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
  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
  64 static inline unsigned long __raw_local_save_flags(void)
  65 {
  66         return native_save_fl();
  67 }
  68
  69 static inline void raw_local_irq_restore(unsigned long flags)
  70 {
  71         native_restore_fl(flags);
  72 }
  73
  74 static inline void raw_local_irq_disable(void)
  75 {
  76         native_irq_disable();
  77 }
  78
  79 static inline void raw_local_irq_enable(void)
  80 {
  81         native_irq_enable();
  82 }
  83
  84 /*
  85  * Used in the idle loop; sti takes one instruction cycle
  86  * to complete:
  87  */
  88 static inline void raw_safe_halt(void)
  89 {
  90         native_safe_halt();
  91 }
  92
  93 /*
  94  * Used when interrupts are already enabled or to
  95  * shutdown the processor:
  96  */
  97 static inline void halt(void)
  98 {
  99         native_halt();
 100 }
 101
 102 /*
 103  * For spinlocks, etc:
 104  */
 105 static inline unsigned long __raw_local_irq_save(void)
 106 {
 107         unsigned long flags = __raw_local_save_flags();
 108
 109         raw_local_irq_disable();
 110
 111         return flags;
 112 }
 113 #else
 114
 115 #define ENABLE_INTERRUPTS(x)    sti
 116 #define DISABLE_INTERRUPTS(x)   cli
 117
 118 #ifdef CONFIG_X86_64
 119 #define SWAPGS  swapgs
 120 /*
 121  * Currently paravirt can't handle swapgs nicely when we
 122  * don't have a stack we can rely on (such as a user space
 123  * stack).  So we either find a way around these or just fault
 124  * and emulate if a guest tries to call swapgs directly.
 125  *
 126  * Either way, this is a good way to document that we don't
 127  * have a reliable stack. x86_64 only.
 128  */
 129 #define SWAPGS_UNSAFE_STACK     swapgs
 130
 131 #define PARAVIRT_ADJUST_EXCEPTION_FRAME /*  */
 132
 133 #define INTERRUPT_RETURN        iretq
 134 #define USERGS_SYSRET64                         \
 135         swapgs;                                 \
 136         sysretq;
 137 #define USERGS_SYSRET32                         \
 138         swapgs;                                 \
 139         sysretl
 140 #define ENABLE_INTERRUPTS_SYSEXIT32             \
 141         swapgs;                                 \
 142         sti;                                    \
 143         sysexit
 144
 145 #else
 146 #define INTERRUPT_RETURN                iret
 147 #define ENABLE_INTERRUPTS_SYSEXIT       sti; sysexit
 148 #define GET_CR0_INTO_EAX                movl %cr0, %eax
 149 #endif
 150
 151
 152 #endif /* __ASSEMBLY__ */
 153 #endif /* CONFIG_PARAVIRT */
 154
 155 #ifndef __ASSEMBLY__
 156 #define raw_local_save_flags(flags)                             \
 157         do { (flags) = __raw_local_save_flags(); } while (0)
 158
 159 #define raw_local_irq_save(flags)                               \
 160         do { (flags) = __raw_local_irq_save(); } while (0)
 161
 162 static inline int raw_irqs_disabled_flags(unsigned long flags)
 163 {
 164         return !(flags & X86_EFLAGS_IF);
 165 }
 166
 167 static inline int raw_irqs_disabled(void)
 168 {
 169         unsigned long flags = __raw_local_save_flags();
 170
 171         return raw_irqs_disabled_flags(flags);
 172 }
 173
 174 #else
 175
 176 #ifdef CONFIG_X86_64
 177 #define ARCH_LOCKDEP_SYS_EXIT           call lockdep_sys_exit_thunk
 178 #define ARCH_LOCKDEP_SYS_EXIT_IRQ       \
 179         TRACE_IRQS_ON; \
 180         sti; \
 181         SAVE_REST; \
 182         LOCKDEP_SYS_EXIT; \
 183         RESTORE_REST; \
 184         cli; \
 185         TRACE_IRQS_OFF;
 186
 187 #else
 188 #define ARCH_LOCKDEP_SYS_EXIT                   \
 189         pushl %eax;                             \
 190         pushl %ecx;                             \
 191         pushl %edx;                             \
 192         call lockdep_sys_exit;                  \
 193         popl %edx;                              \
 194         popl %ecx;                              \
 195         popl %eax;
 196
 197 #define ARCH_LOCKDEP_SYS_EXIT_IRQ
 198 #endif
 199
 200 #ifdef CONFIG_TRACE_IRQFLAGS
 201 #  define TRACE_IRQS_ON         call trace_hardirqs_on_thunk;
 202 #  define TRACE_IRQS_OFF        call trace_hardirqs_off_thunk;
 203 #else
 204 #  define TRACE_IRQS_ON
 205 #  define TRACE_IRQS_OFF
 206 #endif
 207 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 208 #  define LOCKDEP_SYS_EXIT      ARCH_LOCKDEP_SYS_EXIT
 209 #  define LOCKDEP_SYS_EXIT_IRQ  ARCH_LOCKDEP_SYS_EXIT_IRQ
 210 # else
 211 #  define LOCKDEP_SYS_EXIT
 212 #  define LOCKDEP_SYS_EXIT_IRQ
 213 # endif
 214
 215 #endif /* __ASSEMBLY__ */
 216 #endif