Re: Promblem with PREF (prefetching) in memcpy

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

On Fri, 2002-10-04 at 13:11, Carsten Langgaard wrote:
> Is a bus error exception an address related exception ?
> I'm afraid some implementation think it's not.
> 

So you need an option for broken systems, no new news 8)

> What about an UART RX register, we might loose a character ?
> You can also configure you system, so you get a external interrupt from you
> system controller in case of a bus error, there is no way the CPU can
> relate this interrupt to the prefetching.

The use of memcpy for I/O space isnt permitted in Linux, thats why we
have memcpy_*_io stuff. Thus prefetches should never touch 'special'
spaces. (On x86 the older Athlons corrupt their cache if you do this so
its not a mips specific matter)