+- Interrupt support (PPC):
+
+ There are common interrupt_init() and timer_interrupt()
+ for all PPC archs. interrupt_init() calls interrupt_init_cpu()
+ for cpu specific initialization. interrupt_init_cpu()
+ should set decrementer_count to appropriate value. If
+ cpu resets decrementer automatically after interrupt
+ (ppc4xx) it should set decrementer_count to zero.
+ timer_interrupt() calls timer_interrupt_cpu() for cpu
+ specific handling. If board has watchdog / status_led
+ / other_activity_monitor it works automatically from
+ general timer_interrupt().
+