Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756137AbaGQJCZ (ORCPT ); Thu, 17 Jul 2014 05:02:25 -0400 Received: from mail-we0-f171.google.com ([74.125.82.171]:52848 "EHLO mail-we0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755908AbaGQJCH (ORCPT ); Thu, 17 Jul 2014 05:02:07 -0400 Message-ID: <53C790F0.7050409@linaro.org> Date: Thu, 17 Jul 2014 10:01:36 +0100 From: Daniel Thompson User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Harro Haan CC: Russell King , linaro-kernel@lists.linaro.org, Catalin Marinas , patches@linaro.org, kgdb-bugreport@lists.sourceforge.net, Linus Walleij , Nicolas Pitre , linux-kernel@vger.kernel.org, Frederic Weisbecker , Anton Vorontsov , Ben Dooks , John Stultz , Fabio Estevam , Colin Cross , kernel-team@android.com, Dave Martin , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH v8 0/4] arm: KGDB NMI/FIQ support References: <1404118391-3850-1-git-send-email-daniel.thompson@linaro.org> <1404979427-12943-1-git-send-email-daniel.thompson@linaro.org> <53C4F745.3070701@linaro.org> <53C54042.2030507@linaro.org> <53C5600C.1080004@linaro.org> In-Reply-To: X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/07/14 18:15, Harro Haan wrote: >> Anyhow I've put together a new version of my earlier patch that I think >> will retrigger all interrupts except SGIs (I'll look at SGIs and >> compatibility with non-Freescale parts only if this improved approach >> works). >> >> Reported-by: Harro Haan >> Signed-off-by: Daniel Thompson >> --- >> drivers/irqchip/irq-gic.c | 31 ++++++++++++++++++++++++++++++- >> 1 file changed, 30 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c >> index 73ae896..88f92e6 100644 >> --- a/drivers/irqchip/irq-gic.c >> +++ b/drivers/irqchip/irq-gic.c >> @@ -303,6 +303,33 @@ static int gic_set_wake(struct irq_data *d, >> unsigned int on) >> #define gic_set_wake NULL >> #endif >> >> +/* This is a software emulation of the Aliased Interrupt Acknowledge >> Register >> + * (GIC_AIAR) found in GICv2+. >> + */ >> +static u32 gic_handle_spurious_group_0(struct gic_chip_data *gic, u32 >> irqstat) >> +{ >> + u32 irqnr = irqstat & GICC_IAR_INT_ID_MASK; >> + void __iomem *dist_base = gic_data_dist_base(gic); >> + u32 offset, mask; >> + >> + if (!gic_data_fiq_enable(gic) || irqnr >= 1021) >> + return irqnr; >> + >> + offset = irqnr / 32 * 4; >> + mask = 1 << (irqnr % 32); >> + if (readl_relaxed(dist_base + GIC_DIST_IGROUP + offset) & mask) >> + return irqnr; >> + >> + /* this interrupt must be taken as a FIQ so put it back into the >> + * pending state and end our own servicing of it. >> + */ >> + writel_relaxed(mask, dist_base + GIC_DIST_PENDING_SET + offset); >> + readl_relaxed(dist_base + GIC_DIST_PENDING_SET + offset); >> + writel_relaxed(irqstat, gic_data_cpu_base(gic) + GIC_CPU_EOI); >> + >> + return 1023; >> +} >> + >> static void __exception_irq_entry gic_handle_irq(struct pt_regs *regs) >> { >> u32 irqstat, irqnr; >> @@ -310,8 +337,10 @@ static void __exception_irq_entry >> gic_handle_irq(struct pt_regs *regs) >> void __iomem *cpu_base = gic_data_cpu_base(gic); >> >> do { >> + local_fiq_disable(); >> irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK); >> - irqnr = irqstat & GICC_IAR_INT_ID_MASK; >> + irqnr = gic_handle_spurious_group_0(gic, irqstat); >> + local_fiq_enable(); >> >> if (likely(irqnr > 15 && irqnr < 1021)) { >> irqnr = irq_find_mapping(gic->domain, irqnr); >> -- >> 1.9.3 >> >> >> > > I just tested the above code. This approach also works as expected for > edge sensitive interrupts. Awesome [and also a personal relief to get it right this time around ;-) ]. So we have two completely different confirmed-as-working workarounds! -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/