From: Marc Zyngier <marc.zyngier@arm.com>
To: Daniel Thompson <daniel.thompson@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>,
Jason Cooper <jason@lakedaemon.net>
Cc: Russell King <linux@arm.linux.org.uk>,
Will Deacon <Will.Deacon@arm.com>,
Catalin Marinas <Catalin.Marinas@arm.com>,
Stephen Boyd <sboyd@codeaurora.org>,
John Stultz <john.stultz@linaro.org>,
Steven Rostedt <rostedt@goodmis.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"patches@linaro.org" <patches@linaro.org>,
"linaro-kernel@lists.linaro.org" <linaro-kernel@lists.linaro.org>,
Sumit Semwal <sumit.semwal@linaro.org>,
Dirk Behme <dirk.behme@de.bosch.com>,
Daniel Drake <drake@endlessm.com>,
Dmitry Pervushin <dpervushin@gmail.com>,
Tim Sander <tim@krieglstein.org>
Subject: Re: [RESEND PATCH 4.0-rc7 v20 2/6] irqchip: gic: Make gic_raise_softirq FIQ-safe
Date: Tue, 21 Apr 2015 13:54:31 +0100 [thread overview]
Message-ID: <55364887.2000404@arm.com> (raw)
In-Reply-To: <1428659511-9590-3-git-send-email-daniel.thompson@linaro.org>
On 10/04/15 10:51, Daniel Thompson wrote:
> It is currently possible for FIQ handlers to re-enter gic_raise_softirq()
> and lock up.
>
> gic_raise_softirq()
> lock(x);
> -~-> FIQ
> handle_fiq()
> gic_raise_softirq()
> lock(x); <-- Lockup
>
> arch/arm/ uses IPIs to implement arch_irq_work_raise(), thus this issue
> renders it difficult for FIQ handlers to safely defer work to less
> restrictive calling contexts.
>
> This patch fixes the problem by converting the cpu_map_migration_lock
> into a rwlock making it safe to re-enter the function.
>
> Note that having made it safe to re-enter gic_raise_softirq() we no
> longer need to mask interrupts during gic_raise_softirq() because the
> b.L migration is always performed from task context.
>
> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Jason Cooper <jason@lakedaemon.net>
> Cc: Russell King <linux@arm.linux.org.uk>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2015-04-21 12:54 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-24 16:53 [PATCH 4.0-rc5 v19 0/6] irq/arm: Implement arch_trigger_all_cpu_backtrace Daniel Thompson
2015-03-24 16:53 ` [PATCH 4.0-rc5 v19 1/6] irqchip: gic: Optimize locking in gic_raise_softirq Daniel Thompson
2015-03-24 16:53 ` [PATCH 4.0-rc5 v19 2/6] irqchip: gic: Make gic_raise_softirq FIQ-safe Daniel Thompson
2015-03-24 16:53 ` [PATCH 4.0-rc5 v19 3/6] irqchip: gic: Introduce plumbing for IPI FIQ Daniel Thompson
2015-03-24 16:53 ` [PATCH 4.0-rc5 v19 4/6] printk: Simple implementation for NMI backtracing Daniel Thompson
2015-03-24 16:53 ` [PATCH 4.0-rc5 v19 5/6] x86/nmi: Use common printk functions Daniel Thompson
2015-03-24 16:53 ` [PATCH 4.0-rc5 v19 6/6] ARM: Add support for on-demand backtrace of other CPUs Daniel Thompson
2015-04-07 15:37 ` [RESEND PATCH 4.0-rc5 v19 0/6] irq/arm: Implement arch_trigger_all_cpu_backtrace Daniel Thompson
2015-04-07 15:37 ` [RESEND PATCH 4.0-rc5 v19 1/6] irqchip: gic: Optimize locking in gic_raise_softirq Daniel Thompson
2015-04-07 15:37 ` [RESEND PATCH 4.0-rc5 v19 2/6] irqchip: gic: Make gic_raise_softirq FIQ-safe Daniel Thompson
2015-04-07 15:38 ` [RESEND PATCH 4.0-rc5 v19 3/6] irqchip: gic: Introduce plumbing for IPI FIQ Daniel Thompson
2015-04-07 15:38 ` [RESEND PATCH 4.0-rc5 v19 4/6] printk: Simple implementation for NMI backtracing Daniel Thompson
2015-04-07 15:38 ` [RESEND PATCH 4.0-rc5 v19 5/6] x86/nmi: Use common printk functions Daniel Thompson
2015-04-07 16:19 ` Steven Rostedt
2015-04-07 16:37 ` Borislav Petkov
2015-04-07 16:43 ` Steven Rostedt
2015-04-08 12:08 ` Daniel Thompson
2015-04-07 15:38 ` [RESEND PATCH 4.0-rc5 v19 6/6] ARM: Add support for on-demand backtrace of other CPUs Daniel Thompson
2015-04-10 9:51 ` [RESEND PATCH 4.0-rc7 v20 0/6] irq/arm: Implement arch_trigger_all_cpu_backtrace Daniel Thompson
2015-04-10 9:51 ` [RESEND PATCH 4.0-rc7 v20 1/6] irqchip: gic: Optimize locking in gic_raise_softirq Daniel Thompson
2015-04-21 12:51 ` Marc Zyngier
2015-04-10 9:51 ` [RESEND PATCH 4.0-rc7 v20 2/6] irqchip: gic: Make gic_raise_softirq FIQ-safe Daniel Thompson
2015-04-21 12:54 ` Marc Zyngier [this message]
2015-04-10 9:51 ` [RESEND PATCH 4.0-rc7 v20 3/6] irqchip: gic: Introduce plumbing for IPI FIQ Daniel Thompson
2015-04-21 13:45 ` Marc Zyngier
2015-04-21 21:03 ` Daniel Thompson
2015-04-22 9:15 ` Marc Zyngier
2015-04-22 12:45 ` Daniel Thompson
2015-04-22 12:57 ` Marc Zyngier
2015-04-22 15:40 ` Daniel Thompson
2015-04-21 14:50 ` Mark Rutland
2015-04-21 21:15 ` Daniel Thompson
2015-04-22 10:38 ` Mark Rutland
2015-07-02 13:31 ` Daniel Thompson
2015-04-10 9:51 ` [RESEND PATCH 4.0-rc7 v20 4/6] printk: Simple implementation for NMI backtracing Daniel Thompson
2015-04-10 9:51 ` [RESEND PATCH 4.0-rc7 v20 5/6] x86/nmi: Use common printk functions Daniel Thompson
2015-04-10 9:51 ` [RESEND PATCH 4.0-rc7 v20 6/6] ARM: Add support for on-demand backtrace of other CPUs Daniel Thompson
2015-04-10 10:47 ` [RESEND PATCH 4.0-rc7 v20 0/6] irq/arm: Implement arch_trigger_all_cpu_backtrace Daniel Thompson
2015-04-21 12:46 ` Thomas Gleixner
2015-04-21 13:08 ` Marc Zyngier
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