arch/x86/include/asm/irqflags.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _X86_IRQFLAGS_H_
   3 #define _X86_IRQFLAGS_H_
   4
   5 #include <asm/processor-flags.h>
   6
   7 #ifndef __ASSEMBLY__
   8
   9 /* Provide __cpuidle; we can't safely include <linux/cpu.h> */
  10 #define __cpuidle __attribute__((__section__(".cpuidle.text")))
  11
  12 /*
  13  * Interrupt control:
  14  */
  15
  16 static inline unsigned long native_save_fl(void)
  17 {
  18         unsigned long flags;
  19
  20         /*
  21          * "=rm" is safe here, because "pop" adjusts the stack before
  22          * it evaluates its effective address -- this is part of the
  23          * documented behavior of the "pop" instruction.
  24          */
  25         asm volatile("# __raw_save_flags\n\t"
  26                      "pushf ; pop %0"
  27                      : "=rm" (flags)
  28                      : /* no input */
  29                      : "memory");
  30
  31         return flags;
  32 }
  33
  34 static inline void native_restore_fl(unsigned long flags)
  35 {
  36         asm volatile("push %0 ; popf"
  37                      : /* no output */
  38                      :"g" (flags)
  39                      :"memory", "cc");
  40 }
  41
  42 static inline void native_irq_disable(void)
  43 {
  44         asm volatile("cli": : :"memory");
  45 }
  46
  47 static inline void native_irq_enable(void)
  48 {
  49         asm volatile("sti": : :"memory");
  50 }
  51
  52 static inline __cpuidle void native_safe_halt(void)
  53 {
  54         asm volatile("sti; hlt": : :"memory");
  55 }
  56
  57 static inline __cpuidle void native_halt(void)
  58 {
  59         asm volatile("hlt": : :"memory");
  60 }
  61
  62 #endif
  63
  64 #ifdef CONFIG_PARAVIRT
  65 #include <asm/paravirt.h>
  66 #else
  67 #ifndef __ASSEMBLY__
  68 #include <linux/types.h>
  69
  70 static inline notrace unsigned long arch_local_save_flags(void)
  71 {
  72         return native_save_fl();
  73 }
  74
  75 static inline notrace void arch_local_irq_restore(unsigned long flags)
  76 {
  77         native_restore_fl(flags);
  78 }
  79
  80 static inline notrace void arch_local_irq_disable(void)
  81 {
  82         native_irq_disable();
  83 }
  84
  85 static inline notrace void arch_local_irq_enable(void)
  86 {
  87         native_irq_enable();
  88 }
  89
  90 /*
  91  * Used in the idle loop; sti takes one instruction cycle
  92  * to complete:
  93  */
  94 static inline __cpuidle void arch_safe_halt(void)
  95 {
  96         native_safe_halt();
  97 }
  98
  99 /*
 100  * Used when interrupts are already enabled or to
 101  * shutdown the processor:
 102  */
 103 static inline __cpuidle void halt(void)
 104 {
 105         native_halt();
 106 }
 107
 108 /*
 109  * For spinlocks, etc:
 110  */
 111 static inline notrace unsigned long arch_local_irq_save(void)
 112 {
 113         unsigned long flags = arch_local_save_flags();
 114         arch_local_irq_disable();
 115         return flags;
 116 }
 117 #else
 118
 119 #define ENABLE_INTERRUPTS(x)    sti
 120 #define DISABLE_INTERRUPTS(x)   cli
 121
 122 #ifdef CONFIG_X86_64
 123 #define SWAPGS  swapgs
 124 /*
 125  * Currently paravirt can't handle swapgs nicely when we
 126  * don't have a stack we can rely on (such as a user space
 127  * stack).  So we either find a way around these or just fault
 128  * and emulate if a guest tries to call swapgs directly.
 129  *
 130  * Either way, this is a good way to document that we don't
 131  * have a reliable stack. x86_64 only.
 132  */
 133 #define SWAPGS_UNSAFE_STACK     swapgs
 134
 135 #define PARAVIRT_ADJUST_EXCEPTION_FRAME /*  */
 136
 137 #define INTERRUPT_RETURN        jmp native_iret
 138 #define USERGS_SYSRET64                         \
 139         swapgs;                                 \
 140         sysretq;
 141 #define USERGS_SYSRET32                         \
 142         swapgs;                                 \
 143         sysretl
 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 static inline int arch_irqs_disabled_flags(unsigned long flags)
 157 {
 158         return !(flags & X86_EFLAGS_IF);
 159 }
 160
 161 static inline int arch_irqs_disabled(void)
 162 {
 163         unsigned long flags = arch_local_save_flags();
 164
 165         return arch_irqs_disabled_flags(flags);
 166 }
 167 #endif /* !__ASSEMBLY__ */
 168
 169 #ifdef __ASSEMBLY__
 170 #ifdef CONFIG_TRACE_IRQFLAGS
 171 #  define TRACE_IRQS_ON         call trace_hardirqs_on_thunk;
 172 #  define TRACE_IRQS_OFF        call trace_hardirqs_off_thunk;
 173 #else
 174 #  define TRACE_IRQS_ON
 175 #  define TRACE_IRQS_OFF
 176 #endif
 177 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 178 #  ifdef CONFIG_X86_64
 179 #    define LOCKDEP_SYS_EXIT            call lockdep_sys_exit_thunk
 180 #    define LOCKDEP_SYS_EXIT_IRQ \
 181         TRACE_IRQS_ON; \
 182         sti; \
 183         call lockdep_sys_exit_thunk; \
 184         cli; \
 185         TRACE_IRQS_OFF;
 186 #  else
 187 #    define LOCKDEP_SYS_EXIT \
 188         pushl %eax;                             \
 189         pushl %ecx;                             \
 190         pushl %edx;                             \
 191         call lockdep_sys_exit;                  \
 192         popl %edx;                              \
 193         popl %ecx;                              \
 194         popl %eax;
 195 #    define LOCKDEP_SYS_EXIT_IRQ
 196 #  endif
 197 #else
 198 #  define LOCKDEP_SYS_EXIT
 199 #  define LOCKDEP_SYS_EXIT_IRQ
 200 #endif
 201 #endif /* __ASSEMBLY__ */
 202
 203 #endif