From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Tue, 16 Aug 2016 16:26:50 +0100 Subject: [PATCH] ARM: irq_work: Do not attempt to IPI on non IPI-capable HW Message-ID: <1471361210-29914-1-git-send-email-marc.zyngier@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Not all of the ARM HW is IPI capable (i.e. most of the non-SMP systems). Unfortunately, some systems do advertise being SMP capable, even if they have a single core and do not define a cross call method. In this case, irq_work_queue dies as arch_irq_work_has_interrupt() fails to detect this particular case. Let's redefine arch_irq_work_has_interrupt() to actually check if we're IPI capable instead of simply being SMP. This sidesteps the issue entierely. Signed-off-by: Marc Zyngier --- arch/arm/include/asm/irq_work.h | 6 +++++- arch/arm/include/asm/smp_plat.h | 2 ++ arch/arm/kernel/smp.c | 2 +- 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/irq_work.h b/arch/arm/include/asm/irq_work.h index 712d03e..3ba3583 100644 --- a/arch/arm/include/asm/irq_work.h +++ b/arch/arm/include/asm/irq_work.h @@ -5,7 +5,11 @@ static inline bool arch_irq_work_has_interrupt(void) { - return is_smp(); +#ifdef CONFIG_SMP + return !!__smp_cross_call; +#else + return false; +#endif } #endif /* _ASM_ARM_IRQ_WORK_H */ diff --git a/arch/arm/include/asm/smp_plat.h b/arch/arm/include/asm/smp_plat.h index f908071..ffee073 100644 --- a/arch/arm/include/asm/smp_plat.h +++ b/arch/arm/include/asm/smp_plat.h @@ -26,6 +26,8 @@ static inline bool is_smp(void) #endif } +extern void (*__smp_cross_call)(const struct cpumask *, unsigned int); + /** * smp_cpuid_part() - return part id for a given cpu * @cpu: logical cpu id. diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 8615216..f9d771f 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -465,7 +465,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus) } } -static void (*__smp_cross_call)(const struct cpumask *, unsigned int); +void (*__smp_cross_call)(const struct cpumask *, unsigned int); void __init set_smp_cross_call(void (*fn)(const struct cpumask *, unsigned int)) { -- 2.1.4