cregit-Linux how code gets into the kernel

Release 4.14 arch/frv/include/asm/irqflags.h

/* FR-V interrupt handling
 *
 * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#ifndef _ASM_IRQFLAGS_H

#define _ASM_IRQFLAGS_H

/*
 * interrupt flag manipulation
 * - use virtual interrupt management since touching the PSR is slow
 *   - ICC2.Z: T if interrupts virtually disabled
 *   - ICC2.C: F if interrupts really disabled
 * - if Z==1 upon interrupt:
 *   - C is set to 0
 *   - interrupts are really disabled
 *   - entry.S returns immediately
 * - uses TIHI (TRAP if Z==0 && C==0) #2 to really reenable interrupts
 *   - if taken, the trap:
 *     - sets ICC2.C
 *     - enables interrupts
 */

static inline void arch_local_irq_disable(void) { /* set Z flag, but don't change the C flag */ asm volatile(" andcc gr0,gr0,gr0,icc2 \n" : : : "memory", "icc2" ); }

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static inline void arch_local_irq_enable(void) { /* clear Z flag and then test the C flag */ asm volatile(" oricc gr0,#1,gr0,icc2 \n" " tihi icc2,gr0,#2 \n" : : : "memory", "icc2" ); }

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static inline unsigned long arch_local_save_flags(void) { unsigned long flags; asm volatile("movsg ccr,%0" : "=r"(flags) : : "memory"); /* shift ICC2.Z to bit 0 */ flags >>= 26; /* make flags 1 if interrupts disabled, 0 otherwise */ return flags & 1UL; }

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static inline unsigned long arch_local_irq_save(void) { unsigned long flags = arch_local_save_flags(); arch_local_irq_disable(); return flags; }

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David Howells23100.00%1100.00%
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static inline void arch_local_irq_restore(unsigned long flags) { /* load the Z flag by turning 1 if disabled into 0 if disabled * and thus setting the Z flag but not the C flag */ asm volatile(" xoricc %0,#1,gr0,icc2 \n" /* then trap if Z=0 and C=0 */ " tihi icc2,gr0,#2 \n" : : "r"(flags) : "memory", "icc2" ); }

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David Howells17100.00%1100.00%
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static inline bool arch_irqs_disabled_flags(unsigned long flags) { return flags; }

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static inline bool arch_irqs_disabled(void) { return arch_irqs_disabled_flags(arch_local_save_flags()); }

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/* * real interrupt flag manipulation */ #define __arch_local_irq_disable() \ do { \ unsigned long psr; \ asm volatile(" movsg psr,%0 \n" \ " andi %0,%2,%0 \n" \ " ori %0,%1,%0 \n" \ " movgs %0,psr \n" \ : "=r"(psr) \ : "i" (PSR_PIL_14), "i" (~PSR_PIL) \ : "memory"); \ } while (0) #define __arch_local_irq_enable() \ do { \ unsigned long psr; \ asm volatile(" movsg psr,%0 \n" \ " andi %0,%1,%0 \n" \ " movgs %0,psr \n" \ : "=r"(psr) \ : "i" (~PSR_PIL) \ : "memory"); \ } while (0) #define __arch_local_save_flags(flags) \ do { \ typecheck(unsigned long, flags); \ asm("movsg psr,%0" \ : "=r"(flags) \ : \ : "memory"); \ } while (0) #define __arch_local_irq_save(flags) \ do { \ unsigned long npsr; \ typecheck(unsigned long, flags); \ asm volatile(" movsg psr,%0 \n" \ " andi %0,%3,%1 \n" \ " ori %1,%2,%1 \n" \ " movgs %1,psr \n" \ : "=r"(flags), "=r"(npsr) \ : "i" (PSR_PIL_14), "i" (~PSR_PIL) \ : "memory"); \ } while (0) #define __arch_local_irq_restore(flags) \ do { \ typecheck(unsigned long, flags); \ asm volatile(" movgs %0,psr \n" \ : \ : "r" (flags) \ : "memory"); \ } while (0) #define __arch_irqs_disabled() \ ((__get_PSR() & PSR_PIL) >= PSR_PIL_14) #endif /* _ASM_IRQFLAGS_H */

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David Howells178100.00%1100.00%
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