arm64: smp: Fix IPI teardown for GICv5 flow

Sashiko reported that during CPU offlining, __cpu_disable() is
executed by the stopper thread via take_cpu_down() with local
interrupts disabled. __cpu_disable() calls ipi_teardown(), which
invokes ipi_lpi_disable(). For the GICv5 flow, this eventually calls
the sleepable disable_irq().

This can be reproduced easily with CONFIG_DEBUG_ATOMIC_SLEEP=y by
offlining a CPU:

  BUG: sleeping function called from invalid context at kernel/irq/manage.c:702
  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 20, name: migration/1
  preempt_count: 1, expected: 0
  no locks held by migration/1/20.
  irq event stamp: 186
  hardirqs last  enabled at (185): [<ffff800080b084c8>] _raw_spin_unlock_irq+0x38/0x68
  hardirqs last disabled at (186): [<ffff8000801f8e08>] multi_cpu_stop+0xc8/0x190
  softirqs last  enabled at (80): [<ffff8000800c48b8>] handle_softirqs+0x410/0x468
  softirqs last disabled at (75): [<ffff8000800102f4>] __do_softirq+0x1c/0x28

Fix this by using disable_irq_nosync() instead, which is safe in this
atomic context.

Fixes: ba1004f861d1 ("arm64: smp: Support non-SGIs for IPIs")
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

0 files changed, 0 insertions, 0 deletions