pcache_flush_page
void (*pcache_flush_page)(paddr_t, int);
#define pcache_flush_page(pa,flag) cpuinfo.pcache_flush_page(pa,flag)
sc->pcache_flush_page = 0;
MPCOPY(pcache_flush_page);
void (*pcache_flush_page)(paddr_t, int);
} else if (cpuinfo.pcache_flush_page != NULL) {
pcache_flush_page(pa, 0);
pcache_flush_page(pa, 1);
pcache_flush_page(dst, 1);
pcache_flush_page(pa, 1);