From: John Garry <john.garry@xxxxxxxxxx>
On some platforms msi-controller address regions have to be excluded
from normal IOVA allocation in that they are detected and decoded in
a HW specific way by system components and so they cannot be considered
normal IOVA address space.
Add a helper function that retrieves msi address regions through device
tree msi mapping, so that these regions will not be translated by IOMMU
and will be excluded from IOVA allocations.
Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
[Shameer: Modified msi-parent retrieval logic]
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>
---
drivers/iommu/of_iommu.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of_iommu.h | 10 +++++
2 files changed, 105 insertions(+)
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index e60e3db..ffd7fb7 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -21,6 +21,7 @@
#include <linux/iommu.h>
#include <linux/limits.h>
#include <linux/of.h>
+#include <linux/of_address.h>
#include <linux/of_iommu.h>
#include <linux/of_pci.h>
#include <linux/slab.h>
@@ -138,6 +139,14 @@ static int of_iommu_xlate(struct device *dev,
return ops->of_xlate(dev, iommu_spec);
}
+static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)
+{
+ u32 *rid = data;
+
+ *rid = alias;
+ return 0;
+}
+
struct of_pci_iommu_alias_info {
struct device *dev;
struct device_node *np;
@@ -163,6 +172,73 @@ static int of_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
return info->np == pdev->bus->dev.of_node;
}
+static int of_iommu_alloc_resv_region(struct device_node *np,
+ struct list_head *head)
+{
+ int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
+ struct iommu_resv_region *region;
+ struct resource res;
+ int err;
+
+ err = of_address_to_resource(np, 0, &res);
+ if (err)
+ return err;
+
+ region = iommu_alloc_resv_region(res.start, resource_size(&res),
+ prot, IOMMU_RESV_MSI);
+ if (!region)
+ return -ENOMEM;
+
+ list_add_tail(®ion->list, head);
+
+ return 0;
+}
+
+static int of_pci_msi_get_resv_regions(struct device *dev,
+ struct list_head *head)
+{
+ struct device_node *msi_np;
+ struct device *pdev;
+ u32 rid;
+ int err, resv = 0;
+
+ pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid, &rid);
+
+ for_each_node_with_property(msi_np, "msi-controller") {
+ for (pdev = dev; pdev; pdev = pdev->parent) {
+ if (!of_pci_map_rid(pdev->of_node, rid, "msi-map",
+ "msi-map-mask", &msi_np, NULL)) {
+
+ err = of_iommu_alloc_resv_region(msi_np, head);
+ if (err)
+ return err;
+ resv++;
+ }
+ }
+ }
+
+ return resv;
+}
+
+static int of_platform_msi_get_resv_regions(struct device *dev,
+ struct list_head *head)
+{
+ struct of_phandle_args args;
+ int err, resv = 0;
+
+ while (!of_parse_phandle_with_args(dev->of_node, "msi-parent",
+ "#msi-cells", resv, &args)) {
+
+ err = of_iommu_alloc_resv_region(args.np, head);
+ of_node_put(args.np);
+ if (err)
+ return err;
+ resv++;
+ }
+
+ return resv;
+}
+
const struct iommu_ops *of_iommu_configure(struct device *dev,
struct device_node *master_np)
{
@@ -235,6 +311,25 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
return ops;
}
+/**
+ * of_iommu_msi_get_resv_regions - Reserved region driver helper
+ * @dev: Device from iommu_get_resv_regions()
+ * @head: Reserved region list from iommu_get_resv_regions()
+ *
+ * Returns: Number of reserved regions on success (0 if no associated
+ * msi parent), appropriate error value otherwise.
+ */
+int of_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
+{
+
+ if (dev_is_pci(dev))
+ return of_pci_msi_get_resv_regions(dev, head);
+ else if (dev->of_node)
+ return of_platform_msi_get_resv_regions(dev, head);
+
+ return 0;
+}
+
static int __init of_iommu_init(void)
{
struct device_node *np;
diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h
index 13394ac..9267772 100644
--- a/include/linux/of_iommu.h
+++ b/include/linux/of_iommu.h
@@ -14,6 +14,9 @@ extern int of_get_dma_window(struct device_node *dn, const char *prefix,
extern const struct iommu_ops *of_iommu_configure(struct device *dev,
struct device_node *master_np);
+extern int of_iommu_msi_get_resv_regions(struct device *dev,
+ struct list_head *head);
+
#else
static inline int of_get_dma_window(struct device_node *dn, const char *prefix,
@@ -29,6 +32,13 @@ static inline const struct iommu_ops *of_iommu_configure(struct device *dev,
return NULL;
}
+static int of_iommu_msi_get_resv_regions(struct device *dev,
+ struct list_head *head)
+{
+ return -ENODEV;
+}
+
+
#endif /* CONFIG_OF_IOMMU */
extern struct of_device_id __iommu_of_table;
--
1.9.1
--
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