From patchwork Thu Jul 11 16:01:08 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Murray X-Patchwork-Id: 11040381 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1C3FC6C5 for ; Thu, 11 Jul 2019 16:01:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 099E828AF3 for ; Thu, 11 Jul 2019 16:01:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F08A228AF9; Thu, 11 Jul 2019 16:01:32 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 65C5E28AF3 for ; Thu, 11 Jul 2019 16:01:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=ER3xUxUpamqlxYls40kzU1fjxOIXJrhShLsGBgFKEGY=; b=QgyH4oA+M6ByPz l7pP3+4+bcoRBPNcbgMtGPNA80E5ZVlTu+lCz2eEAlDRCPXGhi5lxR3ZuxKBar2noBiI7iz2SPcHw VvfD/CJ0q1JlHri53WBp4XzeNfOT/vTbyK9dU/joE5lqQSeaMYl9GwYUV9kLF5lLlEYFZMStUmvJD JH6YoJ8KGTKhb08aM004YZVER9iJVJhdzNyc6NLNbgeLvAqxI4HH+pOHRGdBszbeb7Cq9TIKnjcP5 KHrQ5bfh6JcjGjrlpyPqa/ZcaZz49NtQDA3sPtR5G3Ia50WpdxP5UffFXiessZUW3/LXTws4UYSAe KUI0LEmfAkOze7JbGfTw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hlbVj-0003yH-Ou; Thu, 11 Jul 2019 16:01:31 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hlbVf-0003xD-Nm for linux-arm-kernel@lists.infradead.org; Thu, 11 Jul 2019 16:01:29 +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 B29412B; Thu, 11 Jul 2019 09:01:24 -0700 (PDT) Received: from e119886-lin.cambridge.arm.com (unknown [10.37.6.20]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2B8613F71F; Thu, 11 Jul 2019 09:01:23 -0700 (PDT) From: Andrew Murray To: Mathieu Poirier , Suzuki K Poulose , Alexander Shishkin Subject: [PATCH v3 0/6] coresight: etm4x: save/restore ETMv4 context across CPU low power states Date: Thu, 11 Jul 2019 17:01:08 +0100 Message-Id: <20190711160114.634-1-andrew.murray@arm.com> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190711_090127_823616_D51725A2 X-CRM114-Status: GOOD ( 15.05 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: coresight@lists.linaro.org, Sudeep Holla , Leo Yan , linux-arm-kernel@lists.infradead.org, Mike Leach Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Some hardware will ignore bit TRCPDCR.PU which is used to signal to hardware that power should not be removed from the trace unit. Let's mitigate against this by conditionally saving and restoring the trace unit state when the CPU enters low power states. This patchset introduces a firmware property named 'arm,coresight-needs-save-restore' - when this is present the hardware state will be conditionally saved and restored. A module parameter 'pm_save_enable' is also introduced which can be configured to override the firmware property. The hardware state is only ever saved and restored when the claim tags indicate that coresight is in use. Changes since v2: - Move the PM notifier block from drvdata to file static - Add section names to document references - Add additional information to commit messages - Remove trcdvcvr and trcdvcmr from saved state and add a comment to describe why - Ensure TRCPDCR_PU is set after restore and add a comment to explain why we bother toggling TRCPDCR_PU on save/restore - Reword the pm_save_enable options and add comments - Miscellaneous style changes - Move device tree binding documentation to its own patch Changes since v1: - Rebased onto coresight/next - Correcly pass bit number rather than BIT macro to coresight_timeout - Abort saving state if a timeout occurs - Fix completely broken pm_notify handling and unregister handler on error - Use state_needs_restore to ensure state is restored only once - Add module parameter description to existing boot_enable parameter and use module_param instead of module_param_named - Add firmware bindings for coresight-needs-save-restore - Rename 'disable_pm_save' to 'pm_save_enable' which allows for disabled, enabled or firmware - Update comment on etm4_os_lock, it incorrectly indicated that the code unlocks the trace registers - Add comments to explain use of OS lock during save/restore - Fix incorrect error description whilst waiting for PM stable - Add WARN_ON_ONCE when cpu isn't as expected during save/restore - Various updates to commit messages Andrew Murray (6): coresight: etm4x: remove superfluous setting of os_unlock coresight: etm4x: use explicit barriers on enable/disable coresight: etm4x: use module_param instead of module_param_named coresight: etm4x: improve clarity of etm4_os_unlock comment coresight: etm4x: save/restore state across CPU low power states dt-bindings: arm: coresight: Add support for coresight-needs-save-restore .../devicetree/bindings/arm/coresight.txt | 3 + drivers/hwtracing/coresight/coresight-etm4x.c | 348 +++++++++++++++++- drivers/hwtracing/coresight/coresight-etm4x.h | 62 ++++ drivers/hwtracing/coresight/coresight.c | 2 +- include/linux/coresight.h | 8 + 5 files changed, 415 insertions(+), 8 deletions(-)