From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760132AbdACSMW (ORCPT ); Tue, 3 Jan 2017 13:12:22 -0500 Received: from smtprelay.synopsys.com ([198.182.60.111]:35474 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760147AbdACSKy (ORCPT ); Tue, 3 Jan 2017 13:10:54 -0500 Subject: Re: [PATCH v3 3/3] ARCv2: MCIP: Deprecate setting of affinity in Device Tree To: Yuriy Kolerov , "linux-snps-arc@lists.infradead.org" References: <1482914786-10490-1-git-send-email-yuriy.kolerov@synopsys.com> <1482914786-10490-4-git-send-email-yuriy.kolerov@synopsys.com> CC: "Alexey.Brodkin@synopsys.com" , "linux-kernel@vger.kernel.org" , "marc.zyngier@arm.com" From: Vineet Gupta Message-ID: Date: Tue, 3 Jan 2017 10:10:45 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <1482914786-10490-4-git-send-email-yuriy.kolerov@synopsys.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.10.161.79] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/28/2016 12:47 AM, Yuriy Kolerov wrote: > Ignore value of interrupt distribution mode for common interrupts in > IDU since setting of affinity using value from Device Tree is deprecated > in ARC. Originally it is done in idu_irq_xlate() function and it is > semantically wrong and does not guaranty that an affinity value will be > set properly. idu_irq_enable() function is better place for > initialization of common interrupts. > > By default send all common interrupts to all available online CPUs. Is this a departure from our original idea to route everything only to boot cpu ? Otherwise this looks OK to me ! -Vineet > The affinity of common interrupts in IDU must be set manually since > in some cases the kernel will not call irq_set_affinity() by itself: > > 1. When the kernel is not configured with support of SMP. > 2. When the kernel is configured with support of SMP but upper > interrupt controllers does not support setting of the affinity > and cannot propagate it to IDU. > > Signed-off-by: Yuriy Kolerov > --- > .../interrupt-controller/snps,archs-idu-intc.txt | 3 ++ > arch/arc/kernel/mcip.c | 52 +++++++++------------- > 2 files changed, 25 insertions(+), 30 deletions(-) > > diff --git a/Documentation/devicetree/bindings/interrupt-controller/snps,archs-idu-intc.txt b/Documentation/devicetree/bindings/interrupt-controller/snps,archs-idu-intc.txt > index 0dcb7c7..9446576 100644 > --- a/Documentation/devicetree/bindings/interrupt-controller/snps,archs-idu-intc.txt > +++ b/Documentation/devicetree/bindings/interrupt-controller/snps,archs-idu-intc.txt > @@ -15,6 +15,9 @@ Properties: > Second cell specifies the irq distribution mode to cores > 0=Round Robin; 1=cpu0, 2=cpu1, 4=cpu2, 8=cpu3 > > + The second cell in interrupts property is deprecated and may be ignored by > + the kernel. > + > intc accessed via the special ARC AUX register interface, hence "reg" property > is not specified. > > diff --git a/arch/arc/kernel/mcip.c b/arch/arc/kernel/mcip.c > index be131b2..d492a3c 100644 > --- a/arch/arc/kernel/mcip.c > +++ b/arch/arc/kernel/mcip.c > @@ -175,7 +175,6 @@ static void idu_irq_unmask(struct irq_data *data) > raw_spin_unlock_irqrestore(&mcip_lock, flags); > } > > -#ifdef CONFIG_SMP > static int > idu_irq_set_affinity(struct irq_data *data, const struct cpumask *cpumask, > bool force) > @@ -205,12 +204,27 @@ idu_irq_set_affinity(struct irq_data *data, const struct cpumask *cpumask, > > return IRQ_SET_MASK_OK; > } > -#endif > + > +static void idu_irq_enable(struct irq_data *data) > +{ > + /* > + * By default send all common interrupts to all available online CPUs. > + * The affinity of common interrupts in IDU must be set manually since > + * in some cases the kernel will not call irq_set_affinity() by itself: > + * 1. When the kernel is not configured with support of SMP. > + * 2. When the kernel is configured with support of SMP but upper > + * interrupt controllers does not support setting of the affinity > + * and cannot propagate it to IDU. > + */ > + idu_irq_set_affinity(data, cpu_online_mask, false); > + idu_irq_unmask(data); > +} > > static struct irq_chip idu_irq_chip = { > .name = "MCIP IDU Intc", > .irq_mask = idu_irq_mask, > .irq_unmask = idu_irq_unmask, > + .irq_enable = idu_irq_enable, > #ifdef CONFIG_SMP > .irq_set_affinity = idu_irq_set_affinity, > #endif > @@ -243,36 +257,14 @@ static int idu_irq_xlate(struct irq_domain *d, struct device_node *n, > const u32 *intspec, unsigned int intsize, > irq_hw_number_t *out_hwirq, unsigned int *out_type) > { > - irq_hw_number_t hwirq = *out_hwirq = intspec[0]; > - int distri = intspec[1]; > - unsigned long flags; > - > + /* > + * Ignore value of interrupt distribution mode for common interrupts in > + * IDU which resides in intspec[1] since setting an affinity using value > + * from Device Tree is deprecated in ARC. > + */ > + *out_hwirq = intspec[0]; > *out_type = IRQ_TYPE_NONE; > > - /* XXX: validate distribution scheme again online cpu mask */ > - if (distri == 0) { > - /* 0 - Round Robin to all cpus, otherwise 1 bit per core */ > - raw_spin_lock_irqsave(&mcip_lock, flags); > - idu_set_dest(hwirq, BIT(num_online_cpus()) - 1); > - idu_set_mode(hwirq, IDU_M_TRIG_LEVEL, IDU_M_DISTRI_RR); > - raw_spin_unlock_irqrestore(&mcip_lock, flags); > - } else { > - /* > - * DEST based distribution for Level Triggered intr can only > - * have 1 CPU, so generalize it to always contain 1 cpu > - */ > - int cpu = ffs(distri); > - > - if (cpu != fls(distri)) > - pr_warn("IDU irq %lx distri mode set to cpu %x\n", > - hwirq, cpu); > - > - raw_spin_lock_irqsave(&mcip_lock, flags); > - idu_set_dest(hwirq, cpu); > - idu_set_mode(hwirq, IDU_M_TRIG_LEVEL, IDU_M_DISTRI_DEST); > - raw_spin_unlock_irqrestore(&mcip_lock, flags); > - } > - > return 0; > } >