Pull RCU updates from Neeraj Upadhyay:
- Documentation and comment updates
- RCU torture, locktorture updates that include cleanups; nolibc init
build support for mips, ppc and rv64; testing of mid stall duration
scenario and fixing fqs task creation conditions
- Misc fixes, most notably restricting usage of RCU CPU stall
notifiers, to confine their usage primarily to debug kernels
- RCU tasks minor fixes
- lockdep annotation fix for NMI-safe accesses, callback
advancing/acceleration cleanup and documentation improvements
* tag 'rcu.release.v6.8' of https://github.com/neeraju/linux:
rcu: Force quiescent states only for ongoing grace period
doc: Clarify historical disclaimers in memory-barriers.txt
doc: Mention address and data dependencies in rcu_dereference.rst
doc: Clarify RCU Tasks reader/updater checklist
rculist.h: docs: Fix wrong function summary
Documentation: RCU: Remove repeated word in comments
srcu: Use try-lock lockdep annotation for NMI-safe access.
srcu: Explain why callbacks invocations can't run concurrently
srcu: No need to advance/accelerate if no callback enqueued
srcu: Remove superfluous callbacks advancing from srcu_gp_start()
rcu: Remove unused macros from rcupdate.h
rcu: Restrict access to RCU CPU stall notifiers
rcu-tasks: Mark RCU Tasks accesses to current->rcu_tasks_idle_cpu
rcutorture: Add fqs_holdoff check before fqs_task is created
rcutorture: Add mid-sized stall to TREE07
rcutorture: add nolibc init support for mips, ppc and rv64
locktorture: Increase Hamming distance between call_rcu_chain and rcu_call_chains