x86/intel_rdt: Introduce test to determine if closid is in use

rchatre · KAGA-KOKO · commit 0b9aa6562650 · 2018-06-23T13:03:41.000+02:00
During CAT feature discovery the capacity bitmasks (CBMs) associated with all the classes of service are initialized to all ones, even if the class of service is not in use. Introduce a test that can be used to determine if a class of service is in use. This test enables code interested in parsing the CBMs to know if its values are meaningful or can be ignored. Temporarily mark the function as unused to silence compile warnings until it is used. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: vikas.shivappa@linux.intel.com Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/798f8d89cd9b12df492d48c14bdc8ee3b39b1c6f.1529706536.git.reinette.chatre@intel.com
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -126,6 +126,18 @@ static void closid_free(int closid)
 	closid_free_map |= 1 << closid;
 }
 
+/**
+ * closid_allocated - test if provided closid is in use
+ * @closid: closid to be tested
+ *
+ * Return: true if @closid is currently associated with a resource group,
+ * false if @closid is free
+ */
+static bool __attribute__ ((unused)) closid_allocated(unsigned int closid)
+{
+	return (closid_free_map & (1 << closid)) == 0;
+}
+
 /**
  * rdtgroup_mode_by_closid - Return mode of resource group with closid
  * @closid: closid if the resource group
