From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162812AbeE1KqL (ORCPT ); Mon, 28 May 2018 06:46:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:36402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937798AbeE1KqE (ORCPT ); Mon, 28 May 2018 06:46:04 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Rutland , Robin Murphy , Will Deacon , Sasha Levin Subject: [PATCH 4.14 104/496] arm64: perf: correct PMUVer probing Date: Mon, 28 May 2018 11:58:09 +0200 Message-Id: <20180528100324.224472328@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180528100319.498712256@linuxfoundation.org> References: <20180528100319.498712256@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Rutland [ Upstream commit 0331365edb1d6ccd6ae68b1038111da85d4c68d1 ] The ID_AA64DFR0_EL1.PMUVer field doesn't follow the usual ID registers scheme. While value 0xf indicates a non-architected PMU is implemented, values 0x1 to 0xe indicate an increasingly featureful architected PMU, as if the field were unsigned. For more details, see ARM DDI 0487C.a, D10.1.4, "Alternative ID scheme used for the Performance Monitors Extension version". Currently, we treat the field as signed, and erroneously bail out for values 0x8 to 0xe. Let's correct that. Signed-off-by: Mark Rutland Reviewed-by: Robin Murphy Cc: Will Deacon Signed-off-by: Will Deacon Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/perf_event.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -914,9 +914,9 @@ static void __armv8pmu_probe_pmu(void *i int pmuver; dfr0 = read_sysreg(id_aa64dfr0_el1); - pmuver = cpuid_feature_extract_signed_field(dfr0, + pmuver = cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_PMUVER_SHIFT); - if (pmuver < 1) + if (pmuver == 0xf || pmuver == 0) return; probe->present = true;