ttm_kmap_obj_virtual(9)

🌸 ttm_kmap_obj_virtual(9) 🌸

okay so real talk, bestie — you're reading a page from the Kernel API Manual and it's literally called ttm_kmap_obj_virtual(9). Yes, that's the whole title. We're in the big leagues now. 💅

---

✨ NAME ✨

ttm_kmap_obj_virtual —

...and that's it. That's the description. Nothing after the dash. She said "my name is enough" and honestly? Main character energy. 👑 No cap, the original page gives you zero words here, so I'm not gonna invent any for you either. We move.

---

🦋 SYNOPSIS 🦋

void * ttm_kmap_obj_virtual (struct ttm_bo_kmap_obj *map , bool
*is_iomem );

That's the whole signature, copied exactly, don't come for me about the spacing — that's how the page prints it. 🫶

---

🎀 ARGUMENTS 🎀

• map — a struct ttm_bo_kmap_obj that you got handed back from ttm_bo_kmap. Not a fresh one you made up yourself, babe. It comes from that function. 💖
• is_iomem — a pointer to an integer, and it's an out kinda situation: on return it tells you 1 if the virtual map is io memory, or 0 if it's normal memory. Think of it as the vibe check for your memory region. ⭐

---

💜 DESCRIPTION 💜

So what does this actually do? It returns the virtual address of a buffer object area that was mapped by ttm_bo_kmap. That's the whole job. Very demure, very mindful. 🌸

But here's the part you cannot skip, and I mean cannot — if *is_iomem is 1 on return, then that virtual address points to an io memory area. And io memory has rules, bestie. It should strictly be accessed by the iowriteXX and similar functions.

🚨 the way that "strictly" is doing a LOT of heavy lifting in that sentence — please respect it. Don't just dereference io memory like it's regular RAM, that's not the move. 🙈

---

🧚 SEE ALSO 🧚

Kernel file ./include/drm/ttm/ttm_bo.h — and then the whole friend group, in this exact order:

• enum ttm_bo_type(9)
• struct ttm_buffer_object(9)
• struct ttm_bo_kmap_obj(9)
• struct ttm_operation_ctx(9)
• struct ttm_lru_walk_arg(9)
• struct ttm_lru_walk(9)
• struct ttm_bo_shrink_flags(9)
• ttm_bo_reserve(9)
• ttm_bo_reserve_slowpath(9)
• ttm_bo_move_null(9)
• ttm_bo_unreserve(9)
• struct ttm_bo_lru_cursor(9)
• ttm_bo_lru_for_each_reserved_guarded(9)

like okay ttm_bo_lru_for_each_reserved_guarded(9) — say it five times fast, I dare you. 😭 iconic name tho.

---

that's the whole page, bestie, you ate that 🍓✨ this lil masterpiece lives in ./include/drm/ttm and it's dated October 2026 — go off, calendar. mwah, study safe, and remember: check *is_iomem before you touch anything 💖🎀🦋