/* * OF helpers for IOMMU * * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. */ #include <linux/export.h> #include <linux/iommu.h> #include <linux/limits.h> #include <linux/of.h> #include <linux/of_iommu.h> #include <linux/slab.h> static const struct of_device_id __iommu_of_table_sentinel __used __section(__iommu_of_table_end); /** * of_get_dma_window - Parse *dma-window property and returns 0 if found. * * @dn: device node * @prefix: prefix for property name if any * @index: index to start to parse * @busno: Returns busno if supported. Otherwise pass NULL * @addr: Returns address that DMA starts * @size: Returns the range that DMA can handle * * This supports different formats flexibly. "prefix" can be * configured if any. "busno" and "index" are optionally * specified. Set 0(or NULL) if not used. */ int of_get_dma_window(struct device_node *dn, const char *prefix, int index, unsigned long *busno, dma_addr_t *addr, size_t *size) { const __be32 *dma_window, *end; int bytes, cur_index = 0; char propname[NAME_MAX], addrname[NAME_MAX], sizename[NAME_MAX]; if (!dn || !addr || !size) return -EINVAL; if (!prefix) prefix = ""; snprintf(propname, sizeof(propname), "%sdma-window", prefix); snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", prefix); snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", prefix); dma_window = of_get_property(dn, propname, &bytes); if (!dma_window) return -ENODEV; end = dma_window + bytes / sizeof(*dma_window); while (dma_window < end) { u32 cells; const void *prop; /* busno is one cell if supported */ if (busno) *busno = be32_to_cpup(dma_window++); prop = of_get_property(dn, addrname, NULL); if (!prop) prop = of_get_property(dn, "#address-cells", NULL); cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn); if (!cells) return -EINVAL; *addr = of_read_number(dma_window, cells); dma_window += cells; prop = of_get_property(dn, sizename, NULL); cells = prop ? be32_to_cpup(prop) : of_n_size_cells(dn); if (!cells) return -EINVAL; *size = of_read_number(dma_window, cells); dma_window += cells; if (cur_index++ == index) break; } return 0; } EXPORT_SYMBOL_GPL(of_get_dma_window); struct of_iommu_node { struct list_head list; struct device_node *np; struct iommu_ops *ops; }; static LIST_HEAD(of_iommu_list); static DEFINE_SPINLOCK(of_iommu_lock); void of_iommu_set_ops(struct device_node *np, struct iommu_ops *ops) { struct of_iommu_node *iommu = kzalloc(sizeof(*iommu), GFP_KERNEL); if (WARN_ON(!iommu)) return; INIT_LIST_HEAD(&iommu->list); iommu->np = np; iommu->ops = ops; spin_lock(&of_iommu_lock); list_add_tail(&iommu->list, &of_iommu_list); spin_unlock(&of_iommu_lock); } struct iommu_ops *of_iommu_get_ops(struct device_node *np) { struct of_iommu_node *node; struct iommu_ops *ops = NULL; spin_lock(&of_iommu_lock); list_for_each_entry(node, &of_iommu_list, list) if (node->np == np) { ops = node->ops; break; } spin_unlock(&of_iommu_lock); return ops; } struct iommu_ops *of_iommu_configure(struct device *dev, struct device_node *master_np) { struct of_phandle_args iommu_spec; struct device_node *np; struct iommu_ops *ops = NULL; int idx = 0; /* * We can't do much for PCI devices without knowing how * device IDs are wired up from the PCI bus to the IOMMU. */ if (dev_is_pci(dev)) return NULL; /* * We don't currently walk up the tree looking for a parent IOMMU. * See the `Notes:' section of * Documentation/devicetree/bindings/iommu/iommu.txt */ while (!of_parse_phandle_with_args(master_np, "iommus", "#iommu-cells", idx, &iommu_spec)) { np = iommu_spec.np; ops = of_iommu_get_ops(np); if (!ops || !ops->of_xlate || ops->of_xlate(dev, &iommu_spec)) goto err_put_node; of_node_put(np); idx++; } return ops; err_put_node: of_node_put(np); return NULL; } void __init of_iommu_init(void) { struct device_node *np; const struct of_device_id *match, *matches = &__iommu_of_table; for_each_matching_node_and_match(np, matches, &match) { const of_iommu_init_fn init_fn = match->data; if (init_fn(np)) pr_err("Failed to initialise IOMMU %s\n", of_node_full_name(np)); } }