From 2f7bbceb5b6aa938024bb4dad93c410fa59ed3b9 Mon Sep 17 00:00:00 2001 From: Alexander Chiang Date: Wed, 10 Jun 2009 19:55:20 +0000 Subject: 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 Acked-by: Bjorn Helgaas Signed-off-by: Len Brown --- drivers/acpi/pci_root.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) (limited to 'drivers/acpi') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 888cb9f5c5f..e5099919e57 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -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 -- cgit v1.2.3