drm_gpusvm_init(9)

💅 drm_gpusvm_init(9) — the Kernel API Manual, bestie edition ✨

okay so this is drm_gpusvm_init(9) from the Kernel API Manual, and it's literally the "get the GPU SVM party started" function. Let's go 🎀

---

🌸 NAME

drm_gpusvm_init — Initialize the GPU SVM.

---

✨ SYNOPSIS

int drm_gpusvm_init (struct drm_gpusvm *gpusvm , const char *name ,
       struct mm_struct *mm , unsigned long mm_start , unsigned long mm_range ,
       unsigned long notifier_size , const struct drm_gpusvm_ops *ops , const
       unsigned long *chunk_sizes , int num_chunks );

It returns an int, so you already know how this ends — it's giving success-or-negative-error-code energy 💀

---

🫶 ARGUMENTS

• gpusvm — Pointer to the GPU SVM structure. This is the main character, the thing you're initializing 🫶
• name — Name of the GPU SVM. Yes, it gets a lil name, iconic.
• mm — Pointer to the mm_struct for the address space.
• mm_start — Start address of GPU SVM.
• mm_range — Range of the GPU SVM.
• notifier_size — Size of individual notifiers.
• ops — Pointer to the operations structure for GPU SVM.
• chunk_sizes — Pointer to the array of chunk sizes used in range allocation. Hiii bestie, pay attention: entries should be powers of 2 in descending order, with the last entry being SZ_4K. No cap, that's a hard requirement, don't be out here doing SZ_4K first 🙈
• num_chunks — Number of chunks. (Just count them, bestie 💅)

---

🦋 DESCRIPTION

This function initializes the GPU SVM. That's it, that's the vibe. It sets the whole thing up ✨

---

👑 NOTE

okay so this part is actually important, listen up 🔥

If you're only using the simple drm_gpusvm_pages API (get/unmap/free), then only gpusvm and name are expected. The drm drm_device for dma mappings is bound per-pages via drm_gpusvm_init_pages before the first drm_gpusvm_get_pages call.

However — and this is the flexible queen moment — the same base gpusvm can also be used with both modes together, in which case the full setup is needed. In that case the core drm_gpusvm_pages API will simply never use the other fields. She's got range, literally 🌈

---

⭐ RETURN

0 on success, a negative error code on failure. So if it's all good you get 0, and if it's not... negative error code, and you get to debug 🫠

---

🧚 SEE ALSO

Kernel file ./drivers/gpu/drm/drm_gpusvm.c Overview(9), Locking(9), Partial Unmapping of Ranges(9), Examples(9), npages_in_range(9), drm_gpusvm_notifier_find(9), drm_gpusvm_range_find(9), drm_gpusvm_notifier_invalidate(9), to_drm_gpusvm_notifier(9),

drm_gpusvm_notifier_insert(9), drm_gpusvm_notifier_remove(9), drm_gpusvm_fini(9), drm_gpusvm_notifier_alloc(9), drm_gpusvm_notifier_free(9), to_drm_gpusvm_range(9),

drm_gpusvm_range_insert(9), __drm_gpusvm_range_remove(9), drm_gpusvm_range_alloc(9), drm_gpusvm_hmm_pfn_to_order(9), drm_gpusvm_check_pages(9), drm_gpusvm_scan_mm(9),

drm_gpusvm_range_chunk_size(9), drm_gpusvm_driver_lock_held(9), drm_gpusvm_find_vma_start(9), drm_gpusvm_range_find_or_insert(9), __drm_gpusvm_unmap_pages(9),

__drm_gpusvm_free_pages(9), drm_gpusvm_free_pages(9), drm_gpusvm_range_remove(9), drm_gpusvm_range_get(9), drm_gpusvm_range_destroy(9), drm_gpusvm_range_put(9),

drm_gpusvm_pages_valid(9), drm_gpusvm_pages_valid_unlocked(9), drm_gpusvm_get_pages(9), drm_gpusvm_unmap_pages(9), drm_gpusvm_range_evict(9), drm_gpusvm_has_mapping(9),

drm_gpusvm_range_set_unmapped(9)

That's a whole friend group, and honestly? Every single one of them is linked for a reason. Go read them, iykyk 💖

---

💜 fr fr, that's the whole page. Now go initialize something.

---

slay, you made it to the end 🎀 this cutie was served fresh from ./drivers/gpu/drm in October 2026, filename drm_gpusvm_init(9). bye bestie, mwah 💋✨