File: /Users/paulross/dev/linux/linux-3.13/arch/x86/include/asm/irqflags.h

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       1: #ifndef _X86_IRQFLAGS_H_
       2: #define _X86_IRQFLAGS_H_
       3: 
       4: #include <asm/processor-flags.h>
       5: 
       6: #ifndef __ASSEMBLY__
       7: /*
       8:  * Interrupt control:
       9:  */
      10: 
      11: static inline unsigned long native_save_fl(void)
      12: {
      13:     unsigned long flags;
      14: 
      15:     /*
      16:      * "=rm" is safe here, because "pop" adjusts the stack before
      17:      * it evaluates its effective address -- this is part of the
      18:      * documented behavior of the "pop" instruction.
      19:      */
      20:     asm volatile("# __raw_save_flags\n\t"
      21:              "pushf ; pop %0"
      22:              : "=rm" (flags)
      23:              : /* no input */
      24:              : "memory");
      25: 
      26:     return flags;
      27: }
      28: 
      29: static inline void native_restore_fl(unsigned long flags)
      30: {
      31:     asm volatile("push %0 ; popf"
      32:              : /* no output */
      33:              :"g" (flags)
      34:              :"memory", "cc");
      35: }
      36: 
      37: static inline void native_irq_disable(void)
      38: {
      39:     asm volatile("cli": : :"memory");
      40: }
      41: 
      42: static inline void native_irq_enable(void)
      43: {
      44:     asm volatile("sti": : :"memory");
      45: }
      46: 
      47: static inline void native_safe_halt(void)
      48: {
      49:     asm volatile("sti; hlt": : :"memory");
      50: }
      51: 
      52: static inline void native_halt(void)
      53: {
      54:     asm volatile("hlt": : :"memory");
      55: }
      56: 
      57: #endif
      58: 
      59: #ifdef CONFIG_PARAVIRT
      60: #include <asm/paravirt.h>
      61: #else
      62: #ifndef __ASSEMBLY__
      63: #include <linux/types.h>
      64: 
      65: static inline notrace unsigned long arch_local_save_flags(void)
      66: {
      67:     return native_save_fl();
      68: }
      69: 
      70: static inline notrace void arch_local_irq_restore(unsigned long flags)
      71: {
      72:     native_restore_fl(flags);
      73: }
      74: 
      75: static inline notrace void arch_local_irq_disable(void)
      76: {
      77:     native_irq_disable();
      78: }
      79: 
      80: static inline notrace void arch_local_irq_enable(void)
      81: {
      82:     native_irq_enable();
      83: }
      84: 
      85: /*
      86:  * Used in the idle loop; sti takes one instruction cycle
      87:  * to complete:
      88:  */
      89: static inline void arch_safe_halt(void)
      90: {
      91:     native_safe_halt();
      92: }
      93: 
      94: /*
      95:  * Used when interrupts are already enabled or to
      96:  * shutdown the processor:
      97:  */
      98: static inline void halt(void)
      99: {
     100:     native_halt();
     101: }
     102: 
     103: /*
     104:  * For spinlocks, etc:
     105:  */
     106: static inline notrace unsigned long arch_local_irq_save(void)
     107: {
     108:     unsigned long flags = arch_local_save_flags();
     109:     arch_local_irq_disable();
     110:     return flags;
     111: }
     112: #else
     113: 
     114: #define ENABLE_INTERRUPTS(x)    sti
     115: #define DISABLE_INTERRUPTS(x)    cli
     116: 
     117: #ifdef CONFIG_X86_64
     118: #define SWAPGS    swapgs
     119: /*
     120:  * Currently paravirt can't handle swapgs nicely when we
     121:  * don't have a stack we can rely on (such as a user space
     122:  * stack).  So we either find a way around these or just fault
     123:  * and emulate if a guest tries to call swapgs directly.
     124:  *
     125:  * Either way, this is a good way to document that we don't
     126:  * have a reliable stack. x86_64 only.
     127:  */
     128: #define SWAPGS_UNSAFE_STACK    swapgs
     129: 
     130: #define PARAVIRT_ADJUST_EXCEPTION_FRAME    /*  */
     131: 
     132: #define INTERRUPT_RETURN    iretq
     133: #define USERGS_SYSRET64                \
     134:     swapgs;                    \
     135:     sysretq;
     136: #define USERGS_SYSRET32                \
     137:     swapgs;                    \
     138:     sysretl
     139: #define ENABLE_INTERRUPTS_SYSEXIT32        \
     140:     swapgs;                    \
     141:     sti;                    \
     142:     sysexit
     143: 
     144: #else
     145: #define INTERRUPT_RETURN        iret
     146: #define ENABLE_INTERRUPTS_SYSEXIT    sti; sysexit
     147: #define GET_CR0_INTO_EAX        movl %cr0, %eax
     148: #endif
     149: 
     150: 
     151: #endif /* __ASSEMBLY__ */
     152: #endif /* CONFIG_PARAVIRT */
     153: 
     154: #ifndef __ASSEMBLY__
     155: static inline int arch_irqs_disabled_flags(unsigned long flags)
     156: {
     157:     return !(flags & X86_EFLAGS_IF);
     158: }
     159: 
     160: static inline int arch_irqs_disabled(void)
     161: {
     162:     unsigned long flags = arch_local_save_flags();
     163: 
     164:     return arch_irqs_disabled_flags(flags);
     165: }
     166: 
     167: #else
     168: 
     169: #ifdef CONFIG_X86_64
     170: #define ARCH_LOCKDEP_SYS_EXIT        call lockdep_sys_exit_thunk
     171: #define ARCH_LOCKDEP_SYS_EXIT_IRQ    \
     172:     TRACE_IRQS_ON; \
     173:     sti; \
     174:     SAVE_REST; \
     175:     LOCKDEP_SYS_EXIT; \
     176:     RESTORE_REST; \
     177:     cli; \
     178:     TRACE_IRQS_OFF;
     179: 
     180: #else
     181: #define ARCH_LOCKDEP_SYS_EXIT            \
     182:     pushl %eax;                \
     183:     pushl %ecx;                \
     184:     pushl %edx;                \
     185:     call lockdep_sys_exit;            \
     186:     popl %edx;                \
     187:     popl %ecx;                \
     188:     popl %eax;
     189: 
     190: #define ARCH_LOCKDEP_SYS_EXIT_IRQ
     191: #endif
     192: 
     193: #ifdef CONFIG_TRACE_IRQFLAGS
     194: #  define TRACE_IRQS_ON        call trace_hardirqs_on_thunk;
     195: #  define TRACE_IRQS_OFF    call trace_hardirqs_off_thunk;
     196: #else
     197: #  define TRACE_IRQS_ON
     198: #  define TRACE_IRQS_OFF
     199: #endif
     200: #ifdef CONFIG_DEBUG_LOCK_ALLOC
     201: #  define LOCKDEP_SYS_EXIT    ARCH_LOCKDEP_SYS_EXIT
     202: #  define LOCKDEP_SYS_EXIT_IRQ    ARCH_LOCKDEP_SYS_EXIT_IRQ
     203: # else
     204: #  define LOCKDEP_SYS_EXIT
     205: #  define LOCKDEP_SYS_EXIT_IRQ
     206: # endif
     207: 
     208: #endif /* __ASSEMBLY__ */
     209: #endif
     210: