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          * Note: this needs to be "=r" not "=rm", because we have the
  17          * stack offset from what gcc expects at the time the "pop" is
  18          * executed, and so a memory reference with respect to the stack
  19          * would end up using the wrong address.
  20          */
  21         asm volatile("# __raw_save_flags\n\t"
  22                      "pushf ; pop %0"
  23                      : "=r" (flags)
  24                      : /* no input */
  25                      : "memory");
  26
  27         return flags;
  28 }
  29
  30 static inline void native_restore_fl(unsigned long flags)
  31 {
  32         asm volatile("push %0 ; popf"
  33                      : /* no output */
  34                      :"g" (flags)
  35                      :"memory", "cc");
  36 }
  37
  38 static inline void native_irq_disable(void)
  39 {
  40         asm volatile("cli": : :"memory");
  41 }
  42
  43 static inline void native_irq_enable(void)
  44 {
  45         asm volatile("sti": : :"memory");
  46 }
  47
  48 static inline void native_safe_halt(void)
  49 {
  50         asm volatile("sti; hlt": : :"memory");
  51 }
  52
  53 static inline void native_halt(void)
  54 {
  55         asm volatile("hlt": : :"memory");
  56 }
  57
  58 #endif
  59
  60 #ifdef CONFIG_PARAVIRT
  61 #include <asm/paravirt.h>
  62 #else
  63 #ifndef __ASSEMBLY__
  64
  65 static inline unsigned long __raw_local_save_flags(void)
  66 {
  67         return native_save_fl();
  68 }
  69
  70 static inline void raw_local_irq_restore(unsigned long flags)
  71 {
  72         native_restore_fl(flags);
  73 }
  74
  75 static inline void raw_local_irq_disable(void)
  76 {
  77         native_irq_disable();
  78 }
  79
  80 static inline void raw_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 raw_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 unsigned long __raw_local_irq_save(void)
 107 {
 108         unsigned long flags = __raw_local_save_flags();
 109
 110         raw_local_irq_disable();
 111
 112         return flags;
 113 }
 114 #else
 115
 116 #define ENABLE_INTERRUPTS(x)    sti
 117 #define DISABLE_INTERRUPTS(x)   cli
 118
 119 #ifdef CONFIG_X86_64
 120 #define SWAPGS  swapgs
 121 /*
 122  * Currently paravirt can't handle swapgs nicely when we
 123  * don't have a stack we can rely on (such as a user space
 124  * stack).  So we either find a way around these or just fault
 125  * and emulate if a guest tries to call swapgs directly.
 126  *
 127  * Either way, this is a good way to document that we don't
 128  * have a reliable stack. x86_64 only.
 129  */
 130 #define SWAPGS_UNSAFE_STACK     swapgs
 131
 132 #define PARAVIRT_ADJUST_EXCEPTION_FRAME /*  */
 133
 134 #define INTERRUPT_RETURN        iretq
 135 #define USERGS_SYSRET64                         \
 136         swapgs;                                 \
 137         sysretq;
 138 #define USERGS_SYSRET32                         \
 139         swapgs;                                 \
 140         sysretl
 141 #define ENABLE_INTERRUPTS_SYSEXIT32             \
 142         swapgs;                                 \
 143         sti;                                    \
 144         sysexit
 145
 146 #else
 147 #define INTERRUPT_RETURN                iret
 148 #define ENABLE_INTERRUPTS_SYSEXIT       sti; sysexit
 149 #define GET_CR0_INTO_EAX                movl %cr0, %eax
 150 #endif
 151
 152
 153 #endif /* __ASSEMBLY__ */
 154 #endif /* CONFIG_PARAVIRT */
 155
 156 #ifndef __ASSEMBLY__
 157 #define raw_local_save_flags(flags)                             \
 158         do { (flags) = __raw_local_save_flags(); } while (0)
 159
 160 #define raw_local_irq_save(flags)                               \
 161         do { (flags) = __raw_local_irq_save(); } while (0)
 162
 163 static inline int raw_irqs_disabled_flags(unsigned long flags)
 164 {
 165         return !(flags & X86_EFLAGS_IF);
 166 }
 167
 168 static inline int raw_irqs_disabled(void)
 169 {
 170         unsigned long flags = __raw_local_save_flags();
 171
 172         return raw_irqs_disabled_flags(flags);
 173 }
 174
 175 #else
 176
 177 #ifdef CONFIG_X86_64
 178 #define ARCH_LOCKDEP_SYS_EXIT           call lockdep_sys_exit_thunk
 179 #define ARCH_LOCKDEP_SYS_EXIT_IRQ       \
 180         TRACE_IRQS_ON; \
 181         sti; \
 182         SAVE_REST; \
 183         LOCKDEP_SYS_EXIT; \
 184         RESTORE_REST; \
 185         cli; \
 186         TRACE_IRQS_OFF;
 187
 188 #else
 189 #define ARCH_LOCKDEP_SYS_EXIT                   \
 190         pushl %eax;                             \
 191         pushl %ecx;                             \
 192         pushl %edx;                             \
 193         call lockdep_sys_exit;                  \
 194         popl %edx;                              \
 195         popl %ecx;                              \
 196         popl %eax;
 197
 198 #define ARCH_LOCKDEP_SYS_EXIT_IRQ
 199 #endif
 200
 201 #ifdef CONFIG_TRACE_IRQFLAGS
 202 #  define TRACE_IRQS_ON         call trace_hardirqs_on_thunk;
 203 #  define TRACE_IRQS_OFF        call trace_hardirqs_off_thunk;
 204 #else
 205 #  define TRACE_IRQS_ON
 206 #  define TRACE_IRQS_OFF
 207 #endif
 208 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 209 #  define LOCKDEP_SYS_EXIT      ARCH_LOCKDEP_SYS_EXIT
 210 #  define LOCKDEP_SYS_EXIT_IRQ  ARCH_LOCKDEP_SYS_EXIT_IRQ
 211 # else
 212 #  define LOCKDEP_SYS_EXIT
 213 #  define LOCKDEP_SYS_EXIT_IRQ
 214 # endif
 215
 216 #endif /* __ASSEMBLY__ */
 217 #endif