LXR linux/arch/x86/include/asm/irqflags.h

   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
  11static 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
  29static 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
  37static inline void native_irq_disable(void)
  38{
  39        asm volatile("cli": : :"memory");
  40}
  41
  42static inline void native_irq_enable(void)
  43{
  44        asm volatile("sti": : :"memory");
  45}
  46
  47static inline void native_safe_halt(void)
  48{
  49        asm volatile("sti; hlt": : :"memory");
  50}
  51
  52static 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
  65static inline notrace unsigned long arch_local_save_flags(void)
  66{
  67        return native_save_fl();
  68}
  69
  70static inline notrace void arch_local_irq_restore(unsigned long flags)
  71{
  72        native_restore_fl(flags);
  73}
  74
  75static inline notrace void arch_local_irq_disable(void)
  76{
  77        native_irq_disable();
  78}
  79
  80static 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 */
  89static 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 */
  98static inline void halt(void)
  99{
 100        native_halt();
 101}
 102
 103/*
 104 * For spinlocks, etc:
 105 */
 106static 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__
 155static inline int arch_irqs_disabled_flags(unsigned long flags)
 156{
 157        return !(flags & X86_EFLAGS_IF);
 158}
 159
 160static 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