genwqe_mmap(9)

💖 genwqe_mmap(9) 💖

okay so welcome to genwqe_mmap(9) from the Kernel API Manual — this is the kernel-internal manual page and it's giving “tiny but important” energy, no cap. 🫶

✨ NAME ✨

• genwqe_mmap — Provide contignous buffers to userspace 💅

🌸 SYNOPSIS 🌸

int genwqe_mmap (struct file *filp , struct vm_area_struct *vma );

🎀 ARGUMENTS 🎀

• filp — File pointer (unused) 💀 like it's literally there but not doing anything.
• vma — VMA area to map 🗺️ the vibe is “map this area, bestie.”

🦋 DESCRIPTION 🦋

okay so the tea ☕: we use mmap to allocate contignous buffers used for DMA transfers. After the buffer is allocated we remap it to user-space and remember a reference to our dma_mapping data structure, where we store the associated DMA address and allocated size. ✨

When we receive a DDCB execution request with the ATS bits set to plain buffer, we lookup our dma_mapping list to find the corresponding DMA address for the associated user-space address. 👑

🌈 SEE ALSO 🌈

• Kernel file ./drivers/misc/genwqe/card_dev.c — the exact kernel file path, right here 💾
• genwqe_search_pin(9)
• __genwqe_search_mapping(9)
• genwqe_kill_fasync(9)
• genwqe_open(9)
• genwqe_fasync(9)
• genwqe_release(9)
• genwqe_vma_close(9)
• do_flash_update(9)
• ddcb_cmd_cleanup(9)
• ddcb_cmd_fixups(9)
• genwqe_execute_ddcb(9)
• genwqe_ioctl(9)
• genwqe_device_create(9)
• genwqe_device_remove(9)

source/version: ./drivers/misc/genwqe 💾 — date: October 2026 📅 — page: genwqe_mmap(9) 💖 — bye bestie, slay your kernel adventures! 🌟