Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 16 Oct 2019 18:03:14 +0200
From:   Joerg Roedel <jroedel@suse.de>
To:     Qian Cai <cai@lca.pw>
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
Subject: Re: "Convert the AMD iommu driver to the dma-iommu api" is buggy
Message-ID: <20191016160314.GH4695@suse.de>
References: <1571237707.5937.58.camel@lca.pw>
 <1571237982.5937.60.camel@lca.pw>
 <20191016153112.GF4695@suse.de>
 <1571241213.5937.64.camel@lca.pw>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <1571241213.5937.64.camel@lca.pw>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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.

Regards,

	Joerg