include/asm-arm/proc-armv/system.h

   1 /*
   2  *  linux/include/asm-arm/proc-armv/system.h
   3  *
   4  *  Copyright (C) 1996 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #ifndef __ASM_PROC_SYSTEM_H
  11 #define __ASM_PROC_SYSTEM_H
  12
  13 #include <linux/config.h>
  14
  15 #define set_cr(x)                                       \
  16         __asm__ __volatile__(                           \
  17         "mcr    p15, 0, %0, c1, c0      @ set CR"       \
  18         : : "r" (x))
  19
  20 #define CR_M    (1 << 0)        /* MMU enable                           */
  21 #define CR_A    (1 << 1)        /* Alignment abort enable               */
  22 #define CR_C    (1 << 2)        /* Dcache enable                        */
  23 #define CR_W    (1 << 3)        /* Write buffer enable                  */
  24 #define CR_P    (1 << 4)        /* 32-bit exception handler             */
  25 #define CR_D    (1 << 5)        /* 32-bit data address range            */
  26 #define CR_L    (1 << 6)        /* Implementation defined               */
  27 #define CD_B    (1 << 7)        /* Big endian                           */
  28 #define CR_S    (1 << 8)        /* System MMU protection                */
  29 #define CD_R    (1 << 9)        /* ROM MMU protection                   */
  30 #define CR_F    (1 << 10)       /* Implementation defined               */
  31 #define CR_Z    (1 << 11)       /* Implementation defined               */
  32 #define CR_I    (1 << 12)       /* Icache enable                        */
  33 #define CR_V    (1 << 13)       /* Vectors relocated to 0xffff0000      */
  34 #define CR_RR   (1 << 14)       /* Round Robin cache replacement        */
  35
  36 extern unsigned long cr_no_alignment;   /* defined in entry-armv.S */
  37 extern unsigned long cr_alignment;      /* defined in entry-armv.S */
  38
  39 #if __LINUX_ARM_ARCH__ >= 4
  40 #define vectors_base()  ((cr_alignment & CR_V) ? 0xffff0000 : 0)
  41 #else
  42 #define vectors_base()  (0)
  43 #endif
  44
  45 /*
  46  * Save the current interrupt enable state & disable IRQs
  47  */
  48 #define local_irq_save(x)                                       \
  49         ({                                                      \
  50                 unsigned long temp;                             \
  51         __asm__ __volatile__(                                   \
  52         "mrs    %0, cpsr                @ local_irq_save\n"     \
  53 "       orr     %1, %0, #128\n"                                 \
  54 "       msr     cpsr_c, %1"                                     \
  55         : "=r" (x), "=r" (temp)                                 \
  56         :                                                       \
  57         : "memory");                                            \
  58         })
  59
  60 /*
  61  * Enable IRQs
  62  */
  63 #define local_irq_enable()                                      \
  64         ({                                                      \
  65                 unsigned long temp;                             \
  66         __asm__ __volatile__(                                   \
  67         "mrs    %0, cpsr                @ local_irq_enable\n"   \
  68 "       bic     %0, %0, #128\n"                                 \
  69 "       msr     cpsr_c, %0"                                     \
  70         : "=r" (temp)                                           \
  71         :                                                       \
  72         : "memory");                                            \
  73         })
  74
  75 /*
  76  * Disable IRQs
  77  */
  78 #define local_irq_disable()                                     \
  79         ({                                                      \
  80                 unsigned long temp;                             \
  81         __asm__ __volatile__(                                   \
  82         "mrs    %0, cpsr                @ local_irq_disable\n"  \
  83 "       orr     %0, %0, #128\n"                                 \
  84 "       msr     cpsr_c, %0"                                     \
  85         : "=r" (temp)                                           \
  86         :                                                       \
  87         : "memory");                                            \
  88         })
  89
  90 /*
  91  * Enable FIQs
  92  */
  93 #define __stf()                                                 \
  94         ({                                                      \
  95                 unsigned long temp;                             \
  96         __asm__ __volatile__(                                   \
  97         "mrs    %0, cpsr                @ stf\n"                \
  98 "       bic     %0, %0, #64\n"                                  \
  99 "       msr     cpsr_c, %0"                                     \
 100         : "=r" (temp)                                           \
 101         :                                                       \
 102         : "memory");                                            \
 103         })
 104
 105 /*
 106  * Disable FIQs
 107  */
 108 #define __clf()                                                 \
 109         ({                                                      \
 110                 unsigned long temp;                             \
 111         __asm__ __volatile__(                                   \
 112         "mrs    %0, cpsr                @ clf\n"                \
 113 "       orr     %0, %0, #64\n"                                  \
 114 "       msr     cpsr_c, %0"                                     \
 115         : "=r" (temp)                                           \
 116         :                                                       \
 117         : "memory");                                            \
 118         })
 119
 120 /*
 121  * Save the current interrupt enable state.
 122  */
 123 #define local_save_flags(x)                                     \
 124         ({                                                      \
 125         __asm__ __volatile__(                                   \
 126         "mrs    %0, cpsr                @ local_save_flags\n"   \
 127           : "=r" (x)                                            \
 128           :                                                     \
 129           : "memory");                                          \
 130         })
 131
 132 /*
 133  * restore saved IRQ & FIQ state
 134  */
 135 #define local_irq_restore(x)                                    \
 136         __asm__ __volatile__(                                   \
 137         "msr    cpsr_c, %0              @ local_irq_restore\n"  \
 138         :                                                       \
 139         : "r" (x)                                               \
 140         : "memory")
 141
 142 #if defined(CONFIG_CPU_SA1100) || defined(CONFIG_CPU_SA110)
 143 /*
 144  * On the StrongARM, "swp" is terminally broken since it bypasses the
 145  * cache totally.  This means that the cache becomes inconsistent, and,
 146  * since we use normal loads/stores as well, this is really bad.
 147  * Typically, this causes oopsen in filp_close, but could have other,
 148  * more disasterous effects.  There are two work-arounds:
 149  *  1. Disable interrupts and emulate the atomic swap
 150  *  2. Clean the cache, perform atomic swap, flush the cache
 151  *
 152  * We choose (1) since its the "easiest" to achieve here and is not
 153  * dependent on the processor type.
 154  */
 155 #define swp_is_buggy
 156 #endif
 157
 158 static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
 159 {
 160         extern void __bad_xchg(volatile void *, int);
 161         unsigned long ret;
 162 #ifdef swp_is_buggy
 163         unsigned long flags;
 164 #endif
 165
 166         switch (size) {
 167 #ifdef swp_is_buggy
 168                 case 1:
 169                         local_irq_save(flags);
 170                         ret = *(volatile unsigned char *)ptr;
 171                         *(volatile unsigned char *)ptr = x;
 172                         local_irq_restore(flags);
 173                         break;
 174
 175                 case 4:
 176                         local_irq_save(flags);
 177                         ret = *(volatile unsigned long *)ptr;
 178                         *(volatile unsigned long *)ptr = x;
 179                         local_irq_restore(flags);
 180                         break;
 181 #else
 182                 case 1: __asm__ __volatile__ ("swpb %0, %1, [%2]"
 183                                         : "=&r" (ret)
 184                                         : "r" (x), "r" (ptr)
 185                                         : "memory");
 186                         break;
 187                 case 4: __asm__ __volatile__ ("swp %0, %1, [%2]"
 188                                         : "=&r" (ret)
 189                                         : "r" (x), "r" (ptr)
 190                                         : "memory");
 191                         break;
 192 #endif
 193                 default: __bad_xchg(ptr, size), ret = 0;
 194         }
 195
 196         return ret;
 197 }
 198
 199 #endif