diff mbox series

[1/7] bus: mhi: core: Pass module owner during client driver registration

Message ID 20200323122108.12851-2-manivannan.sadhasivam@linaro.org (mailing list archive)
State Superseded
Headers show
Series Improvements to MHI Bus | expand

Commit Message

Manivannan Sadhasivam March 23, 2020, 12:21 p.m. UTC
The module owner field can be used to prevent the removal of kernel
modules when there are any device files associated with it opened in
userspace. Hence, modify the API to pass module owner field. For
convenience, module_mhi_driver() macro is used which takes care of
passing the module owner through THIS_MODULE of the module of the
driver and also avoiding the use of specifying the default MHI client
driver register/unregister routines.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/init.c |  5 +++--
 include/linux/mhi.h         | 19 ++++++++++++++++++-
 2 files changed, 21 insertions(+), 3 deletions(-)

Comments

Bjorn Andersson March 23, 2020, 7:05 p.m. UTC | #1
On Mon 23 Mar 05:21 PDT 2020, Manivannan Sadhasivam wrote:

> The module owner field can be used to prevent the removal of kernel
> modules when there are any device files associated with it opened in
> userspace. Hence, modify the API to pass module owner field. For
> convenience, module_mhi_driver() macro is used which takes care of
> passing the module owner through THIS_MODULE of the module of the
> driver and also avoiding the use of specifying the default MHI client
> driver register/unregister routines.
> 
> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

> ---
>  drivers/bus/mhi/core/init.c |  5 +++--
>  include/linux/mhi.h         | 19 ++++++++++++++++++-
>  2 files changed, 21 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index 5fb756ca335e..eb7f556a8531 100644
> --- a/drivers/bus/mhi/core/init.c
> +++ b/drivers/bus/mhi/core/init.c
> @@ -1189,7 +1189,7 @@ static int mhi_driver_remove(struct device *dev)
>  	return 0;
>  }
>  
> -int mhi_driver_register(struct mhi_driver *mhi_drv)
> +int __mhi_driver_register(struct mhi_driver *mhi_drv, struct module *owner)
>  {
>  	struct device_driver *driver = &mhi_drv->driver;
>  
> @@ -1197,12 +1197,13 @@ int mhi_driver_register(struct mhi_driver *mhi_drv)
>  		return -EINVAL;
>  
>  	driver->bus = &mhi_bus_type;
> +	driver->owner = owner;
>  	driver->probe = mhi_driver_probe;
>  	driver->remove = mhi_driver_remove;
>  
>  	return driver_register(driver);
>  }
> -EXPORT_SYMBOL_GPL(mhi_driver_register);
> +EXPORT_SYMBOL_GPL(__mhi_driver_register);
>  
>  void mhi_driver_unregister(struct mhi_driver *mhi_drv)
>  {
> diff --git a/include/linux/mhi.h b/include/linux/mhi.h
> index 79cb9f898544..0e7071dbf2c3 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -514,11 +514,28 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
>   */
>  void mhi_unregister_controller(struct mhi_controller *mhi_cntrl);
>  
> +/*
> + * module_mhi_driver() - Helper macro for drivers that don't do
> + * anything special in module init/exit.  This eliminates a lot of
> + * boilerplate.  Each module may only use this macro once, and
> + * calling it replaces module_init() and module_exit()
> + */
> +#define module_mhi_driver(mhi_drv) \
> +	module_driver(mhi_drv, mhi_driver_register, \
> +		      mhi_driver_unregister)
> +
> +/*
> + * Macro to avoid include chaining to get THIS_MODULE
> + */
> +#define mhi_driver_register(mhi_drv) \
> +	__mhi_driver_register(mhi_drv, THIS_MODULE)
> +
>  /**
>   * mhi_driver_register - Register driver with MHI framework
>   * @mhi_drv: Driver associated with the device
> + * @owner: The module owner
>   */
> -int mhi_driver_register(struct mhi_driver *mhi_drv);
> +int __mhi_driver_register(struct mhi_driver *mhi_drv, struct module *owner);
>  
>  /**
>   * mhi_driver_unregister - Unregister a driver for mhi_devices
> -- 
> 2.17.1
>
diff mbox series

Patch

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 5fb756ca335e..eb7f556a8531 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -1189,7 +1189,7 @@  static int mhi_driver_remove(struct device *dev)
 	return 0;
 }
 
-int mhi_driver_register(struct mhi_driver *mhi_drv)
+int __mhi_driver_register(struct mhi_driver *mhi_drv, struct module *owner)
 {
 	struct device_driver *driver = &mhi_drv->driver;
 
@@ -1197,12 +1197,13 @@  int mhi_driver_register(struct mhi_driver *mhi_drv)
 		return -EINVAL;
 
 	driver->bus = &mhi_bus_type;
+	driver->owner = owner;
 	driver->probe = mhi_driver_probe;
 	driver->remove = mhi_driver_remove;
 
 	return driver_register(driver);
 }
-EXPORT_SYMBOL_GPL(mhi_driver_register);
+EXPORT_SYMBOL_GPL(__mhi_driver_register);
 
 void mhi_driver_unregister(struct mhi_driver *mhi_drv)
 {
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 79cb9f898544..0e7071dbf2c3 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -514,11 +514,28 @@  int mhi_register_controller(struct mhi_controller *mhi_cntrl,
  */
 void mhi_unregister_controller(struct mhi_controller *mhi_cntrl);
 
+/*
+ * module_mhi_driver() - Helper macro for drivers that don't do
+ * anything special in module init/exit.  This eliminates a lot of
+ * boilerplate.  Each module may only use this macro once, and
+ * calling it replaces module_init() and module_exit()
+ */
+#define module_mhi_driver(mhi_drv) \
+	module_driver(mhi_drv, mhi_driver_register, \
+		      mhi_driver_unregister)
+
+/*
+ * Macro to avoid include chaining to get THIS_MODULE
+ */
+#define mhi_driver_register(mhi_drv) \
+	__mhi_driver_register(mhi_drv, THIS_MODULE)
+
 /**
  * mhi_driver_register - Register driver with MHI framework
  * @mhi_drv: Driver associated with the device
+ * @owner: The module owner
  */
-int mhi_driver_register(struct mhi_driver *mhi_drv);
+int __mhi_driver_register(struct mhi_driver *mhi_drv, struct module *owner);
 
 /**
  * mhi_driver_unregister - Unregister a driver for mhi_devices