iommu/arm-smmu: Don't fail device attach if already attached to a domain
The ARM SMMU attach_dev implementations returns -EEXIST if the device
being attached is already attached to a domain. This doesn't play nicely
with the default domain, resulting in splats such as:
WARNING: at drivers/iommu/iommu.c:1257
Modules linked in:
CPU: 3 PID: 1939 Comm: virtio-net-tx Tainted: G S 4.5.0-rc4+ #1
Hardware name: FVP Base (DT)
task: ffffffc87a9d0000 ti: ffffffc07a278000 task.ti: ffffffc07a278000
PC is at __iommu_detach_group+0x68/0xe8
LR is at __iommu_detach_group+0x48/0xe8
This patch fixes the problem by forcefully detaching the device from
its old domain, if present, when attaching to a new one. The unused
->detach_dev callback is also removed the iommu_ops structures.
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index f003b3a..d96d45d 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1638,6 +1638,17 @@
return 0;
}
+static void arm_smmu_detach_dev(struct device *dev)
+{
+ struct arm_smmu_group *smmu_group = arm_smmu_group_get(dev);
+
+ smmu_group->ste.bypass = true;
+ if (IS_ERR_VALUE(arm_smmu_install_ste_for_group(smmu_group)))
+ dev_warn(dev, "failed to install bypass STE\n");
+
+ smmu_group->domain = NULL;
+}
+
static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
{
int ret = 0;
@@ -1650,7 +1661,7 @@
/* Already attached to a different domain? */
if (smmu_group->domain && smmu_group->domain != smmu_domain)
- return -EEXIST;
+ arm_smmu_detach_dev(dev);
smmu = smmu_group->smmu;
mutex_lock(&smmu_domain->init_mutex);
@@ -1687,25 +1698,6 @@
return ret;
}
-static void arm_smmu_detach_dev(struct iommu_domain *domain, struct device *dev)
-{
- struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
- struct arm_smmu_group *smmu_group = arm_smmu_group_get(dev);
-
- BUG_ON(!smmu_domain);
- BUG_ON(!smmu_group);
-
- mutex_lock(&smmu_domain->init_mutex);
- BUG_ON(smmu_group->domain != smmu_domain);
-
- smmu_group->ste.bypass = true;
- if (IS_ERR_VALUE(arm_smmu_install_ste_for_group(smmu_group)))
- dev_warn(dev, "failed to install bypass STE\n");
-
- smmu_group->domain = NULL;
- mutex_unlock(&smmu_domain->init_mutex);
-}
-
static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot)
{
@@ -1943,7 +1935,6 @@
.domain_alloc = arm_smmu_domain_alloc,
.domain_free = arm_smmu_domain_free,
.attach_dev = arm_smmu_attach_dev,
- .detach_dev = arm_smmu_detach_dev,
.map = arm_smmu_map,
.unmap = arm_smmu_unmap,
.iova_to_phys = arm_smmu_iova_to_phys,