+
+/*
+ * Used to reserve address ranges in the aperture (e.g. for exclusion
+ * ranges.
+ */
+static void dma_ops_reserve_addresses(struct dma_ops_domain *dom,
+ unsigned long start_page,
+ unsigned int pages)
+{
+ unsigned int i, last_page = dom->aperture_size >> PAGE_SHIFT;
+
+ if (start_page + pages > last_page)
+ pages = last_page - start_page;
+
+ for (i = start_page; i < start_page + pages; ++i) {
+ int index = i / APERTURE_RANGE_PAGES;
+ int page = i % APERTURE_RANGE_PAGES;
+ __set_bit(page, dom->aperture[index]->bitmap);
+ }
+}
+
+/*
+ * This function is used to add a new aperture range to an existing
+ * aperture in case of dma_ops domain allocation or address allocation
+ * failure.
+ */
+static int alloc_new_range(struct dma_ops_domain *dma_dom,
+ bool populate, gfp_t gfp)
+{
+ int index = dma_dom->aperture_size >> APERTURE_RANGE_SHIFT;
+ struct amd_iommu *iommu;
+ unsigned long i;
+
+#ifdef CONFIG_IOMMU_STRESS
+ populate = false;
+#endif
+
+ if (index >= APERTURE_MAX_RANGES)
+ return -ENOMEM;
+
+ dma_dom->aperture[index] = kzalloc(sizeof(struct aperture_range), gfp);
+ if (!dma_dom->aperture[index])
+ return -ENOMEM;
+
+ dma_dom->aperture[index]->bitmap = (void *)get_zeroed_page(gfp);
+ if (!dma_dom->aperture[index]->bitmap)
+ goto out_free;
+
+ dma_dom->aperture[index]->offset = dma_dom->aperture_size;
+
+ if (populate) {
+ unsigned long address = dma_dom->aperture_size;
+ int i, num_ptes = APERTURE_RANGE_PAGES / 512;
+ u64 *pte, *pte_page;
+
+ for (i = 0; i < num_ptes; ++i) {
+ pte = alloc_pte(&dma_dom->domain, address, PM_MAP_4k,
+ &pte_page, gfp);
+ if (!pte)
+ goto out_free;
+
+ dma_dom->aperture[index]->pte_pages[i] = pte_page;
+
+ address += APERTURE_RANGE_SIZE / 64;
+ }
+ }
+
+ dma_dom->aperture_size += APERTURE_RANGE_SIZE;
+
+ /* Intialize the exclusion range if necessary */
+ for_each_iommu(iommu) {
+ if (iommu->exclusion_start &&
+ iommu->exclusion_start >= dma_dom->aperture[index]->offset
+ && iommu->exclusion_start < dma_dom->aperture_size) {
+ unsigned long startpage;
+ int pages = iommu_num_pages(iommu->exclusion_start,
+ iommu->exclusion_length,
+ PAGE_SIZE);
+ startpage = iommu->exclusion_start >> PAGE_SHIFT;
+ dma_ops_reserve_addresses(dma_dom, startpage, pages);
+ }
+ }
+
+ /*
+ * Check for areas already mapped as present in the new aperture
+ * range and mark those pages as reserved in the allocator. Such
+ * mappings may already exist as a result of requested unity
+ * mappings for devices.
+ */
+ for (i = dma_dom->aperture[index]->offset;
+ i < dma_dom->aperture_size;
+ i += PAGE_SIZE) {
+ u64 *pte = fetch_pte(&dma_dom->domain, i, PM_MAP_4k);
+ if (!pte || !IOMMU_PTE_PRESENT(*pte))
+ continue;
+
+ dma_ops_reserve_addresses(dma_dom, i << PAGE_SHIFT, 1);
+ }
+
+ update_domain(&dma_dom->domain);
+
+ return 0;
+
+out_free:
+ update_domain(&dma_dom->domain);
+
+ free_page((unsigned long)dma_dom->aperture[index]->bitmap);
+
+ kfree(dma_dom->aperture[index]);
+ dma_dom->aperture[index] = NULL;
+
+ return -ENOMEM;
+}
+
+static unsigned long dma_ops_area_alloc(struct device *dev,
+ struct dma_ops_domain *dom,
+ unsigned int pages,
+ unsigned long align_mask,
+ u64 dma_mask,
+ unsigned long start)
+{
+ unsigned long next_bit = dom->next_address % APERTURE_RANGE_SIZE;
+ int max_index = dom->aperture_size >> APERTURE_RANGE_SHIFT;
+ int i = start >> APERTURE_RANGE_SHIFT;
+ unsigned long boundary_size;
+ unsigned long address = -1;
+ unsigned long limit;
+
+ next_bit >>= PAGE_SHIFT;
+
+ boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
+ PAGE_SIZE) >> PAGE_SHIFT;
+
+ for (;i < max_index; ++i) {
+ unsigned long offset = dom->aperture[i]->offset >> PAGE_SHIFT;
+
+ if (dom->aperture[i]->offset >= dma_mask)
+ break;
+
+ limit = iommu_device_max_index(APERTURE_RANGE_PAGES, offset,
+ dma_mask >> PAGE_SHIFT);
+
+ address = iommu_area_alloc(dom->aperture[i]->bitmap,
+ limit, next_bit, pages, 0,
+ boundary_size, align_mask);
+ if (address != -1) {
+ address = dom->aperture[i]->offset +
+ (address << PAGE_SHIFT);
+ dom->next_address = address + (pages << PAGE_SHIFT);
+ break;
+ }
+
+ next_bit = 0;
+ }
+
+ return address;
+}
+