From patchwork Mon May 15 10:00:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zeng Heng X-Patchwork-Id: 682484 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33C4CC77B75 for ; Mon, 15 May 2023 09:29:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240331AbjEOJ3D (ORCPT ); Mon, 15 May 2023 05:29:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238461AbjEOJ23 (ORCPT ); Mon, 15 May 2023 05:28:29 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F0B61995; Mon, 15 May 2023 02:27:49 -0700 (PDT) Received: from kwepemi500024.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4QKYnL4s75zTkmh; Mon, 15 May 2023 17:23:02 +0800 (CST) Received: from huawei.com (10.175.124.27) by kwepemi500024.china.huawei.com (7.221.188.100) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Mon, 15 May 2023 17:27:47 +0800 From: Zeng Heng To: , , CC: , , , , , , Subject: [PATCH 2/2] acpi: CPPC: read delivered_reg and reference_reg in critical section Date: Mon, 15 May 2023 18:00:04 +0800 Message-ID: <20230515100005.3540793-2-zengheng4@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230515100005.3540793-1-zengheng4@huawei.com> References: <20230515100005.3540793-1-zengheng4@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemi500024.china.huawei.com (7.221.188.100) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Reading the content of delivered_reg and reference_reg should be in the same critical section, in case any interrupt comes, which could lead to inaccurate frequency calculation. Signed-off-by: Zeng Heng --- drivers/acpi/cppc_acpi.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index c51d3ccb4cca..176f3e2e67f8 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -1315,6 +1315,7 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs) struct cppc_pcc_data *pcc_ss_data = NULL; u64 delivered, reference, ref_perf, ctr_wrap_time; int ret = 0, regs_in_pcc = 0; + unsigned long flags; if (!cpc_desc) { pr_debug("No CPC descriptor for CPU:%d\n", cpunum); @@ -1350,8 +1351,11 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs) } } + local_irq_save(flags); cpc_read(cpunum, delivered_reg, &delivered); cpc_read(cpunum, reference_reg, &reference); + local_irq_restore(flags); + cpc_read(cpunum, ref_perf_reg, &ref_perf); /*