From patchwork Wed Dec 8 16:09:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Clark X-Patchwork-Id: 12695384 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7C473C433F5 for ; Wed, 8 Dec 2021 16:10:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=kHGR0oFnmYUjJZsrCRe0/37ED5w0a7CNdukHJmydRlU=; b=VugA2oWWp5NXeS BEqnvpj/NTruTWtiPNeTkN3g29Mn7Ofr8HP9mc4o+jqHf5fVjrpooE4kpAbTvlxynKaKvhmxewFWm eMBqQAp3eLVUAhLjo+SKh8OOUnesUcxK+NYDuVEjo6dv7J1lGBqq28toT0DCbxoQP+QcUyQznFsj8 nd9hbWUQS0bzUO8gt0hQ7apVjH8zybeNZtz5VCaO4EqR/0mMA3EMhlr35/Vx1VmImv7VUGVWmR+3l Opk4IeBnpL9rsl8h93fdaVB0rYvLdGOq0LMmazq6CAt844CouEtxctdTsu6dUq/WsVCUi9NnvczCz zeQntZHcotARoScz1QZg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1muzVh-00DU2A-Pn; Wed, 08 Dec 2021 16:09:37 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1muzVR-00DTxu-RY for linux-arm-kernel@lists.infradead.org; Wed, 08 Dec 2021 16:09:23 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B7A1D11FB; Wed, 8 Dec 2021 08:09:20 -0800 (PST) Received: from e121896.arm.com (unknown [10.57.34.62]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 7ADA83F5A1; Wed, 8 Dec 2021 08:09:18 -0800 (PST) From: James Clark To: mathieu.poirier@linaro.org, coresight@lists.linaro.org Cc: suzuki.poulose@arm.com, James Clark , Mike Leach , Leo Yan , John Garry , Will Deacon , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: [PATCH 2/3] coresight: Fail to open with return stacks if they are unavailable Date: Wed, 8 Dec 2021 16:09:06 +0000 Message-Id: <20211208160907.749482-2-james.clark@arm.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20211208160907.749482-1-james.clark@arm.com> References: <20211208160907.749482-1-james.clark@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211208_080921_968169_64F675A7 X-CRM114-Status: GOOD ( 13.42 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Maintain consistency with the other options by failing to open when they aren't supported. For example ETM_OPT_TS, ETM_OPT_CTXTID2 and the newly added ETM_OPT_BRANCH_BROADCAST all return with -EINVAL if they are requested but not supported by hardware. The consequence of not doing this is that the user may not be aware that they are not enabling the feature as it is silently disabled. Signed-off-by: James Clark --- drivers/hwtracing/coresight/coresight-etm4x-core.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index d2bafb50c66a..0a9bb943a5e5 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -674,10 +674,15 @@ static int etm4_parse_event_config(struct coresight_device *csdev, } /* return stack - enable if selected and supported */ - if ((attr->config & BIT(ETM_OPT_RETSTK)) && drvdata->retstack) - /* bit[12], Return stack enable bit */ - config->cfg |= BIT(12); - + if (attr->config & BIT(ETM_OPT_RETSTK)) { + if (!drvdata->retstack) { + ret = -EINVAL; + goto out; + } else { + /* bit[12], Return stack enable bit */ + config->cfg |= BIT(12); + } + } /* * Set any selected configuration and preset. *