1 // SPDX-License-Identifier: GPL-2.0-only
3  * OF helpers for IOMMU
9 #include <linux/iommu.h>
23  * of_get_dma_window - Parse *dma-window property and returns 0 if found.
44 		return -EINVAL;  in of_get_dma_window()
49 	snprintf(propname, sizeof(propname), "%sdma-window", prefix);  in of_get_dma_window()
50 	snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", prefix);  in of_get_dma_window()
51 	snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", prefix);  in of_get_dma_window()
55 		return -ENODEV;  in of_get_dma_window()
68 			prop = of_get_property(dn, "#address-cells", NULL);  in of_get_dma_window()
72 			return -EINVAL;  in of_get_dma_window()
79 			return -EINVAL;  in of_get_dma_window()
94 	struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;  in of_iommu_xlate()
98 	if ((ops && !ops->of_xlate) ||  in of_iommu_xlate()
99 	    !of_device_is_available(iommu_spec->np))  in of_iommu_xlate()
102 	ret = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);  in of_iommu_xlate()
106 	 * The otherwise-empty fwspec handily serves to indicate the specific  in of_iommu_xlate()
107 	 * IOMMU device we're waiting for, which will be useful if we ever get  in of_iommu_xlate()
108 	 * a proper probe-ordering dependency mechanism in future.  in of_iommu_xlate()
113 	if (!try_module_get(ops->owner))  in of_iommu_xlate()
114 		return -ENODEV;  in of_iommu_xlate()
116 	ret = ops->of_xlate(dev, iommu_spec);  in of_iommu_xlate()
117 	module_put(ops->owner);  in of_iommu_xlate()
128 	err = of_map_id(master_np, *id, "iommu-map",  in of_iommu_configure_dev_id()
129 			 "iommu-map-mask", &iommu_spec.np,  in of_iommu_configure_dev_id()
132 		return err == -ENODEV ? NO_IOMMU : err;  in of_iommu_configure_dev_id()
146 					   "#iommu-cells",  in of_iommu_configure_dev()
168 	return of_iommu_configure_dev_id(info->np, info->dev, &input_id);  in of_pci_iommu_init()
190 		if (fwspec->ops)  in of_iommu_configure()
191 			return fwspec->ops;  in of_iommu_configure()
198 	 * We don't currently walk up the tree looking for a parent IOMMU.  in of_iommu_configure()
200 	 * Documentation/devicetree/bindings/iommu/iommu.txt  in of_iommu_configure()
216 			of_property_read_u32(master_np, "pasid-num-bits",  in of_iommu_configure()
217 					     &fwspec->num_pasid_bits);  in of_iommu_configure()
221 	 * Two success conditions can be represented by non-negative err here:  in of_iommu_configure()
222 	 * >0 : there is no IOMMU, or one was unavailable for non-fatal reasons  in of_iommu_configure()
223 	 *  0 : we found an IOMMU, and dev->fwspec is initialised appropriately  in of_iommu_configure()
229 		ops    = fwspec->ops;  in of_iommu_configure()
232 	 * If we have reason to believe the IOMMU driver missed the initial  in of_iommu_configure()
235 	if (!err && dev->bus && !device_iommu_mapped(dev))  in of_iommu_configure()
239 	if (err == -EPROBE_DEFER) {  in of_iommu_configure()
242 		dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);  in of_iommu_configure()