free_rx_bufs(9)

💖 free_rx_bufs(9) — the Kernel API Manual, bestie edition 💖

okay so we're in the Kernel API Manual today and the page is literally called free_rx_bufs(9), and yes it's exactly what it sounds like: it frees RX buffers on an SGE Free List. slay. let's get into it 🦋

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✨ NAME ✨

free_rx_bufs — free RX buffers on an SGE Free List 💅

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🌸 SYNOPSIS 🌸

void free_rx_bufs (struct adapter *adapter , struct sge_fl *fl , int n
);

that's the whole vibe. three args, one void, no notes. 🎀

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🧚 ARGUMENTS 🧚

• adapter — the adapter. that's it, that's the whole description, she's the main character and needs no further introduction 👑
• fl — the SGE Free List to free buffers from 🫶
• n — how many buffers to free. a number. a count. the amount. 🔥

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💜 DESCRIPTION 💜

so what it does: it releases the next n buffers on an SGE Free List RX queue. that's the whole thing, no cap.

⚠️ but listen to me, bestie, this part is NOT a joke: the buffers must be made inaccessible to hardware before calling this function. like, hardware can't still be touching them. do the un-mapping first, then call this. not the other way around. i'm so serious 😭💀

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🌈 SEE ALSO 🌈

the kernel file this lives in, for when you need to go to the source (literally):

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

and the whole friend group, in the order the page gives them (don't come for me, i'm not sorting them):

• 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)
• 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)
• calc_tx_flits(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)

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and that's the page!! 🎀✨ this lil gem comes to you from ./drivers/net/ethernet/chelsio... and it's dated October 2026 — so yeah, from the future, she's ahead of her time, we love that for her. bye bestie, go unmap those buffers first 💜🦋🍓