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 <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
This commit is contained in:
Sudeep Holla 2016-07-21 17:18:07 +01:00 • committed by Rafael J. Wysocki
commit a36a7fecfe
5 changed files with 450 additions and 60 deletions

View file

@ -39,6 +39,7 @@
#define ACPI_CSTATE_SYSTEMIO 0
#define ACPI_CSTATE_FFH 1
#define ACPI_CSTATE_HALT 2
#define ACPI_CSTATE_INTEGER 3
#define ACPI_CX_DESC_LEN 32
@ -67,9 +68,25 @@ struct acpi_processor_cx {
char desc[ACPI_CX_DESC_LEN];
};
struct acpi_lpi_state {
u32 min_residency;
u32 wake_latency; /* worst case */
u32 flags;
u32 arch_flags;
u32 res_cnt_freq;
u32 enable_parent_state;
u64 address;
u8 index;
u8 entry_method;
char desc[ACPI_CX_DESC_LEN];
};
struct acpi_processor_power {
int count;
struct acpi_processor_cx states[ACPI_PROCESSOR_MAX_POWER];
union {
struct acpi_processor_cx states[ACPI_PROCESSOR_MAX_POWER];
struct acpi_lpi_state lpi_states[ACPI_PROCESSOR_MAX_POWER];
};
int timer_broadcast_on_state;
};
@ -189,6 +206,7 @@ struct acpi_processor_flags {
u8 bm_control:1;
u8 bm_check:1;
u8 has_cst:1;
u8 has_lpi:1;
u8 power_setup_done:1;
u8 bm_rld_set:1;
u8 need_hotplug_init:1;
@ -371,7 +389,7 @@ extern struct cpuidle_driver acpi_idle_driver;
#ifdef CONFIG_ACPI_PROCESSOR_IDLE
int acpi_processor_power_init(struct acpi_processor *pr);
int acpi_processor_power_exit(struct acpi_processor *pr);
int acpi_processor_cst_has_changed(struct acpi_processor *pr);
int acpi_processor_power_state_has_changed(struct acpi_processor *pr);
int acpi_processor_hotplug(struct acpi_processor *pr);
#else
static inline int acpi_processor_power_init(struct acpi_processor *pr)
@ -384,7 +402,7 @@ static inline int acpi_processor_power_exit(struct acpi_processor *pr)
return -ENODEV;
}
static inline int acpi_processor_cst_has_changed(struct acpi_processor *pr)
static inline int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
{
return -ENODEV;
}