sg_dma_mark_bus_address(9)

💅 sg_dma_mark_bus_address — the Kernel API Manual, bestie edition ✨

okay so this is sg_dma_mark_bus_address(9), straight out of the Kernel API Manual, and it's honestly such a tiny little function with one very specific job 🎀

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✨ NAME ✨

sg_dma_mark_bus_address — literally just marks the scatterlist entry as a bus address, that's the whole vibe 💅

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🌸 SYNOPSIS 🌸

void sg_dma_mark_bus_address (struct scatterlist *sg );

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🦋 ARGUMENTS 🦋

• sg — the SG entry, bestie. that's the one you're marking 🫶

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🔥 DESCRIPTION 🔥

So what this does is it marks the sg entry you passed in, to indicate that the dma_address is a bus address and doesn't need to be unmapped 👑

Heads up though, this is NOT for everyone — this should only be used by dma_map_sg implementations to mark bus addresses, so that they can be properly cleaned up in dma_unmap_sg. that's it, that's the rule, no cap 😌

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👑 SEE ALSO 👑

Kernel file ./include/linux/scatterlist.h plus the whole scatterlist friend group, all of them present and accounted for:

• sg_next(9)
• sg_assign_page(9)
• sg_set_page(9)
• sg_set_folio(9)
• sg_set_buf(9)
• sg_chain(9)
• sg_mark_end(9)
• sg_unmark_end(9)
• sg_dma_is_bus_address(9)
• sg_dma_unmark_bus_address(9)
• sg_dma_is_swiotlb(9)
• sg_dma_mark_swiotlb(9)
• sg_phys(9)
• sg_virt(9)
• sg_init_marker(9)
• sg_alloc_table_from_pages(9)
• sg_page_iter_page(9)
• sg_page_iter_dma_address(9)
• for_each_sg_page(9)
• for_each_sg_dma_page(9)
• for_each_sgtable_page(9)
• for_each_sgtable_dma_page(9)

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so yeah, that's the page 🍓 it lives over at ./include/linux, dated October 2026, and this whole thing is sg_dma_mark_bus_address(9) from the Kernel API Manual — stan the scatterlist, periodt 💖💅✨