diff options
| author | Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | 2006-09-25 16:28:13 -0700 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2006-10-14 00:35:39 -0400 |
| commit | 991528d7348667924176f3e29addea0675298944 (patch) | |
| tree | ed8552bd4c696700a95ae37b26c4197923207ae7 /include/acpi/processor.h | |
| parent | b4bd8c66435a8cdf8c90334fb3b517a23ff2ab95 (diff) | |
ACPI: Processor native C-states using MWAIT
Intel processors starting with the Core Duo support
support processor native C-state using the MWAIT instruction.
Refer: Intel Architecture Software Developer's Manual
http://www.intel.com/design/Pentium4/manuals/253668.htm
Platform firmware exports the support for Native C-state to OS using
ACPI _PDC and _CST methods.
Refer: Intel Processor Vendor-Specific ACPI: Interface Specification
http://www.intel.com/technology/iapc/acpi/downloads/302223.htm
With Processor Native C-state, we use 'MWAIT' instruction on the processor
to enter different C-states (C1, C2, C3). We won't use the special IO
ports to enter C-state and no SMM mode etc required to enter C-state.
Overall this will mean better C-state support.
One major advantage of using MWAIT for all C-states is, with this and
"treat interrupt as break event" feature of MWAIT, we can now get accurate
timing for the time spent in C1, C2, .. states.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'include/acpi/processor.h')
| -rw-r--r-- | include/acpi/processor.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/include/acpi/processor.h b/include/acpi/processor.h index 9dd5b75961f8..7798d2a9f793 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -29,6 +29,9 @@ #define DOMAIN_COORD_TYPE_SW_ANY 0xfd #define DOMAIN_COORD_TYPE_HW_ALL 0xfe +#define ACPI_CSTATE_SYSTEMIO (0) +#define ACPI_CSTATE_FFH (1) + /* Power Management */ struct acpi_processor_cx; @@ -58,6 +61,8 @@ struct acpi_processor_cx { u8 valid; u8 type; u32 address; + u8 space_id; + u8 index; u32 latency; u32 latency_ticks; u32 power; @@ -206,6 +211,9 @@ void arch_acpi_processor_init_pdc(struct acpi_processor *pr); #ifdef ARCH_HAS_POWER_INIT void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags, unsigned int cpu); +int acpi_processor_ffh_cstate_probe(unsigned int cpu, + struct acpi_processor_cx *cx, struct acpi_power_register *reg); +void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx *cstate); #else static inline void acpi_processor_power_init_bm_check(struct acpi_processor_flags @@ -214,6 +222,16 @@ static inline void acpi_processor_power_init_bm_check(struct flags->bm_check = 1; return; } +static inline int acpi_processor_ffh_cstate_probe(unsigned int cpu, + struct acpi_processor_cx *cx, struct acpi_power_register *reg) +{ + return -1; +} +static inline void acpi_processor_ffh_cstate_enter( + struct acpi_processor_cx *cstate) +{ + return; +} #endif /* in processor_perflib.c */ |