diff options
| author | Will Deacon <will@kernel.org> | 2020-01-15 16:35:16 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-01-15 17:30:28 +0100 |
| commit | 92c1d360dcda0ebd49253c0899bfeeb117be91fe (patch) | |
| tree | c292d09a111905911bb616e66f72770a1e7c55c8 /drivers/iommu | |
| parent | iommu/arm-smmu-v3: Improve add_device() error handling (diff) | |
| download | linux-92c1d360dcda0ebd49253c0899bfeeb117be91fe.tar.xz linux-92c1d360dcda0ebd49253c0899bfeeb117be91fe.zip | |
iommu/arm-smmu-v3: Return -EBUSY when trying to re-add a device
Although we WARN in arm_smmu_add_device() if the device being added has
been added already without a subsequent call to arm_smmu_remove_device(),
we still continue half-heartedly, initialising the stream-table for any
new StreamIDs that may have magically appeared and re-establishing device
links that should still be there from last time.
Given that calling ->add_device() twice without removing the device in the
meantime is indicative of an error in the caller, just return -EBUSY after
warning.
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Jean Philippe-Brucker <jean-philippe@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/arm-smmu-v3.c | 37 |
1 files changed, 16 insertions, 21 deletions
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 59dbd63a2aae..5e04c1f3992a 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -2794,28 +2794,23 @@ static int arm_smmu_add_device(struct device *dev) if (!fwspec || fwspec->ops != &arm_smmu_ops) return -ENODEV; - /* - * We _can_ actually withstand dodgy bus code re-calling add_device() - * without an intervening remove_device()/of_xlate() sequence, but - * we're not going to do so quietly... - */ - if (WARN_ON_ONCE(fwspec->iommu_priv)) { - master = fwspec->iommu_priv; - smmu = master->smmu; - } else { - smmu = arm_smmu_get_by_fwnode(fwspec->iommu_fwnode); - if (!smmu) - return -ENODEV; - master = kzalloc(sizeof(*master), GFP_KERNEL); - if (!master) - return -ENOMEM; - master->dev = dev; - master->smmu = smmu; - master->sids = fwspec->ids; - master->num_sids = fwspec->num_ids; - fwspec->iommu_priv = master; - } + if (WARN_ON_ONCE(fwspec->iommu_priv)) + return -EBUSY; + + smmu = arm_smmu_get_by_fwnode(fwspec->iommu_fwnode); + if (!smmu) + return -ENODEV; + + master = kzalloc(sizeof(*master), GFP_KERNEL); + if (!master) + return -ENOMEM; + + master->dev = dev; + master->smmu = smmu; + master->sids = fwspec->ids; + master->num_sids = fwspec->num_ids; + fwspec->iommu_priv = master; /* Check the SIDs are in range of the SMMU and our stream table */ for (i = 0; i < master->num_sids; i++) { |