From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: [PATCH v2 1/5] irqchip/irq-bcm7038-l1: Add PM support Date: Sun, 22 Sep 2019 11:50:23 -0700 Message-ID: <3952c2c7-c619-eab6-e3ad-d8735104dace@gmail.com> References: <20190913191542.9908-1-f.fainelli@gmail.com> <20190913191542.9908-2-f.fainelli@gmail.com> <20190922133108.09211a17@why> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190922133108.09211a17@why> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Marc Zyngier Cc: linux-kernel@vger.kernel.org, Justin Chen , Thomas Gleixner , Jason Cooper , Rob Herring , Mark Rutland , Kevin Cernekee , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , "open list:BROADCOM BMIPS MIPS ARCHITECTURE" , "open list:BROADCOM BMIPS MIPS ARCHITECTURE" List-Id: devicetree@vger.kernel.org On 9/22/2019 5:31 AM, Marc Zyngier wrote: >> +#ifdef CONFIG_PM_SLEEP >> +static int bcm7038_l1_suspend(void) >> +{ >> + struct bcm7038_l1_chip *intc; >> + unsigned long flags; >> + int boot_cpu, word; >> + >> + /* Wakeup interrupt should only come from the boot cpu */ >> + boot_cpu = cpu_logical_map(smp_processor_id()); > > What guarantees that you're actually running on the boot CPU at this > point? If that's actually the case, why isn't cpu_logical_map(0) enough? This is executed from syscore_suspend() which is executed after suspend_disable_secondary_cpus(), so we are guaranteed to be uni-processor at that point. Good point about using 0 for addressing the boot CPU. > >> + >> + list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) { >> + raw_spin_lock_irqsave(&intc->lock, flags); > > And if this can only run on a single CPU, what's the purpose of this > lock? Humm, yes, we probably do not need that lock, syscore_suspend() is after arch_suspend_disable_irqs(). > >> + for (word = 0; word < intc->n_words; word++) { >> + l1_writel(~intc->wake_mask[word], >> + intc->cpus[boot_cpu]->map_base + >> + reg_mask_set(intc, word)); >> + l1_writel(intc->wake_mask[word], >> + intc->cpus[boot_cpu]->map_base + >> + reg_mask_clr(intc, word)); > > nit: Please don't split the write address across two lines, it makes it > harder to read. > >> + } >> + raw_spin_unlock_irqrestore(&intc->lock, flags); >> + } >> + >> + return 0; >> +} >> + >> +static void bcm7038_l1_resume(void) >> +{ >> + struct bcm7038_l1_chip *intc; >> + unsigned long flags; >> + int boot_cpu, word; >> + >> + boot_cpu = cpu_logical_map(smp_processor_id()); >> + >> + list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) { >> + raw_spin_lock_irqsave(&intc->lock, flags); >> + for (word = 0; word < intc->n_words; word++) { >> + l1_writel(intc->cpus[boot_cpu]->mask_cache[word], >> + intc->cpus[boot_cpu]->map_base + >> + reg_mask_set(intc, word)); >> + l1_writel(~intc->cpus[boot_cpu]->mask_cache[word], >> + intc->cpus[boot_cpu]->map_base + >> + reg_mask_clr(intc, word)); >> + } >> + raw_spin_unlock_irqrestore(&intc->lock, flags); >> + } >> +} >> + >> +static struct syscore_ops bcm7038_l1_syscore_ops = { >> + .suspend = bcm7038_l1_suspend, >> + .resume = bcm7038_l1_resume, >> +}; >> + >> +static int bcm7038_l1_set_wake(struct irq_data *d, unsigned int on) >> +{ >> + struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d); >> + unsigned long flags; >> + u32 word = d->hwirq / IRQS_PER_WORD; >> + u32 mask = BIT(d->hwirq % IRQS_PER_WORD); >> + >> + raw_spin_lock_irqsave(&intc->lock, flags); >> + if (on) >> + intc->wake_mask[word] |= mask; >> + else >> + intc->wake_mask[word] &= ~mask; >> + raw_spin_unlock_irqrestore(&intc->lock, flags); >> + >> + return 0; >> +} >> +#endif >> + >> static struct irq_chip bcm7038_l1_irq_chip = { >> .name = "bcm7038-l1", >> .irq_mask = bcm7038_l1_mask, >> @@ -295,6 +382,9 @@ static struct irq_chip bcm7038_l1_irq_chip = { >> #ifdef CONFIG_SMP >> .irq_cpu_offline = bcm7038_l1_cpu_offline, >> #endif >> +#ifdef CONFIG_PM_SLEEP >> + .irq_set_wake = bcm7038_l1_set_wake, >> +#endif >> }; >> >> static int bcm7038_l1_map(struct irq_domain *d, unsigned int virq, >> @@ -340,6 +430,14 @@ int __init bcm7038_l1_of_init(struct device_node *dn, >> goto out_unmap; >> } >> >> +#ifdef CONFIG_PM_SLEEP >> + /* Add bcm7038_l1_chip into a list */ >> + INIT_LIST_HEAD(&intc->list); >> + list_add_tail(&intc->list, &bcm7038_l1_intcs_list); > > No locking to manipulate this list? Is that safe? It is safe, by virtue of of_irq_init() having being called at init_IRQ() and that interrupt controller being initialized early on boot, but it does not feel safe to assume that, I will add relevant protection to the list. > >> + >> + register_syscore_ops(&bcm7038_l1_syscore_ops); > > Do you really register the syscore_ops for each and every L1 irqchip? We do not need, indeed thanks, I will fix those things in v3. -- Florian