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 #include <asm/nospec-branch.h>
  10
  11 /*
  12  * Interrupt control:
  13  */
  14
  15 /* Declaration required for gcc < 4.9 to prevent -Werror=missing-prototypes */
  16 extern inline unsigned long native_save_fl(void);
  17 extern __always_inline unsigned long native_save_fl(void)
  18 {
  19         unsigned long flags;
  20
  21         /*
  22          * "=rm" is safe here, because "pop" adjusts the stack before
  23          * it evaluates its effective address -- this is part of the
  24          * documented behavior of the "pop" instruction.
  25          */
  26         asm volatile("# __raw_save_flags\n\t"
  27                      "pushf ; pop %0"
  28                      : "=rm" (flags)
  29                      : /* no input */
  30                      : "memory");
  31
  32         return flags;
  33 }
  34
  35 static __always_inline void native_irq_disable(void)
  36 {
  37         asm volatile("cli": : :"memory");
  38 }
  39
  40 static __always_inline void native_irq_enable(void)
  41 {
  42         asm volatile("sti": : :"memory");
  43 }
  44
  45 static __always_inline void native_safe_halt(void)
  46 {
  47         mds_idle_clear_cpu_buffers();
  48         asm volatile("sti; hlt": : :"memory");
  49 }
  50
  51 static __always_inline void native_halt(void)
  52 {
  53         mds_idle_clear_cpu_buffers();
  54         asm volatile("hlt": : :"memory");
  55 }
  56
  57 #endif
  58
  59 #ifdef CONFIG_PARAVIRT_XXL
  60 #include <asm/paravirt.h>
  61 #else
  62 #ifndef __ASSEMBLY__
  63 #include <linux/types.h>
  64
  65 static __always_inline unsigned long arch_local_save_flags(void)
  66 {
  67         return native_save_fl();
  68 }
  69
  70 static __always_inline void arch_local_irq_disable(void)
  71 {
  72         native_irq_disable();
  73 }
  74
  75 static __always_inline void arch_local_irq_enable(void)
  76 {
  77         native_irq_enable();
  78 }
  79
  80 /*
  81  * Used in the idle loop; sti takes one instruction cycle
  82  * to complete:
  83  */
  84 static __always_inline void arch_safe_halt(void)
  85 {
  86         native_safe_halt();
  87 }
  88
  89 /*
  90  * Used when interrupts are already enabled or to
  91  * shutdown the processor:
  92  */
  93 static __always_inline void halt(void)
  94 {
  95         native_halt();
  96 }
  97
  98 /*
  99  * For spinlocks, etc:
 100  */
 101 static __always_inline unsigned long arch_local_irq_save(void)
 102 {
 103         unsigned long flags = arch_local_save_flags();
 104         arch_local_irq_disable();
 105         return flags;
 106 }
 107 #else
 108
 109 #ifdef CONFIG_X86_64
 110 #ifdef CONFIG_DEBUG_ENTRY
 111 #define SAVE_FLAGS              pushfq; popq %rax
 112 #endif
 113
 114 #endif
 115
 116 #endif /* __ASSEMBLY__ */
 117 #endif /* CONFIG_PARAVIRT_XXL */
 118
 119 #ifndef __ASSEMBLY__
 120 static __always_inline int arch_irqs_disabled_flags(unsigned long flags)
 121 {
 122         return !(flags & X86_EFLAGS_IF);
 123 }
 124
 125 static __always_inline int arch_irqs_disabled(void)
 126 {
 127         unsigned long flags = arch_local_save_flags();
 128
 129         return arch_irqs_disabled_flags(flags);
 130 }
 131
 132 static __always_inline void arch_local_irq_restore(unsigned long flags)
 133 {
 134         if (!arch_irqs_disabled_flags(flags))
 135                 arch_local_irq_enable();
 136 }
 137 #endif /* !__ASSEMBLY__ */
 138
 139 #endif