From mboxrd@z Thu Jan 1 00:00:00 1970 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 2D128C433FE for ; Mon, 31 Jan 2022 23:47:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229717AbiAaXrn (ORCPT ); Mon, 31 Jan 2022 18:47:43 -0500 Received: from mga03.intel.com ([134.134.136.65]:57377 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229637AbiAaXrm (ORCPT ); Mon, 31 Jan 2022 18:47:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643672862; x=1675208862; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=VTX+qg1zSqMYZJOMVnJMK11n6omzSFDS/8BFYIJOcI8=; b=MkqFHWNPTrUhMI8G31EG3/TbF7KkGv700/4geNhZRyvHUo4OPguUnbGl r5mUC8DUy8cQwBT0H8TBjoxPnSjDSuIZ83yt/wR6kIZqE0ojbciS3GjyM gvuGBwBju0i5uLFORqCOgw+cQuAt9iyu6IWPz05sZrpk6Hn8LEpt/kzMA +jMkd8YEcmQLXsdhKzEzkRoGeulKN35NB/uzRUzaQuFmWi1nvAzuE94i/ MLMbBdNuje959CFN3YniCAMmiL4OjUrwvAIYD20lhoVlf20UzEgAd3Hrr wcCPKPk3RUQkfr2esUDu6jfvjqL4z3KLMqPBSqko/u0vgKSboKLkuaBNI w==; X-IronPort-AV: E=McAfee;i="6200,9189,10244"; a="247530643" X-IronPort-AV: E=Sophos;i="5.88,332,1635231600"; d="scan'208";a="247530643" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Jan 2022 15:47:42 -0800 X-IronPort-AV: E=Sophos;i="5.88,332,1635231600"; d="scan'208";a="675902526" Received: from sssheth-mobl1.amr.corp.intel.com (HELO intel.com) ([10.252.130.247]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Jan 2022 15:47:41 -0800 Date: Mon, 31 Jan 2022 15:47:40 -0800 From: Ben Widawsky To: Dan Williams Cc: linux-cxl@vger.kernel.org, linux-pci@vger.kernel.org, nvdimm@lists.linux.dev Subject: Re: [PATCH v3 19/40] cxl/port: Up-level cxl_add_dport() locking requirements to the caller Message-ID: <20220131234740.bzg63pqyf2wl3din@intel.com> References: <164298411792.3018233.7493009997525360044.stgit@dwillia2-desk3.amr.corp.intel.com> <164298422000.3018233.4106867312927858722.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <164298422000.3018233.4106867312927858722.stgit@dwillia2-desk3.amr.corp.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On 22-01-23 16:30:20, Dan Williams wrote: > In preparation for moving dport enumeration into the core, require the > port device lock to be acquired by the caller. > > Signed-off-by: Dan Williams > --- > drivers/cxl/acpi.c | 2 ++ > drivers/cxl/core/port.c | 3 +-- > tools/testing/cxl/mock_acpi.c | 4 ++++ > 3 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c > index ab2b76532272..e596dc375267 100644 > --- a/drivers/cxl/acpi.c > +++ b/drivers/cxl/acpi.c > @@ -342,7 +342,9 @@ static int add_host_bridge_dport(struct device *match, void *arg) > return 0; > } > > + device_lock(&root_port->dev); > rc = cxl_add_dport(root_port, match, uid, ctx.chbcr); > + device_unlock(&root_port->dev); > if (rc) { > dev_err(host, "failed to add downstream port: %s\n", > dev_name(match)); > diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c > index ec9587e52423..c51a10154e29 100644 > --- a/drivers/cxl/core/port.c > +++ b/drivers/cxl/core/port.c > @@ -516,7 +516,7 @@ static int add_dport(struct cxl_port *port, struct cxl_dport *new) > { > struct cxl_dport *dup; > > - cxl_device_lock(&port->dev); > + device_lock_assert(&port->dev); > dup = find_dport(port, new->port_id); > if (dup) > dev_err(&port->dev, > @@ -525,7 +525,6 @@ static int add_dport(struct cxl_port *port, struct cxl_dport *new) > dev_name(dup->dport)); > else > list_add_tail(&new->list, &port->dports); > - cxl_device_unlock(&port->dev); > > return dup ? -EEXIST : 0; > } > diff --git a/tools/testing/cxl/mock_acpi.c b/tools/testing/cxl/mock_acpi.c > index 4c8a493ace56..667c032ccccf 100644 > --- a/tools/testing/cxl/mock_acpi.c > +++ b/tools/testing/cxl/mock_acpi.c > @@ -57,7 +57,9 @@ static int match_add_root_port(struct pci_dev *pdev, void *data) > > /* TODO walk DVSEC to find component register base */ > port_num = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap); > + device_lock(&port->dev); > rc = cxl_add_dport(port, &pdev->dev, port_num, CXL_RESOURCE_NONE); > + device_unlock(&port->dev); > if (rc) { > dev_err(dev, "failed to add dport: %s (%d)\n", > dev_name(&pdev->dev), rc); > @@ -78,7 +80,9 @@ static int mock_add_root_port(struct platform_device *pdev, void *data) > struct device *dev = ctx->dev; > int rc; > > + device_lock(&port->dev); > rc = cxl_add_dport(port, &pdev->dev, pdev->id, CXL_RESOURCE_NONE); > + device_unlock(&port->dev); > if (rc) { > dev_err(dev, "failed to add dport: %s (%d)\n", > dev_name(&pdev->dev), rc); > Since I really don't understand, perhaps an explanation as to why you aren't using cxl_device_lock would help? (Is it just to get around not having a cxl_device_lock_assert())?