From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Subject: amd_iommu fallback question
Date: Thu, 5 Apr 2018 21:36:12 +0200
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To: Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
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Hi Joerg,

I've got a little question on the amd_iommu code, hope you (or someone
else on the list) can answer it.  Most of the dma_map_ops methods have
a fallback for the case when get_domain() return -EINVAL, which basically
duplicates the normal no-iommu implementation, with the map_sg method
being and exception that always returns and error (return value of 0
is an error for its calling convention).  Is that an oversight?  If yes
so I wonder why it hasn't been caught yet.  Or is the whole fallback
code dead and can be removed?