sdma_txadd_page(9)

💫 sdma_txadd_page(9) — the Kernel API Manual era 💫

okay bestie, buckle up, because this one lives in the Kernel API Manual and it's literally the function that goes "yeah just toss that page in there" 🎀

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✨ NAME ✨

sdma_txadd_page — adds a page to the sdma_txreq 🦋

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🌸 SYNOPSIS 🌸

int sdma_txadd_page (struct hfi1_devdata *dd , struct sdma_txreq *tx ,
struct page *page , unsigned long offset , u16 len , void *pinning_ctx ,
void (*ctx_get)(void *) , void (*ctx_put)(void *) );

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💅 ARGUMENTS 💅

• dd — the device we're using for mapping, like, the whole vibe check of where this is going down 🔥
• tx — the tx request that the page is getting added to, bestie, it's the destination
• page — the actual page to map 👑
• offset — where inside the page you're pointing, offset within the page, yes
• len — length in bytes, no cap 📏
• pinning_ctx — the context that gets stored on struct sdma_desc .pinning_ctx. Not added if coalesce buffer is used. E.g. pointer to pinned-page cache entry for the sdma_desc. iykyk 🙈
• ctx_get — optional function to take a reference to pinning_ctx. Not called if pinning_ctx is NULL. optional queen behavior only
• ctx_put — optional function to release the reference to pinning_ctx after sdma_desc completes. ⚠️ May be called in interrupt context so must not sleep. Not called if pinning_ctx is NULL. like, do NOT sleep in there, fr fr 💀

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🎀 DESCRIPTION 🎀

So this is the one you use to add a page/offset/length descriptor. simple as that 💖

And the mapping/unmapping of the page/offset/len is automatically handled. not you doing it. it's handled. slay ✨

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🌈 RETURN 🌈

• 0 — success, we ate 🍓
• -ENOSPC — mapping fail 😭
• -ENOMEM — couldn't extend/coalesce descriptor array 💀

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🧚 SEE ALSO 🧚

Kernel file ./drivers/infiniband/hw/hfi1/sdma.h sdma exported routines(9), sdma PSM/verbs API(9), Infrastructure calls(9), struct sdma_engine(9), sdma_empty(9), sdma_running(9), sdma_txinit_ahg(9), sdma_txinit(9), sdma_txadd_daddr(9), sdma_txadd_kvaddr(9), sdma_progress(9), struct sdma_map_elem(9), sdma_engine_progress_schedule(9)

like, go read those too, they're all linked in the group chat 🫶

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💜 okay that's the whole page, go forth and add your pages

this icon of a manpage came from ./drivers/infiniband/hw/hfi1, dated October 2026, and it signs off as sdma_txadd_page(9) — periodt, no notes 💅⭐