LXR linux/arch/arm64/include/asm/irqflags.h

   1/*
   2 * Copyright (C) 2012 ARM Ltd.
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License version 2 as
   6 * published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope that it will be useful,
   9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 * GNU General Public License for more details.
  12 *
  13 * You should have received a copy of the GNU General Public License
  14 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15 */
  16#ifndef __ASM_IRQFLAGS_H
  17#define __ASM_IRQFLAGS_H
  18
  19#ifdef __KERNEL__
  20
  21#include <asm/ptrace.h>
  22
  23/*
  24 * Aarch64 has flags for masking: Debug, Asynchronous (serror), Interrupts and
  25 * FIQ exceptions, in the 'daif' register. We mask and unmask them in 'dai'
  26 * order:
  27 * Masking debug exceptions causes all other exceptions to be masked too/
  28 * Masking SError masks irq, but not debug exceptions. Masking irqs has no
  29 * side effects for other flags. Keeping to this order makes it easier for
  30 * entry.S to know which exceptions should be unmasked.
  31 *
  32 * FIQ is never expected, but we mask it when we disable debug exceptions, and
  33 * unmask it at all other times.
  34 */
  35
  36/*
  37 * CPU interrupt mask handling.
  38 */
  39static inline unsigned long arch_local_irq_save(void)
  40{
  41        unsigned long flags;
  42        asm volatile(
  43                "mrs    %0, daif                // arch_local_irq_save\n"
  44                "msr    daifset, #2"
  45                : "=r" (flags)
  46                :
  47                : "memory");
  48        return flags;
  49}
  50
  51static inline void arch_local_irq_enable(void)
  52{
  53        asm volatile(
  54                "msr    daifclr, #2             // arch_local_irq_enable"
  55                :
  56                :
  57                : "memory");
  58}
  59
  60static inline void arch_local_irq_disable(void)
  61{
  62        asm volatile(
  63                "msr    daifset, #2             // arch_local_irq_disable"
  64                :
  65                :
  66                : "memory");
  67}
  68
  69/*
  70 * Save the current interrupt enable state.
  71 */
  72static inline unsigned long arch_local_save_flags(void)
  73{
  74        unsigned long flags;
  75        asm volatile(
  76                "mrs    %0, daif                // arch_local_save_flags"
  77                : "=r" (flags)
  78                :
  79                : "memory");
  80        return flags;
  81}
  82
  83/*
  84 * restore saved IRQ state
  85 */
  86static inline void arch_local_irq_restore(unsigned long flags)
  87{
  88        asm volatile(
  89                "msr    daif, %0                // arch_local_irq_restore"
  90        :
  91        : "r" (flags)
  92        : "memory");
  93}
  94
  95static inline int arch_irqs_disabled_flags(unsigned long flags)
  96{
  97        return flags & PSR_I_BIT;
  98}
  99#endif
 100#endif
 101