From: Krishna Reddy <vdumpa@nvidia.com>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: Thierry Reding <treding@nvidia.com>,
Bryan Huntsman <bhuntsman@nvidia.com>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
Mikko Perttunen <mperttunen@nvidia.com>,
Timo Alho <talho@nvidia.com>, Sachin Nikam <Snikam@nvidia.com>,
Nicolin Chen <nicolinc@nvidia.com>,
"linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>,
Yu-Huan Hsu <YHsu@nvidia.com>,
Pritesh Raithatha <praithatha@nvidia.com>,
"will@kernel.org" <will@kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
Bitan Biswas <bbiswas@nvidia.com>
Subject: RE: [PATCH v6 1/4] iommu/arm-smmu: add NVIDIA implementation for dual ARM MMU-500 usage
Date: Thu, 25 Jun 2020 23:13:24 +0000 [thread overview]
Message-ID: <BYAPR12MB2822B1D5791811EDAF35C5B2B3920@BYAPR12MB2822.namprd12.prod.outlook.com> (raw)
In-Reply-To: <20200623102927.GD4098287@ulmo>
>Should NVIDIA_TEGRA194_SMMU be a separate value for smmu->model, perhaps? That way we avoid this somewhat odd check here.
NVIDIA haven't made any changes to arm,mmu-500. It is only used in different topology. New model would be mis-leading here.
As suggested by Robin, It can just be moved to end of function.
>> diff --git a/drivers/iommu/arm-smmu-nvidia.c
>> b/drivers/iommu/arm-smmu-nvidia.c
>I wonder if it would be better to name this arm-smmu-tegra.c to make it clearer that this is for a Tegra chip. We do have regular expressions in MAINTAINERS that catch anything with "tegra" in it to make this easier.
>Also, the nsmmu_ prefix looks somewhat odd here. You already use struct nvidia_smmu as the name of the structure, so why not be consistent and continue to use nvidia_smmu_ as the prefix for function names?
>Or perhaps even use tegra_smmu_ as the prefix to match the filename change I suggested earlier.
Prefix can be updated to nvidia_smmu as we seem to be okay for now to keep file name as arm-smmu-nvidia.c after the vendor name.
>> +#define TLB_LOOP_TIMEOUT 1000000 /* 1s! */
>USEC_PER_SEC?
It is not meant for a conversion. Reused Timeout variable from arm-smmu.c for tlb_sync implementation. Can rename it to TLB_LOOP_TIMEOUT_IN_US.
>> + }
>> + dev_err_ratelimited(smmu->dev,
>> + "TLB sync timed out -- SMMU may be deadlocked\n");
>Same here.
>Also, is there anything we can do when this happens?
This is never expected to happen on Silicon. This code and message is reused from arm-smmu.c.
>> +#define nsmmu_page(smmu, inst, page) \
>> + (((inst) ? to_nvidia_smmu(smmu)->bases[(inst)] : smmu->base) + \
>> + ((page) << smmu->pgshift))
>Can we simply define to_nvidia_smmu(smmu)->bases[0] = smmu->base in nvidia_smmu_impl_init()? Then this would become just:
> to_nvidia_smmu(smmu)->bases[inst] + ((page) << (smmu)->pgshift)
> +
>Maybe add this here to simplify the nsmmu_page() macro above:
> nsmmu->bases[0] = smmu->base;
This preferred to avoid the check in nsmmu_page(). But, smmu->base is not yet populated when nvidia_smmu_impl_init() is called.
Let me look at the alternative place to set it.
-KR
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2020-06-25 23:13 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-04 23:44 [PATCH v6 0/4] Nvidia Arm SMMUv2 Implementation Krishna Reddy
2020-06-04 23:44 ` [PATCH v6 1/4] iommu/arm-smmu: add NVIDIA implementation for dual ARM MMU-500 usage Krishna Reddy
2020-06-23 10:29 ` Thierry Reding
2020-06-23 11:16 ` Robin Murphy
2020-06-23 12:47 ` Thierry Reding
2020-06-25 23:13 ` Krishna Reddy [this message]
2020-06-04 23:44 ` [PATCH v6 2/4] dt-bindings: arm-smmu: Add binding for Tegra194 SMMU Krishna Reddy
2020-06-23 8:38 ` Thierry Reding
2020-06-25 22:32 ` Krishna Reddy
2020-06-04 23:44 ` [PATCH v6 3/4] iommu/arm-smmu: Add global/context fault implementation hooks Krishna Reddy
2020-06-23 8:36 ` Thierry Reding
2020-06-23 11:30 ` Robin Murphy
2020-06-23 12:33 ` Thierry Reding
2020-06-04 23:44 ` [PATCH v6 4/4] iommu/arm-smmu-nvidia: fix the warning reported by kbuild test robot Krishna Reddy
2020-06-23 8:33 ` Thierry Reding
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=BYAPR12MB2822B1D5791811EDAF35C5B2B3920@BYAPR12MB2822.namprd12.prod.outlook.com \
--to=vdumpa@nvidia.com \
--cc=Snikam@nvidia.com \
--cc=YHsu@nvidia.com \
--cc=bbiswas@nvidia.com \
--cc=bhuntsman@nvidia.com \
--cc=iommu@lists.linux-foundation.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=mperttunen@nvidia.com \
--cc=nicolinc@nvidia.com \
--cc=praithatha@nvidia.com \
--cc=robin.murphy@arm.com \
--cc=talho@nvidia.com \
--cc=thierry.reding@gmail.com \
--cc=treding@nvidia.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).