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-rw-r--r--drivers/acpi/glue.c99
-rw-r--r--drivers/pci/pci-acpi.c15
2 files changed, 93 insertions, 21 deletions
diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index 17e15d11bd39..408f6b2a5fa8 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -79,34 +79,99 @@ static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
return ret;
}
-static acpi_status do_acpi_find_child(acpi_handle handle, u32 lvl_not_used,
- void *addr_p, void **ret_p)
+static acpi_status acpi_dev_present(acpi_handle handle, u32 lvl_not_used,
+ void *not_used, void **ret_p)
{
- unsigned long long addr, sta;
- acpi_status status;
+ struct acpi_device *adev = NULL;
- status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr);
- if (ACPI_SUCCESS(status) && addr == *((u64 *)addr_p)) {
+ acpi_bus_get_device(handle, &adev);
+ if (adev) {
*ret_p = handle;
- status = acpi_bus_get_status_handle(handle, &sta);
- if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_ENABLED))
- return AE_CTRL_TERMINATE;
+ return AE_CTRL_TERMINATE;
}
return AE_OK;
}
-acpi_handle acpi_get_child(acpi_handle parent, u64 address)
+static bool acpi_extra_checks_passed(acpi_handle handle, bool is_bridge)
{
- void *ret = NULL;
+ unsigned long long sta;
+ acpi_status status;
+
+ status = acpi_bus_get_status_handle(handle, &sta);
+ if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
+ return false;
+
+ if (is_bridge) {
+ void *test = NULL;
+
+ /* Check if this object has at least one child device. */
+ acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
+ acpi_dev_present, NULL, NULL, &test);
+ return !!test;
+ }
+ return true;
+}
+
+struct find_child_context {
+ u64 addr;
+ bool is_bridge;
+ acpi_handle ret;
+ bool ret_checked;
+};
+
+static acpi_status do_find_child(acpi_handle handle, u32 lvl_not_used,
+ void *data, void **not_used)
+{
+ struct find_child_context *context = data;
+ unsigned long long addr;
+ acpi_status status;
- if (!parent)
- return NULL;
+ status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr);
+ if (ACPI_FAILURE(status) || addr != context->addr)
+ return AE_OK;
- acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1, NULL,
- do_acpi_find_child, &address, &ret);
- return (acpi_handle)ret;
+ if (!context->ret) {
+ /* This is the first matching object. Save its handle. */
+ context->ret = handle;
+ return AE_OK;
+ }
+ /*
+ * There is more than one matching object with the same _ADR value.
+ * That really is unexpected, so we are kind of beyond the scope of the
+ * spec here. We have to choose which one to return, though.
+ *
+ * First, check if the previously found object is good enough and return
+ * its handle if so. Second, check the same for the object that we've
+ * just found.
+ */
+ if (!context->ret_checked) {
+ if (acpi_extra_checks_passed(context->ret, context->is_bridge))
+ return AE_CTRL_TERMINATE;
+ else
+ context->ret_checked = true;
+ }
+ if (acpi_extra_checks_passed(handle, context->is_bridge)) {
+ context->ret = handle;
+ return AE_CTRL_TERMINATE;
+ }
+ return AE_OK;
+}
+
+acpi_handle acpi_find_child(acpi_handle parent, u64 addr, bool is_bridge)
+{
+ if (parent) {
+ struct find_child_context context = {
+ .addr = addr,
+ .is_bridge = is_bridge,
+ };
+
+ acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1, do_find_child,
+ NULL, &context, NULL);
+ return context.ret;
+ }
+ return NULL;
}
-EXPORT_SYMBOL(acpi_get_child);
+EXPORT_SYMBOL_GPL(acpi_find_child);
int acpi_bind_one(struct device *dev, acpi_handle handle)
{
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index dbdc5f7e2b29..01e264fb50e0 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -317,13 +317,20 @@ void acpi_pci_remove_bus(struct pci_bus *bus)
/* ACPI bus type */
static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
{
- struct pci_dev * pci_dev;
- u64 addr;
+ struct pci_dev *pci_dev = to_pci_dev(dev);
+ bool is_bridge;
+ u64 addr;
- pci_dev = to_pci_dev(dev);
+ /*
+ * pci_is_bridge() is not suitable here, because pci_dev->subordinate
+ * is set only after acpi_pci_find_device() has been called for the
+ * given device.
+ */
+ is_bridge = pci_dev->hdr_type == PCI_HEADER_TYPE_BRIDGE
+ || pci_dev->hdr_type == PCI_HEADER_TYPE_CARDBUS;
/* Please ref to ACPI spec for the syntax of _ADR */
addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
- *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
+ *handle = acpi_find_child(ACPI_HANDLE(dev->parent), addr, is_bridge);
if (!*handle)
return -ENODEV;
return 0;