static int intel_setup_irq_remapping()

in intel/irq_remapping.c [534:632]

• 76 lines of code
• 12 McCabe index (conditional complexity)

static int intel_setup_irq_remapping(struct intel_iommu *iommu)
{
	struct ir_table *ir_table;
	struct fwnode_handle *fn;
	unsigned long *bitmap;
	struct page *pages;

	if (iommu->ir_table)
		return 0;

	ir_table = kzalloc(sizeof(struct ir_table), GFP_KERNEL);
	if (!ir_table)
		return -ENOMEM;

	pages = alloc_pages_node(iommu->node, GFP_KERNEL | __GFP_ZERO,
				 INTR_REMAP_PAGE_ORDER);
	if (!pages) {
		pr_err("IR%d: failed to allocate pages of order %d\n",
		       iommu->seq_id, INTR_REMAP_PAGE_ORDER);
		goto out_free_table;
	}

	bitmap = bitmap_zalloc(INTR_REMAP_TABLE_ENTRIES, GFP_ATOMIC);
	if (bitmap == NULL) {
		pr_err("IR%d: failed to allocate bitmap\n", iommu->seq_id);
		goto out_free_pages;
	}

	fn = irq_domain_alloc_named_id_fwnode("INTEL-IR", iommu->seq_id);
	if (!fn)
		goto out_free_bitmap;

	iommu->ir_domain =
		irq_domain_create_hierarchy(arch_get_ir_parent_domain(),
					    0, INTR_REMAP_TABLE_ENTRIES,
					    fn, &intel_ir_domain_ops,
					    iommu);
	if (!iommu->ir_domain) {
		irq_domain_free_fwnode(fn);
		pr_err("IR%d: failed to allocate irqdomain\n", iommu->seq_id);
		goto out_free_bitmap;
	}
	iommu->ir_msi_domain =
		arch_create_remap_msi_irq_domain(iommu->ir_domain,
						 "INTEL-IR-MSI",
						 iommu->seq_id);

	ir_table->base = page_address(pages);
	ir_table->bitmap = bitmap;
	iommu->ir_table = ir_table;

	/*
	 * If the queued invalidation is already initialized,
	 * shouldn't disable it.
	 */
	if (!iommu->qi) {
		/*
		 * Clear previous faults.
		 */
		dmar_fault(-1, iommu);
		dmar_disable_qi(iommu);

		if (dmar_enable_qi(iommu)) {
			pr_err("Failed to enable queued invalidation\n");
			goto out_free_bitmap;
		}
	}

	init_ir_status(iommu);

	if (ir_pre_enabled(iommu)) {
		if (!is_kdump_kernel()) {
			pr_warn("IRQ remapping was enabled on %s but we are not in kdump mode\n",
				iommu->name);
			clear_ir_pre_enabled(iommu);
			iommu_disable_irq_remapping(iommu);
		} else if (iommu_load_old_irte(iommu))
			pr_err("Failed to copy IR table for %s from previous kernel\n",
			       iommu->name);
		else
			pr_info("Copied IR table for %s from previous kernel\n",
				iommu->name);
	}

	iommu_set_irq_remapping(iommu, eim_mode);

	return 0;

out_free_bitmap:
	bitmap_free(bitmap);
out_free_pages:
	__free_pages(pages, INTR_REMAP_PAGE_ORDER);
out_free_table:
	kfree(ir_table);

	iommu->ir_table  = NULL;

	return -ENOMEM;
}