From patchwork Tue Apr 5 07:12:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 558311 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 09185C433F5 for ; Tue, 5 Apr 2022 07:39:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231823AbiDEHlw (ORCPT ); Tue, 5 Apr 2022 03:41:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231826AbiDEHlo (ORCPT ); Tue, 5 Apr 2022 03:41:44 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B5D34B40B; Tue, 5 Apr 2022 00:39:45 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B7DED61693; Tue, 5 Apr 2022 07:39:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8B0FC340EE; Tue, 5 Apr 2022 07:39:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649144384; bh=z03uRE2H7zmi68R1Q0lvr3LCmd3ruYnHuWykD/0EvBo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vw1YN8sSUMrgUEvyU7MmOgaP3FJR/SQdAtmFfqmxA4AY2ZO1OC9Ydikq/TbnxLOV9 cwDFIgQS4fBM6WyP8/QaxVyFIqGpyImcC+pBavHF7eAsv2JSGUyezAwogzzjJHVwnB sLEw6tK8U1wGtyz8OPBETO03opmzi4wO+BRY3474= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, James Clark , Mike Leach , Mathieu Poirier , Suzuki K Poulose Subject: [PATCH 5.17 0026/1126] coresight: Fix TRCCONFIGR.QE sysfs interface Date: Tue, 5 Apr 2022 09:12:53 +0200 Message-Id: <20220405070408.318377465@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070407.513532867@linuxfoundation.org> References: <20220405070407.513532867@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: James Clark commit ea75a342aed5ed72c87f38fbe0df2f5df7eae374 upstream. It's impossible to program a valid value for TRCCONFIGR.QE when TRCIDR0.QSUPP==0b10. In that case the following is true: Q element support is implemented, and only supports Q elements without instruction counts. TRCCONFIGR.QE can only take the values 0b00 or 0b11. Currently the low bit of QSUPP is checked to see if the low bit of QE can be written to, but as you can see when QSUPP==0b10 the low bit is cleared making it impossible to ever write the only valid value of 0b11 to QE. 0b10 would be written instead, which is a reserved QE value even for all values of QSUPP. The fix is to allow writing the low bit of QE for any non zero value of QSUPP. This change also ensures that the low bit is always set, even when the user attempts to only set the high bit. Signed-off-by: James Clark Reviewed-by: Mike Leach Fixes: d8c66962084f ("coresight-etm4x: Controls pertaining to the reset, mode, pe and events") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220120113047.2839622-2-james.clark@arm.com Signed-off-by: Mathieu Poirier Signed-off-by: Suzuki K Poulose Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c @@ -367,8 +367,12 @@ static ssize_t mode_store(struct device mode = ETM_MODE_QELEM(config->mode); /* start by clearing QE bits */ config->cfg &= ~(BIT(13) | BIT(14)); - /* if supported, Q elements with instruction counts are enabled */ - if ((mode & BIT(0)) && (drvdata->q_support & BIT(0))) + /* + * if supported, Q elements with instruction counts are enabled. + * Always set the low bit for any requested mode. Valid combos are + * 0b00, 0b01 and 0b11. + */ + if (mode && drvdata->q_support) config->cfg |= BIT(13); /* * if supported, Q elements with and without instruction