drm_pagemap_...system_pages(9)

💅 drm_pagemap_migrate_map_system_pages — a Kernel API Manual moment ✨

okay so this is a page straight out of the Kernel API Manual, and bestie, it's giving "GPU memory migration but make it fashion". sit down, hydrate, let's go 🫶

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✨ NAME ✨

drm_pagemap_migrate_map_system_pages — maps system pages or device coherent migration pages so the GPU can do its SVM migration thing. literally the matchmaker between your pages and the DMA world 💖

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🌸 SYNOPSIS 🌸

int drm_pagemap_migrate_map_system_pages (struct device *dev , struct
drm_pagemap_addr *pagemap_addr , unsigned long *migrate_pfn , unsigned
long npages , enum dma_data_direction dir , struct
drm_pagemap_iova_state *state );

no cap, that's the whole signature. copy it exactly, don't freestyle it 🙈

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🎀 ARGUMENTS 🎀

• dev — the device that's doing the migrating. main character energy, obviously 👑
• pagemap_addr — an array where the DMA info for the mapped pages gets stashed.
• migrate_pfn — array of page frame numbers of the system pages or peer pages you wanna map. the guest list, if you will 💅
• npages — how many system or device coherent pages we're mapping. count 'em.
• dir — direction of the data transfer (like, e.g., DMA_BIDIRECTIONAL). which way the vibes flow 🌈
• state — the DMA IOVA state for the mapping. it's holding the state, it's a state holder.

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🦋 DESCRIPTION 🦋

so what does it do? This function maps pages of memory for migration usage in GPU SVM. It literally iterates over each page frame number you handed it in migrate_pfn, maps the corresponding page, and stores that DMA address in the provided dma_addr array. one by one, page by page, slay by slay ✨

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💜 RETURN 💜

• 0 on success 🎉
• a negative error code on failure 😭

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🌟 SEE ALSO 🌟

the whole friend group, gathered:

Kernel file ./drivers/gpu/drm/drm_pagemap.c, Overview(9), Migration(9), struct drm_pagemap_zdd(9), drm_pagemap_zdd_alloc(9), drm_pagemap_zdd_get(9), drm_pagemap_zdd_destroy(9), drm_pagemap_zdd_put(9), drm_pagemap_migration_unlock_put_folio(9), drm_pagemap_migration_unlock_put_pages(9), drm_pagemap_get_devmem_page(9), drm_pagemap_migrate_map_device_private_pages(9), struct drm_pagemap_iova_state(9), drm_pagemap_migrate_populate_src_pages(9), drm_pagemap_migrate_unmap_pages(9), struct migrate_range_loc(9), drm_pagemap_cpages(9), drm_pagemap_migrate_to_devmem(9), drm_pagemap_migrate_populate_ram_pfn(9), struct drm_pagemap_dev_hold(9), drm_pagemap_reinit(9), drm_pagemap_init(9), drm_pagemap_put(9), drm_pagemap_page_get_flags(9), drm_pagemap_page_set_flags(9), drm_pagemap_retire_migrated_pages(9), drm_pagemap_skip_retired_pages(9), drm_pagemap_evict_to_ram(9), __drm_pagemap_migrate_to_ram(9), drm_pagemap_folio_free(9), drm_pagemap_migrate_to_ram(9), drm_pagemap_pagemap_ops_get(9), drm_pagemap_devmem_init(9), drm_pagemap_page_to_dpagemap(9), drm_pagemap_populate_mm(9)

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💀 friendly reminder that the description says dma_addr array while the argument is called pagemap_addr — that's how it's written, I'm not fixing it, that's the source material bestie, iykyk.

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and that's the page!! sign-off time: this one lives in ./drivers/gpu/drm and it's dated October 2026 ⭐ take care of her, she's iconic 💖🧚🌸