arch/frv/include/asm/irqflags.h

   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  */
  29 static 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
  39 static 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
  50 static 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
  67 static 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
  74 static 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
  88 static inline bool arch_irqs_disabled_flags(unsigned long flags)
  89 {
  90         return flags;
  91 }
  92
  93 static 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()                      \
 102 do {                                                    \
 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()                       \
 114 do {                                                    \
 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)          \
 125 do {                                            \
 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)                    \
 134 do {                                                    \
 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)                 \
 147 do {                                                    \
 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 */