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 /* Provide __cpuidle; we can't safely include <linux/cpu.h> */
   9 #define __cpuidle __attribute__((__section__(".cpuidle.text")))
  10
  11 /*
  12  * Interrupt control:
  13  */
  14
  15 static inline unsigned long native_save_fl(void)
  16 {
  17         unsigned long flags;
  18
  19         /*
  20          * "=rm" is safe here, because "pop" adjusts the stack before
  21          * it evaluates its effective address -- this is part of the
  22          * documented behavior of the "pop" instruction.
  23          */
  24         asm volatile("# __raw_save_flags\n\t"
  25                      "pushf ; pop %0"
  26                      : "=rm" (flags)
  27                      : /* no input */
  28                      : "memory");
  29
  30         return flags;
  31 }
  32
  33 static inline void native_restore_fl(unsigned long flags)
  34 {
  35         asm volatile("push %0 ; popf"
  36                      : /* no output */
  37                      :"g" (flags)
  38                      :"memory", "cc");
  39 }
  40
  41 static inline void native_irq_disable(void)
  42 {
  43         asm volatile("cli": : :"memory");
  44 }
  45
  46 static inline void native_irq_enable(void)
  47 {
  48         asm volatile("sti": : :"memory");
  49 }
  50
  51 static inline __cpuidle void native_safe_halt(void)
  52 {
  53         asm volatile("sti; hlt": : :"memory");
  54 }
  55
  56 static inline __cpuidle void native_halt(void)
  57 {
  58         asm volatile("hlt": : :"memory");
  59 }
  60
  61 #endif
  62
  63 #ifdef CONFIG_PARAVIRT
  64 #include <asm/paravirt.h>
  65 #else
  66 #ifndef __ASSEMBLY__
  67 #include <linux/types.h>
  68
  69 static inline notrace unsigned long arch_local_save_flags(void)
  70 {
  71         return native_save_fl();
  72 }
  73
  74 static inline notrace void arch_local_irq_restore(unsigned long flags)
  75 {
  76         native_restore_fl(flags);
  77 }
  78
  79 static inline notrace void arch_local_irq_disable(void)
  80 {
  81         native_irq_disable();
  82 }
  83
  84 static inline notrace void arch_local_irq_enable(void)
  85 {
  86         native_irq_enable();
  87 }
  88
  89 /*
  90  * Used in the idle loop; sti takes one instruction cycle
  91  * to complete:
  92  */
  93 static inline __cpuidle void arch_safe_halt(void)
  94 {
  95         native_safe_halt();
  96 }
  97
  98 /*
  99  * Used when interrupts are already enabled or to
 100  * shutdown the processor:
 101  */
 102 static inline __cpuidle void halt(void)
 103 {
 104         native_halt();
 105 }
 106
 107 /*
 108  * For spinlocks, etc:
 109  */
 110 static inline notrace unsigned long arch_local_irq_save(void)
 111 {
 112         unsigned long flags = arch_local_save_flags();
 113         arch_local_irq_disable();
 114         return flags;
 115 }
 116 #else
 117
 118 #define ENABLE_INTERRUPTS(x)    sti
 119 #define DISABLE_INTERRUPTS(x)   cli
 120
 121 #ifdef CONFIG_X86_64
 122 #define SWAPGS  swapgs
 123 /*
 124  * Currently paravirt can't handle swapgs nicely when we
 125  * don't have a stack we can rely on (such as a user space
 126  * stack).  So we either find a way around these or just fault
 127  * and emulate if a guest tries to call swapgs directly.
 128  *
 129  * Either way, this is a good way to document that we don't
 130  * have a reliable stack. x86_64 only.
 131  */
 132 #define SWAPGS_UNSAFE_STACK     swapgs
 133
 134 #define PARAVIRT_ADJUST_EXCEPTION_FRAME /*  */
 135
 136 #define INTERRUPT_RETURN        jmp native_iret
 137 #define USERGS_SYSRET64                         \
 138         swapgs;                                 \
 139         sysretq;
 140 #define USERGS_SYSRET32                         \
 141         swapgs;                                 \
 142         sysretl
 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 #endif /* !__ASSEMBLY__ */
 167
 168 #ifdef __ASSEMBLY__
 169 #ifdef CONFIG_TRACE_IRQFLAGS
 170 #  define TRACE_IRQS_ON         call trace_hardirqs_on_thunk;
 171 #  define TRACE_IRQS_OFF        call trace_hardirqs_off_thunk;
 172 #else
 173 #  define TRACE_IRQS_ON
 174 #  define TRACE_IRQS_OFF
 175 #endif
 176 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 177 #  ifdef CONFIG_X86_64
 178 #    define LOCKDEP_SYS_EXIT            call lockdep_sys_exit_thunk
 179 #    define LOCKDEP_SYS_EXIT_IRQ \
 180         TRACE_IRQS_ON; \
 181         sti; \
 182         call lockdep_sys_exit_thunk; \
 183         cli; \
 184         TRACE_IRQS_OFF;
 185 #  else
 186 #    define LOCKDEP_SYS_EXIT \
 187         pushl %eax;                             \
 188         pushl %ecx;                             \
 189         pushl %edx;                             \
 190         call lockdep_sys_exit;                  \
 191         popl %edx;                              \
 192         popl %ecx;                              \
 193         popl %eax;
 194 #    define LOCKDEP_SYS_EXIT_IRQ
 195 #  endif
 196 #else
 197 #  define LOCKDEP_SYS_EXIT
 198 #  define LOCKDEP_SYS_EXIT_IRQ
 199 #endif
 200 #endif /* __ASSEMBLY__ */
 201
 202 #endif