Function tlb_invalidate_range

freebsd/mips/mips/tlb.c:199–265

* Invalidates any TLB entries that map a virtual page from the specified * address range. If "end" is zero, then every virtual page is considered to * be within the address range's upper bound. */

 * be within the address range's upper bound.
 */
void
tlb_invalidate_range(pmap_t pmap, vm_offset_t start, vm_offset_t end)
{
	register_t asid, end_hi, hi, hi_pagemask, s, save_asid, start_hi;
	int i;

	KASSERT(start < end || (end == 0 && start > 0),
	    ("tlb_invalidate_range: invalid range"));

	/*
	 * Truncate the virtual address "start" to an even page frame number,
	 * and round the virtual address "end" to an even page frame number.
	 */
	start &= ~((1 << TLBMASK_SHIFT) - 1);
	end = roundup2(end, 1 << TLBMASK_SHIFT);

	s = intr_disable();
	save_asid = mips_rd_entryhi() & TLBHI_ASID_MASK;

	asid = pmap_asid(pmap);
	start_hi = TLBHI_ENTRY(start, asid);
	end_hi = TLBHI_ENTRY(end, asid);

	/*
	 * Select the fastest method for invalidating the TLB entries.
	 */
	if (end - start < num_tlbentries << TLBMASK_SHIFT || (end == 0 &&
	    start >= -(num_tlbentries << TLBMASK_SHIFT))) {
		/*
		 * The virtual address range is small compared to the size of
		 * the TLB.  Probe the TLB for each even numbered page frame
		 * within the virtual address range.
		 */
		for (hi = start_hi; hi != end_hi; hi += 1 << TLBMASK_SHIFT) {
			mips_wr_pagemask(0);
			mips_wr_entryhi(hi);
			tlb_probe();
			i = mips_rd_index();
			if (i >= 0)
				tlb_invalidate_one(i);
		}
	} else {
		/*
		 * The virtual address range is large compared to the size of
		 * the TLB.  Test every non-wired TLB entry.
		 */
		for (i = mips_rd_wired(); i < num_tlbentries; i++) {
			mips_wr_index(i);
			tlb_read();
			hi = mips_rd_entryhi();
			if ((hi & TLBHI_ASID_MASK) == asid && (hi < end_hi ||
			    end == 0)) {
				/*
				 * If "hi" is a large page that spans
				 * "start_hi", then it must be invalidated.
				 */
				hi_pagemask = mips_rd_pagemask();
				if (hi >= (start_hi & ~(hi_pagemask <<