Re: [PATCH v5 2/8] s390/cio: introduce DMA pools to cio

Cornelia Huck
2019-06-12T14:24:00Z

On Wed, 12 Jun 2019 13:12:30 +0200
Halil Pasic <pasic@linux.ibm.com> wrote:

> To support protected virtualization cio will need to make sure the
> memory used for communication with the hypervisor is DMA memory.
>
> Let us introduce one global pool for cio.
>
> Our DMA pools are implemented as a gen_pool backed with DMA pages. The
> idea is to avoid each allocation effectively wasting a page, as we
> typically allocate much less than PAGE_SIZE.
>
> Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
> Reviewed-by: Sebastian Ott <sebott@linux.ibm.com>
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> ---
> arch/s390/Kconfig | 1 +
> arch/s390/include/asm/cio.h | 11 +++
> drivers/s390/cio/css.c | 133 ++++++++++++++++++++++++++++++++++--
> 3 files changed, 141 insertions(+), 4 deletions(-)

Changes look good to me.