drm_gem_fb_vmap(9)

💅 drm_gem_fb_vmap(9) — the kernel API manual page, bestie edition

okay so you're in the drm_gem_fb_vmap(9) era of your life and honestly? iconic. this is the kernel API manual, and we're getting you through it together 🫶

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✨ NAME ✨

drm_gem_fb_vmap — literally maps all framebuffer BOs into kernel address space. that's the whole vibe 💫

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🌸 SYNOPSIS 🌸

int drm_gem_fb_vmap (struct drm_framebuffer *fb , struct iosys_map *map
, struct iosys_map *data );

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🎀 ARGUMENTS 🎀

• fb — the framebuffer bestie. the main character.
• map — returns the mapping's address for each BO ✨
• data — returns the data address for each BO, and yes it can be NULL 🙈

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🦋 DESCRIPTION 🦋

so what this function does is it maps all the buffer objects of the given framebuffer into kernel address space and stores them in struct iosys_map. slay. 💅

and the way it's actually kind and caring?? if the mapping operation fails for one of the BOs, the function unmaps the already-established mappings automatically. no leaks, no mess, we love a self-cleaning queen 👑

callers that wanna access a BO's stored data should pass data. that argument returns the addresses of the data stored in each BO. heads up though — this is different from map if the framebuffer's offsets field is non-zero. not the same thing, don't mix them up ngl 😭

💀 important vibe check: both map and data must each refer to arrays with at least fb->format->num_planes elements. at least. do not skimp on this, fr fr.

see drm_gem_fb_vunmap for unmapping — that's the reverse-direction bestie 🧚

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🌈 RETURN 🌈

0 on success, or a negative errno code otherwise. that's it, that's the tea ☕

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👑 SEE ALSO 👑

• Kernel file ./drivers/gpu/drm/drm_gem_framebuffer_helper.c overview(9)
• drm_gem_fb_get_obj(9)
• drm_gem_fb_destroy(9)
• drm_gem_fb_create_handle(9)
• drm_gem_fb_init_with_funcs(9)
• drm_gem_fb_create_with_funcs(9)
• drm_gem_fb_create(9)
• drm_gem_fb_create_with_dirty(9)
• drm_gem_fb_vunmap(9)
• drm_gem_fb_begin_cpu_access(9)
• drm_gem_fb_end_cpu_access(9)
• drm_gem_fb_afbc_init(9)

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and that's the whole page, bestie 💖 this one lives in ./drivers/gpu/drm, dated October 2026, and it goes by drm_gem_fb_vmap(9) — go forth and map those BOs, you've got this 🎀✨