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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/iommu/of_iommu.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/iommu/of_iommu.c')
-rw-r--r--drivers/iommu/of_iommu.c180
1 files changed, 180 insertions, 0 deletions
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
new file mode 100644
index 000000000..1fa1db3be
--- /dev/null
+++ b/drivers/iommu/of_iommu.c
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * OF helpers for IOMMU
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
+ */
+
+#include <linux/export.h>
+#include <linux/iommu.h>
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of.h>
+#include <linux/of_iommu.h>
+#include <linux/of_pci.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/fsl/mc.h>
+
+#define NO_IOMMU 1
+
+static int of_iommu_xlate(struct device *dev,
+ struct of_phandle_args *iommu_spec)
+{
+ const struct iommu_ops *ops;
+ struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
+ int ret;
+
+ ops = iommu_ops_from_fwnode(fwnode);
+ if ((ops && !ops->of_xlate) ||
+ !of_device_is_available(iommu_spec->np))
+ return NO_IOMMU;
+
+ ret = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
+ if (ret)
+ return ret;
+ /*
+ * The otherwise-empty fwspec handily serves to indicate the specific
+ * IOMMU device we're waiting for, which will be useful if we ever get
+ * a proper probe-ordering dependency mechanism in future.
+ */
+ if (!ops)
+ return driver_deferred_probe_check_state(dev);
+
+ if (!try_module_get(ops->owner))
+ return -ENODEV;
+
+ ret = ops->of_xlate(dev, iommu_spec);
+ module_put(ops->owner);
+ return ret;
+}
+
+static int of_iommu_configure_dev_id(struct device_node *master_np,
+ struct device *dev,
+ const u32 *id)
+{
+ struct of_phandle_args iommu_spec = { .args_count = 1 };
+ int err;
+
+ err = of_map_id(master_np, *id, "iommu-map",
+ "iommu-map-mask", &iommu_spec.np,
+ iommu_spec.args);
+ if (err)
+ return err == -ENODEV ? NO_IOMMU : err;
+
+ err = of_iommu_xlate(dev, &iommu_spec);
+ of_node_put(iommu_spec.np);
+ return err;
+}
+
+static int of_iommu_configure_dev(struct device_node *master_np,
+ struct device *dev)
+{
+ struct of_phandle_args iommu_spec;
+ int err = NO_IOMMU, idx = 0;
+
+ while (!of_parse_phandle_with_args(master_np, "iommus",
+ "#iommu-cells",
+ idx, &iommu_spec)) {
+ err = of_iommu_xlate(dev, &iommu_spec);
+ of_node_put(iommu_spec.np);
+ idx++;
+ if (err)
+ break;
+ }
+
+ return err;
+}
+
+struct of_pci_iommu_alias_info {
+ struct device *dev;
+ struct device_node *np;
+};
+
+static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
+{
+ struct of_pci_iommu_alias_info *info = data;
+ u32 input_id = alias;
+
+ return of_iommu_configure_dev_id(info->np, info->dev, &input_id);
+}
+
+static int of_iommu_configure_device(struct device_node *master_np,
+ struct device *dev, const u32 *id)
+{
+ return (id) ? of_iommu_configure_dev_id(master_np, dev, id) :
+ of_iommu_configure_dev(master_np, dev);
+}
+
+const struct iommu_ops *of_iommu_configure(struct device *dev,
+ struct device_node *master_np,
+ const u32 *id)
+{
+ const struct iommu_ops *ops = NULL;
+ struct iommu_fwspec *fwspec;
+ int err = NO_IOMMU;
+
+ if (!master_np)
+ return NULL;
+
+ /* Serialise to make dev->iommu stable under our potential fwspec */
+ mutex_lock(&iommu_probe_device_lock);
+ fwspec = dev_iommu_fwspec_get(dev);
+ if (fwspec) {
+ if (fwspec->ops) {
+ mutex_unlock(&iommu_probe_device_lock);
+ return fwspec->ops;
+ }
+ /* In the deferred case, start again from scratch */
+ iommu_fwspec_free(dev);
+ }
+
+ /*
+ * We don't currently walk up the tree looking for a parent IOMMU.
+ * See the `Notes:' section of
+ * Documentation/devicetree/bindings/iommu/iommu.txt
+ */
+ if (dev_is_pci(dev)) {
+ struct of_pci_iommu_alias_info info = {
+ .dev = dev,
+ .np = master_np,
+ };
+
+ pci_request_acs();
+ err = pci_for_each_dma_alias(to_pci_dev(dev),
+ of_pci_iommu_init, &info);
+ } else {
+ err = of_iommu_configure_device(master_np, dev, id);
+ }
+
+ /*
+ * Two success conditions can be represented by non-negative err here:
+ * >0 : there is no IOMMU, or one was unavailable for non-fatal reasons
+ * 0 : we found an IOMMU, and dev->fwspec is initialised appropriately
+ * <0 : any actual error
+ */
+ if (!err) {
+ /* The fwspec pointer changed, read it again */
+ fwspec = dev_iommu_fwspec_get(dev);
+ ops = fwspec->ops;
+ }
+ mutex_unlock(&iommu_probe_device_lock);
+
+ /*
+ * If we have reason to believe the IOMMU driver missed the initial
+ * probe for dev, replay it to get things in order.
+ */
+ if (!err && dev->bus && !device_iommu_mapped(dev))
+ err = iommu_probe_device(dev);
+
+ /* Ignore all other errors apart from EPROBE_DEFER */
+ if (err == -EPROBE_DEFER) {
+ ops = ERR_PTR(err);
+ } else if (err < 0) {
+ dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
+ ops = NULL;
+ }
+
+ return ops;
+}