irqflags.h

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#ifndef _X86_IRQFLAGS_H_
#define _X86_IRQFLAGS_H_

#include <asm/processor-flags.h>

#ifndef __ASSEMBLY__
/*
 * Interrupt control:
 */

static inline unsigned long native_save_fl(void)
{
    unsigned long flags;

    /*
     * "=rm" is safe here, because "pop" adjusts the stack before
     * it evaluates its effective address -- this is part of the
     * documented behavior of the "pop" instruction.
     */
    asm volatile("# __raw_save_flags\n\t"
             "pushf ; pop %0"
             : "=rm" (flags)
             : /* no input */
             : "memory");

    return flags;
}

static inline void native_restore_fl(unsigned long flags)
{
    asm volatile("push %0 ; popf"
             : /* no output */
             :"g" (flags)
             :"memory", "cc");
}

static inline void native_irq_disable(void)
{
    asm volatile("cli": : :"memory");
}

static inline void native_irq_enable(void)
{
    asm volatile("sti": : :"memory");
}

static inline void native_safe_halt(void)
{
    asm volatile("sti; hlt": : :"memory");
}

static inline void native_halt(void)
{
    asm volatile("hlt": : :"memory");
}

#endif

#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#else
#ifndef __ASSEMBLY__
#include <linux/types.h>

static inline notrace unsigned long arch_local_save_flags(void)
{
    return native_save_fl();
}

static inline notrace void arch_local_irq_restore(unsigned long flags)
{
    native_restore_fl(flags);
}

static inline notrace void arch_local_irq_disable(void)
{
    native_irq_disable();
}

static inline notrace void arch_local_irq_enable(void)
{
    native_irq_enable();
}

/*
 * Used in the idle loop; sti takes one instruction cycle
 * to complete:
 */
static inline void arch_safe_halt(void)
{
    native_safe_halt();
}

/*
 * Used when interrupts are already enabled or to
 * shutdown the processor:
 */
static inline void halt(void)
{
    native_halt();
}

/*
 * For spinlocks, etc:
 */
static inline notrace unsigned long arch_local_irq_save(void)
{
    unsigned long flags = arch_local_save_flags();
    arch_local_irq_disable();
    return flags;
}
#else

#define ENABLE_INTERRUPTS(x)    sti
#define DISABLE_INTERRUPTS(x)   cli

#ifdef CONFIG_X86_64
#define SWAPGS  swapgs
/*
 * Currently paravirt can't handle swapgs nicely when we
 * don't have a stack we can rely on (such as a user space
 * stack).  So we either find a way around these or just fault
 * and emulate if a guest tries to call swapgs directly.
 *
 * Either way, this is a good way to document that we don't
 * have a reliable stack. x86_64 only.
 */
#define SWAPGS_UNSAFE_STACK swapgs

#define PARAVIRT_ADJUST_EXCEPTION_FRAME /*  */

#define INTERRUPT_RETURN    iretq
#define USERGS_SYSRET64             \
    swapgs;                 \
    sysretq;
#define USERGS_SYSRET32             \
    swapgs;                 \
    sysretl
#define ENABLE_INTERRUPTS_SYSEXIT32     \
    swapgs;                 \
    sti;                    \
    sysexit

#else
#define INTERRUPT_RETURN        iret
#define ENABLE_INTERRUPTS_SYSEXIT   sti; sysexit
#define GET_CR0_INTO_EAX        movl %cr0, %eax
#endif


#endif /* __ASSEMBLY__ */
#endif /* CONFIG_PARAVIRT */

#ifndef __ASSEMBLY__
static inline int arch_irqs_disabled_flags(unsigned long flags)
{
    return !(flags & X86_EFLAGS_IF);
}

static inline int arch_irqs_disabled(void)
{
    unsigned long flags = arch_local_save_flags();

    return arch_irqs_disabled_flags(flags);
}

#else

#ifdef CONFIG_X86_64
#define ARCH_LOCKDEP_SYS_EXIT       call lockdep_sys_exit_thunk
#define ARCH_LOCKDEP_SYS_EXIT_IRQ   \
    TRACE_IRQS_ON; \
    sti; \
    SAVE_REST; \
    LOCKDEP_SYS_EXIT; \
    RESTORE_REST; \
    cli; \
    TRACE_IRQS_OFF;

#else
#define ARCH_LOCKDEP_SYS_EXIT           \
    pushl %eax;             \
    pushl %ecx;             \
    pushl %edx;             \
    call lockdep_sys_exit;          \
    popl %edx;              \
    popl %ecx;              \
    popl %eax;

#define ARCH_LOCKDEP_SYS_EXIT_IRQ
#endif

#ifdef CONFIG_TRACE_IRQFLAGS
#  define TRACE_IRQS_ON     call trace_hardirqs_on_thunk;
#  define TRACE_IRQS_OFF    call trace_hardirqs_off_thunk;
#else
#  define TRACE_IRQS_ON
#  define TRACE_IRQS_OFF
#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
#  define LOCKDEP_SYS_EXIT  ARCH_LOCKDEP_SYS_EXIT
#  define LOCKDEP_SYS_EXIT_IRQ  ARCH_LOCKDEP_SYS_EXIT_IRQ
# else
#  define LOCKDEP_SYS_EXIT
#  define LOCKDEP_SYS_EXIT_IRQ
# endif

#endif /* __ASSEMBLY__ */
#endif