com32/include/sys/cpu.h

   1 #ifndef _CPU_H
   2 #define _CPU_H
   3
   4 #include <stdbool.h>
   5 #include <stdint.h>
   6 #include <klibc/compiler.h>
   7
   8 #if __SIZEOF_POINTER__ == 4
   9 #include <i386/cpu.h>
  10 #elif __SIZEOF_POINTER__ == 8
  11 #include <x86_64/cpu.h>
  12 #else
  13 #error "unsupported architecture"
  14 #endif
  15
  16 typedef unsigned long irq_state_t;
  17
  18 static inline irq_state_t irq_state(void)
  19 {
  20     irq_state_t __st;
  21
  22     asm volatile("pushf ; pop %0" : "=rm" (__st) : : "memory");
  23     return __st;
  24 }
  25
  26 static inline irq_state_t irq_save(void)
  27 {
  28     irq_state_t __st = irq_state();
  29     cli();
  30     return __st;
  31 }
  32
  33 static inline void irq_restore(irq_state_t __st)
  34 {
  35     asm volatile("push %0 ; popf" : : "rm" (__st) : "memory");
  36 }
  37
  38 /* Standard macro to see if a specific flag is changeable */
  39 static inline __constfunc bool cpu_has_eflag(unsigned long flag)
  40 {
  41         unsigned long f0, f1;
  42         asm("pushf ; "
  43             "pushf ; "
  44             "pop %0 ; "
  45             "mov %0,%1 ; "
  46             "xor %2,%1 ; "
  47             "push %1 ; "
  48             "popf ; "
  49             "pushf ; "
  50             "pop %1 ; "
  51             "popf"
  52             : "=&r" (f0), "=&r" (f1)
  53             : "ri" (flag));
  54         return !!((f0^f1) & flag);
  55 }
  56
  57 #endif