From: Julien Grall <julien.grall@arm.com>
To: Robin Murphy <robin.murphy@arm.com>,
Joerg Roedel <jroedel@suse.de>, Qian Cai <cai@lca.pw>
Cc: Marc Zyngier <maz@kernel.org>,
iommu@lists.linux-foundation.org, Christoph Hellwig <hch@lst.de>,
Tom Murphy <murphyt7@tcd.ie>,
linux-kernel@vger.kernel.org
Subject: Re: "Convert the AMD iommu driver to the dma-iommu api" is buggy
Date: Wed, 16 Oct 2019 17:36:11 +0100 [thread overview]
Message-ID: <fc510899-4e8b-827f-4c5f-2fe89145ac30@arm.com> (raw)
In-Reply-To: <a85f264c-3b74-b92b-ac03-aeba3a56946f@arm.com>
Hi Robin,
On 16/10/2019 17:09, Robin Murphy wrote:
> On 16/10/2019 17:03, Joerg Roedel wrote:
>> On Wed, Oct 16, 2019 at 11:53:33AM -0400, Qian Cai wrote:
>>> On Wed, 2019-10-16 at 17:31 +0200, Joerg Roedel wrote:
>>
>>> The x86 one might just be a mistake.
>>>
>>> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
>>> index ad05484d0c80..63c4b894751d 100644
>>> --- a/drivers/iommu/amd_iommu.c
>>> +++ b/drivers/iommu/amd_iommu.c
>>> @@ -2542,7 +2542,7 @@ static int amd_iommu_map(struct iommu_domain *dom,
>>> unsigned long iova,
>>> if (iommu_prot & IOMMU_WRITE)
>>> prot |= IOMMU_PROT_IW;
>>> - ret = iommu_map_page(domain, iova, paddr, page_size, prot, GFP_KERNEL);
>>> + ret = iommu_map_page(domain, iova, paddr, page_size, prot, gfp);
>>
>> Yeah, that is a bug, I spotted that too.
>>
>>> @@ -1185,7 +1185,7 @@ static struct iommu_dma_msi_page
>>> *iommu_dma_get_msi_page(struct device *dev,
>>> if (!iova)
>>> goto out_free_page;
>>> - if (iommu_map(domain, iova, msi_addr, size, prot))
>>> + if (iommu_map_atomic(domain, iova, msi_addr, size, prot))
>>> goto out_free_iova;
>>
>> Not so sure this is a bug, this code is only about setting up MSIs on
>> ARM. It probably doesn't need to be atomic.
> Right, since the iommu_dma_prepare_msi() operation was broken out to happen at
> MSI domain setup time, I don't think the comment in there applies any more, so
> we can probably stop disabling irqs around the iommu_dma_get_msi_page() call.
Yes, I agree that it does not need to be atomic anymore.
Cheers,
--
Julien Grall
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iommu@lists.linux-foundation.org
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next prev parent reply other threads:[~2019-10-16 16:36 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-16 14:55 "Convert the AMD iommu driver to the dma-iommu api" is buggy Qian Cai
2019-10-16 14:59 ` Qian Cai
2019-10-16 15:31 ` Joerg Roedel
2019-10-16 15:53 ` Qian Cai
2019-10-16 16:03 ` Joerg Roedel
2019-10-16 16:09 ` Robin Murphy
2019-10-16 16:36 ` Julien Grall [this message]
2019-10-16 16:11 ` Qian Cai
2019-10-16 16:26 ` Robin Murphy
2019-10-16 15:44 ` Joerg Roedel
2019-10-17 14:39 ` Qian Cai
2019-10-18 9:39 ` Joerg Roedel
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