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author | Alexander Chiang <achiang@hp.com> | 2009-06-10 19:55:20 +0000 |
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committer | Len Brown <len.brown@intel.com> | 2009-06-17 23:22:15 -0400 |
commit | 2f7bbceb5b6aa938024bb4dad93c410fa59ed3b9 (patch) | |
tree | f34fa26ac7a916f221dc88a5cb32eaf5db7c0e05 /drivers/acpi/pci_root.c | |
parent | 275582031f9b3597a1b973f3ff617adfe639faa2 (diff) | |
download | linux-3.10-2f7bbceb5b6aa938024bb4dad93c410fa59ed3b9.tar.gz linux-3.10-2f7bbceb5b6aa938024bb4dad93c410fa59ed3b9.tar.bz2 linux-3.10-2f7bbceb5b6aa938024bb4dad93c410fa59ed3b9.zip |
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>
Diffstat (limited to 'drivers/acpi/pci_root.c')
-rw-r--r-- | drivers/acpi/pci_root.c | 81 |
1 files changed, 81 insertions, 0 deletions
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 |