Re: [RFC PATCH v3 1/5] swiotlb: Return state of memory from swiotlb_alloc()

[Aneesh Kumar K.V <aneesh.kumar@kernel.org>]

Mostafa Saleh <smostafa@google.com> writes:

> Make swiotlb_alloc() return the state of the allocated memory, at
> the moment all the pools are decrypted but that would change soon.
> In the next patches dma-direct will use the returned state to
> determine whether to decrypt the memory and use the proper memory
> decryption/encryption related functions.
>
> Also, add swiotlb_is_decrypted(), that will be used before calling
> swiotlb_free() to check whether the memory needs to be encrypted
> by the caller.
>
> Signed-off-by: Mostafa Saleh <smostafa@google.com>
> ---
>  include/linux/swiotlb.h | 25 +++++++++++++++++++++++--
>  kernel/dma/direct.c     |  2 +-
>  kernel/dma/swiotlb.c    | 23 ++++++++++++++++++++++-
>  3 files changed, 46 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
> index 3dae0f592063..24be65494ce8 100644
> --- a/include/linux/swiotlb.h
> +++ b/include/linux/swiotlb.h
> @@ -63,6 +63,7 @@ extern void __init swiotlb_update_mem_attributes(void);
>   * @area_nslabs: Number of slots in each area.
>   * @areas:	Array of memory area descriptors.
>   * @slots:	Array of slot descriptors.
> + * @decrypted:	Whether the pool was decrypted or left in default state.
>   * @node:	Member of the IO TLB memory pool list.
>   * @rcu:	RCU head for swiotlb_dyn_free().
>   * @transient:  %true if transient memory pool.
> @@ -77,6 +78,7 @@ struct io_tlb_pool {
>  	unsigned int area_nslabs;
>  	struct io_tlb_area *areas;
>  	struct io_tlb_slot *slots;
> +	bool decrypted;
>  #ifdef CONFIG_SWIOTLB_DYNAMIC
>  	struct list_head node;
>  	struct rcu_head rcu;
> @@ -281,16 +283,31 @@ static inline void swiotlb_sync_single_for_cpu(struct device *dev,
>

Should this be a property of struct io_tlb_mem ? 

-aneesh