From: Pingfan Liu <kernelfans@gmail.com> To: linux-arm-kernel@lists.infradead.org Cc: Pingfan Liu <kernelfans@gmail.com>, Mark Rutland <mark.rutland@arm.com>, "Paul E. McKenney" <paulmck@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>, Joey Gouly <joey.gouly@arm.com>, Sami Tolvanen <samitolvanen@google.com>, Julien Thierry <julien.thierry@arm.com>, Thomas Gleixner <tglx@linutronix.de>, Yuichi Ito <ito-yuichi@fujitsu.com>, linux-kernel@vger.kernel.org Subject: [PATCHv3 1/3] kernel/irq: make irq_{enter,exit}() in handle_domain_irq() arch optional Date: Thu, 30 Sep 2021 21:17:06 +0800 [thread overview] Message-ID: <20210930131708.35328-2-kernelfans@gmail.com> (raw) In-Reply-To: <20210930131708.35328-1-kernelfans@gmail.com> When an IRQ is taken, some accounting needs to be performed to enter and exit IRQ context around the IRQ handler. Historically arch code would leave this to the irqchip or core IRQ code, but these days we want this to happen in exception entry code, and architectures such as arm64 do this. Currently handle_domain_irq() performs this entry/exit accounting, and if used on an architecture where the entry code also does this, the entry/exit accounting will be performed twice per IRQ. This is problematic as core RCU code such as rcu_is_cpu_rrupt_from_idle() depends on this happening once per IRQ, and will not detect quescent periods correctly, leading to stall warnings. As irqchip drivers which use handle_domain_irq() need to work on architectures with or without their own entry/exit accounting, this patch makes handle_domain_irq() conditionally perform the entry accounting depending on a new HAVE_ARCH_IRQENTRY Kconfig symbol that architectures can select if they perform this entry accounting themselves. For architectures which do not select the symbol. there should be no functional change as a result of this patch. Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Joey Gouly <joey.gouly@arm.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Julien Thierry <julien.thierry@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yuichi Ito <ito-yuichi@fujitsu.com> Cc: linux-kernel@vger.kernel.org To: linux-arm-kernel@lists.infradead.org --- kernel/irq/Kconfig | 3 +++ kernel/irq/irqdesc.c | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig index fbc54c2a7f23..defa1db2d664 100644 --- a/kernel/irq/Kconfig +++ b/kernel/irq/Kconfig @@ -100,6 +100,9 @@ config IRQ_MSI_IOMMU config HANDLE_DOMAIN_IRQ bool +config HAVE_ARCH_IRQENTRY + bool + config IRQ_TIMINGS bool diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 4e3c29bb603c..fd5dd9d278b5 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -693,7 +693,9 @@ int handle_domain_irq(struct irq_domain *domain, struct irq_desc *desc; int ret = 0; +#ifndef CONFIG_HAVE_ARCH_IRQENTRY irq_enter(); +#endif /* The irqdomain code provides boundary checks */ desc = irq_resolve_mapping(domain, hwirq); @@ -702,7 +704,9 @@ int handle_domain_irq(struct irq_domain *domain, else ret = -EINVAL; +#ifndef CONFIG_HAVE_ARCH_IRQENTRY irq_exit(); +#endif set_irq_regs(old_regs); return ret; } -- 2.31.1
WARNING: multiple messages have this Message-ID (diff)
From: Pingfan Liu <kernelfans@gmail.com> To: linux-arm-kernel@lists.infradead.org Cc: Pingfan Liu <kernelfans@gmail.com>, Mark Rutland <mark.rutland@arm.com>, "Paul E. McKenney" <paulmck@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>, Joey Gouly <joey.gouly@arm.com>, Sami Tolvanen <samitolvanen@google.com>, Julien Thierry <julien.thierry@arm.com>, Thomas Gleixner <tglx@linutronix.de>, Yuichi Ito <ito-yuichi@fujitsu.com>, linux-kernel@vger.kernel.org Subject: [PATCHv3 1/3] kernel/irq: make irq_{enter, exit}() in handle_domain_irq() arch optional Date: Thu, 30 Sep 2021 21:17:06 +0800 [thread overview] Message-ID: <20210930131708.35328-2-kernelfans@gmail.com> (raw) In-Reply-To: <20210930131708.35328-1-kernelfans@gmail.com> When an IRQ is taken, some accounting needs to be performed to enter and exit IRQ context around the IRQ handler. Historically arch code would leave this to the irqchip or core IRQ code, but these days we want this to happen in exception entry code, and architectures such as arm64 do this. Currently handle_domain_irq() performs this entry/exit accounting, and if used on an architecture where the entry code also does this, the entry/exit accounting will be performed twice per IRQ. This is problematic as core RCU code such as rcu_is_cpu_rrupt_from_idle() depends on this happening once per IRQ, and will not detect quescent periods correctly, leading to stall warnings. As irqchip drivers which use handle_domain_irq() need to work on architectures with or without their own entry/exit accounting, this patch makes handle_domain_irq() conditionally perform the entry accounting depending on a new HAVE_ARCH_IRQENTRY Kconfig symbol that architectures can select if they perform this entry accounting themselves. For architectures which do not select the symbol. there should be no functional change as a result of this patch. Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Joey Gouly <joey.gouly@arm.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Julien Thierry <julien.thierry@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yuichi Ito <ito-yuichi@fujitsu.com> Cc: linux-kernel@vger.kernel.org To: linux-arm-kernel@lists.infradead.org --- kernel/irq/Kconfig | 3 +++ kernel/irq/irqdesc.c | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig index fbc54c2a7f23..defa1db2d664 100644 --- a/kernel/irq/Kconfig +++ b/kernel/irq/Kconfig @@ -100,6 +100,9 @@ config IRQ_MSI_IOMMU config HANDLE_DOMAIN_IRQ bool +config HAVE_ARCH_IRQENTRY + bool + config IRQ_TIMINGS bool diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 4e3c29bb603c..fd5dd9d278b5 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -693,7 +693,9 @@ int handle_domain_irq(struct irq_domain *domain, struct irq_desc *desc; int ret = 0; +#ifndef CONFIG_HAVE_ARCH_IRQENTRY irq_enter(); +#endif /* The irqdomain code provides boundary checks */ desc = irq_resolve_mapping(domain, hwirq); @@ -702,7 +704,9 @@ int handle_domain_irq(struct irq_domain *domain, else ret = -EINVAL; +#ifndef CONFIG_HAVE_ARCH_IRQENTRY irq_exit(); +#endif set_irq_regs(old_regs); return ret; } -- 2.31.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-09-30 13:17 UTC|newest] Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-30 13:17 [PATCHv3 0/3] arm64/irqentry: remove duplicate housekeeping of rcu Pingfan Liu 2021-09-30 13:17 ` Pingfan Liu 2021-09-30 13:17 ` Pingfan Liu [this message] 2021-09-30 13:17 ` [PATCHv3 1/3] kernel/irq: make irq_{enter, exit}() in handle_domain_irq() arch optional Pingfan Liu 2021-10-01 9:15 ` [PATCHv3 1/3] kernel/irq: make irq_{enter,exit}() " Marc Zyngier 2021-10-01 9:15 ` [PATCHv3 1/3] kernel/irq: make irq_{enter, exit}() " Marc Zyngier 2021-10-01 14:33 ` Pingfan Liu 2021-10-01 14:33 ` Pingfan Liu 2021-09-30 13:17 ` [PATCHv3 2/3] arm64: entry: refactor EL1 interrupt entry logic Pingfan Liu 2021-09-30 13:17 ` Pingfan Liu 2021-09-30 14:00 ` Mark Rutland 2021-09-30 14:00 ` Mark Rutland 2021-10-01 2:27 ` Pingfan Liu 2021-10-01 2:27 ` Pingfan Liu 2021-10-01 9:21 ` Marc Zyngier 2021-10-01 9:21 ` Marc Zyngier 2021-10-01 14:12 ` Pingfan Liu 2021-10-01 14:12 ` Pingfan Liu 2021-09-30 13:17 ` [PATCHv3 3/3] arm64/entry-common: supplement irq accounting Pingfan Liu 2021-09-30 13:17 ` Pingfan Liu 2021-09-30 13:53 ` Mark Rutland 2021-09-30 13:53 ` Mark Rutland 2021-10-01 9:22 ` Marc Zyngier 2021-10-01 9:22 ` Marc Zyngier 2021-10-01 14:10 ` Pingfan Liu 2021-10-01 14:10 ` Pingfan Liu
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