Viewing file:  irqflags.h (2.91 KB) -rw-r--r--
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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _X86_IRQFLAGS_H_
#define _X86_IRQFLAGS_H_
#include <asm/processor-flags.h>
#ifndef __ASSEMBLY__
#include <asm/nospec-branch.h>
/* Provide __cpuidle; we can't safely include <linux/cpu.h> */
#define __cpuidle __section(".cpuidle.text")
/*
* Interrupt control:
*/
/* Declaration required for gcc < 4.9 to prevent -Werror=missing-prototypes */
extern inline unsigned long native_save_fl(void);
extern __always_inline unsigned long native_save_fl(void)
{
unsigned long flags;
/*
* "=rm" is safe here, because "pop" adjusts the stack before
* it evaluates its effective address -- this is part of the
* documented behavior of the "pop" instruction.
*/
asm volatile("# __raw_save_flags\n\t"
"pushf ; pop %0"
: "=rm" (flags)
: /* no input */
: "memory");
return flags;
}
static __always_inline void native_irq_disable(void)
{
asm volatile("cli": : :"memory");
}
static __always_inline void native_irq_enable(void)
{
asm volatile("sti": : :"memory");
}
static inline __cpuidle void native_safe_halt(void)
{
mds_idle_clear_cpu_buffers();
asm volatile("sti; hlt": : :"memory");
}
static inline __cpuidle void native_halt(void)
{
mds_idle_clear_cpu_buffers();
asm volatile("hlt": : :"memory");
}
#endif
#ifdef CONFIG_PARAVIRT_XXL
#include <asm/paravirt.h>
#else
#ifndef __ASSEMBLY__
#include <linux/types.h>
static __always_inline unsigned long arch_local_save_flags(void)
{
return native_save_fl();
}
static __always_inline void arch_local_irq_disable(void)
{
native_irq_disable();
}
static __always_inline void arch_local_irq_enable(void)
{
native_irq_enable();
}
/*
* Used in the idle loop; sti takes one instruction cycle
* to complete:
*/
static inline __cpuidle void arch_safe_halt(void)
{
native_safe_halt();
}
/*
* Used when interrupts are already enabled or to
* shutdown the processor:
*/
static inline __cpuidle void halt(void)
{
native_halt();
}
/*
* For spinlocks, etc:
*/
static __always_inline unsigned long arch_local_irq_save(void)
{
unsigned long flags = arch_local_save_flags();
arch_local_irq_disable();
return flags;
}
#else
#ifdef CONFIG_X86_64
#ifdef CONFIG_DEBUG_ENTRY
#define SAVE_FLAGS pushfq; popq %rax
#endif
#define INTERRUPT_RETURN jmp native_iret
#endif
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_PARAVIRT_XXL */
#ifndef __ASSEMBLY__
static __always_inline int arch_irqs_disabled_flags(unsigned long flags)
{
return !(flags & X86_EFLAGS_IF);
}
static __always_inline int arch_irqs_disabled(void)
{
unsigned long flags = arch_local_save_flags();
return arch_irqs_disabled_flags(flags);
}
static __always_inline void arch_local_irq_restore(unsigned long flags)
{
if (!arch_irqs_disabled_flags(flags))
arch_local_irq_enable();
}
#else
#ifdef CONFIG_X86_64
#ifdef CONFIG_XEN_PV
#define SWAPGS ALTERNATIVE "swapgs", "", X86_FEATURE_XENPV
#else
#define SWAPGS swapgs
#endif
#endif
#endif /* !__ASSEMBLY__ */
#endif
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