From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753218AbeEUMLD (ORCPT ); Mon, 21 May 2018 08:11:03 -0400 Received: from foss.arm.com ([217.140.101.70]:48568 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752467AbeEUMK7 (ORCPT ); Mon, 21 May 2018 08:10:59 -0400 Subject: Re: [PATCH v3 1/6] arm64: cpufeature: Allow early detect of specific features To: Daniel Thompson , Suzuki K Poulose Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, marc.zyngier@arm.com, mark.rutland@arm.com, christoffer.dall@arm.com, james.morse@arm.com, joelaf@google.com, joel.opensrc@gmail.com, catalin.marinas@arm.com, will.deacon@arm.com References: <1526902515-13769-1-git-send-email-julien.thierry@arm.com> <1526902515-13769-2-git-send-email-julien.thierry@arm.com> <697af68e-3cee-4d0d-8493-106cc42eed3b@arm.com> <20180521120644.g527aawkutf3etzq@holly.lan> From: Julien Thierry Message-ID: <21e20c10-a2f2-c68f-aedf-b53836bc622e@arm.com> Date: Mon, 21 May 2018 13:10:55 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180521120644.g527aawkutf3etzq@holly.lan> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21/05/18 13:06, Daniel Thompson wrote: > On Mon, May 21, 2018 at 12:45:22PM +0100, Suzuki K Poulose wrote: >> On 21/05/18 12:35, Julien Thierry wrote: >>> From: Daniel Thompson >>> >>> Currently it is not possible to detect features of the boot CPU >>> until the other CPUs have been brought up. >>> >>> This prevents us from reacting to features of the boot CPU until >>> fairly late in the boot process. To solve this we allow a subset >>> of features (that are likely to be common to all clusters) to be >>> detected based on the boot CPU alone. >>> >>> Signed-off-by: Daniel Thompson >>> [julien.thierry@arm.com: check non-boot cpu missing early features, avoid >>> duplicates between early features and normal >>> features] >>> Signed-off-by: Julien Thierry >>> Cc: Catalin Marinas >>> Cc: Will Deacon >>> Cc: Suzuki K Poulose >> >> nit: Since this is completely different from what Daniel started with, >> you could simply reset the author to yourself. The boot CPU feature was >> added keeping this user in mind. > > Agree! It's no longer my patch. > > If you want to retain any credit than Suggested-by: would make quite > sufficient. > Good point, I didn't think of that. I'll change this after I get other reviews for this version. Thanks, > >> >> The patch as such looks good to me. >> >> Reviewed-by: Suzuki K Poulose >> >>> --- >>> arch/arm64/kernel/cpufeature.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c >>> index 9d1b06d..e03e897 100644 >>> --- a/arch/arm64/kernel/cpufeature.c >>> +++ b/arch/arm64/kernel/cpufeature.c >>> @@ -1030,7 +1030,7 @@ static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused) >>> { >>> .desc = "GIC system register CPU interface", >>> .capability = ARM64_HAS_SYSREG_GIC_CPUIF, >>> - .type = ARM64_CPUCAP_SYSTEM_FEATURE, >>> + .type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE, >>> .matches = has_useable_gicv3_cpuif, >>> .sys_reg = SYS_ID_AA64PFR0_EL1, >>> .field_pos = ID_AA64PFR0_GIC_SHIFT, >>> -- >>> 1.9.1 >>> >> -- Julien Thierry