[CPUFREQ] expose cpufreq coordination requirements regardless of coordination mechanism

Currently, affected_cpus shows which CPUs need to have their frequency
coordinated in software.  When hardware coordination is in use, the contents
of this file appear the same as when no coordination is required.  This can
lead to some confusion among user-space programs, for example, that do not
know that extra coordination is required to force a CPU core to a particular
speed to control power consumption.

To fix this, create a "related_cpus" attribute that always displays the
coordination map regardless of whatever coordination strategy the cpufreq
driver uses (sw or hw).  If the cpufreq driver does not provide a value, fall
back to policy->cpus.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index ddd8652..a881fd6 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -83,7 +83,8 @@
 };
 
 struct cpufreq_policy {
-	cpumask_t		cpus;	/* affected CPUs */
+	cpumask_t		cpus;	/* CPUs requiring sw coordination */
+	cpumask_t		related_cpus; /* CPUs with any coordination */
 	unsigned int		shared_type; /* ANY or ALL affected CPUs
 						should set cpufreq */
 	unsigned int		cpu;    /* cpu nr of registered CPU */