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 */