On Mon, 21 Jan 2019 at 20:58, Bhupesh Sharma bhsharma@redhat.com wrote:
Hi Sumit,
On Mon, Jan 21, 2019 at 3:00 PM Sumit Garg sumit.garg@linaro.org wrote:
Introduce a generic TEE bus driver concept for TEE based kernel drivers which would like to communicate with TEE based devices/services.
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 a match() callback function which 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.
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
drivers/tee/tee_core.c | 45 +++++++++++++++++++++++++++++++++++++++++---- include/linux/tee_drv.h | 37 ++++++++++++++++++++++++++++++++++++- 2 files changed, 77 insertions(+), 5 deletions(-)
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index 7b2bb4c..55370d5 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> @@ -1027,6 +1026,30 @@ 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 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)) {if (uuid_equal(&tee_device->id, id_table))return 1;id_table++;}return 0;+}
+struct bus_type tee_bus_type = {
.name = "tee",.match = tee_client_device_match,+}; +EXPORT_SYMBOL_GPL(tee_bus_type);
static int __init tee_init(void) { int rc; @@ -1040,18 +1063,32 @@ 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); diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h index 6cfe058..ba985d8 100644 --- a/include/linux/tee_drv.h +++ b/include/linux/tee_drv.h @@ -15,11 +15,13 @@ #ifndef __TEE_DRV_H #define __TEE_DRV_H
-#include <linux/types.h> +#include <linux/device.h> #include <linux/idr.h> #include <linux/kref.h> #include <linux/list.h> #include <linux/tee.h> +#include <linux/types.h> +#include <linux/uuid.h>
/*
- The file describes the API provided by the generic TEE driver to the
@@ -538,4 +540,37 @@ static inline bool tee_param_is_memref(struct tee_param *param) } }
+extern struct bus_type tee_bus_type;
+/*
- For TEE based client devices we use the device uuid as the
- identifier.
- */
+typedef uuid_t tee_client_device_id;
+/**
- struct tee_client_device - tee based device
- @id: device identifier
- @dev: device structure
- */
+struct tee_client_device {
tee_client_device_id id;struct device dev;+};
+#define to_tee_client_device(d) container_of(d, struct tee_client_device, dev)
+/**
- struct tee_client_driver - tee client driver
- @id_table: device id table supported by this driver
- @driver: driver structure
- */
+struct tee_client_driver {
const tee_client_device_id *id_table;struct device_driver driver;+};
+#define to_tee_client_driver(d) \
container_of(d, struct tee_client_driver, driver)#endif /*__TEE_DRV_H*/
2.7.4
LGTM, if there are no further comments on this patch please free to add: Reviewed-by: Bhupesh Sharma bhsharma@redhat.com
Thanks for this review tag. Actually I have to add support in module device table for TEE bus devices as per Ard's comments on patch #4. So that will require changes in this patch in next version.
-Sumit
Thanks.