[PATCH 2/7] iommu/arm-smmu: add support for multi-master iommu groups
Will Deacon
will.deacon at arm.com
Thu Sep 4 09:50:00 PDT 2014
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 at arm.com>
---
drivers/iommu/arm-smmu.c | 62 ++++++++++++++++++++++++++----------------------
1 file changed, 34 insertions(+), 28 deletions(-)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 958ae8194afe..ef6623dbba9a 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -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 +466,10 @@ 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;
-
- if (dev_is_pci(dev))
- return dev->archdata.iommu;
-
- master = find_smmu_master(smmu, dev->of_node);
- return master ? &master->cfg : NULL;
+ struct iommu_group *group = iommu_group_get(dev);
+ return group ? iommu_group_get_iommudata(group) : NULL;
}
static int insert_smmu_master(struct arm_smmu_device *smmu,
@@ -550,7 +545,7 @@ 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 +1151,10 @@ 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 +1175,10 @@ 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 +1200,7 @@ 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 +1228,7 @@ 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 +1240,7 @@ 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 +1554,19 @@ 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 +1578,6 @@ 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 +1593,20 @@ 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 +1616,6 @@ out_put_group:
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);
}
--
2.1.0
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