Re: Memory corruption

["William J. Earl" <wje@fir.engr.sgi.com>]

Warner Losh writes:
 > In message <XFMail.990707230857.Harald.Koerfgen@home.ivm.de> Harald Koerfgen 
 > writes:
 > : That's definitely true for R3k DECstations, and no, flushing the icache in
 > : flush_tlb_page() does not help. I have added cacheflushing to all tlb 
 > routines,
 > : copy_page and even rw_swap_page_base() and swap_after_unlock_page() without
 > : success.
 > 
 > Don'y you want to flush the dcache as well?  I think that you can run
 > into problems when you have a dirty dcache and then dma into the pages
 > that are dirty.  Instant karma corruption, no?  Or am I thinking of
 > some other problem?

      The R3000 has a write-through cache, so there cannot be dirty cache
lines, although you do have to flush the write buffers to be completely
correct (in the case of a DMA device writing to memory VERY quickly after
the register write which starts it up, on some hardware).