cleanup swiotlb initialization

[Boris Ostrovsky]

On 2/25/22 3:47 AM, Christoph Hellwig wrote:
> On Thu, Feb 24, 2022 at 12:07:26PM -0500, Boris Ostrovsky wrote:
>>>> Just to be clear: this crashes only as dom0. Boots fine as baremetal.
>>> Ah.  I can gues what this might be.  On Xen the hypervisor controls the
>>> IOMMU and we should never end up initializing it in Linux, right?
>>
>> Right, we shouldn't be in that code path.
> Can you try the patch below on top of the series?
>

Yes, this makes dom0 boot fine.


(It also addresses something I wanted to mention while looking at the patches, which was to remove Xen initialization code from pci_swiotlb_detect_4gb() since it had noting to do with what the routine's name implies.)


-boris