include/asm-mips/interrupt.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1994, 95, 96, 97, 98, 99, 2003 by Ralf Baechle
   7  * Copyright (C) 1996 by Paul M. Antoine
   8  * Copyright (C) 1999 Silicon Graphics
   9  * Copyright (C) 2000 MIPS Technologies, Inc.
  10  */
  11 #ifndef _ASM_INTERRUPT_H
  12 #define _ASM_INTERRUPT_H
  13
  14 #include <linux/config.h>
  15 #include <asm/hazards.h>
  16
  17 __asm__ (
  18         "       .macro  local_irq_enable                                \n"
  19         "       .set    push                                            \n"
  20         "       .set    reorder                                         \n"
  21         "       .set    noat                                            \n"
  22 #ifdef CONFIG_CPU_MIPSR2
  23         "       ei                                                      \n"
  24 #else
  25         "       mfc0    $1,$12                                          \n"
  26         "       ori     $1,0x1f                                         \n"
  27         "       xori    $1,0x1e                                         \n"
  28         "       mtc0    $1,$12                                          \n"
  29 #endif
  30         "       irq_enable_hazard                                       \n"
  31         "       .set    pop                                             \n"
  32         "       .endm");
  33
  34 static inline void local_irq_enable(void)
  35 {
  36         __asm__ __volatile__(
  37                 "local_irq_enable"
  38                 : /* no outputs */
  39                 : /* no inputs */
  40                 : "memory");
  41 }
  42
  43 /*
  44  * For cli() we have to insert nops to make sure that the new value
  45  * has actually arrived in the status register before the end of this
  46  * macro.
  47  * R4000/R4400 need three nops, the R4600 two nops and the R10000 needs
  48  * no nops at all.
  49  */
  50 /*
  51  * For TX49, operating only IE bit is not enough.
  52  *
  53  * If mfc0 $12 follows store and the mfc0 is last instruction of a
  54  * page and fetching the next instruction causes TLB miss, the result
  55  * of the mfc0 might wrongly contain EXL bit.
  56  *
  57  * ERT-TX49H2-027, ERT-TX49H3-012, ERT-TX49HL3-006, ERT-TX49H4-008
  58  *
  59  * Workaround: mask EXL bit of the result or place a nop before mfc0.
  60  */
  61 __asm__ (
  62         "       .macro  local_irq_disable\n"
  63         "       .set    push                                            \n"
  64         "       .set    noat                                            \n"
  65 #ifdef CONFIG_CPU_MIPSR2
  66         "       di                                                      \n"
  67 #else
  68         "       mfc0    $1,$12                                          \n"
  69         "       ori     $1,0x1f                                         \n"
  70         "       xori    $1,0x1f                                         \n"
  71         "       .set    noreorder                                       \n"
  72         "       mtc0    $1,$12                                          \n"
  73 #endif
  74         "       irq_disable_hazard                                      \n"
  75         "       .set    pop                                             \n"
  76         "       .endm                                                   \n");
  77
  78 static inline void local_irq_disable(void)
  79 {
  80         __asm__ __volatile__(
  81                 "local_irq_disable"
  82                 : /* no outputs */
  83                 : /* no inputs */
  84                 : "memory");
  85 }
  86
  87 __asm__ (
  88         "       .macro  local_save_flags flags                          \n"
  89         "       .set    push                                            \n"
  90         "       .set    reorder                                         \n"
  91         "       mfc0    \\flags, $12                                    \n"
  92         "       .set    pop                                             \n"
  93         "       .endm                                                   \n");
  94
  95 #define local_save_flags(x)                                             \
  96 __asm__ __volatile__(                                                   \
  97         "local_save_flags %0"                                           \
  98         : "=r" (x))
  99
 100 __asm__ (
 101         "       .macro  local_irq_save result                           \n"
 102         "       .set    push                                            \n"
 103         "       .set    reorder                                         \n"
 104         "       .set    noat                                            \n"
 105 #ifdef CONFIG_CPU_MIPSR2
 106         "       di      \\result                                        \n"
 107         "       andi    \\result, 1                                     \n"
 108 #else
 109         "       mfc0    \\result, $12                                   \n"
 110         "       ori     $1, \\result, 0x1f                              \n"
 111         "       xori    $1, 0x1f                                        \n"
 112         "       .set    noreorder                                       \n"
 113         "       mtc0    $1, $12                                         \n"
 114 #endif
 115         "       irq_disable_hazard                                      \n"
 116         "       .set    pop                                             \n"
 117         "       .endm                                                   \n");
 118
 119 #define local_irq_save(x)                                               \
 120 __asm__ __volatile__(                                                   \
 121         "local_irq_save\t%0"                                            \
 122         : "=r" (x)                                                      \
 123         : /* no inputs */                                               \
 124         : "memory")
 125
 126 __asm__ (
 127         "       .macro  local_irq_restore flags                         \n"
 128         "       .set    push                                            \n"
 129         "       .set    noreorder                                       \n"
 130         "       .set    noat                                            \n"
 131 #if defined(CONFIG_CPU_MIPSR2) && defined(CONFIG_IRQ_CPU)
 132         /*
 133          * Slow, but doesn't suffer from a relativly unlikely race
 134          * condition we're having since days 1.
 135          */
 136         "       beqz    \\flags, 1f                                     \n"
 137         "        di                                                     \n"
 138         "       ei                                                      \n"
 139         "1:                                                             \n"
 140 #elif defined(CONFIG_CPU_MIPSR2)
 141         /*
 142          * Fast, dangerous.  Life is fun, life is good.
 143          */
 144         "       mfc0    $1, $12                                         \n"
 145         "       ins     $1, \\flags, 0, 1                               \n"
 146         "       mtc0    $1, $12                                         \n"
 147 #else
 148         "       mfc0    $1, $12                                         \n"
 149         "       andi    \\flags, 1                                      \n"
 150         "       ori     $1, 0x1f                                        \n"
 151         "       xori    $1, 0x1f                                        \n"
 152         "       or      \\flags, $1                                     \n"
 153         "       mtc0    \\flags, $12                                    \n"
 154 #endif
 155         "       irq_disable_hazard                                      \n"
 156         "       .set    pop                                             \n"
 157         "       .endm                                                   \n");
 158
 159 #define local_irq_restore(flags)                                        \
 160 do {                                                                    \
 161         unsigned long __tmp1;                                           \
 162                                                                         \
 163         __asm__ __volatile__(                                           \
 164                 "local_irq_restore\t%0"                                 \
 165                 : "=r" (__tmp1)                                         \
 166                 : "0" (flags)                                           \
 167                 : "memory");                                            \
 168 } while(0)
 169
 170 #define irqs_disabled()                                                 \
 171 ({                                                                      \
 172         unsigned long flags;                                            \
 173         local_save_flags(flags);                                        \
 174         !(flags & 1);                                                   \
 175 })
 176
 177 #endif /* _ASM_INTERRUPT_H */