From: Thierry Reding <thierry.reding@gmail.com>
To: Dmitry Osipenko <digetx@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>,
Joerg Roedel <joro@8bytes.org>,
iommu@lists.linux-foundation.org, linux-tegra@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 1/4] iommu/tegra: gart: Add debugging facility
Date: Fri, 27 Apr 2018 11:46:12 +0200 [thread overview]
Message-ID: <20180427094612.GM30388@ulmo> (raw)
In-Reply-To: <fe55521bc6fb1c576fb532dd7fb64ede4904beb7.1523304324.git.digetx@gmail.com>
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On Mon, Apr 09, 2018 at 11:07:19PM +0300, Dmitry Osipenko wrote:
> Page mapping could overwritten by an accident (a bug). We can catch this
> case by checking 'VALID' bit of GART's page entry prior to mapping of a
> page. Since that check introduces a small performance impact, it should be
> enabled explicitly using new GART's kernel module 'debug' parameter.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> drivers/iommu/tegra-gart.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
I think this was discussed before, but this really shouldn't be needed
unless the IOVA allocator or GART driver are buggy.
That said, I think this has some usefulness to find such bugs, so:
Acked-by: Thierry Reding <treding@nvidia.com>
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next prev parent reply other threads:[~2018-04-27 9:46 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-09 20:07 [PATCH v1 0/4] Tegra GART fixes and improvements Dmitry Osipenko
[not found] ` <cover.1523304324.git.digetx-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-04-09 20:07 ` [PATCH v1 1/4] iommu/tegra: gart: Add debugging facility Dmitry Osipenko
2018-04-27 9:46 ` Thierry Reding [this message]
2018-04-09 20:07 ` [PATCH v1 2/4] iommu/tegra: gart: Fix gart_iommu_unmap() Dmitry Osipenko
[not found] ` <dd25a9ff7bad7c92b345c0c0ce2bf235c4c3b6e8.1523304324.git.digetx-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-04-27 9:43 ` Thierry Reding
2018-04-09 20:07 ` [PATCH v1 3/4] iommu/tegra: gart: Constify number of GART pages Dmitry Osipenko
[not found] ` <954659be6760130f6ffd5e733db2ad58cbb8e6e4.1523304324.git.digetx-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-04-27 9:49 ` Thierry Reding
2018-04-09 20:07 ` [PATCH v1 4/4] iommu/tegra: gart: Optimize map/unmap Dmitry Osipenko
[not found] ` <f21a7b6a8f141b87f75687904a76f3728ea639a8.1523304324.git.digetx-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-04-27 10:02 ` Thierry Reding
2018-04-27 12:01 ` Dmitry Osipenko
2018-04-27 12:36 ` Robin Murphy
[not found] ` <716edf58-38a7-21e5-1668-b866bf392e34-5wv7dgnIgG8@public.gmane.org>
2018-05-06 21:19 ` Dmitry Osipenko
[not found] ` <6827bda3-1aa2-da60-a749-8e2dd2e595f3-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-05-07 8:04 ` Joerg Roedel
[not found] ` <20180507080420.GB18595-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2018-05-07 15:51 ` Dmitry Osipenko
[not found] ` <a6e26d17-97ac-d02e-7bf4-f009af1a25dc-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-05-07 17:38 ` Dmitry Osipenko
2018-05-07 7:59 ` Joerg Roedel
[not found] ` <20180507075920.GA18595-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2018-05-07 15:46 ` Dmitry Osipenko
2018-05-03 12:52 ` [PATCH v1 0/4] Tegra GART fixes and improvements Joerg Roedel
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