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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>
This commit is contained in:
Will Deacon 2016-02-17 17:41:57 +00:00
parent 25a1c96cd2
commit bc7f2ce0a7
2 changed files with 26 additions and 40 deletions
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33
drivers/iommu/arm-smmu-v3.c
View File

@ -1638,6 +1638,17 @@ static int arm_smmu_install_ste_for_group(struct arm_smmu_group *smmu_group)
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 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
/* 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 @@ out_unlock:
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 @@ static struct iommu_ops arm_smmu_ops = {
.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,

33
drivers/iommu/arm-smmu.c
View File

@ -1131,6 +1131,16 @@ static void arm_smmu_domain_remove_master(struct arm_smmu_domain *smmu_domain,
arm_smmu_master_free_smrs(smmu, cfg);
}
static void arm_smmu_detach_dev(struct device *dev,
struct arm_smmu_master_cfg *cfg)
{
struct iommu_domain *domain = dev->archdata.iommu;
struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
dev->archdata.iommu = NULL;
arm_smmu_domain_remove_master(smmu_domain, cfg);
}
static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
{
int ret;
@ -1144,11 +1154,6 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
return -ENXIO;
}
if (dev->archdata.iommu) {
dev_err(dev, "already attached to IOMMU domain\n");
return -EEXIST;
}
/* Ensure that the domain is finalised */
ret = arm_smmu_init_domain_context(domain, smmu);
if (IS_ERR_VALUE(ret))
@ -1170,25 +1175,16 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
if (!cfg)
return -ENODEV;
/* Detach the dev from its current domain */
if (dev->archdata.iommu)
arm_smmu_detach_dev(dev, cfg);
ret = arm_smmu_domain_add_master(smmu_domain, cfg);
if (!ret)
dev->archdata.iommu = domain;
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_master_cfg *cfg;
cfg = find_smmu_master_cfg(dev);
if (!cfg)
return;
dev->archdata.iommu = NULL;
arm_smmu_domain_remove_master(smmu_domain, cfg);
}
static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot)
{
@ -1464,7 +1460,6 @@ static struct iommu_ops arm_smmu_ops = {
.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,
.map_sg = default_iommu_map_sg,