bnxt_en: Add ethtool mac loopback self test.

The mac loopback self test operates in polling mode.  To support that,
we need to add functions to open and close the NIC half way.  The half
open mode allows the rings to operate without IRQ and NAPI.  We
use the XDP transmit function to send the loopback packet.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 156 insertions, 9 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index 711d7fd56d26..ecb441724b10 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -18,6 +18,7 @@
 #include <linux/firmware.h>
 #include "bnxt_hsi.h"
 #include "bnxt.h"
+#include "bnxt_xdp.h"
 #include "bnxt_ethtool.h"
 #include "bnxt_nvm_defs.h"	/* NVRAM content constant and structure defs */
 #include "bnxt_fw_hdr.h"	/* Firmware hdr constant and structure defs */
@@ -2177,6 +2178,130 @@ static int bnxt_set_phys_id(struct net_device *dev,
 	return rc;
 }
 
+static int bnxt_hwrm_mac_loopback(struct bnxt *bp, bool enable)
+{
+	struct hwrm_port_mac_cfg_input req = {0};
+
+	bnxt_hwrm_cmd_hdr_init(bp, &req, HWRM_PORT_MAC_CFG, -1, -1);
+
+	req.enables = cpu_to_le32(PORT_MAC_CFG_REQ_ENABLES_LPBK);
+	if (enable)
+		req.lpbk = PORT_MAC_CFG_REQ_LPBK_LOCAL;
+	else
+		req.lpbk = PORT_MAC_CFG_REQ_LPBK_NONE;
+	return hwrm_send_message(bp, &req, sizeof(req), HWRM_CMD_TIMEOUT);
+}
+
+static int bnxt_rx_loopback(struct bnxt *bp, struct bnxt_napi *bnapi,
+			    u32 raw_cons, int pkt_size)
+{
+	struct bnxt_cp_ring_info *cpr = &bnapi->cp_ring;
+	struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
+	struct bnxt_sw_rx_bd *rx_buf;
+	struct rx_cmp *rxcmp;
+	u16 cp_cons, cons;
+	u8 *data;
+	u32 len;
+	int i;
+
+	cp_cons = RING_CMP(raw_cons);
+	rxcmp = (struct rx_cmp *)
+		&cpr->cp_desc_ring[CP_RING(cp_cons)][CP_IDX(cp_cons)];
+	cons = rxcmp->rx_cmp_opaque;
+	rx_buf = &rxr->rx_buf_ring[cons];
+	data = rx_buf->data_ptr;
+	len = le32_to_cpu(rxcmp->rx_cmp_len_flags_type) >> RX_CMP_LEN_SHIFT;
+	if (len != pkt_size)
+		return -EIO;
+	i = ETH_ALEN;
+	if (!ether_addr_equal(data + i, bnapi->bp->dev->dev_addr))
+		return -EIO;
+	i += ETH_ALEN;
+	for (  ; i < pkt_size; i++) {
+		if (data[i] != (u8)(i & 0xff))
+			return -EIO;
+	}
+	return 0;
+}
+
+static int bnxt_poll_loopback(struct bnxt *bp, int pkt_size)
+{
+	struct bnxt_napi *bnapi = bp->bnapi[0];
+	struct bnxt_cp_ring_info *cpr;
+	struct tx_cmp *txcmp;
+	int rc = -EIO;
+	u32 raw_cons;
+	u32 cons;
+	int i;
+
+	cpr = &bnapi->cp_ring;
+	raw_cons = cpr->cp_raw_cons;
+	for (i = 0; i < 200; i++) {
+		cons = RING_CMP(raw_cons);
+		txcmp = &cpr->cp_desc_ring[CP_RING(cons)][CP_IDX(cons)];
+
+		if (!TX_CMP_VALID(txcmp, raw_cons)) {
+			udelay(5);
+			continue;
+		}
+
+		/* The valid test of the entry must be done first before
+		 * reading any further.
+		 */
+		dma_rmb();
+		if (TX_CMP_TYPE(txcmp) == CMP_TYPE_RX_L2_CMP) {
+			rc = bnxt_rx_loopback(bp, bnapi, raw_cons, pkt_size);
+			raw_cons = NEXT_RAW_CMP(raw_cons);
+			raw_cons = NEXT_RAW_CMP(raw_cons);
+			break;
+		}
+		raw_cons = NEXT_RAW_CMP(raw_cons);
+	}
+	cpr->cp_raw_cons = raw_cons;
+	return rc;
+}
+
+static int bnxt_run_loopback(struct bnxt *bp)
+{
+	struct bnxt_tx_ring_info *txr = &bp->tx_ring[0];
+	int pkt_size, i = 0;
+	struct sk_buff *skb;
+	dma_addr_t map;
+	u8 *data;
+	int rc;
+
+	pkt_size = min(bp->dev->mtu + ETH_HLEN, bp->rx_copy_thresh);
+	skb = netdev_alloc_skb(bp->dev, pkt_size);
+	if (!skb)
+		return -ENOMEM;
+	data = skb_put(skb, pkt_size);
+	eth_broadcast_addr(data);
+	i += ETH_ALEN;
+	ether_addr_copy(&data[i], bp->dev->dev_addr);
+	i += ETH_ALEN;
+	for ( ; i < pkt_size; i++)
+		data[i] = (u8)(i & 0xff);
+
+	map = dma_map_single(&bp->pdev->dev, skb->data, pkt_size,
+			     PCI_DMA_TODEVICE);
+	if (dma_mapping_error(&bp->pdev->dev, map)) {
+		dev_kfree_skb(skb);
+		return -EIO;
+	}
+	bnxt_xmit_xdp(bp, txr, map, pkt_size, 0);
+
+	/* Sync BD data before updating doorbell */
+	wmb();
+
+	writel(DB_KEY_TX | txr->tx_prod, txr->tx_doorbell);
+	writel(DB_KEY_TX | txr->tx_prod, txr->tx_doorbell);
+	rc = bnxt_poll_loopback(bp, pkt_size);
+
+	dma_unmap_single(&bp->pdev->dev, map, pkt_size, PCI_DMA_TODEVICE);
+	dev_kfree_skb(skb);
+	return rc;
+}
+
 static int bnxt_run_fw_tests(struct bnxt *bp, u8 test_mask, u8 *test_results)
 {
 	struct hwrm_selftest_exec_output *resp = bp->hwrm_cmd_resp_addr;
@@ -2193,7 +2318,8 @@ static int bnxt_run_fw_tests(struct bnxt *bp, u8 test_mask, u8 *test_results)
 	return rc;
 }
 
-#define BNXT_DRV_TESTS			0
+#define BNXT_DRV_TESTS			1
+#define BNXT_MACLPBK_TEST_IDX		(bp->num_tests - BNXT_DRV_TESTS)
 
 static void bnxt_self_test(struct net_device *dev, struct ethtool_test *etest,
 			   u64 *buf)
@@ -2236,6 +2362,23 @@ static void bnxt_self_test(struct net_device *dev, struct ethtool_test *etest,
 		if (rc)
 			return;
 		bnxt_run_fw_tests(bp, test_mask, &test_results);
+
+		buf[BNXT_MACLPBK_TEST_IDX] = 1;
+		bnxt_hwrm_mac_loopback(bp, true);
+		msleep(250);
+		rc = bnxt_half_open_nic(bp);
+		if (rc) {
+			bnxt_hwrm_mac_loopback(bp, false);
+			etest->flags |= ETH_TEST_FL_FAILED;
+			return;
+		}
+		if (bnxt_run_loopback(bp))
+			etest->flags |= ETH_TEST_FL_FAILED;
+		else
+			buf[BNXT_MACLPBK_TEST_IDX] = 0;
+
+		bnxt_half_close_nic(bp);
+		bnxt_hwrm_mac_loopback(bp, false);
 		bnxt_open_nic(bp, false, true);
 	}
 	for (i = 0; i < bp->num_tests - BNXT_DRV_TESTS; i++) {
@@ -2281,14 +2424,18 @@ void bnxt_ethtool_init(struct bnxt *bp)
 		char *str = test_info->string[i];
 		char *fw_str = resp->test0_name + i * 32;
 
-		strlcpy(str, fw_str, ETH_GSTRING_LEN);
-		strncat(str, " test", ETH_GSTRING_LEN - strlen(str));
-		if (test_info->offline_mask & (1 << i))
-			strncat(str, " (offline)",
-				ETH_GSTRING_LEN - strlen(str));
-		else
-			strncat(str, " (online)",
-				ETH_GSTRING_LEN - strlen(str));
+		if (i == BNXT_MACLPBK_TEST_IDX) {
+			strcpy(str, "Mac loopback test (offline)");
+		} else {
+			strlcpy(str, fw_str, ETH_GSTRING_LEN);
+			strncat(str, " test", ETH_GSTRING_LEN - strlen(str));
+			if (test_info->offline_mask & (1 << i))
+				strncat(str, " (offline)",
+					ETH_GSTRING_LEN - strlen(str));
+			else
+				strncat(str, " (online)",
+					ETH_GSTRING_LEN - strlen(str));
+		}
 	}
 
 ethtool_init_exit: