1/* FR-V interrupt handling
2 *
3 * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11
12#ifndef _ASM_IRQFLAGS_H
13#define _ASM_IRQFLAGS_H
14
15/*
16 * interrupt flag manipulation
17 * - use virtual interrupt management since touching the PSR is slow
18 *   - ICC2.Z: T if interrupts virtually disabled
19 *   - ICC2.C: F if interrupts really disabled
20 * - if Z==1 upon interrupt:
21 *   - C is set to 0
22 *   - interrupts are really disabled
23 *   - entry.S returns immediately
24 * - uses TIHI (TRAP if Z==0 && C==0) #2 to really reenable interrupts
25 *   - if taken, the trap:
26 *     - sets ICC2.C
27 *     - enables interrupts
28 */
29static inline void arch_local_irq_disable(void)
30{
31	/* set Z flag, but don't change the C flag */
32	asm volatile("	andcc	gr0,gr0,gr0,icc2	\n"
33		     :
34		     :
35		     : "memory", "icc2"
36		     );
37}
38
39static inline void arch_local_irq_enable(void)
40{
41	/* clear Z flag and then test the C flag */
42	asm volatile("  oricc	gr0,#1,gr0,icc2		\n"
43		     "	tihi	icc2,gr0,#2		\n"
44		     :
45		     :
46		     : "memory", "icc2"
47		     );
48}
49
50static inline unsigned long arch_local_save_flags(void)
51{
52	unsigned long flags;
53
54	asm volatile("movsg ccr,%0"
55		     : "=r"(flags)
56		     :
57		     : "memory");
58
59	/* shift ICC2.Z to bit 0 */
60	flags >>= 26;
61
62	/* make flags 1 if interrupts disabled, 0 otherwise */
63	return flags & 1UL;
64
65}
66
67static inline unsigned long arch_local_irq_save(void)
68{
69	unsigned long flags = arch_local_save_flags();
70	arch_local_irq_disable();
71	return flags;
72}
73
74static inline void arch_local_irq_restore(unsigned long flags)
75{
76	/* load the Z flag by turning 1 if disabled into 0 if disabled
77	 * and thus setting the Z flag but not the C flag */
78	asm volatile("  xoricc	%0,#1,gr0,icc2		\n"
79		     /* then trap if Z=0 and C=0 */
80		     "	tihi	icc2,gr0,#2		\n"
81		     :
82		     : "r"(flags)
83		     : "memory", "icc2"
84		     );
85
86}
87
88static inline bool arch_irqs_disabled_flags(unsigned long flags)
89{
90	return flags;
91}
92
93static inline bool arch_irqs_disabled(void)
94{
95	return arch_irqs_disabled_flags(arch_local_save_flags());
96}
97
98/*
99 * real interrupt flag manipulation
100 */
101#define __arch_local_irq_disable()			\
102do {							\
103	unsigned long psr;				\
104	asm volatile("	movsg	psr,%0		\n"	\
105		     "	andi	%0,%2,%0	\n"	\
106		     "	ori	%0,%1,%0	\n"	\
107		     "	movgs	%0,psr		\n"	\
108		     : "=r"(psr)			\
109		     : "i" (PSR_PIL_14), "i" (~PSR_PIL)	\
110		     : "memory");			\
111} while (0)
112
113#define __arch_local_irq_enable()			\
114do {							\
115	unsigned long psr;				\
116	asm volatile("	movsg	psr,%0		\n"	\
117		     "	andi	%0,%1,%0	\n"	\
118		     "	movgs	%0,psr		\n"	\
119		     : "=r"(psr)			\
120		     : "i" (~PSR_PIL)			\
121		     : "memory");			\
122} while (0)
123
124#define __arch_local_save_flags(flags)		\
125do {						\
126	typecheck(unsigned long, flags);	\
127	asm("movsg psr,%0"			\
128	    : "=r"(flags)			\
129	    :					\
130	    : "memory");			\
131} while (0)
132
133#define	__arch_local_irq_save(flags)			\
134do {							\
135	unsigned long npsr;				\
136	typecheck(unsigned long, flags);		\
137	asm volatile("	movsg	psr,%0		\n"	\
138		     "	andi	%0,%3,%1	\n"	\
139		     "	ori	%1,%2,%1	\n"	\
140		     "	movgs	%1,psr		\n"	\
141		     : "=r"(flags), "=r"(npsr)		\
142		     : "i" (PSR_PIL_14), "i" (~PSR_PIL)	\
143		     : "memory");			\
144} while (0)
145
146#define	__arch_local_irq_restore(flags)			\
147do {							\
148	typecheck(unsigned long, flags);		\
149	asm volatile("	movgs	%0,psr		\n"	\
150		     :					\
151		     : "r" (flags)			\
152		     : "memory");			\
153} while (0)
154
155#define __arch_irqs_disabled()			\
156	((__get_PSR() & PSR_PIL) >= PSR_PIL_14)
157
158#endif /* _ASM_IRQFLAGS_H */
159