ACPI / PAD / xen: use acpi_evaluate_ost() to replace open-coded version

Use public function acpi_evaluate_ost() to replace open-coded
version of evaluating ACPI _OST method.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 7 insertions, 19 deletions

diff --git a/drivers/xen/xen-acpi-pad.c b/drivers/xen/xen-acpi-pad.c
index 40c4bc06b5fa..f83b754505f8 100644
--- a/drivers/xen/xen-acpi-pad.c
+++ b/drivers/xen/xen-acpi-pad.c
@@ -77,27 +77,14 @@ static int acpi_pad_pur(acpi_handle handle)
         return num;
 }
 
-/* Notify firmware how many CPUs are idle */
-static void acpi_pad_ost(acpi_handle handle, int stat,
-        uint32_t idle_nums)
-{
-        union acpi_object params[3] = {
-                {.type = ACPI_TYPE_INTEGER,},
-                {.type = ACPI_TYPE_INTEGER,},
-                {.type = ACPI_TYPE_BUFFER,},
-        };
-        struct acpi_object_list arg_list = {3, params};
-
-        params[0].integer.value = ACPI_PROCESSOR_AGGREGATOR_NOTIFY;
-        params[1].integer.value =  stat;
-        params[2].buffer.length = 4;
-        params[2].buffer.pointer = (void *)&idle_nums;
-        acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
-}
-
 static void acpi_pad_handle_notify(acpi_handle handle)
 {
         int idle_nums;
+        struct acpi_buffer param = {
+                .length = 4,
+                .pointer = (void *)&idle_nums,
+        };
+
 
         mutex_lock(&xen_cpu_lock);
         idle_nums = acpi_pad_pur(handle);
@@ -109,7 +96,8 @@ static void acpi_pad_handle_notify(acpi_handle handle)
         idle_nums = xen_acpi_pad_idle_cpus(idle_nums)
                     ?: xen_acpi_pad_idle_cpus_num();
         if (idle_nums >= 0)
-                acpi_pad_ost(handle, 0, idle_nums);
+                acpi_evaluate_ost(handle, ACPI_PROCESSOR_AGGREGATOR_NOTIFY,
+                                  0, &param);
         mutex_unlock(&xen_cpu_lock);
 }