From patchwork Mon Sep 25 19:20:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Jiang X-Patchwork-Id: 13398294 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 472DBCD54BF for ; Mon, 25 Sep 2023 19:21:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229970AbjIYTVG (ORCPT ); Mon, 25 Sep 2023 15:21:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229481AbjIYTVF (ORCPT ); Mon, 25 Sep 2023 15:21:05 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A5FA0BE for ; Mon, 25 Sep 2023 12:20:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1695669659; x=1727205659; h=subject:from:to:cc:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=OpTLJSCzmnb0yiCSrGuA6JifdeQHVr2HSi/CGtXmI+0=; b=AB9asTMVL0hZkcQc3l+m7UPeEsmFuoxXu4/ksOrKH+NOj8acwKMne1sz ew0ZjlcxzegBXpkmSfbqK+VoUXgaK4BJNZejtOwi421zvxNqdUGaJ/w1/ jeeWtXxgBHPj6vS0K+okfMg/OazYjs44OPI3j6vkarn8lNl7GFcjJLPeW yeGBONw2t2b+Z7dNphM5K3w6v2UEEVidKb8AHh1mA3EGHUAoGD0ghUmFw DhfOCvSGMbpz0bi9gwHRg7aFT6tBFB5BomUtON8It6BCW0VWaIEOyrd2r r3M/K9zqeheGre37B0FXzN4a9Tz/lbFUJzo3cIG5KdBcM3iABIcfr54ve g==; X-IronPort-AV: E=McAfee;i="6600,9927,10843"; a="380223102" X-IronPort-AV: E=Sophos;i="6.03,175,1694761200"; d="scan'208";a="380223102" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2023 12:20:40 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10843"; a="995504800" X-IronPort-AV: E=Sophos;i="6.03,175,1694761200"; d="scan'208";a="995504800" Received: from djiang5-mobl3.amr.corp.intel.com (HELO [192.168.1.177]) ([10.209.161.86]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2023 12:20:40 -0700 Subject: [PATCH 2/2] cxl: Add check for regions before disabling memdev From: Dave Jiang To: vishal.l.verma@intel.com Cc: linux-cxl@vger.kernel.org, nvdimm@lists.linux.dev, lizhijian@fujitsu.com, yangx.jy@fujitsu.com, caoqq@fujitsu.com Date: Mon, 25 Sep 2023 12:20:40 -0700 Message-ID: <169566964012.3704458.3768477727985056846.stgit@djiang5-mobl3> In-Reply-To: <169566963425.3704458.5249885814603187091.stgit@djiang5-mobl3> References: <169566963425.3704458.5249885814603187091.stgit@djiang5-mobl3> User-Agent: StGit/1.5 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org Add a check for memdev disable to see if there are active regions present before disabling the device. This is necessary now regions are present to fulfill the TODO that was left there. The best way to determine if a region is active is to see if there are decoders enabled for the mem device. This is also best effort as the state is only a snapshot the kernel provides and is not atomic WRT the memdev disable operation. The expectation is the admin issuing the command has full control of the mem device and there are no other agents also attempt to control the device. Signed-off-by: Dave Jiang --- cxl/memdev.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) diff --git a/cxl/memdev.c b/cxl/memdev.c index f6a2d3f1fdca..644369321649 100644 --- a/cxl/memdev.c +++ b/cxl/memdev.c @@ -373,11 +373,36 @@ static int action_free_dpa(struct cxl_memdev *memdev, static int action_disable(struct cxl_memdev *memdev, struct action_context *actx) { + struct cxl_decoder *decoder; + struct cxl_endpoint *ep; + bool committed = false; + struct cxl_port *port; + if (!cxl_memdev_is_enabled(memdev)) return 0; - if (!param.force) { - /* TODO: actually detect rather than assume active */ + ep = cxl_memdev_get_endpoint(memdev); + if (!ep) + return -ENODEV; + + port = cxl_endpoint_get_port(ep); + if (!port) + return -ENODEV; + + /* + * Look for a committed decoder, which indicates that the region the + * memdev belongs to is active. This is best effort as the decoder + * state is pulled from sysfs and not atomic. The caller should be in + * control of the device to prevent state changes for the decoder. + */ + cxl_decoder_foreach(port, decoder) { + if (cxl_decoder_is_committed(decoder)) { + committed = true; + break; + } + } + + if (committed && !param.force) { log_err(&ml, "%s is part of an active region\n", cxl_memdev_get_devname(memdev)); return -EBUSY;