cpu/topology: Export die_id

Export die_id in cpu topology, for the benefit of hardware that has
multiple-die/package.

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]>
Cc: [e-mail]
Link: https://lkml.kernel.org/r/e[e-mail]

Documentation/cputopology.txt

···
 	socket number, but the actual value is architecture and platform
 	dependent.
 
+die_id:
+
+	the CPU die ID of cpuX. Typically it is the hardware platform's
+	identifier (rather than the kernel's).  The actual value is
+	architecture and platform dependent.
+
 core_id:
 
 	the CPU core ID of cpuX. Typically it is the hardware platform's
···
 these macros in include/asm-XXX/topology.h::
 
 	#define topology_physical_package_id(cpu)
+	#define topology_die_id(cpu)
 	#define topology_core_id(cpu)
 	#define topology_book_id(cpu)
 	#define topology_drawer_id(cpu)
···
 not defined by include/asm-XXX/topology.h:
 
 1) topology_physical_package_id: -1
-2) topology_core_id: 0
-3) topology_sibling_cpumask: just the given CPU
-4) topology_core_cpumask: just the given CPU
+2) topology_die_id: -1
+3) topology_core_id: 0
+4) topology_sibling_cpumask: just the given CPU
+5) topology_core_cpumask: just the given CPU
+6) topology_die_cpumask: just the given CPU
 
 For architectures that don't support books (CONFIG_SCHED_BOOK) there are no
 default definitions for topology_book_id() and topology_book_cpumask().

drivers/base/topology.c

···
 define_id_show_func(physical_package_id);
 static DEVICE_ATTR_RO(physical_package_id);
 
+define_id_show_func(die_id);
+static DEVICE_ATTR_RO(die_id);
+
 define_id_show_func(core_id);
 static DEVICE_ATTR_RO(core_id);
 
···
 
 static struct attribute *default_attrs[] = {
 	&dev_attr_physical_package_id.attr,
+	&dev_attr_die_id.attr,
 	&dev_attr_core_id.attr,
 	&dev_attr_thread_siblings.attr,
 	&dev_attr_thread_siblings_list.attr,

include/linux/topology.h

···
 #ifndef topology_physical_package_id
 #define topology_physical_package_id(cpu)	((void)(cpu), -1)
 #endif
+#ifndef topology_die_id
+#define topology_die_id(cpu)			((void)(cpu), -1)
+#endif
 #ifndef topology_core_id
 #define topology_core_id(cpu)			((void)(cpu), 0)
 #endif