> I don't have much knowledge about IA64 either. All I see is that while > x86 implements memcpy_fromio() with memcpy [1], ia64 implements it with > readb [2]. There must be a reason for that, and I can only suppose that > memcpy on __iomem pointers doesn't work on IA64. If memcpy doesn't work > then I can't see memcmp working.
On most platforms readb() just ends up doing a regular dereference of the address ... so I'd expect that memcmp would work just fine. The exception is the old SGI sn2 which end up calling ___sn_readb() ... which does something weird with sn_dma_flush() after doing the dereference of *addr. I don't really understand what is going on here - but I assume that it is for real PCI iomapped memory, as opposed to random bits of BIOS reserved memory that we used ioremap() to get a virtual handle on. Not sure how to test ... what would I run to exercise this code? -Tony
