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authorSumit Garg <sumit.garg@linaro.org>2019-01-29 11:19:35 +0530
committerJens Wiklander <jens.wiklander@linaro.org>2019-02-01 15:12:46 +0100
commit0fc1db9d105915021260eb241661b8e96f5c0f1a (patch)
tree5e5d608e2a01aaeec416ade44d47036638ad7289 /drivers/tee
parent42bf4152d8a79f89f5456dee63a1f364fbce2dd6 (diff)
downloadlinux-0fc1db9d105915021260eb241661b8e96f5c0f1a.tar.bz2
tee: add bus driver framework for TEE based devices
Introduce a generic TEE bus driver concept for TEE based kernel drivers which would like to communicate with TEE based devices/services. Also add support in module device table for these new TEE based devices. In this TEE bus concept, devices/services are identified via Universally Unique Identifier (UUID) and drivers register a table of device UUIDs which they can support. So this TEE bus framework registers following apis: - match(): Iterates over the driver UUID table to find a corresponding match for device UUID. If a match is found, then this particular device is probed via corresponding probe api registered by the driver. This process happens whenever a device or a driver is registered with TEE bus. - uevent(): Notifies user-space (udev) whenever a new device is registered on this bus for auto-loading of modularized drivers. Also this framework allows for device enumeration to be specific to corresponding TEE implementation like OP-TEE etc. Signed-off-by: Sumit Garg <sumit.garg@linaro.org> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Diffstat (limited to 'drivers/tee')
-rw-r--r--drivers/tee/tee_core.c54
1 files changed, 50 insertions, 4 deletions
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index adf2588282fc..25f3b9cc8908 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -15,7 +15,6 @@
#define pr_fmt(fmt) "%s: " fmt, __func__
#include <linux/cdev.h>
-#include <linux/device.h>
#include <linux/fs.h>
#include <linux/idr.h>
#include <linux/module.h>
@@ -1040,6 +1039,39 @@ int tee_client_invoke_func(struct tee_context *ctx,
}
EXPORT_SYMBOL_GPL(tee_client_invoke_func);
+static int tee_client_device_match(struct device *dev,
+ struct device_driver *drv)
+{
+ const struct tee_client_device_id *id_table;
+ struct tee_client_device *tee_device;
+
+ id_table = to_tee_client_driver(drv)->id_table;
+ tee_device = to_tee_client_device(dev);
+
+ while (!uuid_is_null(&id_table->uuid)) {
+ if (uuid_equal(&tee_device->id.uuid, &id_table->uuid))
+ return 1;
+ id_table++;
+ }
+
+ return 0;
+}
+
+static int tee_client_device_uevent(struct device *dev,
+ struct kobj_uevent_env *env)
+{
+ uuid_t *dev_id = &to_tee_client_device(dev)->id.uuid;
+
+ return add_uevent_var(env, "MODALIAS=tee:%pUb", dev_id);
+}
+
+struct bus_type tee_bus_type = {
+ .name = "tee",
+ .match = tee_client_device_match,
+ .uevent = tee_client_device_uevent,
+};
+EXPORT_SYMBOL_GPL(tee_bus_type);
+
static int __init tee_init(void)
{
int rc;
@@ -1053,18 +1085,32 @@ static int __init tee_init(void)
rc = alloc_chrdev_region(&tee_devt, 0, TEE_NUM_DEVICES, "tee");
if (rc) {
pr_err("failed to allocate char dev region\n");
- class_destroy(tee_class);
- tee_class = NULL;
+ goto out_unreg_class;
+ }
+
+ rc = bus_register(&tee_bus_type);
+ if (rc) {
+ pr_err("failed to register tee bus\n");
+ goto out_unreg_chrdev;
}
+ return 0;
+
+out_unreg_chrdev:
+ unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
+out_unreg_class:
+ class_destroy(tee_class);
+ tee_class = NULL;
+
return rc;
}
static void __exit tee_exit(void)
{
+ bus_unregister(&tee_bus_type);
+ unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
class_destroy(tee_class);
tee_class = NULL;
- unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
}
subsys_initcall(tee_init);