ACPI 6.0 introduced LPI(Low Power Idle) states that provides an alternate method to describe processor idle states. It extends the specification to allow the expression of idle states like C-states selectable by the OSPM when a processor goes idle, but may affect more than one processor, and may affect other system components. LPI extensions leverages the processor container device(again introduced in ACPI 6.0) allowing to express which parts of the system are affected by a given LPI state. It defines the local power states for each node in a hierarchical processor topology. The OSPM can use _LPI object to select a local power state for each level of processor hierarchy in the system. They used to produce a composite power state request that is presented to the platform by the OSPM. Since multiple processors affect the idle state for any non-leaf hierarchy node, coordination of idle state requests between the processors is required. ACPI supports two different coordination schemes: Platform coordinated and OS initiated. This series aims at providing basic and initial support for platform coordinated LPI states. v2[2]->v3: - rebased against v4.4-rc3 - fixed couple of issues reported by Prashanth and review comments from Ashwin v1[1]->v2[2]: - Fixed support for ACPI0010 processor container - moved sleep state code out of processor_idle Note the ARM64 specific changes are not part of this series as it's still WIP and there are other consolidation happening in there. For reference and testing, I have pushed a branch[3] Regards, Sudeep [1] https://lkml.org/lkml/2015/8/4/789 [2] https://lkml.org/lkml/2015/9/16/422 [3] git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git arm64_lpi_testing Sudeep Holla (5): ACPI / processor : add support for ACPI0010 processor container ACPI / sleep: move acpi_processor_sleep to sleep.c ACPI / processor_idle: replace PREFIX with pr_fmt ACPI / processor_idle : introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE ACPI / processor_idle: Add support for Low Power Idle(LPI) states arch/ia64/Kconfig | 1 + arch/x86/Kconfig | 1 + drivers/acpi/Kconfig | 6 + drivers/acpi/acpi_processor.c | 17 ++ drivers/acpi/bus.c | 8 +- drivers/acpi/processor_driver.c | 4 +- drivers/acpi/processor_idle.c | 553 ++++++++++++++++++++++++++++++++-------- drivers/acpi/sleep.c | 35 +++ include/acpi/processor.h | 42 ++- include/linux/acpi.h | 4 + 10 files changed, 545 insertions(+), 126 deletions(-) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
