From: Nicolin Chen <nicoleotsuka@gmail.com>
To: will@kernel.org
Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
linux-tegra@vger.kernel.org, jonathanh@nvidia.com,
vdumpa@nvidia.com, thierry.reding@gmail.com, joro@8bytes.org
Subject: [PATCH RESEND v2 1/5] iommu/tegra-smmu: Unwrap tegra_smmu_group_get
Date: Wed, 25 Nov 2020 02:10:09 -0800 [thread overview]
Message-ID: <20201125101013.14953-2-nicoleotsuka@gmail.com> (raw)
In-Reply-To: <20201125101013.14953-1-nicoleotsuka@gmail.com>
The tegra_smmu_group_get was added to group devices in different
SWGROUPs and it'd return a NULL group pointer upon a mismatch at
tegra_smmu_find_group(), so for most of clients/devices, it very
likely would mismatch and need a fallback generic_device_group().
But now tegra_smmu_group_get handles devices in same SWGROUP too,
which means that it would allocate a group for every new SWGROUP
or would directly return an existing one upon matching a SWGROUP,
i.e. any device will go through this function.
So possibility of having a NULL group pointer in device_group()
is upon failure of either devm_kzalloc() or iommu_group_alloc().
In either case, calling generic_device_group() no longer makes a
sense. Especially for devm_kzalloc() failing case, it'd cause a
problem if it fails at devm_kzalloc() yet succeeds at a fallback
generic_device_group(), because it does not create a group->list
for other devices to match.
This patch simply unwraps the function to clean it up.
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
---
drivers/iommu/tegra-smmu.c | 19 ++++---------------
1 file changed, 4 insertions(+), 15 deletions(-)
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 0becdbfea306..ec4c9dafff95 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -903,10 +903,12 @@ static void tegra_smmu_group_release(void *iommu_data)
mutex_unlock(&smmu->lock);
}
-static struct iommu_group *tegra_smmu_group_get(struct tegra_smmu *smmu,
- unsigned int swgroup)
+static struct iommu_group *tegra_smmu_device_group(struct device *dev)
{
+ struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+ struct tegra_smmu *smmu = dev_iommu_priv_get(dev);
const struct tegra_smmu_group_soc *soc;
+ unsigned int swgroup = fwspec->ids[0];
struct tegra_smmu_group *group;
struct iommu_group *grp;
@@ -950,19 +952,6 @@ static struct iommu_group *tegra_smmu_group_get(struct tegra_smmu *smmu,
return group->group;
}
-static struct iommu_group *tegra_smmu_device_group(struct device *dev)
-{
- struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
- struct tegra_smmu *smmu = dev_iommu_priv_get(dev);
- struct iommu_group *group;
-
- group = tegra_smmu_group_get(smmu, fwspec->ids[0]);
- if (!group)
- group = generic_device_group(dev);
-
- return group;
-}
-
static int tegra_smmu_of_xlate(struct device *dev,
struct of_phandle_args *args)
{
--
2.17.1
next prev parent reply other threads:[~2020-11-25 10:12 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-25 10:10 [PATCH RESEND v2 0/5] iommu/tegra-smmu: Some pending reviewed changes Nicolin Chen
2020-11-25 10:10 ` Nicolin Chen [this message]
2020-11-25 10:10 ` [PATCH RESEND v2 2/5] iommu/tegra-smmu: Expand mutex protection range Nicolin Chen
2020-11-25 10:10 ` [PATCH RESEND v2 3/5] iommu/tegra-smmu: Use fwspec in tegra_smmu_(de)attach_dev Nicolin Chen
2020-11-25 10:10 ` [PATCH RESEND v2 4/5] iommu/tegra-smmu: Rework tegra_smmu_probe_device() Nicolin Chen
2021-02-04 11:10 ` Guillaume Tucker
2021-02-05 5:24 ` Nicolin Chen
2021-02-05 9:45 ` Nicolin Chen
2021-02-06 13:40 ` Guillaume Tucker
2021-02-10 8:20 ` Nicolin Chen
2021-02-11 15:50 ` Guillaume Tucker
2021-02-18 10:35 ` Nicolin Chen
2021-02-18 20:38 ` Guillaume Tucker
2020-11-25 10:10 ` [PATCH RESEND v2 5/5] iommu/tegra-smmu: Add PCI support Nicolin Chen
2020-11-25 11:03 ` [PATCH RESEND v2 0/5] iommu/tegra-smmu: Some pending reviewed changes Will Deacon
2020-11-25 14:05 ` Will Deacon
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