net: hns3: refactor dump loopback of debugfs

Currently, the debugfs command for loopback is implemented by
"echo xxxx > cmd", and record the information in dmesg. It's
unnecessary and heavy. To improve it, create a single file
"loopback" for it, and query it by command "cat loopback",
return the result to userspace, rather than record in dmesg.

The display style is below:
$ cat loopback
mac id: 0
app loopback: off
serdes serial loopback: off
serdes parallel loopback: off
Signed-off-by: Yufeng Mo <moyufeng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hnae3.h

@@ -260,6 +260,7 @@ enum hnae3_dbg_cmd {
 	HNAE3_DBG_CMD_MAC_UC,
 	HNAE3_DBG_CMD_MAC_MC,
 	HNAE3_DBG_CMD_MNG_TBL,
+	HNAE3_DBG_CMD_LOOPBACK,
 	HNAE3_DBG_CMD_UNKNOWN,
 };
 

drivers/net/ethernet/hisilicon/hns3/hns3_debugfs.c

@@ -97,6 +97,13 @@ static struct hns3_dbg_cmd_info hns3_dbg_cmd[] = {
 		.buf_len = HNS3_DBG_READ_LEN,
 		.init = hns3_dbg_common_file_init,
 	},
+	{
+		.name = "loopback",
+		.cmd = HNAE3_DBG_CMD_LOOPBACK,
+		.dentry = HNS3_DBG_DENTRY_COMMON,
+		.buf_len = HNS3_DBG_READ_LEN,
+		.init = hns3_dbg_common_file_init,
+	},
 };
 
 static struct hns3_dbg_cap_info hns3_dbg_cap[] = {
@@ -495,7 +502,6 @@ static void hns3_dbg_help(struct hnae3_handle *h)
 	dev_info(&h->pdev->dev, "dump m7 info\n");
 	dev_info(&h->pdev->dev, "dump ncl_config <offset> <length>(in hex)\n");
 	dev_info(&h->pdev->dev, "dump mac tnl status\n");
-	dev_info(&h->pdev->dev, "dump loopback\n");
 	dev_info(&h->pdev->dev, "dump qs shaper [qs id]\n");
 	dev_info(&h->pdev->dev, "dump intr\n");
 

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

@@ -8,6 +8,7 @@
 #include "hclge_tm.h"
 #include "hnae3.h"
 
+static const char * const state_str[] = { "off", "on" };
 static const char * const hclge_mac_state_str[] = {
 	"TO_ADD", "TO_DEL", "ACTIVE"
 };
@@ -1566,32 +1567,34 @@ static void hclge_dbg_dump_ncl_config(struct hclge_dev *hdev,
 	}
 }
 
-static void hclge_dbg_dump_loopback(struct hclge_dev *hdev)
+static int hclge_dbg_dump_loopback(struct hclge_dev *hdev, char *buf, int len)
 {
 	struct phy_device *phydev = hdev->hw.mac.phydev;
 	struct hclge_config_mac_mode_cmd *req_app;
 	struct hclge_common_lb_cmd *req_common;
 	struct hclge_desc desc;
 	u8 loopback_en;
+	int pos = 0;
 	int ret;
 
 	req_app = (struct hclge_config_mac_mode_cmd *)desc.data;
 	req_common = (struct hclge_common_lb_cmd *)desc.data;
 
-	dev_info(&hdev->pdev->dev, "mac id: %u\n", hdev->hw.mac.mac_id);
+	pos += scnprintf(buf + pos, len - pos, "mac id: %u\n",
+			 hdev->hw.mac.mac_id);
 
 	hclge_cmd_setup_basic_desc(&desc, HCLGE_OPC_CONFIG_MAC_MODE, true);
 	ret = hclge_cmd_send(&hdev->hw, &desc, 1);
 	if (ret) {
 		dev_err(&hdev->pdev->dev,
 			"failed to dump app loopback status, ret = %d\n", ret);
-		return;
+		return ret;
 	}
 
 	loopback_en = hnae3_get_bit(le32_to_cpu(req_app->txrx_pad_fcs_loop_en),
 				    HCLGE_MAC_APP_LP_B);
-	dev_info(&hdev->pdev->dev, "app loopback: %s\n",
-		 loopback_en ? "on" : "off");
+	pos += scnprintf(buf + pos, len - pos, "app loopback: %s\n",
+			 state_str[loopback_en]);
 
 	hclge_cmd_setup_basic_desc(&desc, HCLGE_OPC_COMMON_LOOPBACK, true);
 	ret = hclge_cmd_send(&hdev->hw, &desc, 1);
@@ -1599,27 +1602,30 @@ static void hclge_dbg_dump_loopback(struct hclge_dev *hdev)
 		dev_err(&hdev->pdev->dev,
 			"failed to dump common loopback status, ret = %d\n",
 			ret);
-		return;
+		return ret;
 	}
 
 	loopback_en = req_common->enable & HCLGE_CMD_SERDES_SERIAL_INNER_LOOP_B;
-	dev_info(&hdev->pdev->dev, "serdes serial loopback: %s\n",
-		 loopback_en ? "on" : "off");
+	pos += scnprintf(buf + pos, len - pos, "serdes serial loopback: %s\n",
+			 state_str[loopback_en]);
 
 	loopback_en = req_common->enable &
-			HCLGE_CMD_SERDES_PARALLEL_INNER_LOOP_B;
-	dev_info(&hdev->pdev->dev, "serdes parallel loopback: %s\n",
-		 loopback_en ? "on" : "off");
+			HCLGE_CMD_SERDES_PARALLEL_INNER_LOOP_B ? 1 : 0;
+	pos += scnprintf(buf + pos, len - pos, "serdes parallel loopback: %s\n",
+			 state_str[loopback_en]);
 
 	if (phydev) {
-		dev_info(&hdev->pdev->dev, "phy loopback: %s\n",
-			 phydev->loopback_enabled ? "on" : "off");
+		loopback_en = phydev->loopback_enabled;
+		pos += scnprintf(buf + pos, len - pos, "phy loopback: %s\n",
+				 state_str[loopback_en]);
 	} else if (hnae3_dev_phy_imp_supported(hdev)) {
 		loopback_en = req_common->enable &
 			      HCLGE_CMD_GE_PHY_INNER_LOOP_B;
-		dev_info(&hdev->pdev->dev, "phy loopback: %s\n",
-			 loopback_en ? "on" : "off");
+		pos += scnprintf(buf + pos, len - pos, "phy loopback: %s\n",
+				 state_str[loopback_en]);
 	}
+
+	return 0;
 }
 
 /* hclge_dbg_dump_mac_tnl_status: print message about mac tnl interrupt
@@ -1785,7 +1791,6 @@ int hclge_dbg_run_cmd(struct hnae3_handle *handle, const char *cmd_buf)
 {
 #define DUMP_REG	"dump reg"
 #define DUMP_TM_MAP	"dump tm map"
-#define DUMP_LOOPBACK	"dump loopback"
 #define DUMP_INTERRUPT	"dump intr"
 
 	struct hclge_vport *vport = hclge_get_vport(handle);
@@ -1818,9 +1823,6 @@ int hclge_dbg_run_cmd(struct hnae3_handle *handle, const char *cmd_buf)
 					  &cmd_buf[sizeof("dump ncl_config")]);
 	} else if (strncmp(cmd_buf, "dump mac tnl status", 19) == 0) {
 		hclge_dbg_dump_mac_tnl_status(hdev);
-	} else if (strncmp(cmd_buf, DUMP_LOOPBACK,
-		   strlen(DUMP_LOOPBACK)) == 0) {
-		hclge_dbg_dump_loopback(hdev);
 	} else if (strncmp(cmd_buf, "dump qs shaper", 14) == 0) {
 		hclge_dbg_dump_qs_shaper(hdev,
 					 &cmd_buf[sizeof("dump qs shaper")]);
@@ -1860,6 +1862,10 @@ static const struct hclge_dbg_func hclge_dbg_cmd_func[] = {
 		.cmd = HNAE3_DBG_CMD_MNG_TBL,
 		.dbg_dump = hclge_dbg_dump_mng_table,
 	},
+	{
+		.cmd = HNAE3_DBG_CMD_LOOPBACK,
+		.dbg_dump = hclge_dbg_dump_loopback,
+	},
 };
 
 int hclge_dbg_read_cmd(struct hnae3_handle *handle, enum hnae3_dbg_cmd cmd,