PCI/ACPI: acpiphp: Identify more removable slots

According to section 6.3.6 of the ACPI spec, the presence of an _RMV
method that evaluates to 1 is sufficient to indicate that a slot is
removable without needing an eject method. This patch refactors the
ejectable slot detection code a little in order to flag these slots as
ejectable and register them. Acpihp then binds to the expresscard slot
on my HP test machine.

Acked-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/hotplug/acpiphp_glue.c

@@ -74,7 +74,7 @@ static void handle_hotplug_event_func(acpi_handle handle, u32 type, void *contex
  * Ejectable slot should satisfy at least these conditions:
  *
  *  1. has _ADR method
- *  2. has _EJ0 method
+ *  2. has _EJ0 method or _RMV method
  *
  * optionally
  *
@@ -87,18 +87,25 @@ static int is_ejectable(acpi_handle handle)
 {
 	acpi_status status;
 	acpi_handle tmp;
+	unsigned long long removable;
 
 	status = acpi_get_handle(handle, "_ADR", &tmp);
-	if (ACPI_FAILURE(status)) {
+	if (ACPI_FAILURE(status))
 		return 0;
-	}
 
 	status = acpi_get_handle(handle, "_EJ0", &tmp);
-	if (ACPI_FAILURE(status)) {
-		return 0;
+	if (ACPI_SUCCESS(status))
+		return 1;
+
+	status = acpi_get_handle(handle, "_RMV", &tmp);
+	if (ACPI_SUCCESS(status)) {
+		status = acpi_evaluate_integer(handle, "_RMV", NULL,
+					       &removable);
+		if (ACPI_SUCCESS(status) && removable)
+			return 1;
 	}
 
-	return 1;
+	return 0;
 }
 
 
@@ -185,16 +192,10 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
 	unsigned long long adr, sun;
 	int device, function, retval;
 
-	status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
-
-	if (ACPI_FAILURE(status))
-		return AE_OK;
-
-	status = acpi_get_handle(handle, "_EJ0", &tmp);
-
-	if (ACPI_FAILURE(status) && !(is_dock_device(handle)))
+	if (!is_ejectable(handle) && !is_dock_device(handle))
 		return AE_OK;
 
+	acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
 	device = (adr >> 16) & 0xffff;
 	function = adr & 0xffff;
 
@@ -205,7 +206,8 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
 	INIT_LIST_HEAD(&newfunc->sibling);
 	newfunc->handle = handle;
 	newfunc->function = function;
-	if (ACPI_SUCCESS(status))
+
+	if (ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
 		newfunc->flags = FUNC_HAS_EJ0;
 
 	if (ACPI_SUCCESS(acpi_get_handle(handle, "_STA", &tmp)))