From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cornelia Huck <cohuck@redhat.com>
Subject: Re: [PATCH v4 2/8] s390/cio: introduce DMA pools to cio
Date: Tue, 11 Jun 2019 11:55:29 +0200
Message-ID: <20190611115529.6e3ae12d.cohuck@redhat.com>
References: <20190606115127.55519-1-pasic@linux.ibm.com>
	<20190606115127.55519-3-pasic@linux.ibm.com>
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To: Halil Pasic <pasic@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>, linux-s390@vger.kernel.org, Thomas Huth <thuth@redhat.com>, Claudio Imbrenda <imbrenda@linux.ibm.com>, kvm@vger.kernel.org, Sebastian Ott <sebott@linux.ibm.com>, "Michael S. Tsirkin" <mst@redhat.com>, Farhan Ali <alifm@linux.ibm.com>, Heiko Carstens <heiko.carstens@de.ibm.com>, Eric Farman <farman@linux.ibm.com>, virtualization@lists.linux-foundation.org, Christoph Hellwig <hch@infradead.org>, Christian Borntraeger <borntraeger@de.ibm.com>, "Jason J. Herne" <jjherne@linux.ibm.com>, Michael Mueller <mimu@linux.ibm.com>, Viktor Mihajlovski <mihajlov@linux.ibm.com>, Janosch Frank <frankja@linux.ibm.com>
List-Id: virtualization@lists.linuxfoundation.org

On Thu,  6 Jun 2019 13:51:21 +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>
> ---
>  arch/s390/Kconfig           |   1 +
>  arch/s390/include/asm/cio.h |  11 +++
>  drivers/s390/cio/css.c      | 131 ++++++++++++++++++++++++++++++++++--
>  3 files changed, 139 insertions(+), 4 deletions(-)

(...)

> +void cio_gp_dma_destroy(struct gen_pool *gp_dma, struct device *dma_dev)
> +{
> +	if (!gp_dma)
> +		return;
> +	/* this is qite ugly but no better idea */

typo: s/qite/quite/

> +	gen_pool_for_each_chunk(gp_dma, __gp_dma_free_dma, dma_dev);
> +	gen_pool_destroy(gp_dma);
> +}

(...)

Reviewed-by: Cornelia Huck <cohuck@redhat.com>