From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751863AbeAWMaW (ORCPT ); Tue, 23 Jan 2018 07:30:22 -0500 Received: from foss.arm.com ([217.140.101.70]:40656 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751566AbeAWM2m (ORCPT ); Tue, 23 Jan 2018 07:28:42 -0500 From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, ard.biesheuvel@linaro.org, will.deacon@arm.com, mark.rutland@arm.com, marc.zyngier@arm.com, catalin.marinas@arm.com, ckadabi@codeaurora.org, jnair@caviumnetworks.com, Suzuki K Poulose Subject: [PATCH 09/16] arm64: capabilities: Introduce strict features based on local CPU Date: Tue, 23 Jan 2018 12:28:02 +0000 Message-Id: <20180123122809.16269-10-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20180123122809.16269-1-suzuki.poulose@arm.com> References: <20180123122809.16269-1-suzuki.poulose@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add type for features that are detected on individual CPUs, rather than on a system wide safe features. This behavior is similar to that of a strict cpu erratum, where a later CPU is not allowed to boot if the system doesn't posses it. Use this for software prefetching capability. Signed-off-by: Suzuki K Poulose --- arch/arm64/include/asm/cpufeature.h | 7 +++++++ arch/arm64/kernel/cpufeature.c | 2 +- 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index a621d2184227..4c3d6987acfc 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -118,6 +118,13 @@ extern struct arm64_ftr_reg arm64_ftr_reg_ctrel0; */ #define ARM64_CPUCAP_BOOT_SYSTEM_FEATURE \ (ARM64_CPUCAP_SCOPE_SYSTEM | ARM64_CPUCAP_LATE_CPU_SAFE_TO_HAVE) +/* + * CPU feature detected at boot time based on feature of one or more CPUs. + * It is not safe for a late CPU to have this feature, when the system doesn't + * have it. But it is safe to miss the feature if the system has it. + */ +#define ARM64_CPUCAP_STRICT_CPU_LOCAL_FEATURE \ + (ARM64_CPUCAP_SCOPE_LOCAL_CPU | ARM64_CPUCAP_LATE_CPU_SAFE_TO_MISS) struct arm64_cpu_capabilities { const char *desc; diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 7ae5cf9092d0..111f6c4b4cd7 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -951,7 +951,7 @@ static const struct arm64_cpu_capabilities arm64_features[] = { { .desc = "Software prefetching using PRFM", .capability = ARM64_HAS_NO_HW_PREFETCH, - .type = ARM64_CPUCAP_BOOT_SYSTEM_FEATURE, + .type = ARM64_CPUCAP_STRICT_CPU_LOCAL_FEATURE, .matches = has_no_hw_prefetch, }, #ifdef CONFIG_ARM64_UAO -- 2.13.6