linux-kernel - Re: [PATCH 6/6] media: uvcvideo: Use dma_alloc

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20210128150955.GA30563@lst.de>
Date:   Thu, 28 Jan 2021 16:09:55 +0100
From:   Christoph Hellwig <hch@....de>
To:     Mauro Carvalho Chehab <mchehab@...nel.org>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        Tomasz Figa <tfiga@...omium.org>,
        Ricardo Ribalda <ribalda@...omium.org>,
        Sergey Senozhatsky <senozhatsky@...gle.com>,
        iommu@...ts.linux-foundation.org
Cc:     linux-media@...r.kernel.org, Robin Murphy <robin.murphy@....com>,
        linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org
Subject: Re: [PATCH 6/6] media: uvcvideo: Use dma_alloc_noncontiguos API

I just included this patch as-is, but here are a few comments:

On Thu, Jan 28, 2021 at 03:58:37PM +0100, Christoph Hellwig wrote:
> +static void uvc_urb_dma_sync(struct uvc_urb *uvc_urb, bool for_device)
> +{
> +	struct device *dma_dev = dma_dev = stream_to_dmadev(uvc_urb->stream);
> +
> +	if (for_device)
> +		dma_sync_sgtable_for_device(dma_dev, uvc_urb->sgt,
> +					    DMA_FROM_DEVICE);
> +	else
> +		dma_sync_sgtable_for_cpu(dma_dev, uvc_urb->sgt,
> +					 DMA_FROM_DEVICE);
> +}

Given that we vmap the addresses this also needs
flush_kernel_vmap_range / invalidate_kernel_vmap_range calls for
VIVT architectures.