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=-8.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 397A8C43381 for ; Thu, 21 Mar 2019 02:08:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8953218A2 for ; Thu, 21 Mar 2019 02:07:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="fspeLboB"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="IuAAXE1/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727739AbfCUCH5 (ORCPT ); Wed, 20 Mar 2019 22:07:57 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:57304 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726487AbfCUCH5 (ORCPT ); Wed, 20 Mar 2019 22:07:57 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 94336609CD; Thu, 21 Mar 2019 02:07:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1553134076; bh=CIyV9GkM+pGMGDsQ75GXvsFmmEVC/LMlMKD9BslShRY=; h=From:To:Cc:Subject:Date:From; b=fspeLboBfhYXVfpof/NVs/Z/gW3/7fEpvvFIDLkio84J/r/V4MYSC2v7xmFq4TZWs dkKqRg/QXU76Gs7tSOla6/gWmGD/O9lRGuIVinAKhyzbciAA9lH8P6eMhUrH8Cs0zy BmGzkHdHQz38TDK+3VsBCKu9Mz4L9QjUlAYrnDWc= Received: from psodagud-linux1.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: psodagud@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id CA84F60159; Thu, 21 Mar 2019 02:07:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1553134074; bh=CIyV9GkM+pGMGDsQ75GXvsFmmEVC/LMlMKD9BslShRY=; h=From:To:Cc:Subject:Date:From; b=IuAAXE1/o4iFStJWbYp0CfjonnFauUisAl4SWw91rctYcfGSmP39QtDThShodFOAs kOqTyYeSD6PqRBXejLsgidJvh4jymIuzk7uebP0euyMzIBXVXrCzn4bQWkWbYGKWwf S39fIQAaF3V5E0bIeWzS9u8C6s+C/bfEZiKfWw9U= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org CA84F60159 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=psodagud@codeaurora.org From: Prasad Sodagudi To: will.deacon@arm.com, mingo@redhat.com, catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org, peterz@infradead.org Cc: linux-kernel@vger.kernel.org, psodagud@codeaurora.org Subject: [PATCH] perf: Change PMCR write to read-modify-write Date: Wed, 20 Mar 2019 19:07:46 -0700 Message-Id: <1553134066-20272-1-git-send-email-psodagud@codeaurora.org> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Preserves the bitfields of PMCR_EL0(AArch64) during PMU reset. Reset routine should write a 1 to PMCR.C and PMCR.P fields only to reset the counters. Other fields should not be changed as they could be set before PMU initialization and their value must be preserved even after reset. Signed-off-by: Prasad Sodagudi --- arch/arm64/kernel/perf_event.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c index 4addb38..0c1afdd 100644 --- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -868,8 +868,8 @@ static void armv8pmu_reset(void *info) * Initialize & Reset PMNC. Request overflow interrupt for * 64 bit cycle counter but cheat in armv8pmu_write_counter(). */ - armv8pmu_pmcr_write(ARMV8_PMU_PMCR_P | ARMV8_PMU_PMCR_C | - ARMV8_PMU_PMCR_LC); + armv8pmu_pmcr_write(armv8pmu_pmcr_read() | ARMV8_PMU_PMCR_P | + ARMV8_PMU_PMCR_C | ARMV8_PMU_PMCR_LC); } static int __armv8_pmuv3_map_event(struct perf_event *event, -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na Linux Foundation Collaborative Project