Some interrupts (such as the rescheduling IPI) rely on not going through the irq_enter()/irq_exit() calls. To distinguish such interrupts, add a new IRQ flag that allows the low-level handling code to sidestep the enter()/exit() calls.
Only the architecture code is expected to use this. It will do the wrong thing on normal interrupts. Note that this is a band-aid until we can move to some more correct infrastructure (such as kernel/entry/common.c). Signed-off-by: Marc Zyngier <m...@kernel.org> --- include/linux/irq.h | 2 ++ kernel/irq/Kconfig | 3 +++ kernel/irq/debugfs.c | 1 + kernel/irq/irqdesc.c | 17 ++++++++++++----- kernel/irq/settings.h | 15 +++++++++++++++ 5 files changed, 33 insertions(+), 5 deletions(-) diff --git a/include/linux/irq.h b/include/linux/irq.h index c55f218d5b61..605ba5949255 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -72,6 +72,7 @@ enum irqchip_irq_state; * mechanism and from core side polling. * IRQ_DISABLE_UNLAZY - Disable lazy irq disable * IRQ_HIDDEN - Don't show up in /proc/interrupts + * IRQ_RAW - Skip tick management and irqtime accounting */ enum { IRQ_TYPE_NONE = 0x00000000, @@ -99,6 +100,7 @@ enum { IRQ_IS_POLLED = (1 << 18), IRQ_DISABLE_UNLAZY = (1 << 19), IRQ_HIDDEN = (1 << 20), + IRQ_RAW = (1 << 21), }; #define IRQF_MODIFY_MASK \ diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig index 164a031cfdb6..ae9b13d5ee91 100644 --- a/kernel/irq/Kconfig +++ b/kernel/irq/Kconfig @@ -109,6 +109,9 @@ config GENERIC_IRQ_MATRIX_ALLOCATOR config GENERIC_IRQ_RESERVATION_MODE bool +config ARCH_WANTS_IRQ_RAW + bool + # Support forced irq threading config IRQ_FORCED_THREADING bool diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c index e4cff358b437..f53475d88072 100644 --- a/kernel/irq/debugfs.c +++ b/kernel/irq/debugfs.c @@ -140,6 +140,7 @@ static const struct irq_bit_descr irqdesc_states[] = { BIT_MASK_DESCR(_IRQ_IS_POLLED), BIT_MASK_DESCR(_IRQ_DISABLE_UNLAZY), BIT_MASK_DESCR(_IRQ_HIDDEN), + BIT_MASK_DESCR(_IRQ_RAW), }; static const struct irq_bit_descr irqdesc_istates[] = { diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 1a7723604399..f5beee546a6f 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -667,10 +667,9 @@ int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq, { struct pt_regs *old_regs = set_irq_regs(regs); unsigned int irq = hwirq; + struct irq_desc *desc; int ret = 0; - irq_enter(); - #ifdef CONFIG_IRQ_DOMAIN if (lookup) irq = irq_find_mapping(domain, hwirq); @@ -680,14 +679,22 @@ int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq, * Some hardware gives randomly wrong interrupts. Rather * than crashing, do something sensible. */ - if (unlikely(!irq || irq >= nr_irqs)) { + if (unlikely(!irq || irq >= nr_irqs || !(desc = irq_to_desc(irq)))) { ack_bad_irq(irq); ret = -EINVAL; + goto out; + } + + if (IS_ENABLED(CONFIG_ARCH_WANTS_IRQ_RAW) && + unlikely(irq_settings_is_raw(desc))) { + generic_handle_irq_desc(desc); } else { - generic_handle_irq(irq); + irq_enter(); + generic_handle_irq_desc(desc); + irq_exit(); } - irq_exit(); +out: set_irq_regs(old_regs); return ret; } diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h index 51acdf43eadc..0033d459fdac 100644 --- a/kernel/irq/settings.h +++ b/kernel/irq/settings.h @@ -18,6 +18,7 @@ enum { _IRQ_IS_POLLED = IRQ_IS_POLLED, _IRQ_DISABLE_UNLAZY = IRQ_DISABLE_UNLAZY, _IRQ_HIDDEN = IRQ_HIDDEN, + _IRQ_RAW = IRQ_RAW, _IRQF_MODIFY_MASK = IRQF_MODIFY_MASK, }; @@ -33,6 +34,7 @@ enum { #define IRQ_IS_POLLED GOT_YOU_MORON #define IRQ_DISABLE_UNLAZY GOT_YOU_MORON #define IRQ_HIDDEN GOT_YOU_MORON +#define IRQ_RAW GOT_YOU_MORON #undef IRQF_MODIFY_MASK #define IRQF_MODIFY_MASK GOT_YOU_MORON @@ -180,3 +182,16 @@ static inline bool irq_settings_is_hidden(struct irq_desc *desc) { return desc->status_use_accessors & _IRQ_HIDDEN; } + +static inline bool irq_settings_is_raw(struct irq_desc *desc) +{ + if (IS_ENABLED(CONFIG_ARCH_WANTS_IRQ_RAW)) + return desc->status_use_accessors & _IRQ_RAW; + + /* + * Using IRQ_RAW on architectures that don't expect it is + * likely to be wrong. + */ + WARN_ON_ONCE(1); + return false; +} -- 2.28.0