you can't take any arbitrary memory region and make it acesible from GPU. it must be properly aligned and page locked. so answer to you question is no.
you should make buffer first then map it and after that load data from HDD/network/etc directly into this mapped region.
Originally posted by: lupescu_grigore Using AMD SDK 2.5 & A6 3650 i have achieved a zero copy from GPU to CPU by allocating a buffer using CL_MEM_ALLOC_HOST_PTR  and switching between devices with enqueueMap/Unmap.
If i have the information already on CPU mem can i map the memory to the GPU region ?
Mapped pointers always on host i.e CPU.
I have looked in the APP SDK programming guide section 4.4 and saw a mention regarding CL_MEM_USE_PERSISTENT_MEM_AMD but if i pass as host_ptr argument in the buffer allocation i get an error saying "INVALID HOST PTR".
Yes it is an invalid combination.