Question about out_unmap section of map_sg in amd_iommu.c

[Jerry Snitselaar]

 out_unmap:
         pr_err("%s: IOMMU mapping error in map_sg (io-pages: %d)\n",
                dev_name(dev), npages);

         for_each_sg(sglist, s, nelems, i) {
                 int j, pages = iommu_num_pages(sg_phys(s), s->length, PAGE_SIZE);

                 for (j = 0; j < pages; ++j) {
                         unsigned long bus_addr;

                         bus_addr  = address + s->dma_address + (j << PAGE_SHIFT);
                         iommu_unmap_page(domain, bus_addr, PAGE_SIZE);

                         if (--mapped_pages)
                                 goto out_free_iova;

Is this condition correct?  My thought is this was meant to break out of the loop early if
all the mapped pages have been unmapped. So if (--mapped == 0) instead?

                 }
         }