From: Joerg Roedel <joro@8bytes.org>
To: Robin Murphy <robin.murphy@arm.com>
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
iommu@lists.linux-foundation.org, jonathan.lemon@gmail.com,
dwmw2@infradead.org, hch@lst.de,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 2/2] iommu/dma: Avoid SAC address trick for PCIe devices
Date: Mon, 13 Jul 2020 15:14:26 +0200 [thread overview]
Message-ID: <20200713131426.GQ27672@8bytes.org> (raw)
In-Reply-To: <d412c292d222eb36469effd338e985f9d9e24cd6.1594207679.git.robin.murphy@arm.com>
On Wed, Jul 08, 2020 at 12:32:42PM +0100, Robin Murphy wrote:
> As for the intel-iommu implementation, relegate the opportunistic
> attempt to allocate a SAC address to the domain of conventional PCI
> devices only, to avoid it increasingly causing far more performance
> issues than possible benefits on modern PCI Express systems.
>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
> drivers/iommu/dma-iommu.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index 4959f5df21bd..0ff124f16ad4 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -426,7 +426,8 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain,
> dma_limit = min(dma_limit, (u64)domain->geometry.aperture_end);
>
> /* Try to get PCI devices a SAC address */
> - if (dma_limit > DMA_BIT_MASK(32) && dev_is_pci(dev))
> + if (dma_limit > DMA_BIT_MASK(32) &&
> + dev_is_pci(dev) && !pci_is_pcie(to_pci_dev(dev)))
> iova = alloc_iova_fast(iovad, iova_len,
> DMA_BIT_MASK(32) >> shift, false);
>
Unfortunatly this patch causes XHCI initialization failures on my AMD
Ryzen system. I will remove both from the IOMMU tree for now.
I guess the XHCI chip in my system does not support full 64bit dma
addresses and needs a quirk or something like that. But until this is
resolved its better to not change the IOVA allocation behavior.
Regards,
Joerg
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2020-07-13 13:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-08 11:32 [PATCH 1/2] iommu/intel: Avoid SAC address trick for PCIe devices Robin Murphy
2020-07-08 11:32 ` [PATCH 2/2] iommu/dma: " Robin Murphy
2020-07-13 13:14 ` Joerg Roedel [this message]
2020-07-14 11:42 ` Robin Murphy
2020-07-22 12:48 ` Joerg Roedel
2020-07-08 12:26 ` [PATCH 1/2] iommu/intel: " Christoph Hellwig
2020-07-10 14:20 ` Joerg Roedel
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=20200713131426.GQ27672@8bytes.org \
--to=joro@8bytes.org \
--cc=dwmw2@infradead.org \
--cc=hch@lst.de \
--cc=iommu@lists.linux-foundation.org \
--cc=jonathan.lemon@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=robin.murphy@arm.com \
/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;
as well as URLs for NNTP newsgroup(s).