Linux/AM5728: Omap_bo memory physical address

Which driver uses omap_bo memory?

Steve K.

I use codec-engine to decode H.264, and copy the decoded H.264 buf out. copy omap _bo memory to user_buf too slow, I want to use dma copy omap_bo memory to cmem.
codec-engine bind displaying closely, I don't need display. gstreamer takes much resource, I need to use codec-engine, that's what I did.
So it's possible to get the physical address of omap_bo memory ?

Thank you Steve.

The dma-buf API is used to allow userspace to pass buffer objects from one kernel driver to another for the purpose of DMA transfer: https://www.kernel.org/doc/html/v4.14/driver-api/dma-buf.html

Linux doesn't expect userspace to be meddling directly with DMA controllers, hence generally doesn't expose physical addresses to userspace. I agree it could nevertheless be useful in some situations, but I'm not aware of any existing mechanism for it (and I suspect any such mechanism would never be accepted in mainline linux).

If you have a kernel driver, use the dma-buf API. What you're describing sounds like precisely the situation for which the dma-buf API was designed.

Part Number: AM5728

Tool/software: Linux

Hi

In kernel mode, how can I get OMAP_BO physical address? what should I do?

Thanks