From: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Current IORT code provides a function (ie iort_get_fwnode())
which looks up a struct fwnode_handle pointer through a
struct acpi_iort_node pointer for SMMU components but it
lacks a function that implements the reverse look-up, namely
struct fwnode_handle* -> struct acpi_iort_node*.
Devices that are not IORT named components cannot be retrieved through
their associated IORT named component scan interface because they just
are not represented in the ACPI namespace; the reverse look-up is
therefore required for all platform devices that represent IORT nodes
(eg SMMUs) so that the struct acpi_iort_node* can be retrieved from the
struct device->fwnode pointer.
Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
[lorenzo.pieralisi@xxxxxxx: re-indented/rewrote the commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
---
drivers/acpi/arm64/iort.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 42 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 0ff7020..03d3dd2 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -126,6 +126,31 @@ static inline void iort_delete_fwnode(struct acpi_iort_node *node)
spin_unlock(&iort_fwnode_lock);
}
+/**
+ * iort_get_iort_node() - Retrieve iort_node associated with an fwnode
+ *
+ * @fwnode: fwnode associated with device to be looked-up
+ *
+ * Returns: iort_node pointer on success, NULL on failure
+ */
+static inline struct acpi_iort_node *iort_get_iort_node(
+ struct fwnode_handle *fwnode)
+{
+ struct iort_fwnode *curr;
+ struct acpi_iort_node *iort_node = NULL;
+
+ spin_lock(&iort_fwnode_lock);
+ list_for_each_entry(curr, &iort_fwnode_list, list) {
+ if (curr->fwnode == fwnode) {
+ iort_node = curr->iort_node;
+ break;
+ }
+ }
+ spin_unlock(&iort_fwnode_lock);
+
+ return iort_node;
+}
+
typedef acpi_status (*iort_find_node_callback)
(struct acpi_iort_node *node, void *context);
@@ -422,9 +447,25 @@ static struct acpi_iort_node *iort_find_dev_node(struct device *dev)
{
struct pci_bus *pbus;
- if (!dev_is_pci(dev))
+ if (!dev_is_pci(dev)) {
+ struct acpi_iort_node *node;
+ /*
+ * scan iort_fwnode_list to see if it's an iort platform
+ * device (such as SMMU, PMCG),its iort node already cached
+ * and associated with fwnode when iort platform devices
+ * were initialized.
+ */
+ node = iort_get_iort_node(dev->fwnode);
+ if (node)
+ return node;
+
+ /*
+ * if not, then it should be a platform device defined in
+ * DSDT/SSDT (with Named Component node in IORT)
+ */
return iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
iort_match_node_callback, dev);
+ }
/* Find a PCI root bus */
pbus = to_pci_dev(dev)->bus;
--
1.7.12.4
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
