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| 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/pdc_intel.h | |
| parent | b4bd8c66435a8cdf8c90334fb3b517a23ff2ab95 (diff) | |
| download | lwn-991528d7348667924176f3e29addea0675298944.tar.gz lwn-991528d7348667924176f3e29addea0675298944.zip | |
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/pdc_intel.h')
| -rw-r--r-- | include/acpi/pdc_intel.h | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/include/acpi/pdc_intel.h b/include/acpi/pdc_intel.h index c5472be6f3a2..e72bfdd887f9 100644 --- a/include/acpi/pdc_intel.h +++ b/include/acpi/pdc_intel.h @@ -13,6 +13,7 @@ #define ACPI_PDC_SMP_C_SWCOORD (0x0040) #define ACPI_PDC_SMP_T_SWCOORD (0x0080) #define ACPI_PDC_C_C1_FFH (0x0100) +#define ACPI_PDC_C_C2C3_FFH (0x0200) #define ACPI_PDC_EST_CAPABILITY_SMP (ACPI_PDC_SMP_C1PT | \ ACPI_PDC_C_C1_HALT | \ @@ -23,8 +24,10 @@ ACPI_PDC_SMP_P_SWCOORD | \ ACPI_PDC_P_FFH) -#define ACPI_PDC_C_CAPABILITY_SMP (ACPI_PDC_SMP_C2C3 | \ - ACPI_PDC_SMP_C1PT | \ - ACPI_PDC_C_C1_HALT) +#define ACPI_PDC_C_CAPABILITY_SMP (ACPI_PDC_SMP_C2C3 | \ + ACPI_PDC_SMP_C1PT | \ + ACPI_PDC_C_C1_HALT | \ + ACPI_PDC_C_C1_FFH | \ + ACPI_PDC_C_C2C3_FFH) #endif /* __PDC_INTEL_H__ */ |