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>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>
---
drivers/iommu/of_iommu.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of_iommu.h | 10 ++++
2 files changed, 127 insertions(+)
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 8cb6082..f2d1a76 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>
@@ -246,6 +247,122 @@ 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()
+ * @list: 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)
+{
+ int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
+ struct iommu_resv_region *region;
+ struct device_node *np;
+ struct resource res;
+ int i, resv = 0, mappings = 0;
+
+ if (dev_is_pci(dev)) {
+ struct device *dma_dev, *bridge;
+ struct of_phandle_args iommu_spec;
+ struct pci_dev *pdev = to_pci_dev(dev);
+ int err, count;
+ u32 rid, map_mask;
+ const __be32 *msi_map;
+
+ bridge = pci_get_host_bridge_device(pdev);
+ dma_dev = bridge->parent;
+ pci_put_host_bridge_device(bridge);
+
+ if (!dma_dev->of_node)
+ return -ENODEV;
+
+ iommu_spec.args_count = 1;
+ np = iommu_spec.np = dma_dev->of_node;
+ pci_for_each_dma_alias(pdev, __get_pci_rid, &iommu_spec);
+
+ rid = iommu_spec.args[0];
+ if (!of_property_read_u32(np, "msi-map-mask", &map_mask))
+ rid &= map_mask;
+
+ msi_map = of_get_property(np, "msi-map", NULL);
+ if (!msi_map)
+ return -ENODEV;
+
+ mappings = of_count_phandle_with_args(np, "msi-map", NULL) / 4;
+
+ for (i = 0, count = mappings; i < count; i++, msi_map += 4) {
+ struct device_node *msi_node;
+ u32 rid_base, rid_len, phandle;
+
+ rid_base = be32_to_cpup(msi_map + 0);
+ phandle = be32_to_cpup(msi_map + 1);
+ rid_len = be32_to_cpup(msi_map + 3);
+
+ /* check rid is within range */
+ if (rid < rid_base || rid >= rid_base + rid_len) {
+ mappings--;
+ continue;
+ }
+
+ msi_node = of_find_node_by_phandle(phandle);
+ if (!msi_node)
+ return -ENODEV;
+
+ err = of_address_to_resource(msi_node, 0, &res);
+ of_node_put(msi_node);
+ if (err)
+ return err;
+
+ region = iommu_alloc_resv_region(res.start,
+ resource_size(&res),
+ prot, IOMMU_RESV_MSI);
+ if (region) {
+ list_add_tail(®ion->list, head);
+ resv++;
+ }
+ }
+ } else if (dev->of_node) {
+ struct device_node *msi_np;
+ int index = 0;
+ int tuples;
+
+ np = dev->of_node;
+
+ tuples = of_count_phandle_with_args(np, "msi-parent", NULL);
+
+ while (index < tuples) {
+ int msi_cells = 0;
+ int err;
+
+ msi_np = of_parse_phandle(np, "msi-parent", index);
+ if (!msi_np)
+ return -ENODEV;
+
+ of_property_read_u32(msi_np, "#msi-cells", &msi_cells);
+
+ err = of_address_to_resource(msi_np, 0, &res);
+ of_node_put(msi_np);
+ if (err)
+ return err;
+
+ mappings++;
+
+ region = iommu_alloc_resv_region(res.start,
+ resource_size(&res),
+ prot, IOMMU_RESV_MSI);
+ if (region) {
+ list_add_tail(®ion->list, head);
+ resv++;
+ }
+ index += 1 + msi_cells;
+ }
+ }
+
+ return (resv == mappings) ? resv : -ENODEV;
+}
+
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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