I have A10-5800K APU and Radeon HD 7970.
First, I installed CentOS on *only* A10 processor and installed APP SDK. It worked fine. I saw 2 devices, 4-core CPU and on-chip GPU.
Next, I attached a discrete 7970 GPU and re-installed the OS. I installed Catalyst GPU deriver and again APP SDK.
I followed this a document "Running_AMD_APP_Apps_Remotely" and clinfo only shows a 4-core CPU and discrete GPU.
I expected clinfo shows 3 processors, CPU, on-chip GPU, and discrete GPU.
So, is it possible to use all of A10's CPU/GPU and Radeon 7970 together with OpenCL ?