irqchip/mips-gic: Fix unbalanced cm_core_lock in for_each_online_cpu_gic()

Commit d9e2ed610a60 ("irqchip/mips-gic: Support multi-cluster in
for_each_online_cpu_gic()") added a gic_unlock_cluster() call to the
macro's loop increment, which unconditionally invokes
mips_cm_unlock_other() on multi-cluster systems. However nothing in the
loop ever acquires the corresponding mips_cm_lock_other(), so on
multi-cluster hardware every invocation of for_each_online_cpu_gic()
releases an unheld per-CPU cm_core_lock.

With CONFIG_PROVE_LOCKING this triggers a "bad unlock balance detected"
warning at boot, e.g. from gic_irq_domain_map() while mapping local
interrupts. Only the first occurrence is reported, since the first
warning permanently disables lockdep (debug_locks = 0); the unbalanced
release itself silently persists.

Fix this by moving both the acquire and release into
__gic_with_next_online_cpu() so they stay balanced. When advancing to a
CPU in a remote cluster, lock the CM redirect block for that cluster via
mips_cm_lock_other(); when leaving a remote cluster (or finishing the
iteration) release it with mips_cm_unlock_other(). Local-cluster CPUs
require no locking, so single-cluster systems are unaffected. This also
makes the redirect region behave correctly when accessing local register
blocks of CPUs in other clusters.

Drop the now-unused gic_unlock_cluster() helper and its call from the
for_each_online_cpu_gic() increment.

Fixes: d9e2ed610a60 ("irqchip/mips-gic: Support multi-cluster in for_each_online_cpu_gic()")
Signed-off-by: Benoît Monin <benoit.monin@bootlin.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Link: https://patch.msgid.link/20260929-sync-gic-counters-v4-1-ec70c4b60434@bootlin.com

0 files changed, 0 insertions, 0 deletions