From patchwork Thu Apr 14 20:32:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ira Weiny X-Patchwork-Id: 12813988 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 F2B82C4167D for ; Thu, 14 Apr 2022 20:32:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346360AbiDNUfV (ORCPT ); Thu, 14 Apr 2022 16:35:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346392AbiDNUfT (ORCPT ); Thu, 14 Apr 2022 16:35:19 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DBA8B0A67; Thu, 14 Apr 2022 13:32:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1649968371; x=1681504371; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=wLJPKq/0myZKFPW0t2HMcu+LNF19JthPW2lDc3HdwCc=; b=JGlBA/LYIWOfLp6VB9ZuapI7SuNebjEj9jzfMk1HnLW98Gc5dPtIn0Xh WaTPHMX50iDBC56RP0+YktAMFyd6tLINcSEx4W0BsnqOCWFhVcQTwL4+j wxdE/a/OG1qSL5BHzEhp7a+lEQGDab+eQfBizWgLGLVyXeb2BsJTOOLlj Jq47tCL62YjQGXcNFgct8cIgGJ8R/B3QKxiqbsB+DT+7B2QXU/2nbQG3T K/B3sE4H5E84MJ4yALaEcohzDVBMdJekV+6Au2L4seggZN4CXvnHASKEI wN+f7oQt5vTq8AI+R1263shJkAjZ2Q0fY6FYyZtzt26eh2C/e9/x33Qlg A==; X-IronPort-AV: E=McAfee;i="6400,9594,10317"; a="262779238" X-IronPort-AV: E=Sophos;i="5.90,260,1643702400"; d="scan'208";a="262779238" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2022 13:32:50 -0700 X-IronPort-AV: E=Sophos;i="5.90,260,1643702400"; d="scan'208";a="661507146" Received: from aimeehax-mobl1.amr.corp.intel.com (HELO localhost) ([10.212.113.132]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2022 13:32:49 -0700 From: ira.weiny@intel.com To: Dan Williams , Bjorn Helgaas , Jonathan Cameron Cc: Ira Weiny , Alison Schofield , Vishal Verma , Ben Widawsky , linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, linux-pci@vger.kernel.org Subject: [PATCH V8 08/10] cxl/cdat: Introduce cxl_cdat_valid() Date: Thu, 14 Apr 2022 13:32:35 -0700 Message-Id: <20220414203237.2198665-9-ira.weiny@intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220414203237.2198665-1-ira.weiny@intel.com> References: <20220414203237.2198665-1-ira.weiny@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org From: Ira Weiny The CDAT data is protected by a checksum and should be the proper length. Introduce cxl_cdat_valid() to validate the data. While at it check and store the sequence number. Signed-off-by: Ira Weiny Reviewed-by: Jonathan Cameron --- Changes from V6 Change name to cxl_cdat_valid() as this validates all the CDAT data not just the header Add error and debug prints Changes from V5 New patch, split out Update cdat_hdr_valid() Remove revision and cs field parsing There is no point in these Add seq check and debug print. --- drivers/cxl/cdat.h | 2 ++ drivers/cxl/pci.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/drivers/cxl/cdat.h b/drivers/cxl/cdat.h index 4722b6bbbaf0..a7725d26f2d2 100644 --- a/drivers/cxl/cdat.h +++ b/drivers/cxl/cdat.h @@ -88,10 +88,12 @@ * * @table: cache of CDAT table * @length: length of cached CDAT table + * @seq: Last read Sequence number of the CDAT table */ struct cxl_cdat { void *table; size_t length; + u32 seq; }; #endif /* !__CXL_CDAT_H__ */ diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c index aecb327911a0..d7952156dd02 100644 --- a/drivers/cxl/pci.c +++ b/drivers/cxl/pci.c @@ -781,6 +781,40 @@ static int cxl_setup_doe_devices(struct cxl_dev_state *cxlds) return 0; } +static bool cxl_cdat_valid(struct device *dev, struct cxl_cdat *cdat) +{ + u32 *table = cdat->table; + u8 *data8 = cdat->table; + u32 length, seq; + u8 check; + int i; + + length = FIELD_GET(CDAT_HEADER_DW0_LENGTH, table[0]); + if ((length < CDAT_HEADER_LENGTH_BYTES) || (length > cdat->length)) { + dev_err(dev, "Invalid length %u (%lu-%lu)\n", length, + CDAT_HEADER_LENGTH_BYTES, cdat->length); + return false; + } + + for (check = 0, i = 0; i < length; i++) + check += data8[i]; + + dev_dbg(dev, "CDAT length %u CS %u\n", length, check); + if (check != 0) { + dev_err(dev, "Invalid checksum %u\n", check); + return false; + } + + seq = FIELD_GET(CDAT_HEADER_DW3_SEQUENCE, table[3]); + /* Store the sequence for now. */ + if (cdat->seq != seq) { + dev_info(dev, "CDAT seq change %x -> %x\n", cdat->seq, seq); + cdat->seq = seq; + } + + return true; +} + #define CDAT_DOE_REQ(entry_handle) \ (FIELD_PREP(CXL_DOE_TABLE_ACCESS_REQ_CODE, \ CXL_DOE_TABLE_ACCESS_REQ_CODE_READ) | \ @@ -892,6 +926,8 @@ static int cxl_cdat_read_table(struct cxl_dev_state *cxlds, release_driver: cxl_pci_doe_put_drv(doe_dev); + if (!rc && !cxl_cdat_valid(cxlds->dev, cdat)) + return -EIO; return rc; }