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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_IRQFLAGS_H
#define __ASM_IRQFLAGS_H
#include <asm/alternative.h>
#include <asm/ptrace.h>
#include <asm/sysreg.h>
/*
* Aarch64 has flags for masking: Debug, Asynchronous (serror), Interrupts and
* FIQ exceptions, in the 'daif' register. We mask and unmask them in 'dai'
* order:
* Masking debug exceptions causes all other exceptions to be masked too/
* Masking SError masks irq, but not debug exceptions. Masking irqs has no
* side effects for other flags. Keeping to this order makes it easier for
* entry.S to know which exceptions should be unmasked.
*
* FIQ is never expected, but we mask it when we disable debug exceptions, and
* unmask it at all other times.
*/
/*
* CPU interrupt mask handling.
*/
static inline void arch_local_irq_enable(void)
{
if (system_has_prio_mask_debugging()) {
u32 pmr = read_sysreg_s(SYS_ICC_PMR_EL1);
WARN_ON_ONCE(pmr != GIC_PRIO_IRQON && pmr != GIC_PRIO_IRQOFF);
}
asm volatile(ALTERNATIVE(
"msr daifclr, #2 // arch_local_irq_enable\n"
"nop",
__msr_s(SYS_ICC_PMR_EL1, "%0")
"dsb sy",
ARM64_HAS_IRQ_PRIO_MASKING)
:
: "r" ((unsigned long) GIC_PRIO_IRQON)
: "memory");
}
static inline void arch_local_irq_disable(void)
{
if (system_has_prio_mask_debugging()) {
u32 pmr = read_sysreg_s(SYS_ICC_PMR_EL1);
WARN_ON_ONCE(pmr != GIC_PRIO_IRQON && pmr != GIC_PRIO_IRQOFF);
}
asm volatile(ALTERNATIVE(
"msr daifset, #2 // arch_local_irq_disable",
__msr_s(SYS_ICC_PMR_EL1, "%0"),
ARM64_HAS_IRQ_PRIO_MASKING)
:
: "r" ((unsigned long) GIC_PRIO_IRQOFF)
: "memory");
}
/*
* Save the current interrupt enable state.
*/
static inline unsigned long arch_local_save_flags(void)
{
unsigned long flags;
asm volatile(ALTERNATIVE(
"mrs %0, daif",
__mrs_s("%0", SYS_ICC_PMR_EL1),
ARM64_HAS_IRQ_PRIO_MASKING)
: "=&r" (flags)
:
: "memory");
return flags;
}
static inline int arch_irqs_disabled_flags(unsigned long flags)
{
int res;
asm volatile(ALTERNATIVE(
"and %w0, %w1, #" __stringify(PSR_I_BIT),
"eor %w0, %w1, #" __stringify(GIC_PRIO_IRQON),
ARM64_HAS_IRQ_PRIO_MASKING)
: "=&r" (res)
: "r" ((int) flags)
: "memory");
return res;
}
static inline unsigned long arch_local_irq_save(void)
{
unsigned long flags;
flags = arch_local_save_flags();
/*
* There are too many states with IRQs disabled, just keep the current
* state if interrupts are already disabled/masked.
*/
if (!arch_irqs_disabled_flags(flags))
arch_local_irq_disable();
return flags;
}
/*
* restore saved IRQ state
*/
static inline void arch_local_irq_restore(unsigned long flags)
{
asm volatile(ALTERNATIVE(
"msr daif, %0\n"
"nop",
__msr_s(SYS_ICC_PMR_EL1, "%0")
"dsb sy",
ARM64_HAS_IRQ_PRIO_MASKING)
:
: "r" (flags)
: "memory");
}
#endif /* __ASM_IRQFLAGS_H */
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