[PATCH net-next] ionic: Add .get_fec_stats ethtool handler

[PATCH net-next] ionic: Add .get_fec_stats ethtool handler

[Eric Joyner]

Reports FEC statistics totals and an 802.3ck FEC histogram. Per-lane counts
currently aren't supported, and the only expected histogram format from
firmware is the one with 16 bins from RS(544,514) FEC.

These are physical port counters, so virtual functions are skipped the
same way ionic_get_link_ext_stats() skips them, rather than reporting the
port's counters as if they belonged to the VF.

The reporting of these statistics is gated by DEV_CAP_EXTRA_STATS and
checks for IONIC_STAT_INVALID, since only the newest devices support
reporting all of these stats. Older devices can only report some of the
statistics or not at all, and so the output will properly exclude those
unsupported statistics.

Assisted-by: Claude:claude-opus-5
Signed-off-by: Eric Joyner <eric.joyner@amd.com>
---
v1: This is an updated version of the last patch that was not applied in
the series "ionic: Add .get_fec_stats ethtool handler", see:
https://lore.kernel.org/netdev/20260615182732.7d28e31a@kernel.org/

 .../ethernet/pensando/ionic/ionic_ethtool.c   | 85 +++++++++++++++++++
 1 file changed, 85 insertions(+)

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c b/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
index c4ab4b5caa0a..0d4bd49cf935 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
@@ -441,6 +441,90 @@ static int ionic_get_fecparam(struct net_device *netdev,
 	return 0;
 }
 
+#define IONIC_FEC_STAT(dst, src)			\
+	do {						\
+		__le64 __val = (src);			\
+							\
+		if (__val != IONIC_STAT_INVALID)	\
+			(dst) = le64_to_cpu(__val);	\
+	} while (0)
+
+static const struct ethtool_fec_hist_range ionic_fec_hist_ranges[] = {
+	{ 0, 0},
+	{ 1, 1},
+	{ 2, 2},
+	{ 3, 3},
+	{ 4, 4},
+	{ 5, 5},
+	{ 6, 6},
+	{ 7, 7},
+	{ 8, 8},
+	{ 9, 9},
+	{ 10, 10},
+	{ 11, 11},
+	{ 12, 12},
+	{ 13, 13},
+	{ 14, 14},
+	{ 15, 15},
+	{ 0, 0},
+};
+
+static void
+ionic_fill_fec_hist(const struct ionic_port_extra_stats *port_extra_stats,
+		    struct ethtool_fec_hist *hist)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(port_extra_stats->fec_codeword_error_bin); i++) {
+		if (port_extra_stats->fec_codeword_error_bin[i] == IONIC_STAT_INVALID)
+			return;
+
+		hist->values[i].sum =
+			le64_to_cpu(port_extra_stats->fec_codeword_error_bin[i]);
+	}
+
+	hist->ranges = ionic_fec_hist_ranges;
+}
+
+static void ionic_get_fec_stats(struct net_device *netdev,
+				struct ethtool_fec_stats *fec_stats,
+				struct ethtool_fec_hist *hist)
+{
+	struct ionic_port_extra_stats port_extra_stats;
+	struct ionic_lif *lif = netdev_priv(netdev);
+	struct ionic_port_info *port_info;
+
+	if (lif->ionic->pdev->is_virtfn)
+		return;
+
+	if (test_bit(IONIC_LIF_F_FW_RESET, lif->state))
+		return;
+
+	if (!(lif->ionic->ident.dev.capabilities &
+	      cpu_to_le64(IONIC_DEV_CAP_EXTRA_STATS)))
+		return;
+
+	port_info = lif->ionic->idev.port_info;
+	if (!port_info) {
+		netdev_err_once(netdev, "port_info not initialized\n");
+		return;
+	}
+
+	if (port_info->config.fec_type != IONIC_PORT_FEC_TYPE_RS)
+		return;
+
+	port_extra_stats = port_info->extra_stats;
+
+	IONIC_FEC_STAT(fec_stats->corrected_blocks.total,
+		       port_extra_stats.rsfec_correctable_blocks);
+	IONIC_FEC_STAT(fec_stats->uncorrectable_blocks.total,
+		       port_extra_stats.rsfec_uncorrectable_blocks);
+	IONIC_FEC_STAT(fec_stats->corrected_bits.total,
+		       port_extra_stats.fec_corrected_bits_total);
+
+	ionic_fill_fec_hist(&port_extra_stats, hist);
+}
+
 static int ionic_set_fecparam(struct net_device *netdev,
 			      struct ethtool_fecparam *fec)
 {
@@ -1177,6 +1261,7 @@ static const struct ethtool_ops ionic_ethtool_ops = {
 	.get_module_eeprom_by_page	= ionic_get_module_eeprom_by_page,
 	.get_pauseparam		= ionic_get_pauseparam,
 	.set_pauseparam		= ionic_set_pauseparam,
+	.get_fec_stats		= ionic_get_fec_stats,
 	.get_fecparam		= ionic_get_fecparam,
 	.set_fecparam		= ionic_set_fecparam,
 	.get_ts_info		= ionic_get_ts_info,

base-commit: 2fbade66245059c78daeaccfce13ecf499fffb51
-- 
2.17.1

Re: [PATCH net-next] ionic: Add .get_fec_stats ethtool handler

[Vadim Fedorenko]

On 31/07/2026 22:40, Eric Joyner wrote:
> Reports FEC statistics totals and an 802.3ck FEC histogram. Per-lane counts
> currently aren't supported, and the only expected histogram format from
> firmware is the one with 16 bins from RS(544,514) FEC.

does it mean the FW will return IONIC_STAT_INVALID for 100G CWDM4 mode
on newest devices?

Re: [PATCH net-next] ionic: Add .get_fec_stats ethtool handler

[Eric Joyner]

On 8/4/2026 3:27 AM, Vadim Fedorenko wrote:
> Caution: This message originated from an External Source. Use proper caution
> when opening attachments, clicking links, or responding.
> 
> 
> On 31/07/2026 22:40, Eric Joyner wrote:
>> Reports FEC statistics totals and an 802.3ck FEC histogram. Per-lane counts
>> currently aren't supported, and the only expected histogram format from
>> firmware is the one with 16 bins from RS(544,514) FEC.
> 
> does it mean the FW will return IONIC_STAT_INVALID for 100G CWDM4 mode
> on newest devices?
> 
> 

The only device we have that supports reporting these FEC histograms doesn't
have a PHY that supports 100G CWDM4; the IP block for it only supports PAM4
media types and not NRZ. So for now, it would return IONIC_STAT_INVALID for
that mode.

Though, I don't know if that'll be the case for future devices; maybe they will
support FEC histogram stat collection with NRZ media that has fewer than 16
histogram bins. I just don't know if it's worth supporting that possibility
right now since I don't know when or if that will happen.

- Eric

Re: [PATCH net-next] ionic: Add .get_fec_stats ethtool handler

[vadim.fedorenko]

On 14/08/2026 05:42, Eric Joyner wrote:
> On 8/4/2026 3:27 AM, Vadim Fedorenko wrote:
>> Caution: This message originated from an External Source. Use proper caution
>> when opening attachments, clicking links, or responding.
>>
>>
>> On 31/07/2026 22:40, Eric Joyner wrote:
>>> Reports FEC statistics totals and an 802.3ck FEC histogram. Per-lane counts
>>> currently aren't supported, and the only expected histogram format from
>>> firmware is the one with 16 bins from RS(544,514) FEC.
>>
>> does it mean the FW will return IONIC_STAT_INVALID for 100G CWDM4 mode
>> on newest devices?
>>
>>
> > The only device we have that supports reporting these FEC histograms doesn't
> have a PHY that supports 100G CWDM4; the IP block for it only supports PAM4
> media types and not NRZ. So for now, it would return IONIC_STAT_INVALID for
> that mode.
> > Though, I don't know if that'll be the case for future devices; maybe they will
> support FEC histogram stat collection with NRZ media that has fewer than 16
> histogram bins. I just don't know if it's worth supporting that possibility
> right now since I don't know when or if that will happen.

Ok, thanks for explaining.

Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>

Re: [PATCH net-next] ionic: Add .get_fec_stats ethtool handler

[Jakub Kicinski]

On Fri, 31 Jul 2026 14:40:21 -0700 Eric Joyner wrote:
> Reports FEC statistics totals and an 802.3ck FEC histogram. Per-lane counts
> currently aren't supported, and the only expected histogram format from
> firmware is the one with 16 bins from RS(544,514) FEC.

To be clear this patch is now too old for us to process, you need to
repost. Before you do - double check the 'shiko, it has things to say:
https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260731214021.15279-1-eric.joyner@amd.com

Re: [PATCH net-next] ionic: Add .get_fec_stats ethtool handler

[Eric Joyner]

On 8/14/2026 12:05 PM, Jakub Kicinski wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
> 
> 
> On Fri, 31 Jul 2026 14:40:21 -0700 Eric Joyner wrote:
>> Reports FEC statistics totals and an 802.3ck FEC histogram. Per-lane counts
>> currently aren't supported, and the only expected histogram format from
>> firmware is the one with 16 bins from RS(544,514) FEC.
> 
> To be clear this patch is now too old for us to process, you need to
> repost. Before you do - double check the 'shiko, it has things to say:
> https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260731214021.15279-1-eric.joyner@amd.com

Ok, I'll address the Sashiko review comments and resubmit.

But a couple questions: the Sashiko instance at this site looks like it's doing
more review than what the Sashiko bot at sashiko.dev does; should I be checking
this site for Sashiko reviews instead? As well, I don't think the upstream
Sashiko repository has support for cross-reviewing; is this site running on a
custom version or some early unreleased code?

- Eric

Re: [PATCH net-next] ionic: Add .get_fec_stats ethtool handler

[Jakub Kicinski]

On Fri, 14 Aug 2026 13:21:41 -0700 Eric Joyner wrote:
> But a couple questions: the Sashiko instance at this site looks like it's doing
> more review than what the Sashiko bot at sashiko.dev does; should I be checking
> this site for Sashiko reviews instead?

Probably as well more than instead

> As well, I don't think the upstream Sashiko repository has support
> for cross-reviewing; is this site running on a custom version or some
> early unreleased code?

Yes