For reference here is the geode lx disable car. CAR is at 80000. The steps are to re-enable cache (for loop), then dirty all the tags for the CAR area (cld; rep movsl; etc); then write it all back (wbinvd).
Works really well.
for (i = 0; i < ARRAY_SIZE(msr_table); i++) wrmsr(msr_table[i].msrnum, msr_table[i].msr);
__asm__ __volatile__("cld; rep movsl" ::"D" (DCACHE_RAM_BASE), "S" (DCACHE_RAM_BASE), "c" (DCACHE_RAM_SIZE/4): "memory");
__asm__ __volatile__ ("wbinvd\n");
Would be great if this worked on k8.
Thanks ron