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 #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