From patchwork Mon Aug 22 00:52:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ira Weiny X-Patchwork-Id: 12950098 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 AE85EC3F6B0 for ; Mon, 22 Aug 2022 00:52:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232138AbiHVAwo (ORCPT ); Sun, 21 Aug 2022 20:52:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231976AbiHVAwn (ORCPT ); Sun, 21 Aug 2022 20:52:43 -0400 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC44B205DC; Sun, 21 Aug 2022 17:52:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1661129561; x=1692665561; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=3ajrhKAlyLex9P+GmLBl7RTGdiFSwUZrPHfyulLogHQ=; b=Xp00l8gWc7bTrF43yUwvkPg0W/fWb1Hwi3hgEf9S4hFu07ABcNm+hlGa 9KP2gvRyrJbEfB6N8ITkz/s+NIUbQ6i1JxfJeBKJCj37yVDmLNVKHfwuQ pNHeO0HcGHcFchZjx56XKKTBylZVECrKYlflkpr7G8afakeNBVhdWGpMv tBAzNdXEx6ewlPaQj0Ir9AF9E0hpsTgEjV26mpLaZRwrIuZ3gQ29f4z2m 7piJ+fS5WLvEo8VFqythFaiPghPQ99NVkrbup0qW+cv8SM7RNf792Lvpa 6Fzc+7v+ZmjEcNOK65MbscCDnn5x032YVBUtmUZNNZ/4OVzI4D00a9nnr w==; X-IronPort-AV: E=McAfee;i="6500,9779,10446"; a="319325792" X-IronPort-AV: E=Sophos;i="5.93,254,1654585200"; d="scan'208";a="319325792" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Aug 2022 17:52:41 -0700 X-IronPort-AV: E=Sophos;i="5.93,254,1654585200"; d="scan'208";a="784677829" Received: from iweiny-mobl.amr.corp.intel.com (HELO localhost) ([10.213.163.128]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Aug 2022 17:52:40 -0700 From: ira.weiny@intel.com To: Dan Williams , Bjorn Helgaas , Greg Kroah-Hartman Cc: Ira Weiny , Jonathan Cameron , Alison Schofield , Vishal Verma , Ben Widawsky , linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: [PATCH 2/2] cxl/doe: Request exclusive DOE access Date: Sun, 21 Aug 2022 20:52:37 -0400 Message-Id: <20220822005237.540039-3-ira.weiny@intel.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220822005237.540039-1-ira.weiny@intel.com> References: <20220822005237.540039-1-ira.weiny@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Ira Weiny The PCIE Data Object Exchange (DOE) mailbox is a protocol run over configuration cycles. It assumes one initiator at a time. While the kernel has control of the mailbox user space writes could interfere with the kernel access. Mark DOE mailbox config space exclusive when iterated by the CXL driver. Signed-off-by: Ira Weiny --- drivers/cxl/pci.c | 5 +++++ include/uapi/linux/pci_regs.h | 1 + 2 files changed, 6 insertions(+) diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c index faeb5d9d7a7a..5b833eb91543 100644 --- a/drivers/cxl/pci.c +++ b/drivers/cxl/pci.c @@ -418,6 +418,11 @@ static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds) continue; } + if (!pci_request_config_region_exclusive(pdev, off, + PCI_DOE_CAP_SIZE, + dev_name(dev))) + pci_err(pdev, "Failed to exclude DOE registers\n"); + if (xa_insert(&cxlds->doe_mbs, off, doe_mb, GFP_KERNEL)) { dev_err(dev, "xa_insert failed to insert MB @ %x\n", off); diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index 57b8e2ffb1dd..f2396bcd09cc 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -1119,6 +1119,7 @@ #define PCI_DOE_STATUS_DATA_OBJECT_READY 0x80000000 /* Data Object Ready */ #define PCI_DOE_WRITE 0x10 /* DOE Write Data Mailbox Register */ #define PCI_DOE_READ 0x14 /* DOE Read Data Mailbox Register */ +#define PCI_DOE_CAP_SIZE (0x14 + 4) /* Size of this register block */ /* DOE Data Object - note not actually registers */ #define PCI_DOE_DATA_OBJECT_HEADER_1_VID 0x0000ffff