From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04EDDC282C0 for ; Wed, 23 Jan 2019 08:56:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D24692183F for ; Wed, 23 Jan 2019 08:56:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727160AbfAWI4Z (ORCPT ); Wed, 23 Jan 2019 03:56:25 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:37626 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726913AbfAWI4Y (ORCPT ); Wed, 23 Jan 2019 03:56:24 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E81F6A78; Wed, 23 Jan 2019 00:56:23 -0800 (PST) Received: from [10.1.197.45] (e112298-lin.cambridge.arm.com [10.1.197.45]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 249EB3F6A8; Wed, 23 Jan 2019 00:56:22 -0800 (PST) Subject: Re: [PATCH v9 09/26] arm64: Unmask PMR before going idle To: Ard Biesheuvel Cc: linux-arm-kernel , Mark Rutland , Daniel Thompson , Marc Zyngier , Catalin Marinas , Will Deacon , Linux Kernel Mailing List , Christoffer Dall , James Morse , Joel Fernandes References: <1548084825-8803-1-git-send-email-julien.thierry@arm.com> <1548084825-8803-10-git-send-email-julien.thierry@arm.com> From: Julien Thierry Message-ID: <6d9cd0ea-d487-bfb0-0461-1e0fcd24a7e1@arm.com> Date: Wed, 23 Jan 2019 08:56:20 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/01/2019 20:18, Ard Biesheuvel wrote: > On Mon, 21 Jan 2019 at 16:36, Julien Thierry wrote: >> >> CPU does not received signals for interrupts with a priority masked by >> ICC_PMR_EL1. This means the CPU might not come back from a WFI >> instruction. >> >> Make sure ICC_PMR_EL1 does not mask interrupts when doing a WFI. >> >> Since the logic of cpu_do_idle is becoming a bit more complex than just >> two instructions, lets turn it from ASM to C. >> >> Signed-off-by: Julien Thierry >> Suggested-by: Daniel Thompson >> Cc: Catalin Marinas >> Cc: Will Deacon >> --- >> arch/arm64/kernel/process.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ >> arch/arm64/mm/proc.S | 11 ----------- >> 2 files changed, 45 insertions(+), 11 deletions(-) >> >> diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c >> index 6d410fc..f05b63f 100644 >> --- a/arch/arm64/kernel/process.c >> +++ b/arch/arm64/kernel/process.c >> @@ -51,6 +51,7 @@ >> #include >> >> #include >> +#include >> #include >> #include >> #include >> @@ -74,6 +75,50 @@ >> >> void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd); >> >> +static inline void __cpu_do_idle(void) >> +{ >> + dsb(sy); >> + wfi(); >> +} >> + >> +static inline void __cpu_do_idle_irqprio(void) > > Can we drop the 'inline's from all the function definitions in .c > files? (not just in this patch) > We tend to leave that to the compiler. > Sure, I guess cpu_do_idle() isn't a performance critical path anyway. Unless anyone argues against it, I'll drop these inlines for the next version. Thanks, Julien >> +{ >> + unsigned long pmr; >> + unsigned long daif_bits; >> + >> + daif_bits = read_sysreg(daif); >> + write_sysreg(daif_bits | PSR_I_BIT, daif); >> + >> + /* >> + * Unmask PMR before going idle to make sure interrupts can >> + * be raised. >> + */ >> + pmr = gic_read_pmr(); >> + gic_write_pmr(GIC_PRIO_IRQON); >> + >> + __cpu_do_idle(); >> + >> + gic_write_pmr(pmr); >> + write_sysreg(daif_bits, daif); >> +} >> + >> +/* >> + * cpu_do_idle() >> + * >> + * Idle the processor (wait for interrupt). >> + * >> + * If the CPU supports priority masking we must do additional work to >> + * ensure that interrupts are not masked at the PMR (because the core will >> + * not wake up if we block the wake up signal in the interrupt controller). >> + */ >> +void cpu_do_idle(void) >> +{ >> + if (system_uses_irq_prio_masking()) >> + __cpu_do_idle_irqprio(); >> + else >> + __cpu_do_idle(); >> +} >> + >> /* >> * This is our default idle handler. >> */ >> diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S >> index 73886a5..3ea4f3b 100644 >> --- a/arch/arm64/mm/proc.S >> +++ b/arch/arm64/mm/proc.S >> @@ -55,17 +55,6 @@ >> >> #define MAIR(attr, mt) ((attr) << ((mt) * 8)) >> >> -/* >> - * cpu_do_idle() >> - * >> - * Idle the processor (wait for interrupt). >> - */ >> -ENTRY(cpu_do_idle) >> - dsb sy // WFI may enter a low-power mode >> - wfi >> - ret >> -ENDPROC(cpu_do_idle) >> - >> #ifdef CONFIG_CPU_PM >> /** >> * cpu_do_suspend - save CPU registers context >> -- >> 1.9.1 >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- Julien Thierry