ACPI: Introduce acpi_get_pci_dev()

Convert an ACPI CA handle to a struct pci_dev.

Performing this lookup dynamically allows us to get rid of the
ACPI-PCI binding code, which:

	- eliminates struct acpi_device vs struct pci_dev lifetime issues
	- lays more groundwork for eliminating .start from acpi_device_ops
	  and thus simplifying ACPI drivers
	- whacks out a lot of code

This change lays the groundwork for eliminating much of pci_bind.c.

Although pci_root.c may not be the most logical place for this
change, putting it here saves us from having to export acpi_pci_find_root.

Signed-off-by: Alex Chiang <achiang@hp.com>
Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Alexander Chiang 2009-06-10 19:55:20 +00:00 committed by Len Brown
parent 275582031f
commit 2f7bbceb5b
2 changed files with 82 additions and 0 deletions

View File

@ -329,6 +329,87 @@ static struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
return NULL;
}
struct acpi_handle_node {
struct list_head node;
acpi_handle handle;
};
/**
* acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
* @handle: the handle in question
*
* Given an ACPI CA handle, the desired PCI device is located in the
* list of PCI devices.
*
* If the device is found, its reference count is increased and this
* function returns a pointer to its data structure. The caller must
* decrement the reference count by calling pci_dev_put().
* If no device is found, %NULL is returned.
*/
struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
{
int dev, fn;
unsigned long long adr;
acpi_status status;
acpi_handle phandle;
struct pci_bus *pbus;
struct pci_dev *pdev = NULL;
struct acpi_handle_node *node, *tmp;
struct acpi_pci_root *root;
LIST_HEAD(device_list);
/*
* Walk up the ACPI CA namespace until we reach a PCI root bridge.
*/
phandle = handle;
while (!acpi_is_root_bridge(phandle)) {
node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
if (!node)
goto out;
INIT_LIST_HEAD(&node->node);
node->handle = phandle;
list_add(&node->node, &device_list);
status = acpi_get_parent(phandle, &phandle);
if (ACPI_FAILURE(status))
goto out;
}
root = acpi_pci_find_root(phandle);
if (!root)
goto out;
pbus = root->bus;
/*
* Now, walk back down the PCI device tree until we return to our
* original handle. Assumes that everything between the PCI root
* bridge and the device we're looking for must be a P2P bridge.
*/
list_for_each_entry(node, &device_list, node) {
acpi_handle hnd = node->handle;
status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
if (ACPI_FAILURE(status))
goto out;
dev = (adr >> 16) & 0xffff;
fn = adr & 0xffff;
pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
if (hnd == handle)
break;
pbus = pdev->subordinate;
pci_dev_put(pdev);
}
out:
list_for_each_entry_safe(node, tmp, &device_list, node)
kfree(node);
return pdev;
}
EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
/**
* acpi_pci_osc_control_set - commit requested control to Firmware
* @handle: acpi_handle for the target ACPI object

View File

@ -98,6 +98,7 @@ void acpi_pci_irq_del_prt(int segment, int bus);
struct pci_bus;
struct pci_dev *acpi_get_pci_dev(acpi_handle);
acpi_status acpi_get_pci_id(acpi_handle handle, struct acpi_pci_id *id);
int acpi_pci_bind_root(struct acpi_device *device, struct acpi_pci_id *id,
struct pci_bus *bus);