[PATCH RFC cpumask] Allow "all", "none", and "last" in cpumask strings

[Paul E. McKenney]

Hello!

This series allows "all", "none", and "last" to be used in cpumask
strings.  This allows these strings to be less dependent on the underlying
system.  For example, currently a string specifying all but the first
CPU must be "1-7" on an eight-CPU system and "1-15" on a 16-CPU system.
With this series, the single string "1-last" can be used regardless of the
number of CPUs (at least assuming that each system has at least one CPU).

1.	Un-inline cpulist_parse for SMP; prepare for ascii helpers,
	courtesy of Paul Gortmaker.

2.	Make "all" alias global and not just RCU, courtesy of Paul
	Gortmaker.

3.	Add a "none" alias to complement "all", courtesy of Paul
	Gortmaker.

4.	Add "last" alias for cpu list specifications, courtesy of Paul
	Gortmaker.

5.	Use "all" and "last" in "nohz_full" and "rcu_nocbs".

						Thanx, Paul

------------------------------------------------------------------------

 Documentation/admin-guide/kernel-parameters.rst            |   20 +
 Documentation/admin-guide/kernel-parameters.txt            |    4 
 include/linux/cpumask.h                                    |    8 
 kernel/rcu/tree_plugin.h                                   |   13 -
 lib/cpumask.c                                              |  136 ++++++++++++-
 tools/testing/selftests/rcutorture/configs/rcu/TREE04.boot |    2 
 tools/testing/selftests/rcutorture/configs/rcu/TREE08.boot |    2 
 7 files changed, 169 insertions(+), 16 deletions(-)