xen/acpi: Move xen_acpi_get_pxm to Xen's acpi.h

So that it could be reused by Xen CPU hotplug logic.

Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/include/xen/acpi.h b/include/xen/acpi.h
index 2b3103b..dc69c91 100644
--- a/include/xen/acpi.h
+++ b/include/xen/acpi.h
@@ -69,4 +69,22 @@
 }
 #endif
 
+static inline int xen_acpi_get_pxm(acpi_handle h)
+{
+	unsigned long long pxm;
+	acpi_status status;
+	acpi_handle handle;
+	acpi_handle phandle = h;
+
+	do {
+		handle = phandle;
+		status = acpi_evaluate_integer(handle, "_PXM", NULL, &pxm);
+		if (ACPI_SUCCESS(status))
+			return pxm;
+		status = acpi_get_parent(handle, &phandle);
+	} while (ACPI_SUCCESS(status));
+
+	return -ENXIO;
+}
+
 #endif	/* _XEN_ACPI_H */