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iommu/of: Handle iommu-map property for PCI 

Now that we have a way to pick up the RID translation and target IOMMU,
hook up of_iommu_configure() to bring PCI devices into the of_xlate
mechanism and allow them IOMMU-backed DMA ops without the need for
driver-specific handling.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Robin Murphy 2016-09-12 17:13:41 +01:00 committed by Will Deacon
parent 987068fcbd
commit b996444cf3
1 changed files with 41 additions and 5 deletions
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46
drivers/iommu/of_iommu.c
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@ -22,6 +22,7 @@
#include <linux/limits.h>
#include <linux/of.h>
#include <linux/of_iommu.h>
#include <linux/of_pci.h>
#include <linux/slab.h>
static const struct of_device_id __iommu_of_table_sentinel
@ -134,6 +135,45 @@ const struct iommu_ops *of_iommu_get_ops(struct device_node *np)
return ops;
}
static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)
{
struct of_phandle_args *iommu_spec = data;
iommu_spec->args[0] = alias;
return iommu_spec->np == pdev->bus->dev.of_node;
}
static const struct iommu_ops
*of_pci_iommu_configure(struct pci_dev *pdev, struct device_node *bridge_np)
{
const struct iommu_ops *ops;
struct of_phandle_args iommu_spec;
/*
* Start by tracing the RID alias down the PCI topology as
* far as the host bridge whose OF node we have...
* (we're not even attempting to handle multi-alias devices yet)
*/
iommu_spec.args_count = 1;
iommu_spec.np = bridge_np;
pci_for_each_dma_alias(pdev, __get_pci_rid, &iommu_spec);
/*
* ...then find out what that becomes once it escapes the PCI
* bus into the system beyond, and which IOMMU it ends up at.
*/
iommu_spec.np = NULL;
if (of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map",
"iommu-map-mask", &iommu_spec.np, iommu_spec.args))
return NULL;
ops = of_iommu_get_ops(iommu_spec.np);
if (!ops || !ops->of_xlate || ops->of_xlate(&pdev->dev, &iommu_spec))
ops = NULL;
of_node_put(iommu_spec.np);
return ops;
}
const struct iommu_ops *of_iommu_configure(struct device *dev,
struct device_node *master_np)
{
@ -142,12 +182,8 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
const struct iommu_ops *ops = NULL;
int idx = 0;
/*
* We can't do much for PCI devices without knowing how
* device IDs are wired up from the PCI bus to the IOMMU.
*/
if (dev_is_pci(dev))
return NULL;
return of_pci_iommu_configure(to_pci_dev(dev), master_np);
/*
* We don't currently walk up the tree looking for a parent IOMMU.