Re: [RFC PATCH v3 2/6] swiotlb: Add restricted DMA pool

[Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>]

On Wed, Jan 06, 2021 at 11:41:20AM +0800, Claire Chang wrote:
> Add the initialization function to create restricted DMA pools from
> matching reserved-memory nodes in the device tree.
> 
> Signed-off-by: Claire Chang <tientzu@xxxxxxxxxxxx>
> ---
>  include/linux/device.h  |   4 ++
>  include/linux/swiotlb.h |   7 +-
>  kernel/dma/Kconfig      |   1 +
>  kernel/dma/swiotlb.c    | 144 ++++++++++++++++++++++++++++++++++------
>  4 files changed, 131 insertions(+), 25 deletions(-)
> 
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 89bb8b84173e..ca6f71ec8871 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -413,6 +413,7 @@ struct dev_links_info {
>   * @dma_pools:       Dma pools (if dma'ble device).
>   * @dma_mem: Internal for coherent mem override.
>   * @cma_area:        Contiguous memory area for dma allocations
> + * @dma_io_tlb_mem: Internal for swiotlb io_tlb_mem override.

Why does this have to be added here?  Shouldn't the platform-specific
code handle it instead?

thanks,

greg k-h