tn40_tx_map_skb(9)

🎀 tn40_tx_map_skb(9): Kernel API Manual, but make it cute 🎀

okay so bestie, this is the manual page for tn40_tx_map_skb — yes, the manual name is literally tn40_tx_map_skb(9), and we are so back. 💅 This is the Kernel API Manual energy you asked for, and it's giving “DMA mappings explained by your favorite group chat.” 🦋

✨ NAME ✨

tn40_tx_map_skb — create and store DMA mappings for skb's data blocks 💖

🌸 SYNOPSIS 🌸

int tn40_tx_map_skb (struct tn40_priv *priv , struct sk_buff *skb ,
       struct tn40_txd_desc *txdd , unsigned int *pkt_len );

🦋 ARGUMENTS 🦋

• priv — NIC private structure. That's the NIC's own private-structure moment, no cap. 🫶
• skb — socket buffer to map. This is the skb getting its DMA-mapping glow-up. ✨
• txdd — pointer to tx descriptor to be updated. It's the descriptor that's about to be edited, bestie. 💅
• pkt_len — pointer to unsigned long value. Yep, literally “pointer to unsigned long value” — keep it moving. 👑

🔥 DESCRIPTION 🔥

okay so the actual tea: this function creates DMA mappings for skb's data blocks and writes them to the PBL of a new tx descriptor. It also stores them in the tx db so they could be unmapped after the data has been sent — no lingering mappings, periodt. 🔥

It is the responsibility of the caller to make sure that there is enough space in the txdb. That is not a suggestion, bestie — check the space. 💀 The last element holds a pointer to skb itself and is marked with a zero length. ✨

💜 RETURN 💜

0 on success and a negative value on error. That's it — iconic, simple, and negative means something went sideways. 😭

🌈 SEE ALSO 🌈

Kernel file ./drivers/net/ethernet/tehuti/tn40.c — plus the whole bestie squad of related calls:

• tn40_create_rx_ring(9)
• tn40_rx_alloc_buffers(9)
• tn40_tx_space(9)
• tn40_tx_push_desc(9)
• tn40_tx_push_desc_safe(9)

signing off from ./drivers/net/ethernet/tehuti — source/version vibes — with the date October 2026, for the manual page tn40_tx_map_skb(9). stay mapped, stay iconic 💖🦋✨