[PATCH v9 net-next 2/4] net: enetc: update max chained Tx BD number for i.MX95 ENETC

Wei Fang
2024-12-19T06:04:31Z

The max chained Tx BDs of latest ENETC (i.MX95 ENETC, rev 4.1) has been
increased to 63, but since the range of MAX_SKB_FRAGS is 17~45, so for
i.MX95 ENETC and later revision, it is better to set ENETC4_MAX_SKB_FRAGS
to MAX_SKB_FRAGS.

In addition, add max_frags in struct enetc_drvdata to indicate the max
chained BDs supported by device. Because the max number of chained BDs
supported by LS1028A and i.MX95 ENETC is different.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Reviewed-by: Simon Horman <horms@kernel.org>
---
v2:
1. Refine the commit message
2. Add Reviewed-by tag
v3 ~ v9: no changes
---
drivers/net/ethernet/freescale/enetc/enetc.c | 13 +++++++++----
drivers/net/ethernet/freescale/enetc/enetc.h | 13 +++++++++++--
.../net/ethernet/freescale/enetc/enetc_pf_common.c | 1 +
drivers/net/ethernet/freescale/enetc/enetc_vf.c | 1 +
4 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index 88f12c88110f..76c33506991b 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -534,6 +534,7 @@ static void enetc_tso_complete_csum(struct enetc_bdr *tx_ring, struct tso_t *tso

static int enetc_map_tx_tso_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb)
{
+ struct enetc_ndev_priv *priv = netdev_priv(tx_ring->ndev);
int hdr_len, total_len, data_len;
struct enetc_tx_swbd *tx_swbd;
union enetc_tx_bd *txbd;
@@ -599,7 +600,7 @@ static int enetc_map_tx_tso_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb
bd_data_num++;
tso_build_data(skb, &tso, size);

- if (unlikely(bd_data_num >= ENETC_MAX_SKB_FRAGS && data_len))
+ if (unlikely(bd_data_num >= priv->max_frags && data_len))
goto err_chained_bd;
}

@@ -660,7 +661,7 @@ static netdev_tx_t enetc_start_xmit(struct sk_buff *skb,
count = enetc_map_tx_tso_buffs(tx_ring, skb);
enetc_unlock_mdio();
} else {
- if (unlikely(skb_shinfo(skb)->nr_frags > ENETC_MAX_SKB_FRAGS))
+ if (unlikely(skb_shinfo(skb)->nr_frags > priv->max_frags))
if (unlikely(skb_linearize(skb)))
goto drop_packet_err;

@@ -678,7 +679,7 @@ static netdev_tx_t enetc_start_xmit(struct sk_buff *skb,
if (unlikely(!count))
goto drop_packet_err;

- if (enetc_bd_unused(tx_ring) < ENETC_TXBDS_MAX_NEEDED)
+ if (enetc_bd_unused(tx_ring) < ENETC_TXBDS_MAX_NEEDED(priv->max_frags))
netif_stop_subqueue(ndev, tx_ring->index);

return NETDEV_TX_OK;
@@ -946,7 +947,8 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget)
if (unlikely(tx_frm_cnt && netif_carrier_ok(ndev) &&
__netif_subqueue_stopped(ndev, tx_ring->index) &&
!test_bit(ENETC_TX_DOWN, &priv->flags) &&
- (enetc_bd_unused(tx_ring) >= ENETC_TXBDS_MAX_NEEDED))) {
+ (enetc_bd_unused(tx_ring) >=
+ ENETC_TXBDS_MAX_NEEDED(priv->max_frags)))) {
netif_wake_subqueue(ndev, tx_ring->index);
}

@@ -3307,18 +3309,21 @@ EXPORT_SYMBOL_GPL(enetc_pci_remove);
static const struct enetc_drvdata enetc_pf_data = {
.sysclk_freq = ENETC_CLK_400M,
.pmac_offset = ENETC_PMAC_OFFSET,
+ .max_frags = ENETC_MAX_SKB_FRAGS,
.eth_ops = &enetc_pf_ethtool_ops,
};

static const struct enetc_drvdata enetc4_pf_data = {
.sysclk_freq = ENETC_CLK_333M,
.tx_csum = true,
+ .max_frags = ENETC4_MAX_SKB_FRAGS,
.pmac_offset = ENETC4_PMAC_OFFSET,
.eth_ops = &enetc4_pf_ethtool_ops,
};

static const struct enetc_drvdata enetc_vf_data = {
.sysclk_freq = ENETC_CLK_400M,
+ .max_frags = ENETC_MAX_SKB_FRAGS,
.eth_ops = &enetc_vf_ethtool_ops,
};

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index e82eb9a9137c..1e680f0f5123 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -59,9 +59,16 @@ struct enetc_rx_swbd {

/* ENETC overhead: optional extension BD + 1 BD gap */
#define ENETC_TXBDS_NEEDED(val) ((val) + 2)
-/* max # of chained Tx BDs is 15, including head and extension BD */
+/* For LS1028A, max # of chained Tx BDs is 15, including head and
+ * extension BD.
+ */
#define ENETC_MAX_SKB_FRAGS 13
-#define ENETC_TXBDS_MAX_NEEDED ENETC_TXBDS_NEEDED(ENETC_MAX_SKB_FRAGS + 1)
+/* For ENETC v4 and later versions, max # of chained Tx BDs is 63,
+ * including head and extension BD, but the range of MAX_SKB_FRAGS
+ * is 17 ~ 45, so set ENETC4_MAX_SKB_FRAGS to MAX_SKB_FRAGS.
+ */
+#define ENETC4_MAX_SKB_FRAGS MAX_SKB_FRAGS
+#define ENETC_TXBDS_MAX_NEEDED(x) ENETC_TXBDS_NEEDED((x) + 1)

struct enetc_ring_stats {
unsigned int packets;
@@ -235,6 +242,7 @@ enum enetc_errata {
struct enetc_drvdata {
u32 pmac_offset; /* Only valid for PSI which supports 802.1Qbu */
u8 tx_csum:1;
+ u8 max_frags;
u64 sysclk_freq;
const struct ethtool_ops *eth_ops;
};
@@ -377,6 +385,7 @@ struct enetc_ndev_priv {
u16 msg_enable;

u8 preemptible_tcs;
+ u8 max_frags; /* The maximum number of BDs for fragments */

enum enetc_active_offloads active_offloads;

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf_common.c b/drivers/net/ethernet/freescale/enetc/enetc_pf_common.c
index 09f2d7ec44eb..00b73a948746 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_pf_common.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pf_common.c
@@ -101,6 +101,7 @@ void enetc_pf_netdev_setup(struct enetc_si *si, struct net_device *ndev,

priv->msg_enable = (NETIF_MSG_WOL << 1) - 1;
priv->sysclk_freq = si->drvdata->sysclk_freq;
+ priv->max_frags = si->drvdata->max_frags;
ndev->netdev_ops = ndev_ops;
enetc_set_ethtool_ops(ndev);
ndev->watchdog_timeo = 5 * HZ;
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_vf.c b/drivers/net/ethernet/freescale/enetc/enetc_vf.c
index a5f8ce576b6e..63d78b2b8670 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_vf.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_vf.c
@@ -136,6 +136,7 @@ static void enetc_vf_netdev_setup(struct enetc_si *si, struct net_device *ndev,

priv->msg_enable = (NETIF_MSG_IFUP << 1) - 1;
priv->sysclk_freq = si->drvdata->sysclk_freq;
+ priv->max_frags = si->drvdata->max_frags;
ndev->netdev_ops = ndev_ops;
enetc_set_ethtool_ops(ndev);
ndev->watchdog_timeo = 5 * HZ;
--
2.34.1