From: Jason Gunthorpe <jgg@nvidia.com>
To: Nicolin Chen <nicolinc@nvidia.com>
Cc: will@kernel.org, robin.murphy@arm.com, joro@8bytes.org,
thierry.reding@gmail.com, vdumpa@nvidia.com,
jonathanh@nvidia.com, linux-kernel@vger.kernel.org,
iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
linux-tegra@vger.kernel.org
Subject: Re: [PATCH v7 6/6] iommu/tegra241-cmdqv: Limit CMDs for guest owned VINTF
Date: Tue, 14 May 2024 12:15:13 -0300 [thread overview]
Message-ID: <ZkOAAdugARILEeBh@nvidia.com> (raw)
In-Reply-To: <ZkE+Fa4BS+LTxvgi@nvidia.com>
On Sun, May 12, 2024 at 03:09:25PM -0700, Nicolin Chen wrote:
> > > -static struct arm_smmu_cmdq *arm_smmu_get_cmdq(struct arm_smmu_device *smmu)
> > > +static struct arm_smmu_cmdq *
> > > +arm_smmu_get_cmdq(struct arm_smmu_device *smmu, u8 opcode)
> > > {
> > > if (arm_smmu_has_tegra241_cmdqv(smmu))
> > > - return tegra241_cmdqv_get_cmdq(smmu);
> > > + return tegra241_cmdqv_get_cmdq(smmu, opcode);
> >
> > It is worth a comment descrbing opcode here, I think.. At least the
> > nesting invalidation will send mixed batches.
>
> Right, this makes the "opcode" look bad, though we know that the
> "opcode" in the nesting invalidation doesn't matter because VCMDQ
> in that case supports all commands with HYP_OWN=1.
Yeah, it isn't a real problem, it just looks a little messy and
should have a small comment someplace at least..
> A CMD_SYNC, on the other hand, is outside the batch struct. And
> here is another assumption that CMD_SYNC is always supported by a
> VCMDQ..
>
> I could clarify the "opcode" here with these assumptions. Or maybe
> we should think think of a better alternative?
I don't think it really needs to be more complex, but we should
document that invalidation is going to be special and doesn't quite
follow this rule.
Jason
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2024-05-14 15:38 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-08 5:56 [PATCH v7 0/6] Add Tegra241 (Grace) CMDQV Support (part 1/2) Nicolin Chen
2024-05-08 5:56 ` [PATCH v7 1/6] iommu/arm-smmu-v3: Make symbols public for CONFIG_TEGRA241_CMDQV Nicolin Chen
2024-05-08 5:56 ` [PATCH v7 2/6] iommu/arm-smmu-v3: Issue a batch of commands to the same cmdq Nicolin Chen
2024-05-12 15:34 ` Jason Gunthorpe
2024-05-08 5:56 ` [PATCH v7 3/6] iommu/arm-smmu-v3: Enforce arm_smmu_cmdq_build_sync_cmd Nicolin Chen
2024-05-12 15:39 ` Jason Gunthorpe
2024-05-12 20:56 ` Nicolin Chen
2024-05-08 5:56 ` [PATCH v7 4/6] iommu/arm-smmu-v3: Add CS_NONE quirk for CONFIG_TEGRA241_CMDQV Nicolin Chen
2024-05-08 5:56 ` [PATCH v7 5/6] iommu/arm-smmu-v3: Add in-kernel support for NVIDIA Tegra241 (Grace) CMDQV Nicolin Chen
2024-05-12 15:54 ` Jason Gunthorpe
2024-05-12 21:00 ` Nicolin Chen
2024-05-08 5:56 ` [PATCH v7 6/6] iommu/tegra241-cmdqv: Limit CMDs for guest owned VINTF Nicolin Chen
2024-05-12 16:06 ` Jason Gunthorpe
2024-05-12 22:09 ` Nicolin Chen
2024-05-14 15:15 ` Jason Gunthorpe [this message]
2024-05-14 22:20 ` Nicolin Chen
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=ZkOAAdugARILEeBh@nvidia.com \
--to=jgg@nvidia.com \
--cc=iommu@lists.linux.dev \
--cc=jonathanh@nvidia.com \
--cc=joro@8bytes.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=nicolinc@nvidia.com \
--cc=robin.murphy@arm.com \
--cc=thierry.reding@gmail.com \
--cc=vdumpa@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 read-only IMAP folder(s) and NNTP newsgroup(s).