[PATCH net-next v1 3/3] net: fec: add basic selftest support

From: Oleksij Rempel
Date: Tue Mar 30 2021 - 09:55:04 EST

Port some parts of the stmmac selftest to the FEC. This patch was tested
on iMX6DL.
With this tests it is possible to detect some basic issues like:
- MAC loopback fail: most probably wrong clock configuration.
- PHY loopback fail: incorrect RGMII timings, damaged traces, etc

Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
drivers/net/ethernet/freescale/Makefile | 2 +-
drivers/net/ethernet/freescale/fec.h | 6 +
drivers/net/ethernet/freescale/fec_main.c | 6 +
.../net/ethernet/freescale/fec_selftests.c | 425 ++++++++++++++++++
4 files changed, 438 insertions(+), 1 deletion(-)
create mode 100644 drivers/net/ethernet/freescale/fec_selftests.c

diff --git a/drivers/net/ethernet/freescale/Makefile b/drivers/net/ethernet/freescale/Makefile
index 67c436400352..b936c6fe5911 100644
--- a/drivers/net/ethernet/freescale/Makefile
+++ b/drivers/net/ethernet/freescale/Makefile
@@ -4,7 +4,7 @@
#

obj-$(CONFIG_FEC) += fec.o
-fec-objs :=fec_main.o fec_ptp.o
+fec-objs :=fec_main.o fec_ptp.o fec_selftests.o

obj-$(CONFIG_FEC_MPC52xx) += fec_mpc52xx.o
ifeq ($(CONFIG_FEC_MPC52xx_MDIO),y)
diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index 0602d5d5d2ee..ade6a80934bf 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -467,6 +467,9 @@ struct bufdesc_ex {
*/
#define FEC_QUIRK_NO_HARD_RESET (1 << 18)

+#define FEC_ENET_DRT (1 << 1)
+#define FEC_ENET_LOOP (1 << 0)
+
struct bufdesc_prop {
int qid;
/* Address of Rx and Tx buffers */
@@ -604,6 +607,9 @@ void fec_ptp_start_cyclecounter(struct net_device *ndev);
void fec_ptp_disable_hwts(struct net_device *ndev);
int fec_ptp_set(struct net_device *ndev, struct ifreq *ifr);
int fec_ptp_get(struct net_device *ndev, struct ifreq *ifr);
+void fec_selftest(struct net_device *ndev, struct ethtool_test *etest, u64 *data);
+int fec_selftest_get_count(void);
+void fec_selftest_get_strings(u8 *data);

/****************************************************************************/
#endif /* FEC_H */
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 3db882322b2b..2ca72f7b5b7d 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -2474,6 +2474,9 @@ static void fec_enet_get_strings(struct net_device *netdev,
{
int i;
switch (stringset) {
+ case ETH_SS_TEST:
+ fec_selftest_get_strings(data);
+ break;
case ETH_SS_STATS:
for (i = 0; i < ARRAY_SIZE(fec_stats); i++)
memcpy(data + i * ETH_GSTRING_LEN,
@@ -2485,6 +2488,8 @@ static void fec_enet_get_strings(struct net_device *netdev,
static int fec_enet_get_sset_count(struct net_device *dev, int sset)
{
switch (sset) {
+ case ETH_SS_TEST:
+ return fec_selftest_get_count();
case ETH_SS_STATS:
return ARRAY_SIZE(fec_stats);
default:
@@ -2738,6 +2743,7 @@ static const struct ethtool_ops fec_enet_ethtool_ops = {
.set_wol = fec_enet_set_wol,
.get_link_ksettings = phy_ethtool_get_link_ksettings,
.set_link_ksettings = phy_ethtool_set_link_ksettings,
+ .self_test = fec_selftest,
};

static int fec_enet_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd)
diff --git a/drivers/net/ethernet/freescale/fec_selftests.c b/drivers/net/ethernet/freescale/fec_selftests.c
new file mode 100644
index 000000000000..788213a6454f
--- /dev/null
+++ b/drivers/net/ethernet/freescale/fec_selftests.c
@@ -0,0 +1,425 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Synopsys, Inc. and/or its affiliates.
+ * stmmac Selftests Support
+ *
+ * Author: Jose Abreu <joabreu@xxxxxxxxxxxx>
+ *
+ * Ported from stmmac to the FEC by:
+ * Copyright (C) 2021 Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
+ */
+
+#include <linux/phy.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+
+#include "fec.h"
+
+struct fec_packet_attrs {
+ unsigned char *src;
+ unsigned char *dst;
+ u32 ip_src;
+ u32 ip_dst;
+ int tcp;
+ int sport;
+ int dport;
+ int timeout;
+ int size;
+ int max_size;
+ u8 id;
+ u16 queue_mapping;
+};
+
+struct fec_test_priv {
+ struct fec_packet_attrs *packet;
+ struct packet_type pt;
+ struct completion comp;
+ int double_vlan;
+ int vlan_id;
+ int ok;
+};
+
+struct fechdr {
+ __be32 version;
+ __be64 magic;
+ u8 id;
+} __packed;
+
+static u8 fec_test_next_id;
+
+#define FEC_TEST_PKT_SIZE (sizeof(struct ethhdr) + sizeof(struct iphdr) + \
+ sizeof(struct fechdr))
+#define FEC_TEST_PKT_MAGIC 0xdeadcafecafedeadULL
+#define FEC_LB_TIMEOUT msecs_to_jiffies(200)
+
+static struct sk_buff *fec_test_get_udp_skb(struct fec_enet_private *fep,
+ struct fec_packet_attrs *attr)
+{
+ struct sk_buff *skb = NULL;
+ struct udphdr *uhdr = NULL;
+ struct tcphdr *thdr = NULL;
+ struct fechdr *shdr;
+ struct ethhdr *ehdr;
+ struct iphdr *ihdr;
+ int iplen, size;
+
+ size = attr->size + FEC_TEST_PKT_SIZE;
+
+ if (attr->tcp)
+ size += sizeof(struct tcphdr);
+ else
+ size += sizeof(struct udphdr);
+
+ if (attr->max_size && (attr->max_size > size))
+ size = attr->max_size;
+
+ skb = netdev_alloc_skb(fep->netdev, size);
+ if (!skb)
+ return NULL;
+
+ prefetchw(skb->data);
+
+ ehdr = skb_push(skb, ETH_HLEN);
+ skb_reset_mac_header(skb);
+
+ skb_set_network_header(skb, skb->len);
+ ihdr = skb_put(skb, sizeof(*ihdr));
+
+ skb_set_transport_header(skb, skb->len);
+ if (attr->tcp)
+ thdr = skb_put(skb, sizeof(*thdr));
+ else
+ uhdr = skb_put(skb, sizeof(*uhdr));
+ eth_zero_addr(ehdr->h_dest);
+ if (attr->src)
+ ether_addr_copy(ehdr->h_source, attr->src);
+ if (attr->dst)
+ ether_addr_copy(ehdr->h_dest, attr->dst);
+
+ ehdr->h_proto = htons(ETH_P_IP);
+
+ if (attr->tcp) {
+ thdr->source = htons(attr->sport);
+ thdr->dest = htons(attr->dport);
+ thdr->doff = sizeof(struct tcphdr) / 4;
+ thdr->check = 0;
+ } else {
+ uhdr->source = htons(attr->sport);
+ uhdr->dest = htons(attr->dport);
+ uhdr->len = htons(sizeof(*shdr) + sizeof(*uhdr) + attr->size);
+ if (attr->max_size)
+ uhdr->len = htons(attr->max_size -
+ (sizeof(*ihdr) + sizeof(*ehdr)));
+ uhdr->check = 0;
+ }
+
+ ihdr->ihl = 5;
+ ihdr->ttl = 32;
+ ihdr->version = 4;
+ if (attr->tcp)
+ ihdr->protocol = IPPROTO_TCP;
+ else
+ ihdr->protocol = IPPROTO_UDP;
+ iplen = sizeof(*ihdr) + sizeof(*shdr) + attr->size;
+ if (attr->tcp)
+ iplen += sizeof(*thdr);
+ else
+ iplen += sizeof(*uhdr);
+
+ if (attr->max_size)
+ iplen = attr->max_size - sizeof(*ehdr);
+
+ ihdr->tot_len = htons(iplen);
+ ihdr->frag_off = 0;
+ ihdr->saddr = htonl(attr->ip_src);
+ ihdr->daddr = htonl(attr->ip_dst);
+ ihdr->tos = 0;
+ ihdr->id = 0;
+ ip_send_check(ihdr);
+
+ shdr = skb_put(skb, sizeof(*shdr));
+ shdr->version = 0;
+ shdr->magic = cpu_to_be64(FEC_TEST_PKT_MAGIC);
+ attr->id = fec_test_next_id;
+ shdr->id = fec_test_next_id++;
+
+ if (attr->size)
+ skb_put(skb, attr->size);
+ if (attr->max_size && (attr->max_size > skb->len))
+ skb_put(skb, attr->max_size - skb->len);
+
+ skb->csum = 0;
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ if (attr->tcp) {
+ thdr->check = ~tcp_v4_check(skb->len, ihdr->saddr, ihdr->daddr, 0);
+ skb->csum_start = skb_transport_header(skb) - skb->head;
+ skb->csum_offset = offsetof(struct tcphdr, check);
+ } else {
+ udp4_hwcsum(skb, ihdr->saddr, ihdr->daddr);
+ }
+
+ skb->protocol = htons(ETH_P_IP);
+ skb->pkt_type = PACKET_HOST;
+ skb->dev = fep->netdev;
+
+ return skb;
+}
+
+static int fec_test_loopback_validate(struct sk_buff *skb,
+ struct net_device *ndev,
+ struct packet_type *pt,
+ struct net_device *orig_ndev)
+{
+ struct fec_test_priv *tpriv = pt->af_packet_priv;
+ unsigned char *src = tpriv->packet->src;
+ unsigned char *dst = tpriv->packet->dst;
+ struct fechdr *shdr;
+ struct ethhdr *ehdr;
+ struct udphdr *uhdr;
+ struct tcphdr *thdr;
+ struct iphdr *ihdr;
+
+ skb = skb_unshare(skb, GFP_ATOMIC);
+ if (!skb)
+ goto out;
+
+ if (skb_linearize(skb))
+ goto out;
+ if (skb_headlen(skb) < (FEC_TEST_PKT_SIZE - ETH_HLEN))
+ goto out;
+
+ ehdr = (struct ethhdr *)skb_mac_header(skb);
+ if (dst) {
+ if (!ether_addr_equal_unaligned(ehdr->h_dest, dst))
+ goto out;
+ }
+
+ if (src) {
+ if (!ether_addr_equal_unaligned(ehdr->h_source, src))
+ goto out;
+ }
+
+ ihdr = ip_hdr(skb);
+ if (tpriv->double_vlan)
+ ihdr = (struct iphdr *)(skb_network_header(skb) + 4);
+
+ if (tpriv->packet->tcp) {
+ if (ihdr->protocol != IPPROTO_TCP)
+ goto out;
+
+ thdr = (struct tcphdr *)((u8 *)ihdr + 4 * ihdr->ihl);
+ if (thdr->dest != htons(tpriv->packet->dport))
+ goto out;
+
+ shdr = (struct fechdr *)((u8 *)thdr + sizeof(*thdr));
+ } else {
+ if (ihdr->protocol != IPPROTO_UDP)
+ goto out;
+
+ uhdr = (struct udphdr *)((u8 *)ihdr + 4 * ihdr->ihl);
+ if (uhdr->dest != htons(tpriv->packet->dport))
+ goto out;
+
+ shdr = (struct fechdr *)((u8 *)uhdr + sizeof(*uhdr));
+ }
+
+ if (shdr->magic != cpu_to_be64(FEC_TEST_PKT_MAGIC))
+ goto out;
+ if (tpriv->packet->id != shdr->id)
+ goto out;
+
+ tpriv->ok = true;
+ complete(&tpriv->comp);
+out:
+ kfree_skb(skb);
+ return 0;
+}
+
+static int __fec_test_loopback(struct fec_enet_private *fep,
+ struct fec_packet_attrs *attr)
+{
+ struct fec_test_priv *tpriv;
+ struct sk_buff *skb = NULL;
+ int ret = 0;
+
+ tpriv = kzalloc(sizeof(*tpriv), GFP_KERNEL);
+ if (!tpriv)
+ return -ENOMEM;
+
+ tpriv->ok = false;
+ init_completion(&tpriv->comp);
+
+ tpriv->pt.type = htons(ETH_P_IP);
+ tpriv->pt.func = fec_test_loopback_validate;
+ tpriv->pt.dev = fep->netdev;
+ tpriv->pt.af_packet_priv = tpriv;
+ tpriv->packet = attr;
+
+ skb = fec_test_get_udp_skb(fep, attr);
+ if (!skb) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+
+ ret = dev_direct_xmit(skb, attr->queue_mapping);
+ if (ret)
+ goto cleanup;
+
+ if (!attr->timeout)
+ attr->timeout = FEC_LB_TIMEOUT;
+
+ wait_for_completion_timeout(&tpriv->comp, attr->timeout);
+ ret = tpriv->ok ? 0 : -ETIMEDOUT;
+
+cleanup:
+ kfree(tpriv);
+ return ret;
+}
+
+static int fec_test_mac_loopback(struct net_device *ndev)
+{
+ struct fec_enet_private *fep = netdev_priv(ndev);
+ struct fec_packet_attrs attr = { };
+
+ attr.dst = ndev->dev_addr;
+ return __fec_test_loopback(fep, &attr);
+}
+
+static int fec_test_phy_loopback(struct net_device *ndev)
+{
+ struct fec_enet_private *fep = netdev_priv(ndev);
+ struct fec_packet_attrs attr = { };
+
+ attr.dst = ndev->dev_addr;
+ return __fec_test_loopback(fep, &attr);
+}
+
+static int fec_test_tcp(struct net_device *ndev)
+{
+ struct fec_enet_private *fep = netdev_priv(ndev);
+ struct fec_packet_attrs attr = { };
+
+ attr.dst = ndev->dev_addr;
+ attr.tcp = true;
+ return __fec_test_loopback(fep, &attr);
+}
+
+#define FEC_LOOPBACK_MAC 0
+#define FEC_LOOPBACK_PHY 1
+
+static const struct fec_test {
+ char name[ETH_GSTRING_LEN];
+ int lb;
+ int (*fn)(struct net_device *ndev);
+} fec_selftests[] = {
+ {
+ .name = "MAC Loopback, UDP ",
+ .lb = FEC_LOOPBACK_MAC,
+ .fn = fec_test_mac_loopback,
+ }, {
+ .name = "PHY Loopback, UDP ",
+ .lb = FEC_LOOPBACK_PHY,
+ .fn = fec_test_phy_loopback,
+ }, {
+ .name = "PHY Loopback, TCP ",
+ .lb = FEC_LOOPBACK_PHY,
+ .fn = fec_test_tcp,
+ },
+};
+
+void fec_selftest(struct net_device *ndev,
+ struct ethtool_test *etest, u64 *buf)
+{
+ struct fec_enet_private *fep = netdev_priv(ndev);
+ int count = fec_selftest_get_count();
+ u32 tmp, r_cntrl;
+ int i, ret;
+
+ memset(buf, 0, sizeof(*buf) * count);
+ fec_test_next_id = 0;
+
+ if (etest->flags != ETH_TEST_FL_OFFLINE) {
+ netdev_err(ndev, "Only offline tests are supported\n");
+ etest->flags |= ETH_TEST_FL_FAILED;
+ return;
+ } else if (!netif_carrier_ok(ndev)) {
+ netdev_err(ndev, "You need valid Link to execute tests\n");
+ etest->flags |= ETH_TEST_FL_FAILED;
+ return;
+ }
+
+ /* Wait for queues drain */
+ msleep(200);
+ for (i = 0; i < count; i++) {
+ ret = 0;
+
+
+ switch (fec_selftests[i].lb) {
+ case FEC_LOOPBACK_PHY:
+ ret = -EOPNOTSUPP;
+ if (ndev->phydev)
+ ret = phy_loopback(ndev->phydev, true);
+ if (!ret)
+ break;
+ fallthrough;
+ case FEC_LOOPBACK_MAC:
+ /* disable half duplex if present and enable MAC loop back */
+ r_cntrl = readl(fep->hwp + FEC_R_CNTRL);
+ tmp = FEC_ENET_LOOP | (r_cntrl & ~FEC_ENET_DRT);
+ writel(tmp, fep->hwp + FEC_R_CNTRL);
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ break;
+ }
+
+ /*
+ * First tests will always be MAC / PHY loobpack. If any of
+ * them is not supported we abort earlier.
+ */
+ if (ret) {
+ netdev_err(ndev, "Loopback is not supported\n");
+ etest->flags |= ETH_TEST_FL_FAILED;
+ break;
+ }
+
+ ret = fec_selftests[i].fn(ndev);
+ if (ret && (ret != -EOPNOTSUPP))
+ etest->flags |= ETH_TEST_FL_FAILED;
+ buf[i] = ret;
+
+ switch (fec_selftests[i].lb) {
+ case FEC_LOOPBACK_PHY:
+ ret = -EOPNOTSUPP;
+ if (ndev->phydev)
+ ret = phy_loopback(ndev->phydev, false);
+ if (!ret)
+ break;
+ fallthrough;
+ case FEC_LOOPBACK_MAC:
+ writel(r_cntrl, fep->hwp + FEC_R_CNTRL);
+ break;
+ default:
+ break;
+ }
+ }
+}
+
+int fec_selftest_get_count(void)
+{
+ return ARRAY_SIZE(fec_selftests);
+}
+
+void fec_selftest_get_strings(u8 *data)
+{
+ u8 *p = data;
+ int i;
+
+ for (i = 0; i < fec_selftest_get_count(); i++) {
+ snprintf(p, ETH_GSTRING_LEN, "%2d. %s", i + 1,
+ fec_selftests[i].name);
+ p += ETH_GSTRING_LEN;
+ }
+}
+
+
--
2.29.2