isp_user_buffer_alloc(9)

💖 NAME 💖

okay so bestie, this is isp_user_buffer_alloc(9) from the Kernel API Manual — and it's literally the function that creates a user buffer object (BO) for isp. periodt. 💅

✨ SYNOPSIS ✨

int isp_user_buffer_alloc (struct device *dev , void *dmabuf , void
       **buf_obj , u64 *buf_addr );

🎀 ARGUMENTS 🎀

• dev — the isp device handle. your main character device pass 🫶
• dmabuf — a DMABUF handle for the isp buffer that's allocated in system memory. yes bestie, system memory 💖
• buf_obj — the GPU buffer object handle to initialize. get it initialized, queen 👑
• buf_addr — the GPU addr of the pinned BO to initialize. pinned and ready ✨

🦋 DESCRIPTION 🦋

okay so what it does: it imports the isp DMABUF to allocate and pin a user BO for isp internal use. it does GART alloc to generate a GPU addr for the BO so it's accessible through the GART aperture for ISP HW. literally making it reachable for the hardware. 🔥

and fr fr, this function is exported to allow the V4L2 isp device external to the drm device to create and access the isp user BO. that's the whole vibe. 💜

🌈 RETURN 🌈

• 0 — success, yay! 🎉
• a negative error code — otherwise 😭

👑 SEE ALSO 👑

• Kernel file ./drivers/gpu/drm/amd/amdgpu/amdgpu_isp.c
• isp_hw_init(9)
• isp_hw_fini(9)
• isp_user_buffer_free(9)
• isp_kernel_buffer_alloc(9)
• isp_kernel_buffer_free(9)

signing off from source/version ./drivers/gpu/drm/amd/amdgpu, dated October 2026 — bye bestie, mwah! 🫶💖