From patchwork Wed Aug 9 08:18:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yicong Yang X-Patchwork-Id: 1819178 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by legolas.ozlabs.org (Postfix) with ESMTP id 4RLNKn3T65z1yfl for ; Wed, 9 Aug 2023 18:20:45 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231683AbjHIIUn (ORCPT ); Wed, 9 Aug 2023 04:20:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229783AbjHIIUl (ORCPT ); Wed, 9 Aug 2023 04:20:41 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1EC3610FE; Wed, 9 Aug 2023 01:20:41 -0700 (PDT) Received: from canpemm500009.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4RLNHS2JX9zVl7M; Wed, 9 Aug 2023 16:18:44 +0800 (CST) Received: from localhost.localdomain (10.50.163.32) by canpemm500009.china.huawei.com (7.192.105.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Wed, 9 Aug 2023 16:20:38 +0800 From: Yicong Yang To: , , , CC: , , , , , , Subject: [PATCH 1/5] hwtracing: hisi_ptt: Disable interrupt after trace end Date: Wed, 9 Aug 2023 16:18:21 +0800 Message-ID: <20230809081825.11518-2-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20230809081825.11518-1-yangyicong@huawei.com> References: <20230809081825.11518-1-yangyicong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.50.163.32] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500009.china.huawei.com (7.192.105.203) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Yicong Yang On trace end we disable the hardware but leave the interrupt unmasked. Mask the interrupt to make the process reverse to the start. No actual issue since hardware should send no interrupt after disabled. Signed-off-by: Yicong Yang Acked-by: Jonathan Cameron --- drivers/hwtracing/ptt/hisi_ptt.c | 4 ++++ drivers/hwtracing/ptt/hisi_ptt.h | 1 + 2 files changed, 5 insertions(+) diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c index ba081b6d2435..5f0a8e653ae8 100644 --- a/drivers/hwtracing/ptt/hisi_ptt.c +++ b/drivers/hwtracing/ptt/hisi_ptt.c @@ -183,6 +183,10 @@ static void hisi_ptt_wait_dma_reset_done(struct hisi_ptt *hisi_ptt) static void hisi_ptt_trace_end(struct hisi_ptt *hisi_ptt) { writel(0, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL); + + /* Mask the interrupt on the end */ + writel(HISI_PTT_TRACE_INT_MASK_ALL, hisi_ptt->iobase + HISI_PTT_TRACE_INT_MASK); + hisi_ptt->trace_ctrl.started = false; } diff --git a/drivers/hwtracing/ptt/hisi_ptt.h b/drivers/hwtracing/ptt/hisi_ptt.h index e17f045d7e72..46030aa88081 100644 --- a/drivers/hwtracing/ptt/hisi_ptt.h +++ b/drivers/hwtracing/ptt/hisi_ptt.h @@ -47,6 +47,7 @@ #define HISI_PTT_TRACE_INT_STAT 0x0890 #define HISI_PTT_TRACE_INT_STAT_MASK GENMASK(3, 0) #define HISI_PTT_TRACE_INT_MASK 0x0894 +#define HISI_PTT_TRACE_INT_MASK_ALL GENMASK(3, 0) #define HISI_PTT_TUNING_INT_STAT 0x0898 #define HISI_PTT_TUNING_INT_STAT_MASK BIT(0) #define HISI_PTT_TRACE_WR_STS 0x08a0 From patchwork Wed Aug 9 08:18:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yicong Yang X-Patchwork-Id: 1819180 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by legolas.ozlabs.org (Postfix) with ESMTP id 4RLNKp0pl2z1yfD for ; Wed, 9 Aug 2023 18:20:46 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231847AbjHIIUo (ORCPT ); Wed, 9 Aug 2023 04:20:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230081AbjHIIUm (ORCPT ); Wed, 9 Aug 2023 04:20:42 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25EE41703; Wed, 9 Aug 2023 01:20:42 -0700 (PDT) Received: from canpemm500009.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4RLNFf5Jtmz9tjF; Wed, 9 Aug 2023 16:17:10 +0800 (CST) Received: from localhost.localdomain (10.50.163.32) by canpemm500009.china.huawei.com (7.192.105.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Wed, 9 Aug 2023 16:20:39 +0800 From: Yicong Yang To: , , , CC: , , , , , , Subject: [PATCH 2/5] hwtracing: hisi_ptt: Handle the interrupt in hardirq context Date: Wed, 9 Aug 2023 16:18:22 +0800 Message-ID: <20230809081825.11518-3-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20230809081825.11518-1-yangyicong@huawei.com> References: <20230809081825.11518-1-yangyicong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.50.163.32] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500009.china.huawei.com (7.192.105.203) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Yicong Yang Handle the trace interrupt in the hardirq context, make sure the irq core won't threaded it by declaring IRQF_NO_THREAD and userspace won't balance it by declaring IRQF_NOBALANCING. Otherwise we may violate the synchronization requirements of the perf core, referenced to the change of arm-ccn PMU commit 0811ef7e2f54 ("bus: arm-ccn: fix PMU interrupt flags"). In the interrupt handler we mainly doing 2 things: - Copy the data from the local DMA buffer to the AUX buffer - Commit the data in the AUX buffer Signed-off-by: Yicong Yang Acked-by: Jonathan Cameron --- drivers/hwtracing/ptt/hisi_ptt.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c index 5f0a8e653ae8..89638ed96cf9 100644 --- a/drivers/hwtracing/ptt/hisi_ptt.c +++ b/drivers/hwtracing/ptt/hisi_ptt.c @@ -346,9 +346,9 @@ static int hisi_ptt_register_irq(struct hisi_ptt *hisi_ptt) return ret; hisi_ptt->trace_irq = pci_irq_vector(pdev, HISI_PTT_TRACE_DMA_IRQ); - ret = devm_request_threaded_irq(&pdev->dev, hisi_ptt->trace_irq, - NULL, hisi_ptt_isr, 0, - DRV_NAME, hisi_ptt); + ret = devm_request_irq(&pdev->dev, hisi_ptt->trace_irq, hisi_ptt_isr, + IRQF_NOBALANCING | IRQF_NO_THREAD, DRV_NAME, + hisi_ptt); if (ret) { pci_err(pdev, "failed to request irq %d, ret = %d\n", hisi_ptt->trace_irq, ret); From patchwork Wed Aug 9 08:18:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yicong Yang X-Patchwork-Id: 1819179 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by legolas.ozlabs.org (Postfix) with ESMTP id 4RLNKn5rDjz20G8 for ; Wed, 9 Aug 2023 18:20:45 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231715AbjHIIUn (ORCPT ); Wed, 9 Aug 2023 04:20:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230006AbjHIIUm (ORCPT ); Wed, 9 Aug 2023 04:20:42 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 947BB10FF; Wed, 9 Aug 2023 01:20:41 -0700 (PDT) Received: from canpemm500009.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4RLNJH6G7NzmXZF; Wed, 9 Aug 2023 16:19:27 +0800 (CST) Received: from localhost.localdomain (10.50.163.32) by canpemm500009.china.huawei.com (7.192.105.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Wed, 9 Aug 2023 16:20:39 +0800 From: Yicong Yang To: , , , CC: , , , , , , Subject: [PATCH 3/5] hwtracing: hisi_ptt: Optimize the trace data committing Date: Wed, 9 Aug 2023 16:18:23 +0800 Message-ID: <20230809081825.11518-4-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20230809081825.11518-1-yangyicong@huawei.com> References: <20230809081825.11518-1-yangyicong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.50.163.32] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500009.china.huawei.com (7.192.105.203) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Yicong Yang Currently during the PTT trace, we'll only commit the data to the perf core when its full, which means after 4 interrupts and totally 16MiB data while the AUX buffer is 16MiB length. Then the userspace gets notified and handle the data. The driver cannot apply a new AUX buffer immediately until the committed data are handled and there's enough room in the buffer again. This patch tries to optimize this by commit the data in every interrupts in a 4MiB granularity. Then the userspace can have enough time to consume the data and there's always enough room in the AUX buffer. Signed-off-by: Yicong Yang Acked-by: Jonathan Cameron --- drivers/hwtracing/ptt/hisi_ptt.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c index 89638ed96cf9..3aba7bb6e548 100644 --- a/drivers/hwtracing/ptt/hisi_ptt.c +++ b/drivers/hwtracing/ptt/hisi_ptt.c @@ -274,15 +274,14 @@ static int hisi_ptt_update_aux(struct hisi_ptt *hisi_ptt, int index, bool stop) buf->pos += size; /* - * Just commit the traced data if we're going to stop. Otherwise if the - * resident AUX buffer cannot contain the data of next trace buffer, - * apply a new one. + * Always commit the data to the AUX buffer in time to make sure + * userspace got enough time to consume the data. + * + * If we're not going to stop, apply a new one and check whether + * there's enough room for the next trace. */ - if (stop) { - perf_aux_output_end(handle, buf->pos); - } else if (buf->length - buf->pos < HISI_PTT_TRACE_BUF_SIZE) { - perf_aux_output_end(handle, buf->pos); - + perf_aux_output_end(handle, size); + if (!stop) { buf = perf_aux_output_begin(handle, event); if (!buf) return -EINVAL; From patchwork Wed Aug 9 08:18:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yicong Yang X-Patchwork-Id: 1819181 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by legolas.ozlabs.org (Postfix) with ESMTP id 4RLNKp2v0qz1yfl for ; Wed, 9 Aug 2023 18:20:46 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229592AbjHIIUo (ORCPT ); Wed, 9 Aug 2023 04:20:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231718AbjHIIUn (ORCPT ); Wed, 9 Aug 2023 04:20:43 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 682F11705; Wed, 9 Aug 2023 01:20:42 -0700 (PDT) Received: from canpemm500009.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4RLNJJ0XFBzmXZJ; Wed, 9 Aug 2023 16:19:28 +0800 (CST) Received: from localhost.localdomain (10.50.163.32) by canpemm500009.china.huawei.com (7.192.105.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Wed, 9 Aug 2023 16:20:39 +0800 From: Yicong Yang To: , , , CC: , , , , , , Subject: [PATCH 4/5] hwtracing: hisi_ptt: Don't try to attach a task Date: Wed, 9 Aug 2023 16:18:24 +0800 Message-ID: <20230809081825.11518-5-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20230809081825.11518-1-yangyicong@huawei.com> References: <20230809081825.11518-1-yangyicong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.50.163.32] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500009.china.huawei.com (7.192.105.203) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Yicong Yang PTT is an uncore PMU and shouldn't be attached to any task. Block the usage in pmu::event_init(). Signed-off-by: Yicong Yang Acked-by: Jonathan Cameron --- drivers/hwtracing/ptt/hisi_ptt.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c index 3aba7bb6e548..916686c6a9c8 100644 --- a/drivers/hwtracing/ptt/hisi_ptt.c +++ b/drivers/hwtracing/ptt/hisi_ptt.c @@ -1003,6 +1003,9 @@ static int hisi_ptt_pmu_event_init(struct perf_event *event) return -EOPNOTSUPP; } + if (event->attach_state & PERF_ATTACH_TASK) + return -EOPNOTSUPP; + if (event->attr.type != hisi_ptt->hisi_ptt_pmu.type) return -ENOENT; From patchwork Wed Aug 9 08:18:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yicong Yang X-Patchwork-Id: 1819182 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by legolas.ozlabs.org (Postfix) with ESMTP id 4RLNKp5G8mz20G8 for ; Wed, 9 Aug 2023 18:20:46 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231897AbjHIIUo (ORCPT ); Wed, 9 Aug 2023 04:20:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36274 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229702AbjHIIUo (ORCPT ); Wed, 9 Aug 2023 04:20:44 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4212FE7D; Wed, 9 Aug 2023 01:20:43 -0700 (PDT) Received: from canpemm500009.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4RLNJJ29p6zmXZQ; Wed, 9 Aug 2023 16:19:28 +0800 (CST) Received: from localhost.localdomain (10.50.163.32) by canpemm500009.china.huawei.com (7.192.105.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Wed, 9 Aug 2023 16:20:39 +0800 From: Yicong Yang To: , , , CC: , , , , , , Subject: [PATCH 5/5] hwtracing: hisi_ptt: Add dummy callback pmu::read() Date: Wed, 9 Aug 2023 16:18:25 +0800 Message-ID: <20230809081825.11518-6-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20230809081825.11518-1-yangyicong@huawei.com> References: <20230809081825.11518-1-yangyicong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.50.163.32] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500009.china.huawei.com (7.192.105.203) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Junhao He When start trace with perf option "-C $cpu" and immediately stop it with SIGTERM or others, the perf core will invoke pmu::read() while the driver doesn't implement it. Add a dummy pmu::read() to avoid any issues. Signed-off-by: Junhao He Signed-off-by: Yicong Yang Acked-by: Jonathan Cameron --- drivers/hwtracing/ptt/hisi_ptt.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c index 916686c6a9c8..7392e039b8c1 100644 --- a/drivers/hwtracing/ptt/hisi_ptt.c +++ b/drivers/hwtracing/ptt/hisi_ptt.c @@ -1184,6 +1184,10 @@ static void hisi_ptt_pmu_del(struct perf_event *event, int flags) hisi_ptt_pmu_stop(event, PERF_EF_UPDATE); } +static void hisi_ptt_pmu_read(struct perf_event *event) +{ +} + static void hisi_ptt_remove_cpuhp_instance(void *hotplug_node) { cpuhp_state_remove_instance_nocalls(hisi_ptt_pmu_online, hotplug_node); @@ -1227,6 +1231,7 @@ static int hisi_ptt_register_pmu(struct hisi_ptt *hisi_ptt) .stop = hisi_ptt_pmu_stop, .add = hisi_ptt_pmu_add, .del = hisi_ptt_pmu_del, + .read = hisi_ptt_pmu_read, }; reg = readl(hisi_ptt->iobase + HISI_PTT_LOCATION);