Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752171AbaBGRJp (ORCPT ); Fri, 7 Feb 2014 12:09:45 -0500 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:33579 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751319AbaBGRJo (ORCPT ); Fri, 7 Feb 2014 12:09:44 -0500 Date: Fri, 7 Feb 2014 17:09:03 +0000 From: Will Deacon To: Fabrice GASNIER Cc: "linux@arm.linux.org.uk" , "u.kleine-koenig@pengutronix.de" , Jonathan Austin , Catalin Marinas , "nico@linaro.org" , "sboyd@codeaurora.org" , Marc Zyngier , "ben.dooks@codethink.co.uk" , "vgupta@synopsys.com" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "maxime.coquelin@st.com" Subject: Re: [RFC PATCH] ARM: Add imprecise abort enable/disable macro Message-ID: <20140207170903.GT5976@mudshark.cambridge.arm.com> References: <1391789955-26927-1-git-send-email-fabrice.gasnier@st.com> <1391789955-26927-2-git-send-email-fabrice.gasnier@st.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1391789955-26927-2-git-send-email-fabrice.gasnier@st.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 07, 2014 at 04:19:15PM +0000, Fabrice GASNIER wrote: > This patch adds imprecise abort enable/disable macros. > It also enables imprecise aborts when starting kernel. > > Signed-off-by: Fabrice Gasnier > --- > arch/arm/include/asm/irqflags.h | 33 +++++++++++++++++++++++++++++++++ > arch/arm/kernel/smp.c | 1 + > arch/arm/kernel/traps.c | 4 ++++ > 3 files changed, 38 insertions(+) > > diff --git a/arch/arm/include/asm/irqflags.h b/arch/arm/include/asm/irqflags.h > index 3b763d6..82e3834 100644 > --- a/arch/arm/include/asm/irqflags.h > +++ b/arch/arm/include/asm/irqflags.h > @@ -51,6 +51,9 @@ 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") > + > +#define local_abt_enable() __asm__("cpsie a @ __sta" : : : "memory", "cc") > +#define local_abt_disable() __asm__("cpsid a @ __cla" : : : "memory", "cc") > #else > > /* > @@ -130,6 +133,36 @@ static inline void arch_local_irq_disable(void) > : "memory", "cc"); \ > }) > > +/* > + * Enable Aborts > + */ > +#define local_abt_enable() \ > + ({ \ > + unsigned long temp; \ > + __asm__ __volatile__( \ > + "mrs %0, cpsr @ sta\n" \ > +" bic %0, %0, %1\n" \ > +" msr cpsr_c, %0" \ > + : "=r" (temp) \ > + : "r" (PSR_A_BIT) \ Can you use "i" instead of a register for this constant? > + : "memory", "cc"); \ You don't need the "cc" clobber. > + }) > + > +/* > + * Disable Aborts > + */ > +#define local_abt_disable() \ > + ({ \ > + unsigned long temp; \ > + __asm__ __volatile__( \ > + "mrs %0, cpsr @ cla\n" \ > +" orr %0, %0, %1\n" \ > +" msr cpsr_c, %0" \ > + : "=r" (temp) \ > + : "r" (PSR_A_BIT) \ > + : "memory", "cc"); \ > + }) Same comments here. > #endif > > /* > diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c > index dc894ab..c2093cb 100644 > --- a/arch/arm/kernel/smp.c > +++ b/arch/arm/kernel/smp.c > @@ -377,6 +377,7 @@ 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 4636d56..ef15709 100644 > --- a/arch/arm/kernel/traps.c > +++ b/arch/arm/kernel/traps.c > @@ -900,6 +900,10 @@ 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(); Surely we want to enable this as early as possible? Now, putting this into head.S is ugly, as it duplicating it across all the proc*.S files, so why not setup_arch? Will -- 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/