calc_tx_flits(9)

💅 calc_tx_flits — like, the whole vibe check ✨

okay so bestie, welcome to the Kernel API Manual entry for calc_tx_flits(9) and yes we are doing this, pull up a chair 🎀

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🌸 NAME 🌸

calc_tx_flits — bestie it literally calculates the number of flits for a packet TX WR, that's the whole job, that's the assignment, no notes 💅

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✨ SYNOPSIS ✨

unsigned int calc_tx_flits (const struct sk_buff *skb );

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🦋 ARGUMENTS 🦋

• skb — the packet 🫶 like, the actual Ethernet packet we're talking about here, that one

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💖 DESCRIPTION 💖

okay so here's the tea: this function returns the number of flits needed for a TX Work Request for the Ethernet packet you handed it.

and not just the flits for the packet itself, no ma'am — it also counts the WR and CPL headers you need. inclusive queen behavior 👑 so it's the packet plus the WR and CPL headers, all bundled into one number, and it hands that number back to you as an unsigned int 🔥

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🌈 SEE ALSO 🌈

okay so this function has, like, so many friends, it's giving main character with a whole group chat 😭 here's the full squad:

Kernel file ./drivers/net/ethernet/chelsio/cxgb4vf/sge.c

and then, alphabetically unhinged but we respect it:

get_buf_addr(9), is_buf_mapped(9), need_skb_unmap(9), txq_avail(9), fl_cap(9), fl_starving(9), map_skb(9), free_tx_desc(9), reclaim_completed_tx(9), get_buf_size(9), free_rx_bufs(9), unmap_rx_buf(9), ring_fl_db(9), set_rx_sw_desc(9), refill_fl(9), alloc_ring(9), sgl_len(9), flits_to_desc(9), is_eth_imm(9), write_sgl(9), ring_tx_db(9), inline_tx_skb(9), t4vf_eth_xmit(9), copy_frags(9), t4vf_pktgl_to_skb(9), t4vf_pktgl_free(9), do_gro(9), t4vf_ethrx_handler(9), is_new_response(9), restore_rx_bufs(9), rspq_next(9), process_responses(9), napi_rx_handler(9), t4vf_intr_handler(9), sge_rx_timer_cb(9), sge_tx_timer_cb(9), bar2_address(9), t4vf_sge_alloc_rxq(9), t4vf_sge_alloc_eth_txq(9), t4vf_free_sge_resources(9), t4vf_sge_start(9), t4vf_sge_stop(9), t4vf_sge_init(9)

like, go read them, they're iconic, they're all in the cxgb4vf sge.c cinematic universe 🍓

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ngl there's no EXAMPLES section in this one, no BUGS, no RETURN VALUE section either — the number comes back as unsigned int and that's just how it is, periodt. don't come for me, I don't make the manpage rules 💀

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and that's the page babes 🧚 this little love letter to calc_tx_flits(9) comes from ./drivers/net/ethernet/chelsio... (yeah the path is literally abbreviated with ... in the original, I don't make the rules, I just report them 🙈) and it's dated October 2026. stay hydrated, count your flits, and remember the headers 💜✨