On 20/12/15 20:52, Daniel Thompson wrote:
Currently gic_raise_softirq() is locked using irq_controller_lock. This lock is primarily used to make register read-modify-write sequences atomic but gic_raise_softirq() uses it instead to ensure that the big.LITTLE migration logic can figure out when it is safe to migrate interrupts between physical cores.
This is sub-optimal in closely related ways:
No locking at all is required on systems where the b.L switcher is not configured.
Finer grain locking can be used on systems where the b.L switcher is present.
This patch resolves both of the above by introducing a separate finer grain lock and providing conditionally compiled inlines to lock/unlock it.
Signed-off-by: Daniel Thompson daniel.thompson@linaro.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Jason Cooper jason@lakedaemon.net Cc: Russell King linux@arm.linux.org.uk Cc: Marc Zyngier marc.zyngier@arm.com Acked-by: Nicolas Pitre nicolas.pitre@linaro.org
Acked-by: Marc Zyngier marc.zyngier@arm.com
M.