diff options
Diffstat (limited to 'drivers/firmware/arm_ffa/bus.c')
| -rw-r--r-- | drivers/firmware/arm_ffa/bus.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/drivers/firmware/arm_ffa/bus.c b/drivers/firmware/arm_ffa/bus.c new file mode 100644 index 000000000000..83166e02b191 --- /dev/null +++ b/drivers/firmware/arm_ffa/bus.c @@ -0,0 +1,210 @@ +// 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 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); + + if (!ffa_device_match(dev, dev->driver)) + return -ENODEV; + + return ffa_drv->probe(ffa_dev); +} + +static int ffa_device_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + 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, + .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; + + 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); + + kfree(ffa_dev); +} + +static int __ffa_devices_unregister(struct device *dev, void *data) +{ + ffa_release_device(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) +{ + int ret; + struct device *dev; + struct ffa_device *ffa_dev; + + ffa_dev = kzalloc(sizeof(*ffa_dev), GFP_KERNEL); + if (!ffa_dev) + return NULL; + + dev = &ffa_dev->dev; + dev->bus = &ffa_bus_type; + dev->release = ffa_release_device; + dev_set_name(&ffa_dev->dev, "arm-ffa-%04x", vm_id); + + ffa_dev->vm_id = vm_id; + 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); +} |