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| author | Arthur Heymans <arthur@aheymans.xyz> | 2016-10-06 12:14:14 +0200 |
|---|---|---|
| committer | Martin Roth <martinroth@google.com> | 2016-10-09 21:37:50 +0200 |
| commit | aacd548c26f251583f1035d4ecc544198721f937 (patch) | |
| tree | 0b27dc4487e846b6b6568f402cefd6963e478592 /src/cpu/intel | |
| parent | e7aeb2f60212077521f7d71a4f485c8f4a26f6c6 (diff) | |
| download | coreboot-aacd548c26f251583f1035d4ecc544198721f937.tar.xz | |
cpu/intel/model_6ex: Set msr bits for dynamic L2, C2E, C4E
The datasheets "Intel® Core™ Duo Processor and Intel® Core™ Solo
Processor on 65 nm Process" mentions cpu C-states substates which can
either be attained by adding a substate hint to the MWAIT/P_LVLx request
or automatically by setting some msr bits correctly.
This just sets the same msr bits as model_6fx to enable
dynamic L2 cache, C2E and C4E acpi cpu states.
The result is that when limiting a thinkpad x60 with a yonah T2400
cpu to the acpi cpu C2 state, the idle power usage drops from 18W to
14W. When the lowest C-state is set to C4 the idle power usage seems
to remain similar.
Change-Id: I6c422656ace04659f32082a5944617eda6c79ec3
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/16901
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
Diffstat (limited to 'src/cpu/intel')
| -rw-r--r-- | src/cpu/intel/model_6ex/model_6ex_init.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/src/cpu/intel/model_6ex/model_6ex_init.c b/src/cpu/intel/model_6ex/model_6ex_init.c index 91633ecd9d..d42ff694ee 100644 --- a/src/cpu/intel/model_6ex/model_6ex_init.c +++ b/src/cpu/intel/model_6ex/model_6ex_init.c @@ -69,7 +69,7 @@ static void configure_c_states(void) msr.lo |= (1 << 15); // config lock until next reset. msr.lo |= (1 << 10); // Enable I/O MWAIT redirection for C-States msr.lo &= ~(1 << 9); // Issue a single stop grant cycle upon stpclk - // TODO Do we want Deep C4 and Dynamic L2 shrinking? + msr.lo |= (1 << 3); //dynamic L2 /* Number of supported C-States */ msr.lo &= ~7; @@ -103,7 +103,13 @@ static void configure_misc(void) // TODO: Only if IA32_PLATFORM_ID[17] = 0 and IA32_PLATFORM_ID[50] = 1 msr.lo |= (1 << 16); /* Enhanced SpeedStep Enable */ - // TODO Do we want Deep C4 and Dynamic L2 shrinking? + /* Enable C2E */ + msr.lo |= (1 << 26); + + /* Enable C4E */ + msr.hi |= (1 << (32 - 32)); // C4E + msr.hi |= (1 << (33 - 32)); // Hard C4E + wrmsr(IA32_MISC_ENABLE, msr); msr.lo |= (1 << 20); /* Lock Enhanced SpeedStep Enable */ |