[PATCH net-next v6 2/2] net: ti: icssg-prueth: Add ethtool ops for Frame Preemption MAC Merge
Meghana Malladi
m-malladi at ti.com
Thu Jun 4 06:45:08 PDT 2026
On 5/26/26 01:05, Maxime Chevallier wrote:
> Hi,
>
> On 5/25/26 20:27, Meghana Malladi wrote:
>> From: MD Danish Anwar <danishanwar at ti.com>
>>
>> Add driver support for viewing and changing the MAC Merge sublayer
>> parameters via ethtool ops: .set_mm(), .get_mm() and .get_mm_stats().
>>
>> The minimum size of non-final mPacket fragments supported by the firmware
>> without leading errors is 64 Bytes (including FCS). Verify time
>> bounded to
>> 1-128 ms per 802.3-2018 clause 30.14.1.6. Add a check to ensure
>> user passed tx_min_frag_size argument via ethtool, honors this.
>> Add pa stats registers to check statistics for preemption, which can be
>> dumped using ethtool ops.
>>
>> Fix emac_get_stat_by_name() to return u64 instead of int and return 0 on
>> error instead of -EINVAL. This prevents invalid stat lookups from
>> corrupting
>> output stats with signed error codes cast to u64. Error conditions are
>> still
>> logged via netdev_err().
>>
>> Signed-off-by: MD Danish Anwar <danishanwar at ti.com>
>> Signed-off-by: Meghana Malladi <m-malladi at ti.com>
>> ---
>>
>> v6-v5:
>> - Initialize tx_min_frag_size and verify_time with valid values
>> to avoid returning corrupted values during get_mm()
>> - Fix rx_min_frag_size to ETH_ZLEN excluding ETH_FCS_LEN
>> - Fix return codes for emac_set_mm()
>> All the above changes address the comments raised by sashiko
>>
>> drivers/net/ethernet/ti/icssg/icssg_ethtool.c | 106 ++++++++++++++++++
>> drivers/net/ethernet/ti/icssg/icssg_prueth.h | 7 +-
>> drivers/net/ethernet/ti/icssg/icssg_qos.h | 46 ++++++++
>> drivers/net/ethernet/ti/icssg/icssg_stats.c | 4 +-
>> drivers/net/ethernet/ti/icssg/icssg_stats.h | 7 +-
>> .../net/ethernet/ti/icssg/icssg_switch_map.h | 5 +
>> 6 files changed, 168 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/ti/icssg/icssg_ethtool.c b/drivers/
>> net/ethernet/ti/icssg/icssg_ethtool.c
>> index b715af21d23ac..ee940051644d6 100644
>> --- a/drivers/net/ethernet/ti/icssg/icssg_ethtool.c
>> +++ b/drivers/net/ethernet/ti/icssg/icssg_ethtool.c
>> @@ -294,6 +294,109 @@ static int emac_set_per_queue_coalesce(struct
>> net_device *ndev, u32 queue,
>> return 0;
>> }
>> +static int emac_get_mm(struct net_device *ndev, struct
>> ethtool_mm_state *state)
>> +{
>> + struct prueth_emac *emac = netdev_priv(ndev);
>> + struct prueth_qos_iet *iet = &emac->qos.iet;
>> + enum icssg_ietfpe_verify_states verify_status;
>> +
>> + if (emac->is_sr1)
>> + return -EOPNOTSUPP;
>> +
>> + mutex_lock(&iet->fpe_lock);
>> + state->tx_enabled = iet->fpe_enabled;
>> + state->tx_min_frag_size = iet->tx_min_frag_size;
>> + state->tx_active = iet->fpe_active;
>> + state->verify_enabled = iet->mac_verify_configure;
>> + state->verify_time = iet->verify_time_ms;
>> + verify_status = iet->verify_status;
>> + mutex_unlock(&iet->fpe_lock);
>> +
>> + state->rx_min_frag_size = ETH_ZLEN;
>> + state->pmac_enabled = true;
>> +
>> + switch (verify_status) {
>> + case ICSSG_IETFPE_STATE_DISABLED:
>> + state->verify_status = ETHTOOL_MM_VERIFY_STATUS_DISABLED;
>> + break;
>> + case ICSSG_IETFPE_STATE_INITIAL:
>> + state->verify_status = ETHTOOL_MM_VERIFY_STATUS_INITIAL;
>> + break;
>> + case ICSSG_IETFPE_STATE_VERIFYING:
>> + state->verify_status = ETHTOOL_MM_VERIFY_STATUS_VERIFYING;
>> + break;
>> + case ICSSG_IETFPE_STATE_SUCCEEDED:
>> + state->verify_status = ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED;
>> + break;
>> + case ICSSG_IETFPE_STATE_FAILED:
>> + state->verify_status = ETHTOOL_MM_VERIFY_STATUS_FAILED;
>> + break;
>> + default:
>> + state->verify_status = ETHTOOL_MM_VERIFY_STATUS_UNKNOWN;
>> + break;
>> + }
>> +
>> + /* 802.3-2018 clause 30.14.1.6, says that the aMACMergeVerifyTime
>> + * variable has a range between 1 and 128 ms inclusive. Limit to
>> that.
>> + */
>> + state->max_verify_time = ETHTOOL_MM_MAX_VERIFY_TIME_MS;
>> +
>> + return 0;
>> +}
>> +
>> +static int emac_set_mm(struct net_device *ndev, struct ethtool_mm_cfg
>> *cfg,
>> + struct netlink_ext_ack *extack)
>> +{
>> + struct prueth_emac *emac = netdev_priv(ndev);
>> + struct prueth_qos_iet *iet = &emac->qos.iet;
>> + int err;
>> +
>> + if (emac->is_sr1)
>> + return -EOPNOTSUPP;
>> +
>> + if (!cfg->pmac_enabled) {
>> + NL_SET_ERR_MSG_MOD(extack, "preemptible MAC is always enabled");
>> + return -EOPNOTSUPP;
>> + }
>> +
>> + err = icssg_qos_validate_tx_min_frag_size(cfg->tx_min_frag_size,
>> extack);
>> + if (err)
>> + return err;
>> +
>> + err = icssg_qos_validate_verify_time(cfg->verify_time, extack);
>> + if (err)
>> + return err;
>
> The ethnl code already validates the verify_time :
>
> https://elixir.bootlin.com/linux/v7.0.9/source/net/ethtool/mm.c#L153
>
I remember getting a comment asking me to add a comment or check to
validate tx_min_frag_size, I don't remember at this point why I added
for verify_time as well, lost track in the comments lot. I will remove
it. Just to confirm, do I need icssg_qos_validate_tx_min_frag_size() or
can I remove it as well ?
>> +
>> + mutex_lock(&iet->fpe_lock);
>> + iet->verify_time_ms = cfg->verify_time;
>> + iet->tx_min_frag_size = cfg->tx_min_frag_size;
>> + iet->fpe_enabled = cfg->tx_enabled;
>> + iet->mac_verify_configure = cfg->verify_enabled;
>> + err = icssg_config_ietfpe(ndev, cfg->tx_enabled);
>> + mutex_unlock(&iet->fpe_lock);
>> +
>> + return err;
>> +}
>> +
>> +static void emac_get_mm_stats(struct net_device *ndev,
>> + struct ethtool_mm_stats *s)
>> +{
>> + struct prueth_emac *emac = netdev_priv(ndev);
>> +
>> + if (emac->is_sr1)
>> + return;
>> +
>> + if (!emac->prueth->pa_stats)
>> + return;
>> +
>> + /* MACMergeHoldCount stats is not tracked by the firmware */
>> + s->MACMergeFrameAssOkCount = emac_get_stat_by_name(emac,
>> "FW_PREEMPT_ASSEMBLY_OK");
>> + s->MACMergeFrameAssErrorCount = emac_get_stat_by_name(emac,
>> "FW_PREEMPT_ASSEMBLY_ERR");
>> + s->MACMergeFragCountRx = emac_get_stat_by_name(emac,
>> "FW_PREEMPT_FRAG_CNT_RX");
>> + s->MACMergeFragCountTx = emac_get_stat_by_name(emac,
>> "FW_PREEMPT_FRAG_CNT_TX");
>> + s->MACMergeFrameSmdErrorCount = emac_get_stat_by_name(emac,
>> "FW_PREEMPT_BAD_FRAG");
>> +}
>> +
>> const struct ethtool_ops icssg_ethtool_ops = {
>> .get_drvinfo = emac_get_drvinfo,
>> .get_msglevel = emac_get_msglevel,
>> @@ -317,5 +420,8 @@ const struct ethtool_ops icssg_ethtool_ops = {
>> .set_eee = emac_set_eee,
>> .nway_reset = emac_nway_reset,
>> .get_rmon_stats = emac_get_rmon_stats,
>> + .get_mm = emac_get_mm,
>> + .set_mm = emac_set_mm,
>> + .get_mm_stats = emac_get_mm_stats,
>> };
>> EXPORT_SYMBOL_GPL(icssg_ethtool_ops);
>> diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/
>> net/ethernet/ti/icssg/icssg_prueth.h
>> index 85f7017d2c8e7..61320c252bec2 100644
>> --- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h
>> +++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
>> @@ -45,6 +45,7 @@
>> #include "icss_iep.h"
>> #include "icssg_switch_map.h"
>> #include "icssg_qos.h"
>> +#include "icssg_stats.h"
>> #define PRUETH_MAX_MTU (2000 - ETH_HLEN - ETH_FCS_LEN)
>> #define PRUETH_MIN_PKT_SIZE (VLAN_ETH_ZLEN)
>> @@ -58,8 +59,8 @@
>> #define ICSSG_MAX_RFLOWS 8 /* per slice */
>> -#define ICSSG_NUM_PA_STATS 32
>> -#define ICSSG_NUM_MIIG_STATS 60
>> +#define ICSSG_NUM_PA_STATS ARRAY_SIZE(icssg_all_pa_stats)
>> +#define ICSSG_NUM_MIIG_STATS ARRAY_SIZE(icssg_all_miig_stats)
>> /* Number of ICSSG related stats */
>> #define ICSSG_NUM_STATS (ICSSG_NUM_MIIG_STATS + ICSSG_NUM_PA_STATS)
>> #define ICSSG_NUM_STANDARD_STATS 31
>> @@ -460,7 +461,7 @@ int emac_fdb_flow_id_updated(struct prueth_emac
>> *emac);
>> void icssg_stats_work_handler(struct work_struct *work);
>> void emac_update_hardware_stats(struct prueth_emac *emac);
>> -int emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name);
>> +u64 emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name);
>> /* Common functions */
>> void prueth_cleanup_rx_chns(struct prueth_emac *emac,
>> diff --git a/drivers/net/ethernet/ti/icssg/icssg_qos.h b/drivers/net/
>> ethernet/ti/icssg/icssg_qos.h
>> index 9355e96bbcda8..87ca031afcaa4 100644
>> --- a/drivers/net/ethernet/ti/icssg/icssg_qos.h
>> +++ b/drivers/net/ethernet/ti/icssg/icssg_qos.h
>> @@ -13,6 +13,7 @@
>> #define ICSSG_EXPRESS_Q_MASK_ALL 0xFF
>> #define ICSSG_IET_MAX_VERIFY_TIME 128
>> #define ICSSG_IET_MIN_VERIFY_TIME 1
>> +#define ICSSG_IET_MAX_TX_MIN_FRAG_SIZE 252
>> /**
>> * enum icssg_ietfpe_verify_states - status of MAC Merge Verify
>> returned by firmware
>> @@ -63,4 +64,49 @@ void icssg_qos_link_state_update(struct net_device
>> *ndev);
>> int icssg_qos_ndo_setup_tc(struct net_device *ndev, enum
>> tc_setup_type type,
>> void *type_data);
>> int icssg_config_ietfpe(struct net_device *ndev, bool enable);
>> +static inline int icssg_qos_validate_tx_min_frag_size(u32 min_frag_size,
>> + struct netlink_ext_ack *extack)
>> +{
>> + /* Firmware takes min_frag_size including FCS length.
>> + * The firmware requires the fragment size (including FCS) to be
>> + * a multiple of 64 bytes. Since 64 bytes = ETH_ZLEN + ETH_FCS_LEN,
>> + * valid user-facing values are: 60, 124, 188, 252.
>> + */
>> +
>> + if (min_frag_size < ETH_ZLEN) {
>> + NL_SET_ERR_MSG_MOD(extack,
>> + "tx_min_frag_size must be at least 60 bytes");
>> + return -EINVAL;
>> + }
>> +
>> + if (min_frag_size > ICSSG_IET_MAX_TX_MIN_FRAG_SIZE) {
>> + NL_SET_ERR_MSG_MOD(extack,
>> + "tx_min_frag_size must not exceed 252 bytes");
>> + return -EINVAL;
>> + }
>> +
>> + if ((min_frag_size + ETH_FCS_LEN) % (ETH_ZLEN + ETH_FCS_LEN)) {
>> + NL_SET_ERR_MSG_MOD(extack,
>> + "tx_min_frag_size must be a multiple of 64 bytes
>> minus 4");
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>
> Is there any reason this helper is in a header file instead
> of being directly in icssg_ethtool.c ?
>
I don't have any strong reason as such, I didn't want to put any helper
functions in icssg_ethtool.c.
>> +
>> +static inline int icssg_qos_validate_verify_time(u32 verify_time_ms,
>> + struct netlink_ext_ack *extack)
>> +{
>> + /* 802.3-2018 clause 30.14.1.6: aMACMergeVerifyTime must be
>> + * between 1 and 128 ms inclusive
>> + */
>> + if (verify_time_ms < ICSSG_IET_MIN_VERIFY_TIME ||
>> + verify_time_ms > ICSSG_IET_MAX_VERIFY_TIME) {
>> + NL_SET_ERR_MSG_MOD(extack,
>> + "verify_time must be between 1 and 128 ms");
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>
> And this shouldn't be needed as the ethnl mm code already validates
> these boundaries, as they are straight from the standard.
>
Will remove this is my next version.
>> #endif /* __NET_TI_ICSSG_QOS_H */
>> diff --git a/drivers/net/ethernet/ti/icssg/icssg_stats.c b/drivers/
>> net/ethernet/ti/icssg/icssg_stats.c
>> index 7159baa0155cf..cfdb6f5dc5da1 100644
>> --- a/drivers/net/ethernet/ti/icssg/icssg_stats.c
>> +++ b/drivers/net/ethernet/ti/icssg/icssg_stats.c
>> @@ -74,7 +74,7 @@ void icssg_stats_work_handler(struct work_struct *work)
>> }
>> EXPORT_SYMBOL_GPL(icssg_stats_work_handler);
>> -int emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name)
>> +u64 emac_get_stat_by_name(struct prueth_emac *emac, char *stat_name)
>> {
>> int i;
>> @@ -91,5 +91,5 @@ int emac_get_stat_by_name(struct prueth_emac *emac,
>> char *stat_name)
>> }
>> netdev_err(emac->ndev, "Invalid stats %s\n", stat_name);
>> - return -EINVAL;
>> + return 0;
>> }
>> diff --git a/drivers/net/ethernet/ti/icssg/icssg_stats.h b/drivers/
>> net/ethernet/ti/icssg/icssg_stats.h
>> index 5ec0b38e0c67d..8073deac35c3e 100644
>> --- a/drivers/net/ethernet/ti/icssg/icssg_stats.h
>> +++ b/drivers/net/ethernet/ti/icssg/icssg_stats.h
>> @@ -8,8 +8,6 @@
>> #ifndef __NET_TI_ICSSG_STATS_H
>> #define __NET_TI_ICSSG_STATS_H
>> -#include "icssg_prueth.h"
>> -
>> #define STATS_TIME_LIMIT_1G_MS 25000 /* 25 seconds @ 1G */
>> struct miig_stats_regs {
>> @@ -189,6 +187,11 @@ static const struct icssg_pa_stats
>> icssg_all_pa_stats[] = {
>> ICSSG_PA_STATS(FW_INF_DROP_PRIOTAGGED),
>> ICSSG_PA_STATS(FW_INF_DROP_NOTAG),
>> ICSSG_PA_STATS(FW_INF_DROP_NOTMEMBER),
>> + ICSSG_PA_STATS(FW_PREEMPT_BAD_FRAG),
>> + ICSSG_PA_STATS(FW_PREEMPT_ASSEMBLY_ERR),
>> + ICSSG_PA_STATS(FW_PREEMPT_FRAG_CNT_TX),
>> + ICSSG_PA_STATS(FW_PREEMPT_ASSEMBLY_OK),
>> + ICSSG_PA_STATS(FW_PREEMPT_FRAG_CNT_RX),
>> ICSSG_PA_STATS(FW_RX_EOF_SHORT_FRMERR),
>> ICSSG_PA_STATS(FW_RX_B0_DROP_EARLY_EOF),
>> ICSSG_PA_STATS(FW_TX_JUMBO_FRM_CUTOFF),
>> diff --git a/drivers/net/ethernet/ti/icssg/icssg_switch_map.h b/
>> drivers/net/ethernet/ti/icssg/icssg_switch_map.h
>> index 7e053b8af3ece..855fd4ed0b3f6 100644
>> --- a/drivers/net/ethernet/ti/icssg/icssg_switch_map.h
>> +++ b/drivers/net/ethernet/ti/icssg/icssg_switch_map.h
>> @@ -256,6 +256,11 @@
>> #define FW_INF_DROP_PRIOTAGGED 0x0148
>> #define FW_INF_DROP_NOTAG 0x0150
>> #define FW_INF_DROP_NOTMEMBER 0x0158
>> +#define FW_PREEMPT_BAD_FRAG 0x0160
>> +#define FW_PREEMPT_ASSEMBLY_ERR 0x0168
>> +#define FW_PREEMPT_FRAG_CNT_TX 0x0170
>> +#define FW_PREEMPT_ASSEMBLY_OK 0x0178
>> +#define FW_PREEMPT_FRAG_CNT_RX 0x0180
>> #define FW_RX_EOF_SHORT_FRMERR 0x0188
>> #define FW_RX_B0_DROP_EARLY_EOF 0x0190
>> #define FW_TX_JUMBO_FRM_CUTOFF 0x0198
>
> Maxime
Thanks,
Meghana
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