In some SMP systems, cpu-local timers may stop delivering interrupts when in low power states, or not all CPUs may have local timers. To support these systems we have a mechanism for broadcasting timer ticks to other CPUs. This mechanism relies on the struct clock_event_device::broadcast function pointer, which is a driver-specific mechanism for broadcasting ticks to other CPUs.
As the broadcast mechanism is architecture-specific, placing the broadcast function on struct clock_event_device ties each driver to a single architecture. Additionally the driver or architecture backend must handle the routing of broadcast ticks to the correct clock_event_device, leading to duplication of the list of active clock_event_devices. These patches introduce a generic mechanism for handling the receipt of timer broadcasts, and an optional architecture-specific broadcast function which allows drivers to be decoupled from a particular architecture will retaining support for timer tick broadcasts. These mechanisms are wired up for the arm port, and have been boot-tested on a pandaboard. Thanks, Mark. Mark Rutland (5): ARM: remove useless guard in smp.c clockevents: Add generic timer broadcast receiver ARM: Use generic timer broadcast receive clockevents: Add generic timer broadcast function ARM: Add generic timer broadcast support arch/arm/Kconfig | 1 + arch/arm/kernel/smp.c | 15 ++------------- include/linux/clockchips.h | 9 +++++++++ kernel/time/Kconfig | 4 ++++ kernel/time/tick-broadcast.c | 30 ++++++++++++++++++++++++++++++ 5 files changed, 46 insertions(+), 13 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/