powerpc: Make core sibling information available to userspace

Implement the notion of "core siblings" for powerpc.  This makes
/sys/devices/system/cpu/cpu*/topology/core_siblings present sensible
values, indicating online CPUs which share an L2 cache.

BenH: Made cpu_to_l2cache() use of_find_node_by_phandle() instead
of IBM-specific open coded search

Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 2 insertions, 0 deletions

diff --git a/include/asm-powerpc/smp.h b/include/asm-powerpc/smp.h
index 416d4c288cea..32e910006250 100644
--- a/include/asm-powerpc/smp.h
+++ b/include/asm-powerpc/smp.h
@@ -62,6 +62,7 @@ extern int smp_hw_index[];
 #endif
 
 DECLARE_PER_CPU(cpumask_t, cpu_sibling_map);
+DECLARE_PER_CPU(cpumask_t, cpu_core_map);
 
 /* Since OpenPIC has only 4 IPIs, we use slightly different message numbers.
  *
diff --git a/include/asm-powerpc/topology.h b/include/asm-powerpc/topology.h
index 100c6fbfc587..f00e8e551738 100644
--- a/include/asm-powerpc/topology.h
+++ b/include/asm-powerpc/topology.h
@@ -108,6 +108,7 @@ static inline void sysfs_remove_device_from_node(struct sys_device *dev,
 #include <asm/smp.h>
 
 #define topology_thread_siblings(cpu)   (per_cpu(cpu_sibling_map, cpu))
+#define topology_core_siblings(cpu)     (per_cpu(cpu_core_map, cpu))
 #endif
 #endif