From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932908AbcIBPwi (ORCPT ); Fri, 2 Sep 2016 11:52:38 -0400 Received: from foss.arm.com ([217.140.101.70]:55090 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932468AbcIBPwd (ORCPT ); Fri, 2 Sep 2016 11:52:33 -0400 Date: Fri, 2 Sep 2016 16:52:25 +0100 From: Catalin Marinas To: Suzuki K Poulose Cc: linux-arm-kernel@lists.infradead.org, Will Deacon , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] arm64: Use static keys for CPU features Message-ID: <20160902155224.GC391@e104818-lin.cambridge.arm.com> References: <1472145992-10660-1-git-send-email-catalin.marinas@arm.com> <1472145992-10660-3-git-send-email-catalin.marinas@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 26, 2016 at 10:22:13AM +0100, Suzuki K. Poulose wrote: > On 25/08/16 18:26, Catalin Marinas wrote: > > static inline int __attribute_const__ > >diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > >index 62272eac1352..919b2d0d68ae 100644 > >--- a/arch/arm64/kernel/cpufeature.c > >+++ b/arch/arm64/kernel/cpufeature.c > >@@ -46,6 +46,9 @@ unsigned int compat_elf_hwcap2 __read_mostly; > > > > DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS); > > > >+DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS); > >+EXPORT_SYMBOL(cpu_hwcap_keys); > >+ > > #define __ARM64_FTR_BITS(SIGNED, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \ > > { \ > > .sign = SIGNED, \ > >diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c > >index ed1b84fe6925..6a141e399daf 100644 > >--- a/arch/arm64/kernel/cpuinfo.c > >+++ b/arch/arm64/kernel/cpuinfo.c > >@@ -377,6 +377,12 @@ void cpuinfo_store_cpu(void) > > void __init cpuinfo_store_boot_cpu(void) > > { > > struct cpuinfo_arm64 *info = &per_cpu(cpu_data, 0); > >+ > >+ /* > >+ * Initialise the static keys early as they may be enabled by > >+ * check_local_cpu_errata() -> update_cpu_capabilities(). > >+ */ > >+ jump_label_init(); > > __cpuinfo_store_cpu(info); > > Just a heads up. I have a patch [1] which moves the "check_local_cpu_errata()" > around to smp_prepare_boot_cpu(). This patch should still work fine with that > case. Only that may be we could move the jump_lable_init() to smp_prepare_boot_cpu(), > before we call "update_cpu_errata_work_arounds()" for Boot CPU. IIUC, we wouldn't call update_cpu_errata_work_arounds() until the CPU feature infrastructure is initialised via cpuinfo_store_boot_cpu(). So I don't think moving the jump_label_init() call above is necessary. > [1] https://lkml.kernel.org/r/1471525832-21209-4-git-send-email-suzuki.poulose@arm.com -- Catalin