DT based systems have a generic kernel API to configure IOMMUs
for devices (ie of_iommu_configure()).
On ARM based ACPI systems, the of_iommu_configure() equivalent can
be implemented atop ACPI IORT kernel API, with the corresponding
functions to map device identifiers to IOMMUs and retrieve the
corresponding IOMMU operations necessary for DMA operations set-up.
By relying on the iommu_fwspec generic kernel infrastructure,
implement the IORT based IOMMU configuration for ARM ACPI systems
and hook it up in the ACPI kernel layer that implements DMA
configuration for a device.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
Cc: Hanjun Guo <hanjun....@linaro.org>
Cc: Tomasz Nowicki <t...@semihalf.com>
Cc: "Rafael J. Wysocki" <r...@rjwysocki.net>
---
drivers/acpi/arm64/iort.c | 96
+++++++++++++++++++++++++++++++++++++++++++++++
drivers/acpi/scan.c | 7 +++-
include/linux/acpi_iort.h | 6 +++
3 files changed, 108 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 7c68eb4..55a4ae9 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -19,6 +19,7 @@
#define pr_fmt(fmt) "ACPI: IORT: " fmt
#include <linux/acpi_iort.h>
+#include <linux/iommu-fwspec.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/pci.h>
@@ -27,6 +28,8 @@
#define IORT_TYPE_MASK(type) (1 << (type))
#define IORT_MSI_TYPE (1 << ACPI_IORT_NODE_ITS_GROUP)
+#define IORT_IOMMU_TYPE ((1 << ACPI_IORT_NODE_SMMU) | \
+ (1 << ACPI_IORT_NODE_SMMU_V3))
struct iort_its_msi_chip {
struct list_head list;
@@ -467,6 +470,99 @@ struct irq_domain *iort_get_device_domain(struct
device *dev, u32 req_id)
return irq_find_matching_fwnode(handle, DOMAIN_BUS_PCI_MSI);
}
+static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)
+{
+ u32 *rid = data;
+
+ *rid = alias;
+ return 0;
+}
+
+static int arm_smmu_iort_xlate(struct device *dev, u32 streamid,
+ struct fwnode_handle *fwnode)
+{
+ int ret = iommu_fwspec_init(dev, fwnode);
+
+ if (!ret)
+ ret = iommu_fwspec_add_ids(dev, &streamid, 1);
+
+ return ret;
+}
+
+static const struct iommu_ops *iort_iommu_xlate(struct device *dev,
+ struct acpi_iort_node *node,
+ u32 streamid)
+{
+ struct fwnode_handle *iort_fwnode = NULL;
+ int ret;
+
+ if (node) {
+ iort_fwnode = iort_get_fwnode(node);
+ if (!iort_fwnode)
+ return NULL;
+
+ ret = arm_smmu_iort_xlate(dev, streamid,
+ iort_fwnode);
+ if (!ret)
+ return fwspec_iommu_get_ops(iort_fwnode);
+ }
+
+ return NULL;
+}
+
+/**
+ * iort_iommu_configure - Set-up IOMMU configuration for a device.
+ *
+ * @dev: device to configure
+ *
+ * Returns: iommu_ops pointer on configuration success
+ * NULL on configuration failure
+ */
+const struct iommu_ops *iort_iommu_configure(struct device *dev)
+{
+ struct acpi_iort_node *node, *parent;
+ const struct iommu_ops *ops = NULL;
+ u32 streamid = 0;
+
+ if (dev_is_pci(dev)) {
+ struct pci_bus *bus = to_pci_dev(dev)->bus;
+ u32 rid;
+
+ pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid,
+ &rid);
+
+ node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
+ iort_match_node_callback, &bus->dev);
+ if (!node)
+ return NULL;
+
+ parent = iort_node_map_rid(node, rid, &streamid,
+ IORT_IOMMU_TYPE);
+
+ ops = iort_iommu_xlate(dev, parent, streamid);
+
+ } else {
+ int i = 0;
+
+ node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
+ iort_match_node_callback, dev);
+ if (!node)
+ return NULL;
+
