Commit 8f68f8e2 authored by Will Deacon's avatar Will Deacon
Browse files

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



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: default avatarWill Deacon <will.deacon@arm.com>
parent 4cf740b0

drivers/iommu/arm-smmu.c

+39 −26
Original line number Original line Diff line number Diff line
@@ -431,17 +431,17 @@ static void parse_driver_options(struct arm_smmu_device *smmu) 
	} while (arm_smmu_options[++i].opt);

	} 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)) {

	if (dev_is_pci(dev)) {

		struct pci_bus *bus = to_pci_dev(dev)->bus;

		struct pci_bus *bus = to_pci_dev(dev)->bus;





		while (!pci_is_root_bus(bus))

		while (!pci_is_root_bus(bus))

			bus = bus->parent;

			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,

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 *

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))

	if (group) {

		return dev->archdata.iommu;

		cfg = iommu_group_get_iommudata(group);

		iommu_group_put(group);

	}





	master = find_smmu_master(smmu, dev->of_node);

	return cfg;

	return master ? &master->cfg : NULL;

}

}





static int insert_smmu_master(struct arm_smmu_device *smmu,

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_device *smmu;

	struct arm_smmu_master *master = NULL;

	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);

	spin_lock(&arm_smmu_devices_lock);

	list_for_each_entry(smmu, &arm_smmu_devices, list) {

	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;

	struct arm_smmu_device *smmu = smmu_domain->smmu;

	void __iomem *gr0_base = ARM_SMMU_GR0(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);

	ret = arm_smmu_master_configure_smrs(smmu, cfg);

	if (ret)

	if (ret)

		return ret;

		return ret == -EEXIST ? 0 : ret;





	for (i = 0; i < cfg->num_streamids; ++i) {

	for (i = 0; i < cfg->num_streamids; ++i) {

		u32 idx, s2cr;

		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;

	struct arm_smmu_device *smmu = smmu_domain->smmu;

	void __iomem *gr0_base = ARM_SMMU_GR0(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

	 * We *must* clear the S2CR first, because freeing the SMR means

	 * that it can be re-allocated immediately.

	 * 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_device *smmu, *dom_smmu;

	struct arm_smmu_master_cfg *cfg;

	struct arm_smmu_master_cfg *cfg;





	smmu = dev_get_master_dev(dev)->archdata.iommu;

	smmu = find_smmu_for_device(dev);

	if (!smmu) {

	if (!smmu) {

		dev_err(dev, "cannot attach to SMMU, is it on the same bus?\n");

		dev_err(dev, "cannot attach to SMMU, is it on the same bus?\n");

		return -ENXIO;

		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 */

	/* 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)

	if (!cfg)

		return -ENODEV;

		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_domain *smmu_domain = domain->priv;

	struct arm_smmu_master_cfg *cfg;

	struct arm_smmu_master_cfg *cfg;





	cfg = find_smmu_master_cfg(smmu_domain->smmu, dev);

	cfg = find_smmu_master_cfg(dev);

	if (cfg)

	if (cfg)

		arm_smmu_domain_remove_master(smmu_domain, 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 */

	return 0; /* Continue walking */

}

}





static void __arm_smmu_release_pci_iommudata(void *data)

{

	kfree(data);

}



static int arm_smmu_add_device(struct device *dev)

static int arm_smmu_add_device(struct device *dev)

{

{

	struct arm_smmu_device *smmu;

	struct arm_smmu_device *smmu;

	struct arm_smmu_master_cfg *cfg;

	struct iommu_group *group;

	struct iommu_group *group;

	void (*releasefn)(void *) = NULL;

	int ret;

	int ret;





	if (dev->archdata.iommu) {

		dev_warn(dev, "IOMMU driver already assigned to device\n");

		return -EINVAL;

	}



	smmu = find_smmu_for_device(dev);

	smmu = find_smmu_for_device(dev);

	if (!smmu)

	if (!smmu)

		return -ENODEV;

		return -ENODEV;
@@ -1576,7 +1585,6 @@ static int arm_smmu_add_device(struct device *dev) 
	}

	}





	if (dev_is_pci(dev)) {

	if (dev_is_pci(dev)) {

		struct arm_smmu_master_cfg *cfg;

		struct pci_dev *pdev = to_pci_dev(dev);

		struct pci_dev *pdev = to_pci_dev(dev);





		cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);

		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,

		pci_for_each_dma_alias(pdev, __arm_smmu_get_pci_sid,

				       &cfg->streamids[0]);

				       &cfg->streamids[0]);

		dev->archdata.iommu = cfg;

		releasefn = __arm_smmu_release_pci_iommudata;

	} else {

	} 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);

	ret = iommu_group_add_device(group, dev);





out_put_group:

out_put_group:
@@ -1606,10 +1623,6 @@ out_put_group: 




static void arm_smmu_remove_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);

	iommu_group_remove_device(dev);

}

}

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