Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755138AbbHNOVE (ORCPT ); Fri, 14 Aug 2015 10:21:04 -0400 Received: from metis.ext.pengutronix.de ([92.198.50.35]:41288 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752402AbbHNOVC (ORCPT ); Fri, 14 Aug 2015 10:21:02 -0400 Message-ID: <1439562059.13210.61.camel@pengutronix.de> Subject: Re: [PATCH] ARM: keystone: add a work around to handle asynchronous external abort From: Lucas Stach To: Russell King - ARM Linux Cc: Murali Karicheri , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, ssantosh@kernel.org Date: Fri, 14 Aug 2015 16:20:59 +0200 In-Reply-To: <20150814140934.GX7557@n2100.arm.linux.org.uk> References: <1439320409-20084-1-git-send-email-m-karicheri2@ti.com> <55CDF579.4050408@ti.com> <20150814140934.GX7557@n2100.arm.linux.org.uk> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.9-1+b1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2001:67c:670:100:fa0f:41ff:fe58:4010 X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3827 Lines: 121 Hi Russell, Am Freitag, den 14.08.2015, 15:09 +0100 schrieb Russell King - ARM Linux: [...] > > What causes the abort? We shouldn't be adding hacks like this to the > kernel without having the full picture... > some of the issues with tracking down such imprecise external aborts are due to the fact that we only enable the signaling of those aborts on entering the user-space. So the first schedule() crashes on the previous dangling abort. I'm carrying this patch locally to enable imprecise aborts much earlier in the boot process. I think it has already been on the list some times, but apparently it has fallen through the cracks. If you agree that this is the right thing to do I can do a proper repost. Regards, Lucas ---------------------->8--------------------------------------------- >From bb9117d94cc2f1061dc364f42c446ccd9191e869 Mon Sep 17 00:00:00 2001 From: Lucas Stach Date: Thu, 19 Feb 2015 18:12:50 +0100 Subject: [PATCH] ARM: Add imprecise abort enable/disable macro This patch adds imprecise abort enable/disable macros. It also enables imprecise aborts when starting kernel. Changes in v2: Only ARMv6 and later have CPSR.A bit. On earlier CPUs, and ARMv7M this should be a no-op. Signed-off-by: Fabrice Gasnier Signed-off-by: Lucas Stach --- lst: rebased on v3.19 --- arch/arm/include/asm/irqflags.h | 10 ++++++++++ arch/arm/kernel/smp.c | 1 + arch/arm/kernel/traps.c | 4 ++++ 3 files changed, 15 insertions(+) diff --git a/arch/arm/include/asm/irqflags.h b/arch/arm/include/asm/irqflags.h index 3b763d6652a0..8301f875564e 100644 --- a/arch/arm/include/asm/irqflags.h +++ b/arch/arm/include/asm/irqflags.h @@ -51,6 +51,14 @@ static inline void arch_local_irq_disable(void) #define local_fiq_enable() __asm__("cpsie f @ __stf" : : : "memory", "cc") #define local_fiq_disable() __asm__("cpsid f @ __clf" : : : "memory", "cc") + +#ifndef CONFIG_CPU_V7M +#define local_abt_enable() __asm__("cpsie a @ __sta" : : : "memory", "cc") +#define local_abt_disable() __asm__("cpsid a @ __cla" : : : "memory", "cc") +#else +#define local_abt_enable() do { } while (0) +#define local_abt_disable() do { } while (0) +#endif #else /* @@ -130,6 +138,8 @@ static inline void arch_local_irq_disable(void) : "memory", "cc"); \ }) +#define local_abt_enable() do { } while (0) +#define local_abt_disable() do { } while (0) #endif /* diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 86ef244c5a24..7b6b93cabef4 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -378,6 +378,7 @@ asmlinkage void secondary_start_kernel(void) local_irq_enable(); local_fiq_enable(); + local_abt_enable(); /* * OK, it's off to the idle thread for us diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 788e23fe64d8..466726ba9bdb 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -881,6 +881,10 @@ void __init early_trap_init(void *vectors_base) flush_icache_range(vectors, vectors + PAGE_SIZE * 2); modify_domain(DOMAIN_USER, DOMAIN_CLIENT); + + /* Enable imprecise aborts */ + local_abt_enable(); + #else /* ifndef CONFIG_CPU_V7M */ /* * on V7-M there is no need to copy the vector table to a dedicated -- 2.1.4 -- Pengutronix e.K. | Lucas Stach | Industrial Linux Solutions | http://www.pengutronix.de/ | -- 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/