From patchwork Fri Apr 16 02:49:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12206545 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F4C3C433ED for ; Fri, 16 Apr 2021 02:49:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 273DE6117A for ; Fri, 16 Apr 2021 02:49:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235937AbhDPCtq (ORCPT ); Thu, 15 Apr 2021 22:49:46 -0400 Received: from mga05.intel.com ([192.55.52.43]:26635 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235482AbhDPCtp (ORCPT ); Thu, 15 Apr 2021 22:49:45 -0400 IronPort-SDR: IdhnRoKrA4+s8rjwOqrjHu8X0e5XdtPuFLvp0G11/beB8FbDkR3zxuuL/hRe+SSByZYnf7gdDM CVHeaq04r0qQ== X-IronPort-AV: E=McAfee;i="6200,9189,9955"; a="280297464" X-IronPort-AV: E=Sophos;i="5.82,226,1613462400"; d="scan'208";a="280297464" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Apr 2021 19:49:19 -0700 IronPort-SDR: BUVzbvU9lm2hj43qfQcctSAAtLewDloc2SP1LNuUf3TAlAQyd355weItuFvK2Rjocuunxb/aIQ ssJgKOnjtwaw== X-IronPort-AV: E=Sophos;i="5.82,226,1613462400"; d="scan'208";a="615834756" Received: from skanuri-mobl.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.135.175]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Apr 2021 19:49:18 -0700 From: Ben Widawsky To: linux-cxl@vger.kernel.org Cc: Ben Widawsky , linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, ira.weiny@intel.com, vishal.l.verma@intel.com, alison.schofield@intel.com, dan.j.williams@intel.com, linux-kernel@vger.kernel.org Subject: [PATCH v2] cxl/mem: Fix register block offset calculation Date: Thu, 15 Apr 2021 19:49:12 -0700 Message-Id: <20210416024912.638180-1-ben.widawsky@intel.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210415232610.603273-1-ben.widawsky@intel.com> References: <20210415232610.603273-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org The offset for the register block should be a 64K aligned value, and therefore FIELD_GET (which will shift) is not correct for the calculation. From 8.1.9.1 of the CXL 2.0 spec: A[31:16] of offset from the address contained by one of the Function's Base Address Registers to point to the base of the Register Block. Register Block Offset is 64K aligned. Hence A[15:0] is zero The "Register Offset Low" register of a "DVSEC Register Locator" contains the 64K aligned offset for the registers along with the BAR indicator and an ID. The implementation was treating the "Register Block Offset Low" field a value rather than as a pre-aligned component of the 64-bit offset. So, just mask, don't mask and shift (FIELD_GET). This wasn't found earlier because the primary development done in the QEMU environment only uses 0 offsets Fixes: 8adaf747c9f0 ("cxl/mem: Find device capabilities") Reported-by: Vishal Verma Signed-off-by: Ben Widawsky --- drivers/cxl/mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index e3003f49b329..1b5078311f7d 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -998,7 +998,7 @@ static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo, return NULL; } - offset = ((u64)reg_hi << 32) | FIELD_GET(CXL_REGLOC_ADDR_MASK, reg_lo); + offset = ((u64)reg_hi << 32) | (reg_lo & CXL_REGLOC_ADDR_MASK); bar = FIELD_GET(CXL_REGLOC_BIR_MASK, reg_lo); /* Basic sanity check that BAR is big enough */