cpuset: Update HK_TYPE_DOMAIN cpumask from cpuset

cpuset: Update HK_TYPE_DOMAIN cpumask from cpuset

Until now, HK_TYPE_DOMAIN used to only include boot defined isolated
CPUs passed through isolcpus= boot option. Users interested in also
knowing the runtime defined isolated CPUs through cpuset must use
different APIs: cpuset_cpu_is_isolated(), cpu_is_isolated(), etc...

There are many drawbacks to that approach:

1) Most interested subsystems want to know about all isolated CPUs, not
  just those defined on boot time.

2) cpuset_cpu_is_isolated() / cpu_is_isolated() are not synchronized with
  concurrent cpuset changes.

3) Further cpuset modifications are not propagated to subsystems

Solve 1) and 2) and centralize all isolated CPUs within the
HK_TYPE_DOMAIN housekeeping cpumask.

Subsystems can rely on RCU to synchronize against concurrent changes.

The propagation mentioned in 3) will be handled in further patches.

[Chen Ridong: Fix cpu_hotplug_lock deadlock and use correct static
branch API]

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Reviewed-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Cc: "Michal Koutný" <mkoutny@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Marco Crivellari <marco.crivellari@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: cgroups@vger.kernel.org