sdma_send_txlist(9)

💅 sdma_send_txlist(9) — Kernel API Manual era ✨

okay so bestie, we're in the Kernel API Manual and this page is sdma_send_txlist(9), the call that submits a list of tx req to the ring. it's giving efficient packet submission, periodt 🫶

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🌸 NAME 🌸

sdma_send_txlist — submit a list of tx req to ring 💫

✨ SYNOPSIS ✨

int sdma_send_txlist (struct sdma_engine *sde , struct iowait_work *wait
       , struct list_head *tx_list , u16 *count_out );

🎀 ARGUMENTS 🎀

• sde — the sdma engine to use 💅
• wait — the SE wait structure to use when full (may be NULL) 🙈
• tx_list — the list of sdma_txreqs to submit ✨
• count_out — pointer to a u16 which, after return, will contain the total number of sdma_txreqs removed from the tx_list. This will include sdma_txreqs whose SDMA descriptors are submitted to the ring and the sdma_txreqs which are added to SDMA engine flush list if the SDMA engine state is not running. no cap 🫶

🔥 DESCRIPTION 🔥

The call submits the list into the ring. main character behavior, honestly.

If the iowait structure is non-NULL and not equal to the iowait list, the unprocessed part of the list will be appended to the list in wait. okay so that's the little handoff moment 💫

In all cases, the tx_list will be updated so the head of the tx_list is the list of descriptors that have yet to be transmitted. slay.

The intent of this call is to provide a more efficient way of submitting multiple packets to SDMA while holding the tail side locking. iykyk 🔥

⭐ RETURN ⭐

• 0 — Success 🎀
• -EINVAL — sdma_txreq incomplete 😭
• -EBUSY — no space in ring (wait == NULL) 💀
• -EIOCBQUEUED — tx queued to iowait ✨
• -ECOMM — bad sdma state 🙈

🦋 SEE ALSO 🦋

Kernel file: ./drivers/infiniband/hw/hfi1/sdma.c — and the whole friend group is sdma_state_name(9), sdma_get_descq_cnt(9), sdma_engine_get_vl(9), sdma_select_engine_vl(9), sdma_select_engine_sc(9), sdma_seqfile_dump_cpu_list(9), sdma_map_init(9), sdma_clean(9), sdma_init(9), sdma_all_running(9), sdma_start(9), sdma_exit(9), __sdma_txclean(9), sdma_engine_error(9), sdma_seqfile_dump_sde(9), sdma_send_txreq(9), sdma_ahg_alloc(9), sdma_ahg_free(9), _sdma_engine_progress_schedule(9). go off, bestie 👑

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okay that's the whole page, bestie — the source/version path is ./drivers/infiniband/hw/hfi1 and the date is October 2026. mwah 💖