Question on __pv_stub

Hi All, I am just trying to understand __va macro. I can see two definitions,one in include/asm-generic/page.h and other is in arch/arm/include/asm/memory.h. The first definition is just adding PAGE_OFFSET,but the second one boil downs to __pv_stub.Could anybody please help me to understand what this __pv_stub for? With Regards Subin Gangadharan Everything should be made as simple as possible,but not simpler.