Re: [PATCH 2/3] ipack: save carrier owner to allow device to get it

[Samuel Iglesias Gonsálvez]

On Tue, 2014-09-02 at 17:31 +0200, Federico Vaga wrote:
> There was not any kind of protection against carrier driver removal.
> In this way, device driver can 'get' the carrier driver when it is
> using it.
> 
> Signed-off-by: Federico Vaga <federico.vaga@xxxxxxx>
> ---
>  drivers/ipack/carriers/tpci200.c |    3 ++-
>  drivers/ipack/ipack.c            |    4 +++-
>  include/linux/ipack.h            |   24 +++++++++++++++++++++++-
>  3 files changed, 28 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/ipack/carriers/tpci200.c b/drivers/ipack/carriers/tpci200.c
> index de5e321..9b23843 100644
> --- a/drivers/ipack/carriers/tpci200.c
> +++ b/drivers/ipack/carriers/tpci200.c
> @@ -572,7 +572,8 @@ static int tpci200_pci_probe(struct pci_dev *pdev,
>  	/* Register the carrier in the industry pack bus driver */
>  	tpci200->info->ipack_bus = ipack_bus_register(&pdev->dev,
>  						      TPCI200_NB_SLOT,
> -						      &tpci200_bus_ops);
> +						      &tpci200_bus_ops,
> +						      THIS_MODULE);
>  	if (!tpci200->info->ipack_bus) {
>  		dev_err(&pdev->dev,
>  			"error registering the carrier on ipack driver\n");
> diff --git a/drivers/ipack/ipack.c b/drivers/ipack/ipack.c
> index d0016ba..c0e7b62 100644
> --- a/drivers/ipack/ipack.c
> +++ b/drivers/ipack/ipack.c
> @@ -206,7 +206,8 @@ static struct bus_type ipack_bus_type = {
>  };
>  
>  struct ipack_bus_device *ipack_bus_register(struct device *parent, int slots,
> -					    const struct ipack_bus_ops *ops)
> +					    const struct ipack_bus_ops *ops,
> +					    struct module *owner)
>  {
>  	int bus_nr;
>  	struct ipack_bus_device *bus;
> @@ -225,6 +226,7 @@ struct ipack_bus_device *ipack_bus_register(struct device *parent, int slots,
>  	bus->parent = parent;
>  	bus->slots = slots;
>  	bus->ops = ops;
> +	bus->owner = owner;
>  	return bus;
>  }
>  EXPORT_SYMBOL_GPL(ipack_bus_register);
> diff --git a/include/linux/ipack.h b/include/linux/ipack.h
> index 1888e06..8bddc3f 100644
> --- a/include/linux/ipack.h
> +++ b/include/linux/ipack.h
> @@ -172,6 +172,7 @@ struct ipack_bus_ops {
>   *	@ops: bus operations for the mezzanine drivers
>   */
>  struct ipack_bus_device {
> +	struct module *owner;
>  	struct device *parent;
>  	int slots;
>  	int bus_nr;
> @@ -189,7 +190,8 @@ struct ipack_bus_device {
>   * available bus device in ipack.
>   */
>  struct ipack_bus_device *ipack_bus_register(struct device *parent, int slots,
> -					    const struct ipack_bus_ops *ops);
> +					    const struct ipack_bus_ops *ops,
> +					    struct module *owner);
>  
>  /**
>   *	ipack_bus_unregister -- unregister an ipack bus
> @@ -265,3 +267,23 @@ void ipack_put_device(struct ipack_device *dev);
>  	 .format = (_format), \
>  	 .vendor = (vend), \
>  	 .device = (dev)
> +
> +/**
> + * ipack_get_carrier - it increase the carrier ref. counter of
> + *                     the carrier module
> + * @dev: mezzanine device which wants to get the carrier
> + */
> +static inline int ipack_get_carrier(struct ipack_device *dev)
> +{
> +	return try_module_get(dev->bus->owner);
> +}
> +
> +/**
> + * ipack_get_carrier - it decrease the carrier ref. counter of
> + *                     the carrier module
> + * @dev: mezzanine device which wants to get the carrier
> + */
> +static inline void ipack_put_carrier(struct ipack_device *dev)
> +{
> +	module_put(dev->bus->owner);
> +}

Acked-by: Samuel Iglesias Gonsalvez <siglesias@xxxxxxxxxx>

Sam

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