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 */
 16extern inline unsigned long native_save_fl(void);
 17extern __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		     : ASM_OUTPUT_RM (flags)
 29		     : /* no input */
 30		     : "memory");
 31
 32	return flags;
 33}
 34
 35static __always_inline void native_irq_disable(void)
 36{
 37	asm volatile("cli": : :"memory");
 38}
 39
 40static __always_inline void native_irq_enable(void)
 41{
 42	asm volatile("sti": : :"memory");
 43}
 44
 45static __always_inline void native_safe_halt(void)
 46{
 47	x86_idle_clear_cpu_buffers();
 48	asm volatile("sti; hlt": : :"memory");
 49}
 50
 51static __always_inline void native_halt(void)
 52{
 53	x86_idle_clear_cpu_buffers();
 54	asm volatile("hlt": : :"memory");
 55}
 56
 57static __always_inline int native_irqs_disabled_flags(unsigned long flags)
 58{
 59	return !(flags & X86_EFLAGS_IF);
 60}
 61
 62static __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
 71static __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 */
 85static __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 */
 94static __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
107static __always_inline unsigned long arch_local_save_flags(void)
108{
109	return native_save_fl();
110}
111
112static __always_inline void arch_local_irq_disable(void)
113{
114	native_irq_disable();
115}
116
117static __always_inline void arch_local_irq_enable(void)
118{
119	native_irq_enable();
120}
121
122/*
123 * For spinlocks, etc:
124 */
125static __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__
144static __always_inline int arch_irqs_disabled_flags(unsigned long flags)
145{
146	return !(flags & X86_EFLAGS_IF);
147}
148
149static __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
156static __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