diff mbox series

[v4,1/4] tee: add bus driver framework for TEE based devices

Message ID 1548062959-31860-2-git-send-email-sumit.garg@linaro.org (mailing list archive)
State New, archived
Headers show
Series Introduce TEE bus driver framework | expand

Commit Message

Sumit Garg Jan. 21, 2019, 9:29 a.m. UTC
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(-)

Comments

Bhupesh Sharma Jan. 21, 2019, 3:28 p.m. UTC | #1
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.
Sumit Garg Jan. 22, 2019, 1:33 p.m. UTC | #2
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.
diff mbox series

Patch

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*/