include/asm-x86/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
  11 static inline unsigned long native_save_fl(void)
  12 {
  13         unsigned long flags;
  14
  15         asm volatile("# __raw_save_flags\n\t"
  16                      "pushf ; pop %0"
  17                      : "=g" (flags)
  18                      : /* no input */
  19                      : "memory");
  20
  21         return flags;
  22 }
  23
  24 static inline void native_restore_fl(unsigned long flags)
  25 {
  26         asm volatile("push %0 ; popf"
  27                      : /* no output */
  28                      :"g" (flags)
  29                      :"memory", "cc");
  30 }
  31
  32 static inline void native_irq_disable(void)
  33 {
  34         asm volatile("cli": : :"memory");
  35 }
  36
  37 static inline void native_irq_enable(void)
  38 {
  39         asm volatile("sti": : :"memory");
  40 }
  41
  42 static inline void native_safe_halt(void)
  43 {
  44         asm volatile("sti; hlt": : :"memory");
  45 }
  46
  47 static inline void native_halt(void)
  48 {
  49         asm volatile("hlt": : :"memory");
  50 }
  51
  52 #endif
  53
  54 #ifdef CONFIG_PARAVIRT
  55 #include <asm/paravirt.h>
  56 #else
  57 #ifndef __ASSEMBLY__
  58
  59 static inline unsigned long __raw_local_save_flags(void)
  60 {
  61         return native_save_fl();
  62 }
  63
  64 static inline void raw_local_irq_restore(unsigned long flags)
  65 {
  66         native_restore_fl(flags);
  67 }
  68
  69 static inline void raw_local_irq_disable(void)
  70 {
  71         native_irq_disable();
  72 }
  73
  74 static inline void raw_local_irq_enable(void)
  75 {
  76         native_irq_enable();
  77 }
  78
  79 /*
  80  * Used in the idle loop; sti takes one instruction cycle
  81  * to complete:
  82  */
  83 static inline void raw_safe_halt(void)
  84 {
  85         native_safe_halt();
  86 }
  87
  88 /*
  89  * Used when interrupts are already enabled or to
  90  * shutdown the processor:
  91  */
  92 static inline void halt(void)
  93 {
  94         native_halt();
  95 }
  96
  97 /*
  98  * For spinlocks, etc:
  99  */
 100 static inline unsigned long __raw_local_irq_save(void)
 101 {
 102         unsigned long flags = __raw_local_save_flags();
 103
 104         raw_local_irq_disable();
 105
 106         return flags;
 107 }
 108 #else
 109
 110 #define ENABLE_INTERRUPTS(x)    sti
 111 #define DISABLE_INTERRUPTS(x)   cli
 112
 113 #ifdef CONFIG_X86_64
 114 #define INTERRUPT_RETURN        iretq
 115 #define ENABLE_INTERRUPTS_SYSCALL_RET                   \
 116                         movq    %gs:pda_oldrsp, %rsp;   \
 117                         swapgs;                         \
 118                         sysretq;
 119 #else
 120 #define INTERRUPT_RETURN                iret
 121 #define ENABLE_INTERRUPTS_SYSCALL_RET   sti; sysexit
 122 #define GET_CR0_INTO_EAX                movl %cr0, %eax
 123 #endif
 124
 125
 126 #endif /* __ASSEMBLY__ */
 127 #endif /* CONFIG_PARAVIRT */
 128
 129 #ifndef __ASSEMBLY__
 130 #define raw_local_save_flags(flags)                             \
 131         do { (flags) = __raw_local_save_flags(); } while (0)
 132
 133 #define raw_local_irq_save(flags)                               \
 134         do { (flags) = __raw_local_irq_save(); } while (0)
 135
 136 static inline int raw_irqs_disabled_flags(unsigned long flags)
 137 {
 138         return !(flags & X86_EFLAGS_IF);
 139 }
 140
 141 static inline int raw_irqs_disabled(void)
 142 {
 143         unsigned long flags = __raw_local_save_flags();
 144
 145         return raw_irqs_disabled_flags(flags);
 146 }
 147
 148 /*
 149  * makes the traced hardirq state match with the machine state
 150  *
 151  * should be a rarely used function, only in places where its
 152  * otherwise impossible to know the irq state, like in traps.
 153  */
 154 static inline void trace_hardirqs_fixup_flags(unsigned long flags)
 155 {
 156         if (raw_irqs_disabled_flags(flags))
 157                 trace_hardirqs_off();
 158         else
 159                 trace_hardirqs_on();
 160 }
 161
 162 static inline void trace_hardirqs_fixup(void)
 163 {
 164         unsigned long flags = __raw_local_save_flags();
 165
 166         trace_hardirqs_fixup_flags(flags);
 167 }
 168
 169 #else
 170
 171 #ifdef CONFIG_X86_64
 172 /*
 173  * Currently paravirt can't handle swapgs nicely when we
 174  * don't have a stack we can rely on (such as a user space
 175  * stack).  So we either find a way around these or just fault
 176  * and emulate if a guest tries to call swapgs directly.
 177  *
 178  * Either way, this is a good way to document that we don't
 179  * have a reliable stack. x86_64 only.
 180  */
 181 #define SWAPGS_UNSAFE_STACK     swapgs
 182 #define ARCH_LOCKDEP_SYS_EXIT           call lockdep_sys_exit_thunk
 183 #define ARCH_LOCKDEP_SYS_EXIT_IRQ       \
 184         TRACE_IRQS_ON; \
 185         sti; \
 186         SAVE_REST; \
 187         LOCKDEP_SYS_EXIT; \
 188         RESTORE_REST; \
 189         cli; \
 190         TRACE_IRQS_OFF;
 191
 192 #else
 193 #define ARCH_LOCKDEP_SYS_EXIT                   \
 194         pushl %eax;                             \
 195         pushl %ecx;                             \
 196         pushl %edx;                             \
 197         call lockdep_sys_exit;                  \
 198         popl %edx;                              \
 199         popl %ecx;                              \
 200         popl %eax;
 201
 202 #define ARCH_LOCKDEP_SYS_EXIT_IRQ
 203 #endif
 204
 205 #ifdef CONFIG_TRACE_IRQFLAGS
 206 #  define TRACE_IRQS_ON         call trace_hardirqs_on_thunk;
 207 #  define TRACE_IRQS_OFF        call trace_hardirqs_off_thunk;
 208 #else
 209 #  define TRACE_IRQS_ON
 210 #  define TRACE_IRQS_OFF
 211 #endif
 212 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 213 #  define LOCKDEP_SYS_EXIT      ARCH_LOCKDEP_SYS_EXIT
 214 #  define LOCKDEP_SYS_EXIT_IRQ  ARCH_LOCKDEP_SYS_EXIT_IRQ
 215 # else
 216 #  define LOCKDEP_SYS_EXIT
 217 #  define LOCKDEP_SYS_EXIT_IRQ
 218 # endif
 219
 220 #endif /* __ASSEMBLY__ */
 221 #endif