From patchwork Fri Nov 17 20:15:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robert Richter X-Patchwork-Id: 13459239 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="frFgT9tP" Received: from NAM10-BN7-obe.outbound.protection.outlook.com (mail-bn7nam10on2076.outbound.protection.outlook.com [40.107.92.76]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26CCF19B2; Fri, 17 Nov 2023 12:15:45 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=DCbgZKzi3Mb9Ca5HWws7uqi6LWnBrAHq5mIA2cuRtRV9aU8I9YfkArJJcVZxNZi1Pc4Oo9tMK5/GZ+8C1kZ3cdfsYsvq3GAGF2MVRd5YvtM/+KmMATkZVJveTs+Zkez0tVM/MB5QTniU89kiSG/NtSyCaRxiEWUDrYnMrzeG1W80g69wI3lpuTRdvOuzawZ6Bxj0vXlh9ChirUZretTi3y8hG3W38iRN9gWO3ThkSwtQAUZRoxw1H8kbnvCH1I9D6EH28rs76uHbUF/bQk7NGhzdgC46tZdAdmJT+BY0UZEY5SaegqwkRdl7Cthc5HU5BeWGn7Y+VvJsNQlzzWn+4g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=/mhMu3XVa9U34TEQSnw8CdH2MCgx1O5RDKfbMFTwQSU=; b=kvgmF40c/i0ORw57cRKHxFGaJRIil8KKNhivMuQQ7M60S1P/WeyFz8aZFDzn+jCpBuAsXZZY/lb13OzcNJgTWtzKX6CJNF3siJ9DlPuVXrLiCjxeeX4vs4iBtipNGzcUo8IueYYlFq3NUpiexaYt/n70MzRn+10UXgJYrjlyZELxtd8kQgyMGw0rKiNsKfuvEQIhBB0T8K325M5kuZjGzx23itr9IhKfCH4/GQTkMAgVFVZbFgznrTH6w8gIAYE4JRtmjpLFWPA5bluaisFsP8AUZtznc/UBVLYgj/JgeodjPpkb8el6jSnGf0fWAYHD801NhZ/UiGXFqNoaDZaSrw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=/mhMu3XVa9U34TEQSnw8CdH2MCgx1O5RDKfbMFTwQSU=; b=frFgT9tPWkXehoAZw3lqht/sma+JutpBLYUy6bP6sW0qLH/ZO20p8VA8Rlst7PGwRIrI2NF14geh0h0NrgU8M2WrcfkFAuhrWexObpXBjU3/bWRW7e53636EBhUE+pQ+5nMLe/EXjAre3yyJXtRXto0cH5ON8VZ6T3IS1dNhrAo= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from DM6PR12MB3657.namprd12.prod.outlook.com (2603:10b6:5:149::18) by CH2PR12MB4312.namprd12.prod.outlook.com (2603:10b6:610:af::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7002.23; Fri, 17 Nov 2023 20:15:42 +0000 Received: from DM6PR12MB3657.namprd12.prod.outlook.com ([fe80::5786:22a:27df:9a70]) by DM6PR12MB3657.namprd12.prod.outlook.com ([fe80::5786:22a:27df:9a70%7]) with mapi id 15.20.7002.022; Fri, 17 Nov 2023 20:15:42 +0000 Date: Fri, 17 Nov 2023 21:15:36 +0100 From: Robert Richter To: Dan Williams Cc: Ira Weiny , Davidlohr Bueso , Jonathan Cameron , Dave Jiang , Alison Schofield , Vishal Verma , linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, Fan Ni , Lukas Wunner Subject: [PATCH] cxl/pci: Get rid of pointer arithmetic reading CDAT table Message-ID: References: <20231116-fix-cdat-devm-free-v1-1-b148b40707d7@intel.com> Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: FR2P281CA0044.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:92::18) To DM6PR12MB3657.namprd12.prod.outlook.com (2603:10b6:5:149::18) Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM6PR12MB3657:EE_|CH2PR12MB4312:EE_ X-MS-Office365-Filtering-Correlation-Id: 929f79f5-2e92-478c-1dac-08dbe7a9f975 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM6PR12MB3657.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230031)(346002)(136003)(396003)(39860400002)(366004)(376002)(230922051799003)(64100799003)(451199024)(186009)(1800799009)(54906003)(66946007)(66556008)(66476007)(6666004)(316002)(6916009)(83380400001)(478600001)(6486002)(7416002)(5660300002)(6506007)(53546011)(38100700002)(2906002)(41300700001)(26005)(9686003)(4326008)(6512007)(8936002)(8676002)(26583001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 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 X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 929f79f5-2e92-478c-1dac-08dbe7a9f975 X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB3657.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Nov 2023 20:15:42.5822 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Cb0S2ibHdmehFoYEiqQNTe9nZMzGW3tLpt9dqvvw7LUKFC58y5n5du8FA82I7N6jvbMqpLT+VtrQBR4eVVCIBw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR12MB4312 On 17.11.23 21:09:18, Robert Richter wrote: > I will send an on-top patch for 6.8 that reworks that code area to > remove the pointer arithmetic. Here it is: From 13787f72c20b8c54754ae86015d982307eae0397 Mon Sep 17 00:00:00 2001 From: Robert Richter Subject: [PATCH] cxl/pci: Get rid of pointer arithmetic reading CDAT table Reading the CDAT table using DOE requires a Table Access Response Header in addition to the CDAT entry. In current implementation this has caused offsets with sizeof(__le32) to the actual buffers. This led to hardly readable code and even bugs (see fix of devm_kfree() in read_cdat_data()). Rework code to avoid calculations with sizeof(__le32). Introduce struct cdat_doe for this which contains the Table Access Response Header and a variable payload size for various data structures afterwards to access the CDAT table and its CDAT Data Structures without recalculating buffer offsets. Cc: Lukas Wunner Cc: Dave Jiang Cc: Fan Ni Signed-off-by: Robert Richter Reviewed-by: Dave Jiang --- drivers/cxl/core/pci.c | 80 ++++++++++++++++++++---------------------- drivers/cxl/cxlpci.h | 19 ++++++++++ 2 files changed, 57 insertions(+), 42 deletions(-) diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c index 5aaa0b36c42a..f900740c6dea 100644 --- a/drivers/cxl/core/pci.c +++ b/drivers/cxl/core/pci.c @@ -517,14 +517,14 @@ EXPORT_SYMBOL_NS_GPL(cxl_hdm_decode_init, CXL); FIELD_PREP(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, (entry_handle))) static int cxl_cdat_get_length(struct device *dev, - struct pci_doe_mb *cdat_doe, + struct pci_doe_mb *doe_mb, size_t *length) { __le32 request = CDAT_DOE_REQ(0); __le32 response[2]; int rc; - rc = pci_doe(cdat_doe, PCI_DVSEC_VENDOR_ID_CXL, + rc = pci_doe(doe_mb, PCI_DVSEC_VENDOR_ID_CXL, CXL_DOE_PROTOCOL_TABLE_ACCESS, &request, sizeof(request), &response, sizeof(response)); @@ -542,56 +542,54 @@ static int cxl_cdat_get_length(struct device *dev, } static int cxl_cdat_read_table(struct device *dev, - struct pci_doe_mb *cdat_doe, - void *cdat_table, size_t *cdat_length) + struct pci_doe_mb *doe_mb, + struct cdat_doe *doe, size_t *length) { - size_t length = *cdat_length + sizeof(__le32); - __le32 *data = cdat_table; + size_t received, remaining = *length; int entry_handle = 0; __le32 saved_dw = 0; do { __le32 request = CDAT_DOE_REQ(entry_handle); - struct cdat_entry_header *entry; - size_t entry_dw; int rc; - rc = pci_doe(cdat_doe, PCI_DVSEC_VENDOR_ID_CXL, + rc = pci_doe(doe_mb, PCI_DVSEC_VENDOR_ID_CXL, CXL_DOE_PROTOCOL_TABLE_ACCESS, &request, sizeof(request), - data, length); + doe, sizeof(*doe) + remaining); if (rc < 0) { dev_err(dev, "DOE failed: %d", rc); return rc; } - /* 1 DW Table Access Response Header + CDAT entry */ - entry = (struct cdat_entry_header *)(data + 1); + if (rc < sizeof(*doe)) + return -EIO; + + received = rc - sizeof(*doe); + if ((entry_handle == 0 && - rc != sizeof(__le32) + sizeof(struct cdat_header)) || + received != sizeof(doe->header[0])) || (entry_handle > 0 && - (rc < sizeof(__le32) + sizeof(*entry) || - rc != sizeof(__le32) + le16_to_cpu(entry->length)))) + (received < sizeof(doe->entry[0]) || + received != le16_to_cpu(doe->entry->length)))) return -EIO; /* Get the CXL table access header entry handle */ entry_handle = FIELD_GET(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, - le32_to_cpu(data[0])); - entry_dw = rc / sizeof(__le32); - /* Skip Header */ - entry_dw -= 1; + le32_to_cpu(doe->doe_header)); + /* * Table Access Response Header overwrote the last DW of * previous entry, so restore that DW */ - *data = saved_dw; - length -= entry_dw * sizeof(__le32); - data += entry_dw; - saved_dw = *data; + doe->doe_header = saved_dw; + remaining -= received; + doe = (void *)doe + received; + saved_dw = doe->doe_header; } while (entry_handle != CXL_DOE_TABLE_ACCESS_LAST_ENTRY); /* Length in CDAT header may exceed concatenation of CDAT entries */ - *cdat_length -= length - sizeof(__le32); + *length -= remaining; return 0; } @@ -616,11 +614,11 @@ void read_cdat_data(struct cxl_port *port) { struct device *uport = port->uport_dev; struct device *dev = &port->dev; - struct pci_doe_mb *cdat_doe; + struct pci_doe_mb *doe_mb; struct pci_dev *pdev = NULL; struct cxl_memdev *cxlmd; - size_t cdat_length; - void *cdat_table, *cdat_buf; + struct cdat_doe *doe; + size_t length; int rc; if (is_cxl_memdev(uport)) { @@ -637,40 +635,38 @@ void read_cdat_data(struct cxl_port *port) if (!pdev) return; - cdat_doe = pci_find_doe_mailbox(pdev, PCI_DVSEC_VENDOR_ID_CXL, - CXL_DOE_PROTOCOL_TABLE_ACCESS); - if (!cdat_doe) { + doe_mb = pci_find_doe_mailbox(pdev, PCI_DVSEC_VENDOR_ID_CXL, + CXL_DOE_PROTOCOL_TABLE_ACCESS); + if (!doe_mb) { dev_dbg(dev, "No CDAT mailbox\n"); return; } port->cdat_available = true; - if (cxl_cdat_get_length(dev, cdat_doe, &cdat_length)) { + if (cxl_cdat_get_length(dev, doe_mb, &length)) { dev_dbg(dev, "No CDAT length\n"); return; } - cdat_buf = devm_kzalloc(dev, cdat_length + sizeof(__le32), - GFP_KERNEL); - if (!cdat_buf) - return; + doe = devm_kzalloc(dev, sizeof(*doe) + length, GFP_KERNEL); + if (!doe) + goto err; - rc = cxl_cdat_read_table(dev, cdat_doe, cdat_buf, &cdat_length); + rc = cxl_cdat_read_table(dev, doe_mb, doe, &length); if (rc) goto err; - cdat_table = cdat_buf + sizeof(__le32); - if (cdat_checksum(cdat_table, cdat_length)) + if (cdat_checksum(doe->table, length)) goto err; - port->cdat.table = cdat_table; - port->cdat.length = cdat_length; - return; + port->cdat.table = doe->table; + port->cdat.length = length; + return; err: /* Don't leave table data allocated on error */ - devm_kfree(dev, cdat_buf); + devm_kfree(dev, doe); dev_err(dev, "Failed to read/validate CDAT.\n"); } EXPORT_SYMBOL_NS_GPL(read_cdat_data, CXL); diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h index 0fa4799ea316..d12ed9d8dec1 100644 --- a/drivers/cxl/cxlpci.h +++ b/drivers/cxl/cxlpci.h @@ -85,6 +85,25 @@ struct cdat_entry_header { __le16 length; } __packed; +/* + * Response contains the CDAT only response header of the DOE. The + * response payload is a CDAT structure (either CDAT header or entry), + * it may also mark the beginning of the CDAT table. + * + * Spec refs: + * + * CXL 3.1 Table 8-14: Read Entry Response + * CDAT Specification 1.03: 2 CDAT Data Structures + */ +struct cdat_doe { + __le32 doe_header; + union { + u8 table[0]; + struct cdat_header header[0]; + struct cdat_entry_header entry[0]; + }; +} __packed; + int devm_cxl_port_enumerate_dports(struct cxl_port *port); struct cxl_dev_state; int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm,