Function insert_region

freebsd/kern/subr_physmem.c:276–308

* Insertion-sort a new entry into a regions list; sorted by start address. */

 * Insertion-sort a new entry into a regions list; sorted by start address.
 */
static size_t
insert_region(struct region *regions, size_t rcnt, vm_paddr_t addr,
    vm_size_t size, uint32_t flags)
{
	size_t i;
	struct region *ep, *rp;

	ep = regions + rcnt;
	for (i = 0, rp = regions; i < rcnt; ++i, ++rp) {
		if (rp->addr == addr && rp->size == size) /* Pure dup. */
			return (rcnt);
		if (flags == rp->flags) {
			if (addr + size == rp->addr) {
				rp->addr = addr;
				rp->size += size;
				return (rcnt);
			} else if (rp->addr + rp->size == addr) {
				rp->size += size;
				return (rcnt);
			}
		}
		if (addr < rp->addr) {
			bcopy(rp, rp + 1, (ep - rp) * sizeof(*rp));
			break;
		}
	}
	rp->addr  = addr;
	rp->size  = size;
	rp->flags = flags;
	rcnt++;

	return (rcnt);
}

/*
 * Add a hardware memory region.