--- /dev/null
+/*
+ * 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;
+
+ if (dev_is_pci(dev)) {
+ dev_err(dev, "IOMMU is currently not supported for PCI\n");
+ 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));
+ }
+}
Code Review / kvmfornfv.git / blobdiff