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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 E3EB8C46475 for ; Mon, 5 Nov 2018 11:55:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B7C8020854 for ; Mon, 5 Nov 2018 11:55:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B7C8020854 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729411AbeKEVPO (ORCPT ); Mon, 5 Nov 2018 16:15:14 -0500 Received: from foss.arm.com ([217.140.101.70]:41800 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729165AbeKEVPN (ORCPT ); Mon, 5 Nov 2018 16:15:13 -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 3923B1682; Mon, 5 Nov 2018 03:55:51 -0800 (PST) Received: from en101.cambridge.arm.com (en101.cambridge.arm.com [10.1.196.93]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id D85EC3F5BD; Mon, 5 Nov 2018 03:55:49 -0800 (PST) From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, vladimir.murzin@arm.com, will.deacon@arm.com, catalin.marinas@arm.com, mark.rutland@arm.com, Suzuki K Poulose Subject: [PATCH 5/7] arm64: capabilities: Optimize this_cpu_has_cap Date: Mon, 5 Nov 2018 11:55:15 +0000 Message-Id: <1541418917-14219-6-git-send-email-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1541418917-14219-1-git-send-email-suzuki.poulose@arm.com> References: <1541418917-14219-1-git-send-email-suzuki.poulose@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make use of the sorted capability list to access the capability entry in this_cpu_has_cap() to avoid iterating over the two tables. Cc: Vladimir Murzin Signed-off-by: Suzuki K Poulose --- arch/arm64/kernel/cpufeature.c | 31 +++++++++---------------------- 1 file changed, 9 insertions(+), 22 deletions(-) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 7e9ebbe..96e687e 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1508,25 +1508,6 @@ static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps) cap_set_elf_hwcap(hwcaps); } -/* - * Check if the current CPU has a given feature capability. - * Should be called from non-preemptible context. - */ -static bool __this_cpu_has_cap(const struct arm64_cpu_capabilities *cap_array, - unsigned int cap) -{ - const struct arm64_cpu_capabilities *caps; - - if (WARN_ON(preemptible())) - return false; - - for (caps = cap_array; caps->matches; caps++) - if (caps->capability == cap) - return caps->matches(caps, SCOPE_LOCAL_CPU); - - return false; -} - static void __update_cpu_capabilities(const struct arm64_cpu_capabilities *caps, u16 scope_mask, const char *info) { @@ -1776,10 +1757,16 @@ static void __init mark_const_caps_ready(void) static_branch_enable(&arm64_const_caps_ready); } -bool this_cpu_has_cap(unsigned int cap) +bool this_cpu_has_cap(unsigned int n) { - return (__this_cpu_has_cap(arm64_features, cap) || - __this_cpu_has_cap(arm64_errata, cap)); + if (!WARN_ON(preemptible()) && n < ARM64_NCAPS) { + const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n]; + + if (cap) + return cap->matches(cap, SCOPE_LOCAL_CPU); + } + + return false; } static void __init setup_system_capabilities(void) -- 2.7.4