[PATCH v2 1/4] ACPI/IORT: Look up IORT node through struct fwnode_handle pointer
From: guohanjun@huawei.com (Hanjun Guo)
Date: 2017-10-13 07:09:47
Also in:
linux-acpi
Subsystem:
acpi, the rest · Maintainers:
"Rafael J. Wysocki", Linus Torvalds
From: Hanjun Guo <redacted> 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 <redacted> [lorenzo.pieralisi at arm.com: re-indented/rewrote the commit log] Signed-off-by: Lorenzo Pieralisi <redacted> --- 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