ACPI: Make acpi_dev_get_resources() method agnostic

The function acpi_dev_get_resources() is completely generic and
can be used to parse resource objects that are not necessarily
coming from the _CRS method but also from other objects eg _DMA
that have the same _CRS resource format.

Create an acpi_dev_get_resources() helper, internal to the ACPI
resources parsing compilation unit, __acpi_dev_get_resources(),
that takes a const char* parameter to detect which ACPI method should be
called to retrieve the resources list and make acpi_dev_get_resources()
call it with a method name _CRS leaving the API behaviour unchanged.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Nate Watterson <nwatters@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index cd4c4271dc4cd6ec5c676eb849cabcdc6a1736b7..93f1b5ce89b963d2afa38da914c47cb2ea17294e 100644 (file)
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -573,6 +573,35 @@ static acpi_status acpi_dev_process_resource(struct acpi_resource *ares,
        return AE_OK;
 }
 
+static int __acpi_dev_get_resources(struct acpi_device *adev,
+                                   struct list_head *list,
+                                   int (*preproc)(struct acpi_resource *, void *),
+                                   void *preproc_data, char *method)
+{
+       struct res_proc_context c;
+       acpi_status status;
+
+       if (!adev || !adev->handle || !list_empty(list))
+               return -EINVAL;
+
+       if (!acpi_has_method(adev->handle, method))
+               return 0;
+
+       c.list = list;
+       c.preproc = preproc;
+       c.preproc_data = preproc_data;
+       c.count = 0;
+       c.error = 0;
+       status = acpi_walk_resources(adev->handle, method,
+                                    acpi_dev_process_resource, &c);
+       if (ACPI_FAILURE(status)) {
+               acpi_dev_free_resource_list(list);
+               return c.error ? c.error : -EIO;
+       }
+
+       return c.count;
+}
+
 /**
  * acpi_dev_get_resources - Get current resources of a device.
  * @adev: ACPI device node to get the resources for.
@@ -601,28 +630,8 @@ int acpi_dev_get_resources(struct acpi_device *adev, struct list_head *list,
                           int (*preproc)(struct acpi_resource *, void *),
                           void *preproc_data)
 {
-       struct res_proc_context c;
-       acpi_status status;
-
-       if (!adev || !adev->handle || !list_empty(list))
-               return -EINVAL;
-
-       if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
-               return 0;
-
-       c.list = list;
-       c.preproc = preproc;
-       c.preproc_data = preproc_data;
-       c.count = 0;
-       c.error = 0;
-       status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
-                                    acpi_dev_process_resource, &c);
-       if (ACPI_FAILURE(status)) {
-               acpi_dev_free_resource_list(list);
-               return c.error ? c.error : -EIO;
-       }
-
-       return c.count;
+       return __acpi_dev_get_resources(adev, list, preproc, preproc_data,
+                                       METHOD_NAME__CRS);
 }
 EXPORT_SYMBOL_GPL(acpi_dev_get_resources);