Function _pmap_unwire_ptp

freebsd/mips/mips/pmap.c:1004–1061

}

static void
_pmap_unwire_ptp(pmap_t pmap, vm_offset_t va, vm_page_t m)
{
	pd_entry_t *pde;
	vm_offset_t sva, eva;

	PMAP_LOCK_ASSERT(pmap, MA_OWNED);
	/*
	 * unmap the page table page
	 */
#ifdef __mips_n64
	if (m->pindex < NUPDE) {
		pde = pmap_pde(pmap, va);
		sva = va & ~PDRMASK;
		eva = sva + NBPDR;
	} else {
		pde = pmap_segmap(pmap, va);
		sva = va & ~SEGMASK;
		eva = sva + NBSEG;
	}
#else
	pde = pmap_pde(pmap, va);
	sva = va & ~SEGMASK;
	eva = sva + NBSEG;
#endif
	*pde = 0;
	pmap->pm_stats.resident_count--;

#ifdef __mips_n64
	if (m->pindex < NUPDE) {
		pd_entry_t *pdp;
		vm_page_t pdpg;

		/*
		 * Recursively decrement next level pagetable refcount.
		 * Either that shoots down a larger range from TLBs (below)
		 * or we're to shoot down just the page in question.
		 */
		pdp = (pd_entry_t *)*pmap_segmap(pmap, va);
		pdpg = PHYS_TO_VM_PAGE(MIPS_DIRECT_TO_PHYS(pdp));
		if (!pmap_unwire_ptp(pmap, va, pdpg)) {
			pmap_invalidate_range(pmap, sva, eva);
		}
	} else {
		/* Segmap entry shootdown */
		pmap_invalidate_range(pmap, sva, eva);
	}
#else
	/* Segmap entry shootdown */
	pmap_invalidate_range(pmap, sva, eva);
#endif

	/*
	 * If the page is finally unwired, simply free it.
	 */
	vm_page_free_zero(m);
	vm_wire_sub(1);
}