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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/barrier.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 'daif'
* order:
* Masking debug exceptions causes all other exceptions to be masked too/
* Masking SError masks IRQ/FIQ, but not debug exceptions. IRQ and FIQ are
* always masked and unmasked together, and have no side effects for other
* flags. Keeping to this order makes it easier for entry.S to know which
* exceptions should be unmasked.
*/
static __always_inline bool __irqflags_uses_pmr(void)
{
return IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) &&
alternative_has_cap_unlikely(ARM64_HAS_GIC_PRIO_MASKING);
}
static __always_inline void __daif_local_irq_enable(void)
{
barrier();
asm volatile("msr daifclr, #3");
barrier();
}
static __always_inline void __pmr_local_irq_enable(void)
{
if (IS_ENABLED(CONFIG_ARM64_DEBUG_PRIORITY_MASKING)) {
u32 pmr = read_sysreg_s(SYS_ICC_PMR_EL1);
WARN_ON_ONCE(pmr != GIC_PRIO_IRQON && pmr != GIC_PRIO_IRQOFF);
}
barrier();
write_sysreg_s(GIC_PRIO_IRQON, SYS_ICC_PMR_EL1);
pmr_sync();
barrier();
}
static inline void arch_local_irq_enable(void)
{
if (__irqflags_uses_pmr()) {
__pmr_local_irq_enable();
} else {
__daif_local_irq_enable();
}
}
static __always_inline void __daif_local_irq_disable(void)
{
barrier();
asm volatile("msr daifset, #3");
barrier();
}
static __always_inline void __pmr_local_irq_disable(void)
{
if (IS_ENABLED(CONFIG_ARM64_DEBUG_PRIORITY_MASKING)) {
u32 pmr = read_sysreg_s(SYS_ICC_PMR_EL1);
WARN_ON_ONCE(pmr != GIC_PRIO_IRQON && pmr != GIC_PRIO_IRQOFF);
}
barrier();
write_sysreg_s(GIC_PRIO_IRQOFF, SYS_ICC_PMR_EL1);
barrier();
}
static inline void arch_local_irq_disable(void)
{
if (__irqflags_uses_pmr()) {
__pmr_local_irq_disable();
} else {
__daif_local_irq_disable();
}
}
static __always_inline unsigned long __daif_local_save_flags(void)
{
return read_sysreg(daif);
}
static __always_inline unsigned long __pmr_local_save_flags(void)
{
return read_sysreg_s(SYS_ICC_PMR_EL1);
}
/*
* Save the current interrupt enable state.
*/
static inline unsigned long arch_local_save_flags(void)
{
if (__irqflags_uses_pmr()) {
return __pmr_local_save_flags();
} else {
return __daif_local_save_flags();
}
}
static __always_inline bool __daif_irqs_disabled_flags(unsigned long flags)
{
return flags & PSR_I_BIT;
}
static __always_inline bool __pmr_irqs_disabled_flags(unsigned long flags)
{
return flags != GIC_PRIO_IRQON;
}
static inline bool arch_irqs_disabled_flags(unsigned long flags)
{
if (__irqflags_uses_pmr()) {
return __pmr_irqs_disabled_flags(flags);
} else {
return __daif_irqs_disabled_flags(flags);
}
}
static __always_inline bool __daif_irqs_disabled(void)
{
return __daif_irqs_disabled_flags(__daif_local_save_flags());
}
static __always_inline bool __pmr_irqs_disabled(void)
{
return __pmr_irqs_disabled_flags(__pmr_local_save_flags());
}
static inline bool arch_irqs_disabled(void)
{
if (__irqflags_uses_pmr()) {
return __pmr_irqs_disabled();
} else {
return __daif_irqs_disabled();
}
}
static __always_inline unsigned long __daif_local_irq_save(void)
{
unsigned long flags = __daif_local_save_flags();
__daif_local_irq_disable();
return flags;
}
static __always_inline unsigned long __pmr_local_irq_save(void)
{
unsigned long flags = __pmr_local_save_flags();
/*
* There are too many states with IRQs disabled, just keep the current
* state if interrupts are already disabled/masked.
*/
if (!__pmr_irqs_disabled_flags(flags))
__pmr_local_irq_disable();
return flags;
}
static inline unsigned long arch_local_irq_save(void)
{
if (__irqflags_uses_pmr()) {
return __pmr_local_irq_save();
} else {
return __daif_local_irq_save();
}
}
static __always_inline void __daif_local_irq_restore(unsigned long flags)
{
barrier();
write_sysreg(flags, daif);
barrier();
}
static __always_inline void __pmr_local_irq_restore(unsigned long flags)
{
barrier();
write_sysreg_s(flags, SYS_ICC_PMR_EL1);
pmr_sync();
barrier();
}
/*
* restore saved IRQ state
*/
static inline void arch_local_irq_restore(unsigned long flags)
{
if (__irqflags_uses_pmr()) {
__pmr_local_irq_restore(flags);
} else {
__daif_local_irq_restore(flags);
}
}
#endif /* __ASM_IRQFLAGS_H */
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