From patchwork Wed Jan 17 11:54:39 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Thierry X-Patchwork-Id: 10169197 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CEAA2603ED for ; Wed, 17 Jan 2018 11:55:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BCD2E27E63 for ; Wed, 17 Jan 2018 11:55:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AF898280CF; Wed, 17 Jan 2018 11:55:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 1CA5127E63 for ; Wed, 17 Jan 2018 11:55:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=VtYwbhe4z8f3oHl8tKw3SrcIYsZEBTbWeafYSS2dsUc=; b=kmUg08KKIIJ2HdaCtVlEKqa7my 7n/6VYneuTk6gc8aB1kggivGeMpgwPNq7GmIcy8Lzk5srlfcEUYNdrN40966YdpHtK4M3LMzXa8Kx bSSqkkeen4TIip+CjO0era6wJfnhUwvaTXVIvRgBiECXwe6pIiXorgFEyWoWe5TnMpEEFu441in16 Un+btxXkXnv5QQVW914LSprxg3Dld/l8jliNNVRwlfC7sDg/65klseOVrY2hKtunFD6M6g12Ct124 eQ/Ifa9HSNTpgJhTJ6DXdPKqgdTS4x6V//7QuAC6U35n6+QB9Z2UJR7Ud2Uof0X06YuOopCp1QErb mRlT53QA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.89 #1 (Red Hat Linux)) id 1ebmJi-0004qh-07; Wed, 17 Jan 2018 11:55:42 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.89 #1 (Red Hat Linux)) id 1ebmJP-0004Yb-Lz for linux-arm-kernel@lists.infradead.org; Wed, 17 Jan 2018 11:55:26 +0000 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 2C68815A2; Wed, 17 Jan 2018 03:55:13 -0800 (PST) Received: from e112298-lin.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 83BE93F53D; Wed, 17 Jan 2018 03:55:11 -0800 (PST) From: Julien Thierry To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/6] arm64: cpufeature: Allow early detect of specific features Date: Wed, 17 Jan 2018 11:54:39 +0000 Message-Id: <1516190084-18978-2-git-send-email-julien.thierry@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1516190084-18978-1-git-send-email-julien.thierry@arm.com> References: <1516190084-18978-1-git-send-email-julien.thierry@arm.com> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, daniel.thompson@linaro.org, Julien Thierry , marc.zyngier@arm.com, Catalin Marinas , Suzuki K Poulose , Will Deacon , james.morse@arm.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- arch/arm64/kernel/cpufeature.c | 69 ++++++++++++++++++++++++++++-------------- 1 file changed, 47 insertions(+), 22 deletions(-) -- 1.9.1 diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index a73a592..6698404 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -52,6 +52,8 @@ DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS); EXPORT_SYMBOL(cpu_hwcaps); +static void __init setup_early_feature_capabilities(void); + /* * Flag to indicate if we have computed the system wide * capabilities based on the boot time active CPUs. This @@ -542,6 +544,8 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info) init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr); sve_init_vq_map(); } + + setup_early_feature_capabilities(); } static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new) @@ -846,7 +850,7 @@ static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unus ID_AA64PFR0_FP_SHIFT) < 0; } -static const struct arm64_cpu_capabilities arm64_features[] = { +static const struct arm64_cpu_capabilities arm64_early_features[] = { { .desc = "GIC system register CPU interface", .capability = ARM64_HAS_SYSREG_GIC_CPUIF, @@ -857,6 +861,10 @@ static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unus .sign = FTR_UNSIGNED, .min_field_value = 1, }, + {} +}; + +static const struct arm64_cpu_capabilities arm64_features[] = { #ifdef CONFIG_ARM64_PAN { .desc = "Privileged Access Never", @@ -1111,6 +1119,29 @@ void __init enable_cpu_capabilities(const struct arm64_cpu_capabilities *caps) } } +/* Returns false on a capability mismatch */ +static bool +verify_local_cpu_features(const struct arm64_cpu_capabilities *caps) +{ + for (; caps->matches; caps++) { + if (!cpus_have_cap(caps->capability)) + continue; + /* + * If the new CPU misses an advertised feature, we cannot + * proceed further, park the cpu. + */ + if (!caps->matches(caps, SCOPE_LOCAL_CPU)) { + pr_crit("CPU%d: missing feature: %s\n", + smp_processor_id(), caps->desc); + return false; + } + if (caps->enable) + caps->enable(NULL); + } + + return true; +} + /* * Check for CPU features that are used in early boot * based on the Boot CPU value. @@ -1119,6 +1150,9 @@ static void check_early_cpu_features(void) { verify_cpu_run_el(); verify_cpu_asid_bits(); + + if (!verify_local_cpu_features(arm64_early_features)) + cpu_panic_kernel(); } static void @@ -1133,26 +1167,6 @@ static void check_early_cpu_features(void) } } -static void -verify_local_cpu_features(const struct arm64_cpu_capabilities *caps) -{ - for (; caps->matches; caps++) { - if (!cpus_have_cap(caps->capability)) - continue; - /* - * If the new CPU misses an advertised feature, we cannot proceed - * further, park the cpu. - */ - if (!caps->matches(caps, SCOPE_LOCAL_CPU)) { - pr_crit("CPU%d: missing feature: %s\n", - smp_processor_id(), caps->desc); - cpu_die_early(); - } - if (caps->enable) - caps->enable(NULL); - } -} - static void verify_sve_features(void) { u64 safe_zcr = read_sanitised_ftr_reg(SYS_ZCR_EL1); @@ -1181,7 +1195,10 @@ static void verify_sve_features(void) static void verify_local_cpu_capabilities(void) { verify_local_cpu_errata_workarounds(); - verify_local_cpu_features(arm64_features); + + if (!verify_local_cpu_features(arm64_features)) + cpu_die_early(); + verify_local_elf_hwcaps(arm64_elf_hwcaps); if (system_supports_32bit_el0()) @@ -1211,6 +1228,13 @@ void check_local_cpu_capabilities(void) verify_local_cpu_capabilities(); } +static void __init setup_early_feature_capabilities(void) +{ + update_cpu_capabilities(arm64_early_features, + "early detected feature:"); + enable_cpu_capabilities(arm64_early_features); +} + static void __init setup_feature_capabilities(void) { update_cpu_capabilities(arm64_features, "detected feature:"); @@ -1249,6 +1273,7 @@ static bool __this_cpu_has_cap(const struct arm64_cpu_capabilities *cap_array, bool this_cpu_has_cap(unsigned int cap) { return (__this_cpu_has_cap(arm64_features, cap) || + __this_cpu_has_cap(arm64_early_features, cap) || __this_cpu_has_cap(arm64_errata, cap)); }