From: "Koenig, Christian" <Christian.Koenig@amd.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Logan Gunthorpe <logang@deltatee.com>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>
Subject: Re: [PATCH] PCI/P2PDMA: Root complex whitelist should not apply when an IOMMU is present
Date: Thu, 23 May 2019 10:06:28 +0000 [thread overview]
Message-ID: <b09d61f0-cc6d-5043-1cb3-6891e589a872@amd.com> (raw)
In-Reply-To: <20190523095057.GA15185@lst.de>
Am 23.05.19 um 11:50 schrieb Christoph Hellwig:
> [CAUTION: External Email]
>
> On Thu, May 23, 2019 at 09:48:40AM +0000, Koenig, Christian wrote:
>> I don't adjust the address manually anywhere. I just call
>> dma_map_resource() and use the resulting DMA address to access the other
>> devices PCI BAR.
>>
>> At least on my test system (AMD CPU + AMD GPUs) this seems to work
>> totally fine. Currently trying to find time and an Intel box to test it
>> there as well.
> The problem shows up if pci_bus_address() returns a different address
> than pci_resource_start(), should be easy to check if that happens.
> IIRC it is something mostly seen on embedded SOCs.
Ok, we certainly don't have a system which exercise this user case.
Could ask around if we have an ARM SOC with that properties somewhere.
But asking the other way around: Where is the right place to start
fixing all this? dma_map_resource()?
Christian.
next prev parent reply other threads:[~2019-05-23 10:06 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <a98bff67-a76e-4ddc-a317-96f2bdc9af72@email.android.com>
2019-05-22 20:41 ` [PATCH] PCI/P2PDMA: Root complex whitelist should not apply when an IOMMU is present Logan Gunthorpe
2019-05-23 8:12 ` Koenig, Christian
2019-05-23 9:43 ` Christoph Hellwig
2019-05-23 9:48 ` Koenig, Christian
2019-05-23 9:50 ` Christoph Hellwig
2019-05-23 10:06 ` Koenig, Christian [this message]
2019-05-23 10:26 ` Christoph Hellwig
2019-05-23 15:59 ` Logan Gunthorpe
2019-05-23 15:53 ` Logan Gunthorpe
2019-05-23 15:59 ` Christoph Hellwig
2019-05-24 12:40 ` Koenig, Christian
2019-05-24 14:12 ` Christoph Hellwig
2019-05-24 16:18 ` Logan Gunthorpe
2019-05-24 16:06 ` Logan Gunthorpe
2019-05-23 16:14 ` Logan Gunthorpe
2019-05-23 15:47 ` Logan Gunthorpe
2019-05-22 20:12 Logan Gunthorpe
2019-06-18 20:40 ` Bjorn Helgaas
2019-06-18 20:51 ` Logan Gunthorpe
2019-06-18 23:50 ` Logan Gunthorpe
2019-06-19 9:26 ` Koenig, Christian
2019-06-19 9:29 ` Christoph Hellwig
2019-06-19 9:39 ` Koenig, Christian
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