Re: [PATCH v3 07/14] iommu/ioasid: Add an iterator API for ioasid_set

[Jean-Philippe Brucker]

On Mon, Sep 28, 2020 at 02:38:34PM -0700, Jacob Pan wrote:
> Users of an ioasid_set may not keep track of all the IOASIDs allocated
> under the set. When collective actions are needed for each IOASIDs, it
> is useful to iterate over all the IOASIDs within the set. For example,
> when the ioasid_set is freed, the user might perform the same cleanup
> operation on each IOASID.
> 
> This patch adds an API to iterate all the IOASIDs within the set.
> 
> Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>

Could add a short description of the function parameters, but

Reviewed-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>

> ---
>  drivers/iommu/ioasid.c | 17 +++++++++++++++++
>  include/linux/ioasid.h |  9 +++++++++
>  2 files changed, 26 insertions(+)
> 
> diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c
> index cf8c7d34e2de..9628e78b2ab4 100644
> --- a/drivers/iommu/ioasid.c
> +++ b/drivers/iommu/ioasid.c
> @@ -701,6 +701,23 @@ int ioasid_adjust_set(struct ioasid_set *set, int quota)
>  EXPORT_SYMBOL_GPL(ioasid_adjust_set);
>  
>  /**
> + * ioasid_set_for_each_ioasid - Iterate over all the IOASIDs within the set
> + *
> + * Caller must hold a reference of the set and handles its own locking.
> + */
> +void ioasid_set_for_each_ioasid(struct ioasid_set *set,
> +				void (*fn)(ioasid_t id, void *data),
> +				void *data)
> +{
> +	struct ioasid_data *entry;
> +	unsigned long index;
> +
> +	xa_for_each(&set->xa, index, entry)
> +		fn(index, data);
> +}
> +EXPORT_SYMBOL_GPL(ioasid_set_for_each_ioasid);
> +
> +/**
>   * ioasid_find - Find IOASID data
>   * @set: the IOASID set
>   * @ioasid: the IOASID to find
> diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
> index 0a5e82148eb9..aab58bc26714 100644
> --- a/include/linux/ioasid.h
> +++ b/include/linux/ioasid.h
> @@ -75,6 +75,9 @@ int ioasid_register_allocator(struct ioasid_allocator_ops *allocator);
>  void ioasid_unregister_allocator(struct ioasid_allocator_ops *allocator);
>  int ioasid_attach_data(ioasid_t ioasid, void *data);
>  void ioasid_detach_data(ioasid_t ioasid);
> +void ioasid_set_for_each_ioasid(struct ioasid_set *sdata,
> +				void (*fn)(ioasid_t id, void *data),
> +				void *data);
>  #else /* !CONFIG_IOASID */
>  static inline void ioasid_install_capacity(ioasid_t total)
>  {
> @@ -131,5 +134,11 @@ static inline int ioasid_attach_data(ioasid_t ioasid, void *data)
>  static inline void ioasid_detach_data(ioasid_t ioasid)
>  {
>  }
> +
> +static inline void ioasid_set_for_each_ioasid(struct ioasid_set *sdata,
> +					      void (*fn)(ioasid_t id, void *data),
> +					      void *data)
> +{
> +}
>  #endif /* CONFIG_IOASID */
>  #endif /* __LINUX_IOASID_H */
> -- 
> 2.7.4
>