hmm_range_fault related fixes and legacy API removal v3

[Jason Gunthorpe]

On Wed, Jul 24, 2019 at 08:52:51AM +0200, Christoph Hellwig wrote:
> Hi Jérôme, Ben and Jason,
> 
> below is a series against the hmm tree which fixes up the mmap_sem
> locking in nouveau and while at it also removes leftover legacy HMM APIs
> only used by nouveau.
> 
> The first 4 patches are a bug fix for nouveau, which I suspect should
> go into this merge window even if the code is marked as staging, just
> to avoid people copying the breakage.
> 
> Changes since v2:
>  - new patch from Jason to document FAULT_FLAG_ALLOW_RETRY semantics
>    better
>  - remove -EAGAIN handling in nouveau earlier

I don't see Ralph's tested by, do you think it changed enough to
require testing again? If so, Ralph would you be so kind?

In any event, I'm sending this into linux-next and intend to forward
the first four next week.

Thanks,
Jason