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ACPI/IORT: Look up IORT node through struct fwnode_handle pointer 

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@linaro.org>
[lorenzo.pieralisi@arm.com: re-indented/rewrote the commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
This commit is contained in:
Hanjun Guo 2017-10-13 15:09:47 +08:00 committed by Lorenzo Pieralisi
parent 896dd2c324
commit 0a71d8b95f
1 changed files with 42 additions and 1 deletions
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43
drivers/acpi/arm64/iort.c
View File

@ -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;