topology: Create package_cpus sysfs attribute

The existing sysfs cpu/topology/core_siblings (and core_siblings_list)
attributes are documented, implemented, and used by programs to represent
set of logical CPUs sharing the same package.

This makes sense if the next topology level above a core is always a
package. But on systems where there is a die topology level between a core
and a package, the name and its definition become inconsistent.

So without changing its function, add a name for this map that describes
what it actually is -- package CPUs -- the set of CPUs that share the same
package.

This new name will be immune to changes in topology, since it describes
threads at the current level, not siblings at a contained level.

Suggested-by: Brice Goglin <[e-mail]>
Signed-off-by: Len Brown <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Reviewed-by: Ingo Molnar <[e-mail]>
Acked-by: Peter Zijlstra (Intel) <[e-mail]>
Link: https://lkml.kernel.org/r/d[e-mail]

Documentation/cputopology.txt

···
 	human-readable list of cpuX's hardware threads within the same
 	core as cpuX.
 
-core_siblings:
+package_cpus:
 
-	internal kernel map of cpuX's hardware threads within the same
-	physical_package_id.
+	internal kernel map of the CPUs sharing the same physical_package_id.
+	(deprecated name: "core_siblings")
 
-core_siblings_list:
+package_cpus_list:
 
-	human-readable list of cpuX's hardware threads within the same
-	physical_package_id.
+	human-readable list of CPUs sharing the same physical_package_id.
+	(deprecated name: "core_siblings_list")
 
 book_siblings:
 

drivers/base/topology.c

···
 static DEVICE_ATTR_RO(core_siblings);
 static DEVICE_ATTR_RO(core_siblings_list);
 
+define_siblings_show_func(package_cpus, core_cpumask);
+static DEVICE_ATTR_RO(package_cpus);
+static DEVICE_ATTR_RO(package_cpus_list);
+
 #ifdef CONFIG_SCHED_BOOK
 define_id_show_func(book_id);
 static DEVICE_ATTR_RO(book_id);
···
 	&dev_attr_thread_siblings_list.attr,
 	&dev_attr_core_siblings.attr,
 	&dev_attr_core_siblings_list.attr,
+	&dev_attr_package_cpus.attr,
+	&dev_attr_package_cpus_list.attr,
 #ifdef CONFIG_SCHED_BOOK
 	&dev_attr_book_id.attr,
 	&dev_attr_book_siblings.attr,