diff options
| author | Sudeep Holla <Sudeep.Holla@arm.com> | 2016-07-21 17:18:07 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-07-21 23:25:58 +0200 |
| commit | a36a7fecfe6071732075ad5aa31196adce13181b (patch) | |
| tree | e3d88c1b278e013b10bd1280dc0257d5b23cba3c /drivers/acpi/bus.c | |
| parent | 35ae713355868aa493edbfbabf615473473215cc (diff) | |
ACPI / processor_idle: Add support for Low Power Idle(LPI) states
ACPI 6.0 introduced an optional object _LPI that provides an alternate
method to describe Low Power Idle states. 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 patch adds initial support for Platform coordination scheme of LPI.
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/bus.c')
| -rw-r--r-- | drivers/acpi/bus.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index 262ca31b86d9..80ebb05e387c 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -302,6 +302,14 @@ out_kfree: EXPORT_SYMBOL(acpi_run_osc); bool osc_sb_apei_support_acked; + +/* + * ACPI 6.0 Section 8.4.4.2 Idle State Coordination + * OSPM supports platform coordinated low power idle(LPI) states + */ +bool osc_pc_lpi_support_confirmed; +EXPORT_SYMBOL_GPL(osc_pc_lpi_support_confirmed); + static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48"; static void acpi_bus_osc_support(void) { @@ -322,6 +330,7 @@ static void acpi_bus_osc_support(void) capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PPC_OST_SUPPORT; capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_OST_SUPPORT; + capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PCLPI_SUPPORT; if (!ghes_disable) capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT; @@ -329,9 +338,12 @@ static void acpi_bus_osc_support(void) return; if (ACPI_SUCCESS(acpi_run_osc(handle, &context))) { u32 *capbuf_ret = context.ret.pointer; - if (context.ret.length > OSC_SUPPORT_DWORD) + if (context.ret.length > OSC_SUPPORT_DWORD) { osc_sb_apei_support_acked = capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT; + osc_pc_lpi_support_confirmed = + capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_PCLPI_SUPPORT; + } kfree(context.ret.pointer); } /* do we need to check other returned cap? Sounds no */ |