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iommu/arm-smmu: add support for multi-master iommu groups

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Whilst the driver currently creates one IOMMU group per device, this
will soon change when we start supporting non-transparent PCI bridges
which require all upstream masters to be assigned to the same address
space.

This patch reworks our IOMMU group code so that we can easily support
multi-master groups. The master configuration (streamids and smrs) is
stored as private iommudata on the group, whilst the low-level attach/detach
code is updated to avoid double alloc/free when dealing with multiple
masters sharing the same SMMU configuration. This unifies device
handling, regardless of whether the device sits on the platform or pci
bus.

Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Will Deacon 2014-07-15 11:27:08 +01:00
parent 4cf740b0b6
commit 8f68f8e282
1 changed files with 39 additions and 26 deletions
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65
drivers/iommu/arm-smmu.c
View file

@ -431,17 +431,17 @@ static void parse_driver_options(struct arm_smmu_device *smmu)
} while (arm_smmu_options[++i].opt);
}
static struct device *dev_get_master_dev(struct device *dev)
static struct device_node *dev_get_dev_node(struct device *dev)
{
if (dev_is_pci(dev)) {
struct pci_bus *bus = to_pci_dev(dev)->bus;
while (!pci_is_root_bus(bus))
bus = bus->parent;
return bus->bridge->parent;
return bus->bridge->parent->of_node;
}
return dev;
return dev->of_node;
}
static struct arm_smmu_master *find_smmu_master(struct arm_smmu_device *smmu,
@ -466,15 +466,17 @@ static struct arm_smmu_master *find_smmu_master(struct arm_smmu_device *smmu,
}
static struct arm_smmu_master_cfg *
find_smmu_master_cfg(struct arm_smmu_device *smmu, struct device *dev)
find_smmu_master_cfg(struct device *dev)
{
struct arm_smmu_master *master;
struct arm_smmu_master_cfg *cfg = NULL;
struct iommu_group *group = iommu_group_get(dev);
if (dev_is_pci(dev))
return dev->archdata.iommu;
if (group) {
cfg = iommu_group_get_iommudata(group);
iommu_group_put(group);
}
master = find_smmu_master(smmu, dev->of_node);
return master ? &master->cfg : NULL;
return cfg;
}
static int insert_smmu_master(struct arm_smmu_device *smmu,
@ -550,7 +552,7 @@ static struct arm_smmu_device *find_smmu_for_device(struct device *dev)
{
struct arm_smmu_device *smmu;
struct arm_smmu_master *master = NULL;
struct device_node *dev_node = dev_get_master_dev(dev)->of_node;
struct device_node *dev_node = dev_get_dev_node(dev);
spin_lock(&arm_smmu_devices_lock);
list_for_each_entry(smmu, &arm_smmu_devices, list) {
@ -1156,9 +1158,10 @@ static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain,
struct arm_smmu_device *smmu = smmu_domain->smmu;
void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
/* Devices in an IOMMU group may already be configured */
ret = arm_smmu_master_configure_smrs(smmu, cfg);
if (ret)
return ret;
return ret == -EEXIST ? 0 : ret;
for (i = 0; i < cfg->num_streamids; ++i) {
u32 idx, s2cr;
@ -1179,6 +1182,10 @@ static void arm_smmu_domain_remove_master(struct arm_smmu_domain *smmu_domain,
struct arm_smmu_device *smmu = smmu_domain->smmu;
void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
/* An IOMMU group is torn down by the first device to be removed */
if ((smmu->features & ARM_SMMU_FEAT_STREAM_MATCH) && !cfg->smrs)
return;
/*
* We *must* clear the S2CR first, because freeing the SMR means
* that it can be re-allocated immediately.
@ -1200,7 +1207,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
struct arm_smmu_device *smmu, *dom_smmu;
struct arm_smmu_master_cfg *cfg;
smmu = dev_get_master_dev(dev)->archdata.iommu;
smmu = find_smmu_for_device(dev);
if (!smmu) {
dev_err(dev, "cannot attach to SMMU, is it on the same bus?\n");
return -ENXIO;
@ -1228,7 +1235,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
}
/* Looks ok, so add the device to the domain */
cfg = find_smmu_master_cfg(smmu_domain->smmu, dev);
cfg = find_smmu_master_cfg(dev);
if (!cfg)
return -ENODEV;
@ -1240,7 +1247,7 @@ static void arm_smmu_detach_dev(struct iommu_domain *domain, struct device *dev)
struct arm_smmu_domain *smmu_domain = domain->priv;
struct arm_smmu_master_cfg *cfg;
cfg = find_smmu_master_cfg(smmu_domain->smmu, dev);
cfg = find_smmu_master_cfg(dev);
if (cfg)
arm_smmu_domain_remove_master(smmu_domain, cfg);
}
@ -1554,17 +1561,19 @@ static int __arm_smmu_get_pci_sid(struct pci_dev *pdev, u16 alias, void *data)
return 0; /* Continue walking */
}
static void __arm_smmu_release_pci_iommudata(void *data)
{
kfree(data);
}
static int arm_smmu_add_device(struct device *dev)
{
struct arm_smmu_device *smmu;
struct arm_smmu_master_cfg *cfg;
struct iommu_group *group;
void (*releasefn)(void *) = NULL;
int ret;
if (dev->archdata.iommu) {
dev_warn(dev, "IOMMU driver already assigned to device\n");
return -EINVAL;
}
smmu = find_smmu_for_device(dev);
if (!smmu)
return -ENODEV;
@ -1576,7 +1585,6 @@ static int arm_smmu_add_device(struct device *dev)
}
if (dev_is_pci(dev)) {
struct arm_smmu_master_cfg *cfg;
struct pci_dev *pdev = to_pci_dev(dev);
cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
@ -1592,11 +1600,20 @@ static int arm_smmu_add_device(struct device *dev)
*/
pci_for_each_dma_alias(pdev, __arm_smmu_get_pci_sid,
&cfg->streamids[0]);
dev->archdata.iommu = cfg;
releasefn = __arm_smmu_release_pci_iommudata;
} else {
dev->archdata.iommu = smmu;
struct arm_smmu_master *master;
master = find_smmu_master(smmu, dev->of_node);
if (!master) {
ret = -ENODEV;
goto out_put_group;
}
cfg = &master->cfg;
}
iommu_group_set_iommudata(group, cfg, releasefn);
ret = iommu_group_add_device(group, dev);
out_put_group:
@ -1606,10 +1623,6 @@ static int arm_smmu_add_device(struct device *dev)
static void arm_smmu_remove_device(struct device *dev)
{
if (dev_is_pci(dev))
kfree(dev->archdata.iommu);
dev->archdata.iommu = NULL;
iommu_group_remove_device(dev);
}