vce_v1_0_ens...o_32bit_addr(9)

💅 vce_v1_0_ens...o_32bit_addr — the Kernel API Manual moment (section 9, bestie)

okay so this is a page straight out of the Kernel API Manual, section 9, and the name got truncated at the party like vce_v1_0_ens...o_32bit_addr — the full glow-up name is vce_v1_0_ensure_vcpu_bo_32bit_addr. iconic. let's get into it ✨

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🌸 NAME 🌸

vce_v1_0_ensure_vcpu_bo_32bit_addr — literally just making sure the VCPU BO has a 32-bit address 🎀

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🦋 SYNOPSIS 🦋

int vce_v1_0_ensure_vcpu_bo_32bit_addr (struct amdgpu_device *adev );

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💖 ARGUMENTS 💖

• adev — an amdgpu_device pointer. that's the whole vibe, it's the only thing you're handing over 🫶

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✨ DESCRIPTION ✨

so the tea is: due to various hardware limitations, VCE1 needs the VCPU BO to live down in the low 32-bit address range. no negotiating. and this function is the one that ensures the VCPU BO actually has a 32-bit GPU address — or, if that's just not possible, it returns an error code 😭

to accommodate that (and yes, we're spelling it right this time 💅), the move is: we put GART in the LOW address range and reserve some GART pages where we map the VCPU BO, so that it ends up with a 32-bit address. slay. that's the whole strategy 👑

and the BAR address? it's zero, and we genuinely can't change it because of the firmware validation mechanism. it's giving non-negotiable. from what we can tell, it fails to initialize if the address is >= 128 MiB 💀 so like, don't.

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⭐ SEE ALSO ⭐

kernel file, for the girlies who want to read the source:

• ./drivers/gpu/drm/amd/amdgpu/vce_v1_0.c
• vce_v1_0_ring_get_rptr(9)
• vce_v1_0_ring_get_wptr(9)
• vce_v1_0_ring_set_wptr(9)
• vce_v1_0_load_fw(9)
• vce_v1_0_is_idle(9)
• vce_v1_0_start(9)
• vce_v1_0_hw_init(9)

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reminder bestie: VCE1 will not be flexing on you if the address sneaks up to >= 128 MiB, and that BAR address stays at zero because firmware said so. periodt. 🔥

and that's the page!! brought to you by ./drivers/gpu/drm/amd/amdgpu, dated October 2026, filed under vce_v1_0_ens...o_32bit_addr(9) 🧚💜 mwah, go read the other vce_v1_0_* pages, ily 🎀