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Message-ID: <1571241213.5937.64.camel@lca.pw>
Subject: Re: "Convert the AMD iommu driver to the dma-iommu api" is buggy
From:   Qian Cai <cai@lca.pw>
To:     Joerg Roedel <jroedel@suse.de>
Cc:     Tom Murphy <murphyt7@tcd.ie>, Robin Murphy <robin.murphy@arm.com>,
        Christoph Hellwig <hch@lst.de>,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Date:   Wed, 16 Oct 2019 11:53:33 -0400
In-Reply-To: <20191016153112.GF4695@suse.de>
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         <1571237982.5937.60.camel@lca.pw> <20191016153112.GF4695@suse.de>
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On Wed, 2019-10-16 at 17:31 +0200, Joerg Roedel wrote:
> Hi Qian,
> 
> thanks for the report!
> 
> On Wed, Oct 16, 2019 at 10:59:42AM -0400, Qian Cai wrote:
> > On Wed, 2019-10-16 at 10:55 -0400, Qian Cai wrote:
> > > Today's linux-next generates a lot of warnings on multiple servers during boot
> > > due to the series "iommu/amd: Convert the AMD iommu driver to the dma-iommu api"
> > > [1]. Reverted the whole things fixed them.
> > > 
> > > [1] https://lore.kernel.org/lkml/20190908165642.22253-1-murphyt7@tcd.ie/
> > > 
> > 
> > BTW, the previous x86 warning was from only reverted one patch "iommu: Add gfp
> > parameter to iommu_ops::map" where proved to be insufficient. Now, pasting the
> > correct warning.

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);
 
        domain_flush_np_cache(domain, iova, page_size);

The arm64 -- does it forget to do this?

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index ecc08aef9b58..8dd0ef0656f4 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -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;
 
        INIT_LIST_HEAD(&msi_page->list);