FreeBSD/sys/i386/i386/pmap.c
/*
 *	pmap_zero_page zeros the specified hardware page by mapping 
 *	the page into KVM and using bzero to clear its contents.
 */
pmap_zero_page zeros the specified hardware page by mapping
the page into KVM and using bzero to clear its contents.
pmap_zero_page zeros the specified hardware page by mapping the page into KVM and using bzero to clear its contents .
void
pmap_zero_page(vm_page_t m)
{
	struct sysmaps *sysmaps;
	sysmaps = &sysmaps_pcpu[PCPU_GET(cpuid)];
	mtx_lock(&sysmaps->lock);
	if (*sysmaps->CMAP2)
		panic("pmap_zero_page: CMAP2 busy");
	sched_pin();
	*sysmaps->CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS(m) | PG_A | PG_M |
	    pmap_cache_bits(m->md.pat_mode, 0);
	invlcaddr(sysmaps->CADDR2);
	pagezero(sysmaps->CADDR2);
	*sysmaps->CMAP2 = 0;
	sched_unpin();
	mtx_unlock(&sysmaps->lock);
}
void pmap_zero_page ( vm_page_t m ) { struct sysmaps * sysmaps ; sysmaps = & sysmaps_pcpu [ PCPU_GET ( cpuid ) ] ; mtx_lock ( & sysmaps -> lock ) ; if ( * sysmaps -> CMAP2 ) panic ( " " ) ; sched_pin ( ) ; * sysmaps -> CMAP2 = PG_V | PG_RW | VM_PAGE_TO_PHYS ( m ) | PG_A | PG_M | pmap_cache_bits ( m -> md . pat_mode , 0 ) ; invlcaddr ( sysmaps -> CADDR2 ) ; pagezero ( sysmaps -> CADDR2 ) ; * sysmaps -> CMAP2 = 0 ; sched_unpin ( ) ; mtx_unlock ( & sysmaps -> lock ) ; }
pmap_zero_page zeros the specified hardware page by mapping
      the page into KVM and using bzero to clear its contents.
pmap_zero_page zeros the specified hardware page by mapping the page into KVM and using bzero to clear its contents .