powerpc/smp: Add cpu_l2_cache_map

We want to add an extra level to the CPU scheduler topology to account
for cores which share a cache. To do this we need to build a cpumask
for each CPU that indicates which CPUs share this cache to use as an
input to the scheduler.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index 8ea9850..fac963e 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -97,6 +97,7 @@ static inline void set_hard_smp_processor_id(int cpu, int phys)
 #endif
 
 DECLARE_PER_CPU(cpumask_var_t, cpu_sibling_map);
+DECLARE_PER_CPU(cpumask_var_t, cpu_l2_cache_map);
 DECLARE_PER_CPU(cpumask_var_t, cpu_core_map);
 
 static inline struct cpumask *cpu_sibling_mask(int cpu)
@@ -109,6 +110,11 @@ static inline struct cpumask *cpu_core_mask(int cpu)
 	return per_cpu(cpu_core_map, cpu);
 }
 
+static inline struct cpumask *cpu_l2_cache_mask(int cpu)
+{
+	return per_cpu(cpu_l2_cache_map, cpu);
+}
+
 extern int cpu_to_core_id(int cpu);
 
 /* Since OpenPIC has only 4 IPIs, we use slightly different message numbers.