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| author | Nicolin Chen <nicoleotsuka@gmail.com> | 2020-11-25 13:10:09 +0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-11-25 14:04:41 +0300 |
| commit | cf910f61aff3c1c7cac4dc0706811389051c0f98 (patch) | |
| tree | e2357470c931a4c4a5a21e626ec9c433dd04c853 /drivers/iommu/tegra-smmu.c | |
| parent | f8394f232b1eab649ce2df5c5f15b0e528c92091 (diff) | |
| download | linux-cf910f61aff3c1c7cac4dc0706811389051c0f98.tar.xz | |
iommu/tegra-smmu: Unwrap tegra_smmu_group_get
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.
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20201125101013.14953-2-nicoleotsuka@gmail.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers/iommu/tegra-smmu.c')
| -rw-r--r-- | drivers/iommu/tegra-smmu.c | 19 |
1 files 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) { |