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 __ASSEMBLER__
   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 static __always_inline int native_irqs_disabled_flags(unsigned long flags)
  58 {
  59         return !(flags & X86_EFLAGS_IF);
  60 }
  61
  62 static __always_inline unsigned long native_local_irq_save(void)
  63 {
  64         unsigned long flags = native_save_fl();
  65
  66         native_irq_disable();
  67
  68         return flags;
  69 }
  70
  71 static __always_inline void native_local_irq_restore(unsigned long flags)
  72 {
  73         if (!native_irqs_disabled_flags(flags))
  74                 native_irq_enable();
  75 }
  76
  77 #endif
  78
  79 #ifndef CONFIG_PARAVIRT
  80 #ifndef __ASSEMBLY__
  81 /*
  82  * Used in the idle loop; sti takes one instruction cycle
  83  * to complete:
  84  */
  85 static __always_inline void arch_safe_halt(void)
  86 {
  87         native_safe_halt();
  88 }
  89
  90 /*
  91  * Used when interrupts are already enabled or to
  92  * shutdown the processor:
  93  */
  94 static __always_inline void halt(void)
  95 {
  96         native_halt();
  97 }
  98 #endif /* __ASSEMBLY__ */
  99 #endif /* CONFIG_PARAVIRT */
 100
 101 #ifdef CONFIG_PARAVIRT_XXL
 102 #include <asm/paravirt.h>
 103 #else
 104 #ifndef __ASSEMBLER__
 105 #include <linux/types.h>
 106
 107 static __always_inline unsigned long arch_local_save_flags(void)
 108 {
 109         return native_save_fl();
 110 }
 111
 112 static __always_inline void arch_local_irq_disable(void)
 113 {
 114         native_irq_disable();
 115 }
 116
 117 static __always_inline void arch_local_irq_enable(void)
 118 {
 119         native_irq_enable();
 120 }
 121
 122 /*
 123  * For spinlocks, etc:
 124  */
 125 static __always_inline unsigned long arch_local_irq_save(void)
 126 {
 127         unsigned long flags = arch_local_save_flags();
 128         arch_local_irq_disable();
 129         return flags;
 130 }
 131 #else
 132
 133 #ifdef CONFIG_X86_64
 134 #ifdef CONFIG_DEBUG_ENTRY
 135 #define SAVE_FLAGS              pushfq; popq %rax
 136 #endif
 137
 138 #endif
 139
 140 #endif /* __ASSEMBLER__ */
 141 #endif /* CONFIG_PARAVIRT_XXL */
 142
 143 #ifndef __ASSEMBLER__
 144 static __always_inline int arch_irqs_disabled_flags(unsigned long flags)
 145 {
 146         return !(flags & X86_EFLAGS_IF);
 147 }
 148
 149 static __always_inline int arch_irqs_disabled(void)
 150 {
 151         unsigned long flags = arch_local_save_flags();
 152
 153         return arch_irqs_disabled_flags(flags);
 154 }
 155
 156 static __always_inline void arch_local_irq_restore(unsigned long flags)
 157 {
 158         if (!arch_irqs_disabled_flags(flags))
 159                 arch_local_irq_enable();
 160 }
 161 #endif /* !__ASSEMBLER__ */
 162
 163 #endif