *
 * - A double-word or a variable shift may give an incorrect result
 *   if executed while an integer multiplication is in progress:
 *   "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0",
 *   errata #16 & #28
 *
 * - An integer division may give an incorrect result if started in
 *   a delay slot of a taken branch or a jump:
 *   "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0",
 *   erratum #52
 */
#ifdef CONFIG_CPU_R4000_WORKAROUNDS
#define R4000_WAR 1
#else
#define R4000_WAR 0
#endif

/*
 * Work around certain R4400 CPU errata (as implemented by GCC):
 *
 * - A double-word or a variable shift may give an incorrect result
 *   if executed immediately after starting an integer division:
 *   "MIPS R4400MC Errata, Processor Revision 1.0", erratum #10
 *   "MIPS R4400MC Errata, Processor Revision 2.0 & 3.0", erratum #4
 */
#ifdef CONFIG_CPU_R4400_WORKAROUNDS
#define R4400_WAR 1
#else
#define R4400_WAR 0
#endif

/*
 * Work around the "daddi" and "daddiu" CPU errata:
 *
 * - The `daddi' instruction fails to trap on overflow.
 *   "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0",
 *   erratum #23
 *
 * - The `daddiu' instruction can produce an incorrect result.
 *   "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0",
 *   erratum #41
 *   "MIPS R4000MC Errata, Processor Revision 2.2 and 3.0", erratum
 *   #15
 *   "MIPS R4400PC/SC Errata, Processor Revision 1.0", erratum #7
 *   "MIPS R4400MC Errata, Processor Revision 1.0", erratum #5
 */
#ifdef CONFIG_CPU_DADDI_WORKAROUNDS
#define DADDI_WAR 1
#else
#define DADDI_WAR 0
#endif

#endif /* _ASM_WAR_H */