kernel/patches/0580-net-hns3-remove-always-exist-devlink-pointer-check.patch

From f4f0868a16ec55852cbe66e42f6d32ce13b649d2 Mon Sep 17 00:00:00 2001
From: Leon Romanovsky <leonro@nvidia.com>
Date: Sat, 21 Aug 2021 17:00:42 +0800
Subject: [PATCH 219/283] net: hns3: remove always exist devlink pointer check

mainline inclusion
from mainline-v5.15-rc1
commit a1fcb106ae97cc34cc8101efafb89eaa837be009
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I8EN49
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a1fcb106ae97cc34cc8101efafb89eaa837be009

----------------------------------------------------------------------

The devlink pointer always exists after hclge_devlink_init() succeed.
Remove that check together with NULL setting after release and ensure
that devlink_register is last command prior to call to devlink_reload_enable().

Fixes: b741269b2759 ("net: hns3: add support for registering devlink for PF")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Yongxin Li <liyongxin1@huawei.com>
Signed-off-by: Junxin Chen <chenjunxin1@huawei.com>
(fix conflicts: interface devlink_register adapt)
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Signed-off-by: Xiaodong Li <lixiaodong67@huawei.com>

 Conflicts:
	drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_devlink.c
	drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_devlink.c
---
 .../hisilicon/hns3/hns3pf/hclge_devlink.c     |  8 ++---
 .../hisilicon/hns3/hns3vf/hclgevf_devlink.c   |  8 ++---
 include/net/devlink.h                         |  5 +++
 net/core/devlink.c                            | 36 +++++++++++++++++++
 4 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_devlink.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_devlink.c
index 03b822b0a8e7..3a0be591112e 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_devlink.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_devlink.c
@@ -22,6 +22,7 @@ int hclge_devlink_init(struct hclge_dev *hdev)
 
 	priv = devlink_priv(devlink);
 	priv->hdev = hdev;
+	hdev->devlink = devlink;
 
 	ret = devlink_register(devlink, &pdev->dev);
 	if (ret) {
@@ -30,7 +31,7 @@ int hclge_devlink_init(struct hclge_dev *hdev)
 		goto out_reg_fail;
 	}
 
-	hdev->devlink = devlink;
+	devlink_reload_enable(devlink);
 
 	return 0;
 
@@ -43,12 +44,9 @@ void hclge_devlink_uninit(struct hclge_dev *hdev)
 {
 	struct devlink *devlink = hdev->devlink;
 
-	if (!devlink)
-		return;
+	devlink_reload_disable(devlink);
 
 	devlink_unregister(devlink);
 
 	devlink_free(devlink);
-
-	hdev->devlink = NULL;
 }
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_devlink.c b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_devlink.c
index 55337a975981..a2495ebbea02 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_devlink.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_devlink.c
@@ -22,6 +22,7 @@ int hclgevf_devlink_init(struct hclgevf_dev *hdev)
 
 	priv = devlink_priv(devlink);
 	priv->hdev = hdev;
+	hdev->devlink = devlink;
 
 	ret = devlink_register(devlink, &pdev->dev);
 	if (ret) {
@@ -30,7 +31,7 @@ int hclgevf_devlink_init(struct hclgevf_dev *hdev)
 		goto out_reg_fail;
 	}
 
-	hdev->devlink = devlink;
+	devlink_reload_enable(devlink);
 
 	return 0;
 
@@ -43,12 +44,9 @@ void hclgevf_devlink_uninit(struct hclgevf_dev *hdev)
 {
 	struct devlink *devlink = hdev->devlink;
 
-	if (!devlink)
-		return;
+	devlink_reload_disable(devlink);
 
 	devlink_unregister(devlink);
 
 	devlink_free(devlink);
-
-	hdev->devlink = NULL;
 }
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 99efc156a309..669c3cb59fcf 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -35,6 +35,9 @@ struct devlink {
 	struct device *dev;
 	possible_net_t _net;
 	struct mutex lock;
+	u8 reload_failed:1,
+	   reload_enabled:1,
+	   registered:1;
 	char priv[0] __aligned(NETDEV_ALIGN);
 };
 
@@ -477,6 +480,8 @@ struct ib_device;
 struct devlink *devlink_alloc(const struct devlink_ops *ops, size_t priv_size);
 int devlink_register(struct devlink *devlink, struct device *dev);
 void devlink_unregister(struct devlink *devlink);
+void devlink_reload_enable(struct devlink *devlink);
+void devlink_reload_disable(struct devlink *devlink);
 void devlink_free(struct devlink *devlink);
 int devlink_port_register(struct devlink *devlink,
 			  struct devlink_port *devlink_port,
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 6ad095264896..c9b36811529d 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -3900,12 +3900,48 @@ EXPORT_SYMBOL_GPL(devlink_register);
 void devlink_unregister(struct devlink *devlink)
 {
 	mutex_lock(&devlink_mutex);
+	WARN_ON(devlink->reload_enabled);
 	devlink_notify(devlink, DEVLINK_CMD_DEL);
 	list_del(&devlink->list);
 	mutex_unlock(&devlink_mutex);
 }
 EXPORT_SYMBOL_GPL(devlink_unregister);
 
+/**
+ *	devlink_reload_enable - Enable reload of devlink instance
+ *
+ *	@devlink: devlink
+ *
+ *	Should be called at end of device initialization
+ *	process when reload operation is supported.
+ */
+void devlink_reload_enable(struct devlink *devlink)
+{
+	mutex_lock(&devlink_mutex);
+	devlink->reload_enabled = true;
+	mutex_unlock(&devlink_mutex);
+}
+EXPORT_SYMBOL_GPL(devlink_reload_enable);
+
+/**
+ *	devlink_reload_disable - Disable reload of devlink instance
+ *
+ *	@devlink: devlink
+ *
+ *	Should be called at the beginning of device cleanup
+ *	process when reload operation is supported.
+ */
+void devlink_reload_disable(struct devlink *devlink)
+{
+	mutex_lock(&devlink_mutex);
+	/* Mutex is taken which ensures that no reload operation is in
+	 * progress while setting up forbidded flag.
+	 */
+	devlink->reload_enabled = false;
+	mutex_unlock(&devlink_mutex);
+}
+EXPORT_SYMBOL_GPL(devlink_reload_disable);
+
 /**
  *	devlink_free - Free devlink instance resources
  *
-- 
2.34.1