[PATCH v2 0/3] irqchip/gic-v3-its: Fix LPI pending table handling vs PREEMPT_RT

[Valentin Schneider]

Hi folks,

This is my take at fixing [1]. Reading about the LPI tables situation was
entertaining.

Tested against kexec on an Ampere eMAG. Seems to be working fine atop
5.15-rc6. On the other hand, I can only issue one kexec from
5.15-rc6-rt12 - if I then issue another one on the new kernel, I get tasks
hanging. That is true even without my patches and without
CONFIG_PREEMPT_RT.

[1]: http://lore.kernel.org/r/20210810134127.1394269-3-valentin.schneider@arm.com

Revisions
=========

v1 -> v2
++++++++

o Ditched RDIST_FLAGS renaming; moved to "RD_LOCAL" prefix for new flags
  (Marc) 
o Simplified cpuhp callback logic: body now runs at most once per CPU
o Changed cpuhp callback installation to happen *after* the BP has invoked
  its_cpu_init(); the BP cpuhp state is immediately set to CPUHP_ONLINE, so
  cpuhp state alone doesn't guarantee its_cpu_init() has been run.
  
Cheers,
Valentin

Valentin Schneider (3):
  irqchip/gic-v3-its: Give the percpu rdist struct its own flags field
  irqchip/gic-v3-its: Postpone LPI pending table freeing and memreserve
  irqchip/gic-v3-its: Limit memreserve cpuhp state lifetime

 drivers/irqchip/irq-gic-v3-its.c   | 82 +++++++++++++++++++++++++++---
 drivers/irqchip/irq-gic-v3.c       |  1 +
 include/linux/irqchip/arm-gic-v3.h |  4 +-
 3 files changed, 79 insertions(+), 8 deletions(-)

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2.25.1