From mboxrd@z Thu Jan  1 00:00:00 1970
From: Will Deacon <will-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Subject: Re: [PATCH v3 3/4] iommu/arm-smmu: Add support to handle Qcom's
	wait-for-safe logic
Date: Tue, 25 Jun 2019 14:39:25 +0100
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To: Vivek Gautam <vivek.gautam-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
Cc: "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" <devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, linux-arm-msm <linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>, open list <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Bjorn Andersson <bjorn.andersson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>, David Brown <david.brown-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>, "list-Y9sIeH5OGRo@public.gmane.org:IOMMU DRIVERS <iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>,
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On Tue, Jun 25, 2019 at 12:34:56PM +0530, Vivek Gautam wrote:
> On Mon, Jun 24, 2019 at 10:33 PM Will Deacon <will-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
> > Instead, I think this needs to be part of a separate file that is maintained
> > by you, which follows on from the work that Krishna is doing for nvidia
> > built on top of Robin's prototype patches:
> >
> > http://linux-arm.org/git?p=linux-rm.git;a=shortlog;h=refs/heads/iommu/smmu-impl
> 
> Looking at this branch quickly, it seem there can be separate implementation
> level configuration file that can be added.
> But will this also handle separate page table ops when required in future.

Nothing's set in stone, but having the implementation-specific code
constrain the page-table format (especially wrt quirks) sounds reasonable to
me. I'm currently waiting for Krishna to respin the nvidia changes [1] on
top of this so that we can see how well the abstractions are holding up.

I certainly won't merge the stuff until we have a user.

Will

[1] https://lkml.kernel.org/r/1543887414-18209-1-git-send-email-vdumpa-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org