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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        "Wei Hu (Xavier)" <xavier.huwei@huawei.com>,
        Jason Gunthorpe <jgg@mellanox.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.0 75/93] RDMA/hns: Fix the Oops during rmmod or insmod ko when reset occurs
Date:   Thu, 18 Apr 2019 19:57:53 +0200
Message-Id: <20190418160444.699351184@linuxfoundation.org>
In-Reply-To: <20190418160436.781762249@linuxfoundation.org>
References: <20190418160436.781762249@linuxfoundation.org>
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[ Upstream commit d061effc36f7bd38a12912977a37a50ac9140d11 ]

In the reset process, the hns3 NIC driver notifies the RoCE driver to
perform reset related processing by calling the .reset_notify() interface
registered by the RoCE driver in hip08 SoC.

In the current version, if a reset occurs simultaneously during the
execution of rmmod or insmod ko, there may be Oops error as below:

 Internal error: Oops: 86000007 [#1] PREEMPT SMP
 Modules linked in: hns_roce(O) hns3(O) hclge(O) hnae3(O) [last unloaded: hns_roce_hw_v2]
 CPU: 0 PID: 14 Comm: kworker/0:1 Tainted: G           O      4.19.0-ge00d540 #1
 Hardware name: Huawei Technologies Co., Ltd.
 Workqueue: events hclge_reset_service_task [hclge]
 pstate: 60c00009 (nZCv daif +PAN +UAO)
 pc : 0xffff00000100b0b8
 lr : 0xffff00000100aea0
 sp : ffff000009afbab0
 x29: ffff000009afbab0 x28: 0000000000000800
 x27: 0000000000007ff0 x26: ffff80002f90c004
 x25: 00000000000007ff x24: ffff000008f97000
 x23: ffff80003efee0a8 x22: 0000000000001000
 x21: ffff80002f917ff0 x20: ffff8000286ea070
 x19: 0000000000000800 x18: 0000000000000400
 x17: 00000000c4d3225d x16: 00000000000021b8
 x15: 0000000000000400 x14: 0000000000000400
 x13: 0000000000000000 x12: ffff80003fac6e30
 x11: 0000800036303000 x10: 0000000000000001
 x9 : 0000000000000000 x8 : ffff80003016d000
 x7 : 0000000000000000 x6 : 000000000000003f
 x5 : 0000000000000040 x4 : 0000000000000000
 x3 : 0000000000000004 x2 : 00000000000007ff
 x1 : 0000000000000000 x0 : 0000000000000000
 Process kworker/0:1 (pid: 14, stack limit = 0x00000000af8f0ad9)
 Call trace:
  0xffff00000100b0b8
  0xffff00000100b3a0
  hns_roce_init+0x624/0xc88 [hns_roce]
  0xffff000001002df8
  0xffff000001006960
  hclge_notify_roce_client+0x74/0xe0 [hclge]
  hclge_reset_service_task+0xa58/0xbc0 [hclge]
  process_one_work+0x1e4/0x458
  worker_thread+0x40/0x450
  kthread+0x12c/0x130
  ret_from_fork+0x10/0x18
 Code: bad PC value

In the reset process, we will release the resources firstly, and after the
hardware reset is completed, we will reapply resources and reconfigure the
hardware.

We can solve this problem by modifying both the NIC and the RoCE
driver. We can modify the concurrent processing in the NIC driver to avoid
calling the .reset_notify and .uninit_instance ops at the same time. And
we need to modify the RoCE driver to record the reset stage and the
driver's init/uninit state, and check the state in the .reset_notify,
.init_instance. and uninit_instance functions to avoid NULL pointer
operation.

Fixes: cb7a94c9c808 ("RDMA/hns: Add reset process for RoCE in hip08")
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/hw/hns/hns_roce_device.h |  21 ++++
 drivers/infiniband/hw/hns/hns_roce_hw_v2.c  | 103 +++++++++++++++++---
 drivers/infiniband/hw/hns/hns_roce_hw_v2.h  |   1 +
 3 files changed, 112 insertions(+), 13 deletions(-)

diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h b/drivers/infiniband/hw/hns/hns_roce_device.h
index 509e467843f6..f4cac63194d9 100644
--- a/drivers/infiniband/hw/hns/hns_roce_device.h
+++ b/drivers/infiniband/hw/hns/hns_roce_device.h
@@ -216,6 +216,26 @@ enum {
 	HNS_ROCE_DB_PER_PAGE = PAGE_SIZE / 4
 };
 
+enum hns_roce_reset_stage {
+	HNS_ROCE_STATE_NON_RST,
+	HNS_ROCE_STATE_RST_BEF_DOWN,
+	HNS_ROCE_STATE_RST_DOWN,
+	HNS_ROCE_STATE_RST_UNINIT,
+	HNS_ROCE_STATE_RST_INIT,
+	HNS_ROCE_STATE_RST_INITED,
+};
+
+enum hns_roce_instance_state {
+	HNS_ROCE_STATE_NON_INIT,
+	HNS_ROCE_STATE_INIT,
+	HNS_ROCE_STATE_INITED,
+	HNS_ROCE_STATE_UNINIT,
+};
+
+enum {
+	HNS_ROCE_RST_DIRECT_RETURN		= 0,
+};
+
 #define HNS_ROCE_CMD_SUCCESS			1
 
 #define HNS_ROCE_PORT_DOWN			0
@@ -898,6 +918,7 @@ struct hns_roce_dev {
 	spinlock_t		bt_cmd_lock;
 	bool			active;
 	bool			is_reset;
+	unsigned long		reset_cnt;
 	struct hns_roce_ib_iboe iboe;
 
 	struct list_head        pgdir_list;
diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
index 543fa1504cd3..7ac06576d791 100644
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
@@ -5800,6 +5800,7 @@ MODULE_DEVICE_TABLE(pci, hns_roce_hw_v2_pci_tbl);
 static int hns_roce_hw_v2_get_cfg(struct hns_roce_dev *hr_dev,
 				  struct hnae3_handle *handle)
 {
+	struct hns_roce_v2_priv *priv = hr_dev->priv;
 	const struct pci_device_id *id;
 	int i;
 
@@ -5830,10 +5831,13 @@ static int hns_roce_hw_v2_get_cfg(struct hns_roce_dev *hr_dev,
 	hr_dev->cmd_mod = 1;
 	hr_dev->loop_idc = 0;
 
+	hr_dev->reset_cnt = handle->ae_algo->ops->ae_dev_reset_cnt(handle);
+	priv->handle = handle;
+
 	return 0;
 }
 
-static int hns_roce_hw_v2_init_instance(struct hnae3_handle *handle)
+static int __hns_roce_hw_v2_init_instance(struct hnae3_handle *handle)
 {
 	struct hns_roce_dev *hr_dev;
 	int ret;
@@ -5850,7 +5854,6 @@ static int hns_roce_hw_v2_init_instance(struct hnae3_handle *handle)
 
 	hr_dev->pci_dev = handle->pdev;
 	hr_dev->dev = &handle->pdev->dev;
-	handle->priv = hr_dev;
 
 	ret = hns_roce_hw_v2_get_cfg(hr_dev, handle);
 	if (ret) {
@@ -5864,6 +5867,8 @@ static int hns_roce_hw_v2_init_instance(struct hnae3_handle *handle)
 		goto error_failed_get_cfg;
 	}
 
+	handle->priv = hr_dev;
+
 	return 0;
 
 error_failed_get_cfg:
@@ -5875,7 +5880,7 @@ static int hns_roce_hw_v2_init_instance(struct hnae3_handle *handle)
 	return ret;
 }
 
-static void hns_roce_hw_v2_uninit_instance(struct hnae3_handle *handle,
+static void __hns_roce_hw_v2_uninit_instance(struct hnae3_handle *handle,
 					   bool reset)
 {
 	struct hns_roce_dev *hr_dev = (struct hns_roce_dev *)handle->priv;
@@ -5883,24 +5888,78 @@ static void hns_roce_hw_v2_uninit_instance(struct hnae3_handle *handle,
 	if (!hr_dev)
 		return;
 
+	handle->priv = NULL;
 	hns_roce_exit(hr_dev);
 	kfree(hr_dev->priv);
 	ib_dealloc_device(&hr_dev->ib_dev);
 }
 
+static int hns_roce_hw_v2_init_instance(struct hnae3_handle *handle)
+{
+	const struct hnae3_ae_ops *ops = handle->ae_algo->ops;
+	struct device *dev = &handle->pdev->dev;
+	int ret;
+
+	handle->rinfo.instance_state = HNS_ROCE_STATE_INIT;
+
+	if (ops->ae_dev_resetting(handle) || ops->get_hw_reset_stat(handle)) {
+		handle->rinfo.instance_state = HNS_ROCE_STATE_NON_INIT;
+		goto reset_chk_err;
+	}
+
+	ret = __hns_roce_hw_v2_init_instance(handle);
+	if (ret) {
+		handle->rinfo.instance_state = HNS_ROCE_STATE_NON_INIT;
+		dev_err(dev, "RoCE instance init failed! ret = %d\n", ret);
+		if (ops->ae_dev_resetting(handle) ||
+		    ops->get_hw_reset_stat(handle))
+			goto reset_chk_err;
+		else
+			return ret;
+	}
+
+	handle->rinfo.instance_state = HNS_ROCE_STATE_INITED;
+
+
+	return 0;
+
+reset_chk_err:
+	dev_err(dev, "Device is busy in resetting state.\n"
+		     "please retry later.\n");
+
+	return -EBUSY;
+}
+
+static void hns_roce_hw_v2_uninit_instance(struct hnae3_handle *handle,
+					   bool reset)
+{
+	if (handle->rinfo.instance_state != HNS_ROCE_STATE_INITED)
+		return;
+
+	handle->rinfo.instance_state = HNS_ROCE_STATE_UNINIT;
+
+	__hns_roce_hw_v2_uninit_instance(handle, reset);
+
+	handle->rinfo.instance_state = HNS_ROCE_STATE_NON_INIT;
+}
 static int hns_roce_hw_v2_reset_notify_down(struct hnae3_handle *handle)
 {
-	struct hns_roce_dev *hr_dev = (struct hns_roce_dev *)handle->priv;
+	struct hns_roce_dev *hr_dev;
 	struct ib_event event;
 
-	if (!hr_dev) {
-		dev_err(&handle->pdev->dev,
-			"Input parameter handle->priv is NULL!\n");
-		return -EINVAL;
+	if (handle->rinfo.instance_state != HNS_ROCE_STATE_INITED) {
+		set_bit(HNS_ROCE_RST_DIRECT_RETURN, &handle->rinfo.state);
+		return 0;
 	}
 
+	handle->rinfo.reset_state = HNS_ROCE_STATE_RST_DOWN;
+	clear_bit(HNS_ROCE_RST_DIRECT_RETURN, &handle->rinfo.state);
+
+	hr_dev = (struct hns_roce_dev *)handle->priv;
+	if (!hr_dev)
+		return 0;
+
 	hr_dev->active = false;
-	hr_dev->is_reset = true;
 
 	event.event = IB_EVENT_DEVICE_FATAL;
 	event.device = &hr_dev->ib_dev;
@@ -5912,17 +5971,29 @@ static int hns_roce_hw_v2_reset_notify_down(struct hnae3_handle *handle)
 
 static int hns_roce_hw_v2_reset_notify_init(struct hnae3_handle *handle)
 {
+	struct device *dev = &handle->pdev->dev;
 	int ret;
 
-	ret = hns_roce_hw_v2_init_instance(handle);
+	if (test_and_clear_bit(HNS_ROCE_RST_DIRECT_RETURN,
+			       &handle->rinfo.state)) {
+		handle->rinfo.reset_state = HNS_ROCE_STATE_RST_INITED;
+		return 0;
+	}
+
+	handle->rinfo.reset_state = HNS_ROCE_STATE_RST_INIT;
+
+	dev_info(&handle->pdev->dev, "In reset process RoCE client reinit.\n");
+	ret = __hns_roce_hw_v2_init_instance(handle);
 	if (ret) {
 		/* when reset notify type is HNAE3_INIT_CLIENT In reset notify
 		 * callback function, RoCE Engine reinitialize. If RoCE reinit
 		 * failed, we should inform NIC driver.
 		 */
 		handle->priv = NULL;
-		dev_err(&handle->pdev->dev,
-			"In reset process RoCE reinit failed %d.\n", ret);
+		dev_err(dev, "In reset process RoCE reinit failed %d.\n", ret);
+	} else {
+		handle->rinfo.reset_state = HNS_ROCE_STATE_RST_INITED;
+		dev_info(dev, "Reset done, RoCE client reinit finished.\n");
 	}
 
 	return ret;
@@ -5930,8 +6001,14 @@ static int hns_roce_hw_v2_reset_notify_init(struct hnae3_handle *handle)
 
 static int hns_roce_hw_v2_reset_notify_uninit(struct hnae3_handle *handle)
 {
+	if (test_bit(HNS_ROCE_RST_DIRECT_RETURN, &handle->rinfo.state))
+		return 0;
+
+	handle->rinfo.reset_state = HNS_ROCE_STATE_RST_UNINIT;
+	dev_info(&handle->pdev->dev, "In reset process RoCE client uninit.\n");
 	msleep(100);
-	hns_roce_hw_v2_uninit_instance(handle, false);
+	__hns_roce_hw_v2_uninit_instance(handle, false);
+
 	return 0;
 }
 
diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.h b/drivers/infiniband/hw/hns/hns_roce_hw_v2.h
index b72d0443c835..5398aa718cfc 100644
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.h
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.h
@@ -1546,6 +1546,7 @@ struct hns_roce_link_table_entry {
 #define HNS_ROCE_LINK_TABLE_NXT_PTR_M GENMASK(31, 20)
 
 struct hns_roce_v2_priv {
+	struct hnae3_handle *handle;
 	struct hns_roce_v2_cmq cmq;
 	struct hns_roce_link_table tsq;
 	struct hns_roce_link_table tpq;
-- 
2.19.1