From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] virtio_mmio: Set DMA masks appropriately
Date: Tue, 10 Jan 2017 14:15:57 +0100 [thread overview]
Message-ID: <2220292.9CN9cxzsPe@wuerfel> (raw)
In-Reply-To: <50defbbe87d75db85a9d22f914258975d661208a.1484051089.git.robin.murphy@arm.com>
On Tuesday, January 10, 2017 12:26:01 PM CET Robin Murphy wrote:
> @@ -548,6 +550,14 @@ static int virtio_mmio_probe(struct platform_device *pdev)
> if (vm_dev->version == 1)
> writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
>
> + rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
> + if (rc)
> + rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
You don't seem to do anything different when 64-bit DMA is unsupported.
How do you prevent the use of kernel buffers that are above the first 4G
here?
> + else if (vm_dev->version == 1)
> + dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32 + PAGE_SHIFT));
Why is this limitation only for the coherent mask?
Arnd
next prev parent reply other threads:[~2017-01-10 13:15 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-10 12:26 [PATCH] virtio_mmio: Set DMA masks appropriately Robin Murphy
2017-01-10 13:15 ` Arnd Bergmann [this message]
2017-01-10 13:25 ` Russell King - ARM Linux
2017-01-10 13:44 ` Robin Murphy
2017-01-10 14:10 ` Arnd Bergmann
2017-01-10 14:54 ` Michael S. Tsirkin
2017-01-10 15:55 ` Robin Murphy
2017-01-10 16:07 ` Michael S. Tsirkin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2220292.9CN9cxzsPe@wuerfel \
--to=arnd@arndb.de \
--cc=linux-arm-kernel@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox