vmw_ttm_map_for_dma(9)

✨ vmw_ttm_map_for_dma(9) ✨

okay bestie, this page is straight from the Kernel API Manual and it's all about vmw_ttm_map_for_dma(9). 🫶

🎀 NAME 🎀

vmw_ttm_map_for_dma — map TTM pages to get device addresses. 💅

🌸 SYNOPSIS 🌸

int vmw_ttm_map_for_dma (struct vmw_ttm_tt *vmw_tt );

🦋 ARGUMENTS 🦋

• vmw_tt — Pointer to a struct vmw_ttm_backend. 🎀

💖 DESCRIPTION 💖

okay so picture this: this function is the one you use to get device addresses from the kernel DMA layer. ✨

But here's the tea, and it is important: it's violating the DMA API. 😭 Once this operation has been performed, it's illegal for the CPU to write to the pages without first unmapping the DMA mappings, or calling dma_sync_sg_for_cpu. Not a vibe check you want to fail, fr fr. 💀

bestie, that means it is only legal to call this function if we know that dma_sync_sg_for_cpu is a NOP, and dma_sync_sg_for_device is at most a CPU write buffer flush. Periodt. 👑

🌈 SEE ALSO 🌈

• Kernel file ./drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
• __vmw_piter_non_sg_next(9)
• vmw_piter_start(9)
• vmw_ttm_unmap_from_dma(9)
• vmw_ttm_map_dma(9)
• vmw_ttm_unmap_dma(9)
• vmw_bo_sg_table(9)
• vmw_move_notify(9)
• vmw_swap_notify(9)

And that's the whole page, bestie. Cute little sign-off: this one comes from the source/version stamp ./drivers/gpu/drm/vmwgfx, dated October 2026, under the manual title vmw_ttm_map_for_dma(9). Mwah 💋✨