net: hns3: reduce resources use in kdump kernel

When the kdump kernel started, the HNS3 driver fail to register:
[14.753340] hns3 0000:7d:00.0: Alloc umv space failed, want 512, get 0
[14.795034] hns3 0000:7d:00.0: add uc mac address fail, ret =-22.

By default, the HNS3 driver will use about 512M memory, but
usually the reserved memory of kdump kernel is 576M, so the HNS3
driver fail to register. This patch reduces the memory use in
kdump kernel to about 16M.

And when the kdump kernel starts, we must clear ucast mac address
first to avoid add fail.
Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c

@@ -12,6 +12,7 @@
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/if_vlan.h>
+#include <linux/crash_dump.h>
 #include <net/rtnetlink.h>
 #include "hclge_cmd.h"
 #include "hclge_dcb.h"
@@ -1015,6 +1016,23 @@ static int hclge_get_cap(struct hclge_dev *hdev)
 	return ret;
 }
 
+static void hclge_init_kdump_kernel_config(struct hclge_dev *hdev)
+{
+#define HCLGE_MIN_TX_DESC	64
+#define HCLGE_MIN_RX_DESC	64
+
+	if (!is_kdump_kernel())
+		return;
+
+	dev_info(&hdev->pdev->dev,
+		 "Running kdump kernel. Using minimal resources\n");
+
+	/* minimal queue pairs equals to the number of vports */
+	hdev->num_tqps = hdev->num_vmdq_vport + hdev->num_req_vfs + 1;
+	hdev->num_tx_desc = HCLGE_MIN_TX_DESC;
+	hdev->num_rx_desc = HCLGE_MIN_RX_DESC;
+}
+
 static int hclge_configure(struct hclge_dev *hdev)
 {
 	struct hclge_cfg cfg;
@@ -1074,6 +1092,8 @@ static int hclge_configure(struct hclge_dev *hdev)
 
 	hdev->tx_sch_mode = HCLGE_FLAG_TC_BASE_SCH_MODE;
 
+	hclge_init_kdump_kernel_config(hdev);
+
 	return ret;
 }
 
@@ -6293,7 +6313,8 @@ static int hclge_set_mac_addr(struct hnae3_handle *handle, void *p,
 		return -EINVAL;
 	}
 
-	if (!is_first && hclge_rm_uc_addr(handle, hdev->hw.mac.mac_addr))
+	if ((!is_first || is_kdump_kernel()) &&
+	    hclge_rm_uc_addr(handle, hdev->hw.mac.mac_addr))
 		dev_warn(&hdev->pdev->dev,
 			 "remove old uc mac address fail.\n");