Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Liming Wu <liming.wu@jaguarmicro.com>
To:     bhelgaas@google.com
Cc:     Liming Wu <liming.wu@jaguarmicro.com>, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org, alex.williamson@redhat.com,
        398776277@qq.com
Subject: [PATCH] PCI/IOV: Expose error return to dmesg
Date:   Tue, 13 Dec 2022 16:16:07 +0800
Message-Id: <20221213081607.1641-1-liming.wu@jaguarmicro.com>
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?h+a58TJXw5VLq6MsvVomo4WPx4o6udLBE29jcX0xWC91lotwDb5gyUrxybXe?=
 =?us-ascii?Q?mSYYb8/P3TmERMmqT4uiisj974CneCz9lEG3xFo281qs6cZ4u/3/23FUuFfv?=
 =?us-ascii?Q?D/8pPfrdU6MOrhBBSsmdGgLLHwjIPEyaYRJtIxSmjbPqM+z8NQuHUxuU6IIz?=
 =?us-ascii?Q?9C07HfXyOCDPsOu1CNT2c/4A1VxRzBh418IsR4uUVGMVWSlZyfGto9MRPr5n?=
 =?us-ascii?Q?wq8YTDzDo3tHaZ+uk5rioau9Dnkj8Nekq3BrdYXcygL1tZvvLB0l9geYphg+?=
 =?us-ascii?Q?XNep295cKv1GWD/DuzJUJqzKcMd/rWg1Hm40itFjFoYg8kkYeJpenfHUtCLQ?=
 =?us-ascii?Q?QrzGxtxKpfGRnhUdUryWFBXRPfg4R7EShdtoRcbakRaA0tIVnfu6aeB8R27N?=
 =?us-ascii?Q?iQXMBL1hlwpRruORFOBh4YNuNU5KpC+T7NUb8P7G19UvHLxS/UNngkuqUdKG?=
 =?us-ascii?Q?zSuEsipTaK5qDpmH+LU23hbDiQuewvniU+ENUlk6J9l9C4Lkauzk0zZD4keb?=
 =?us-ascii?Q?XgOM5EnFGnXYbLhUsKTDg+AUOVM2pfqCCVIoI9P4YTIrcwGyA+MubL+HR5OZ?=
 =?us-ascii?Q?A4D45GqTR+eybnKfxQWtRn0thWzHXJh/RWWbKByeeZQQN9sGQC0pXz1kLtd+?=
 =?us-ascii?Q?cSKfc1if1PE7gwx24Ge1/f5MW4EMGtDppShjhY/f1StYdIATKhf1YkHuX/By?=
 =?us-ascii?Q?SdeGsm0Tgb6O9FXmEUDMK/HEWOGHrQ5Cd1/v/mqPBljVPeWLWjBprtJxC+GN?=
 =?us-ascii?Q?7bdwB6xLu5JY1ZoF8FwBvjD3ybVQdybyooABbAP8i9G89cAJjaQUFx2Jk5nm?=
 =?us-ascii?Q?FCofntfNENgFf1Zt4FV0tU7zL5D9kF4BpW69UabbZuZyIcgs0FcWp5V/yRxL?=
 =?us-ascii?Q?E9JhtcldKVtqD1jz3UvNGUgpqvZYd4/FBkVvjfQGeB9q+Q2qvXEHkEwQk70N?=
 =?us-ascii?Q?qqMKum6+PWSXmiOeZBJuSfdb83a+wYIxuyq3On7SIIRGuagtC+oH5YyCe8u2?=
 =?us-ascii?Q?WorF7j576RiCtLd+LhIjTJYMSB2TevUk45QmiH1bT97xYbQGBaL73IESsmA2?=
 =?us-ascii?Q?Z0LwNdE3Z95HdGuz9Y2QNjHZLxPV9pwNFN4MVh/2rcxXOGq/ox0J7BreV3/V?=
 =?us-ascii?Q?VOCiLFlri4kTWia+Xg3OZSShI6hJmtwynuNukEW1VTFzKNs0DJ9PSf0JC5tP?=
 =?us-ascii?Q?P4IEa1Z1OCWQYc1hLfrx+qMCf1zxUUVhXRE6fsD6HjQmiOtH+0+LSYZ/bzAW?=
 =?us-ascii?Q?grCQ0FOeSdgrum9Niq+562CJi6OXmenCQiZfSKJrT8zyzuiizZqi7Rmk6HFt?=
 =?us-ascii?Q?xCmGzIda+iKjTMdgIkku9wL8BKJIIm4tydG4tTyvIYxR2jPl6pleKVXFp6nC?=
 =?us-ascii?Q?GdAsDbirurrGe0+nxM6lwrHUkrO7ZPjXDEaHoDmee9cmAsBOpPULQo+/OE0T?=
 =?us-ascii?Q?Ob7rbpk08tqls6edsOrns5oWcbrUp+2MpwleCZhBM+XPGvbb8z2oxUKdxko1?=
 =?us-ascii?Q?MWgPyiGiJU047tKrBeYDgBdFzxD4IcKtRW3j4sk5jCYS4ZmQ6dwI14lb/qxb?=
 =?us-ascii?Q?jHbn8OeDJ8sIKMbt7qtVUWUeNeOnyVCodCHvjihG9p6Xdq2rUvsryAk89Hnx?=
 =?us-ascii?Q?Kg=3D=3D?=
X-OriginatorOrg: jaguarmicro.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 9da1d0c4-df96-46a8-7b1d-08dadce25605
X-MS-Exchange-CrossTenant-AuthSource: PSAPR06MB3942.apcprd06.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Dec 2022 08:16:29.2140
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 1e45a5c2-d3e1-46b3-a0e6-c5ebf6d8ba7b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 9kFmYmxGV/nyJ9NdBY0ZU5GNyvLlJuyIKmXmB8l98UyPax1xvYYuvlKwqGqhg3aNNMRzpFjy3AH3NvGtmhGVWPq3IxUgF5RpFiBTcVUmocc=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: TYZPR06MB4046
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

There are many errors returned during the initialization of sriov,
such as -EIO/-ENOMEM, but they are not exposed to dmesg.
Let's expose the real errors to the user.

In addition, -ENODEV doesn't make much sense and is not returned
just like any other capabilities.

Signed-off-by: Liming Wu <liming.wu@jaguarmicro.com>
---
 drivers/pci/iov.c   | 9 ++++++---
 drivers/pci/pci.h   | 2 --
 drivers/pci/probe.c | 6 +++++-
 3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 952217572113..519aa2b48236 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -767,8 +767,11 @@ static int sriov_init(struct pci_dev *dev, int pos)
 	pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
 
 	pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
-	if (!total)
+	if (!total) {
+		pci_info(dev, "SR-IOV capability is enabled but has %d VFs)\n",
+			total);
 		return 0;
+	}
 
 	pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
 	i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
@@ -899,13 +902,13 @@ int pci_iov_init(struct pci_dev *dev)
 	int pos;
 
 	if (!pci_is_pcie(dev))
-		return -ENODEV;
+		return;
 
 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
 	if (pos)
 		return sriov_init(dev, pos);
 
-	return -ENODEV;
+	return;
 }
 
 /**
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index b1ebb7ab8805..c4836104f697 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -485,10 +485,8 @@ extern const struct attribute_group sriov_vf_dev_attr_group;
 #else
 static inline int pci_iov_init(struct pci_dev *dev)
 {
-	return -ENODEV;
 }
 static inline void pci_iov_release(struct pci_dev *dev)
-
 {
 }
 static inline void pci_iov_remove(struct pci_dev *dev)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b66fa42c4b1f..c951e0a50388 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2449,6 +2449,7 @@ void pcie_report_downtraining(struct pci_dev *dev)
 
 static void pci_init_capabilities(struct pci_dev *dev)
 {
+	int ret;
 	pci_ea_init(dev);		/* Enhanced Allocation */
 	pci_msi_init(dev);		/* Disable MSI */
 	pci_msix_init(dev);		/* Disable MSI-X */
@@ -2459,7 +2460,10 @@ static void pci_init_capabilities(struct pci_dev *dev)
 	pci_pm_init(dev);		/* Power Management */
 	pci_vpd_init(dev);		/* Vital Product Data */
 	pci_configure_ari(dev);		/* Alternative Routing-ID Forwarding */
-	pci_iov_init(dev);		/* Single Root I/O Virtualization */
+	ret = pci_iov_init(dev);		/* Single Root I/O Virtualization */
+	if (ret)
+		pci_err(dev, "SR-IOV: init failed (%d)\n", ret);
+
 	pci_ats_init(dev);		/* Address Translation Services */
 	pci_pri_init(dev);		/* Page Request Interface */
 	pci_pasid_init(dev);		/* Process Address Space ID */
-- 
2.25.1