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path: root/drivers/firmware/arm_ffa/bus.c
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Diffstat (limited to 'drivers/firmware/arm_ffa/bus.c')
-rw-r--r--drivers/firmware/arm_ffa/bus.c232
1 files changed, 232 insertions, 0 deletions
diff --git a/drivers/firmware/arm_ffa/bus.c b/drivers/firmware/arm_ffa/bus.c
new file mode 100644
index 0000000000..7865438b36
--- /dev/null
+++ b/drivers/firmware/arm_ffa/bus.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 ARM Ltd.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/arm_ffa.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "common.h"
+
+static DEFINE_IDA(ffa_bus_id);
+
+static int ffa_device_match(struct device *dev, struct device_driver *drv)
+{
+ const struct ffa_device_id *id_table;
+ struct ffa_device *ffa_dev;
+
+ id_table = to_ffa_driver(drv)->id_table;
+ ffa_dev = to_ffa_dev(dev);
+
+ while (!uuid_is_null(&id_table->uuid)) {
+ /*
+ * FF-A v1.0 doesn't provide discovery of UUIDs, just the
+ * partition IDs, so fetch the partitions IDs for this
+ * id_table UUID and assign the UUID to the device if the
+ * partition ID matches
+ */
+ if (uuid_is_null(&ffa_dev->uuid))
+ ffa_device_match_uuid(ffa_dev, &id_table->uuid);
+
+ if (uuid_equal(&ffa_dev->uuid, &id_table->uuid))
+ return 1;
+ id_table++;
+ }
+
+ return 0;
+}
+
+static int ffa_device_probe(struct device *dev)
+{
+ struct ffa_driver *ffa_drv = to_ffa_driver(dev->driver);
+ struct ffa_device *ffa_dev = to_ffa_dev(dev);
+
+ return ffa_drv->probe(ffa_dev);
+}
+
+static void ffa_device_remove(struct device *dev)
+{
+ struct ffa_driver *ffa_drv = to_ffa_driver(dev->driver);
+
+ if (ffa_drv->remove)
+ ffa_drv->remove(to_ffa_dev(dev));
+}
+
+static int ffa_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+ const struct ffa_device *ffa_dev = to_ffa_dev(dev);
+
+ return add_uevent_var(env, "MODALIAS=arm_ffa:%04x:%pUb",
+ ffa_dev->vm_id, &ffa_dev->uuid);
+}
+
+static ssize_t partition_id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct ffa_device *ffa_dev = to_ffa_dev(dev);
+
+ return sprintf(buf, "0x%04x\n", ffa_dev->vm_id);
+}
+static DEVICE_ATTR_RO(partition_id);
+
+static ssize_t uuid_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct ffa_device *ffa_dev = to_ffa_dev(dev);
+
+ return sprintf(buf, "%pUb\n", &ffa_dev->uuid);
+}
+static DEVICE_ATTR_RO(uuid);
+
+static struct attribute *ffa_device_attributes_attrs[] = {
+ &dev_attr_partition_id.attr,
+ &dev_attr_uuid.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(ffa_device_attributes);
+
+struct bus_type ffa_bus_type = {
+ .name = "arm_ffa",
+ .match = ffa_device_match,
+ .probe = ffa_device_probe,
+ .remove = ffa_device_remove,
+ .uevent = ffa_device_uevent,
+ .dev_groups = ffa_device_attributes_groups,
+};
+EXPORT_SYMBOL_GPL(ffa_bus_type);
+
+int ffa_driver_register(struct ffa_driver *driver, struct module *owner,
+ const char *mod_name)
+{
+ int ret;
+
+ if (!driver->probe)
+ return -EINVAL;
+
+ driver->driver.bus = &ffa_bus_type;
+ driver->driver.name = driver->name;
+ driver->driver.owner = owner;
+ driver->driver.mod_name = mod_name;
+
+ ret = driver_register(&driver->driver);
+ if (!ret)
+ pr_debug("registered new ffa driver %s\n", driver->name);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(ffa_driver_register);
+
+void ffa_driver_unregister(struct ffa_driver *driver)
+{
+ driver_unregister(&driver->driver);
+}
+EXPORT_SYMBOL_GPL(ffa_driver_unregister);
+
+static void ffa_release_device(struct device *dev)
+{
+ struct ffa_device *ffa_dev = to_ffa_dev(dev);
+
+ ida_free(&ffa_bus_id, ffa_dev->id);
+ kfree(ffa_dev);
+}
+
+static int __ffa_devices_unregister(struct device *dev, void *data)
+{
+ device_unregister(dev);
+
+ return 0;
+}
+
+static void ffa_devices_unregister(void)
+{
+ bus_for_each_dev(&ffa_bus_type, NULL, NULL,
+ __ffa_devices_unregister);
+}
+
+bool ffa_device_is_valid(struct ffa_device *ffa_dev)
+{
+ bool valid = false;
+ struct device *dev = NULL;
+ struct ffa_device *tmp_dev;
+
+ do {
+ dev = bus_find_next_device(&ffa_bus_type, dev);
+ tmp_dev = to_ffa_dev(dev);
+ if (tmp_dev == ffa_dev) {
+ valid = true;
+ break;
+ }
+ put_device(dev);
+ } while (dev);
+
+ put_device(dev);
+
+ return valid;
+}
+
+struct ffa_device *ffa_device_register(const uuid_t *uuid, int vm_id,
+ const struct ffa_ops *ops)
+{
+ int id, ret;
+ struct device *dev;
+ struct ffa_device *ffa_dev;
+
+ id = ida_alloc_min(&ffa_bus_id, 1, GFP_KERNEL);
+ if (id < 0)
+ return NULL;
+
+ ffa_dev = kzalloc(sizeof(*ffa_dev), GFP_KERNEL);
+ if (!ffa_dev) {
+ ida_free(&ffa_bus_id, id);
+ return NULL;
+ }
+
+ dev = &ffa_dev->dev;
+ dev->bus = &ffa_bus_type;
+ dev->release = ffa_release_device;
+ dev_set_name(&ffa_dev->dev, "arm-ffa-%d", id);
+
+ ffa_dev->id = id;
+ ffa_dev->vm_id = vm_id;
+ ffa_dev->ops = ops;
+ uuid_copy(&ffa_dev->uuid, uuid);
+
+ ret = device_register(&ffa_dev->dev);
+ if (ret) {
+ dev_err(dev, "unable to register device %s err=%d\n",
+ dev_name(dev), ret);
+ put_device(dev);
+ return NULL;
+ }
+
+ return ffa_dev;
+}
+EXPORT_SYMBOL_GPL(ffa_device_register);
+
+void ffa_device_unregister(struct ffa_device *ffa_dev)
+{
+ if (!ffa_dev)
+ return;
+
+ device_unregister(&ffa_dev->dev);
+}
+EXPORT_SYMBOL_GPL(ffa_device_unregister);
+
+int arm_ffa_bus_init(void)
+{
+ return bus_register(&ffa_bus_type);
+}
+
+void arm_ffa_bus_exit(void)
+{
+ ffa_devices_unregister();
+ bus_unregister(&ffa_bus_type);
+ ida_destroy(&ffa_bus_id);
+}