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cpu/intel/haswell: Enable timed MWAIT if supported 

Broadwell code unconditionally enables timed MWAIT, but not all Haswell
steppings support it. In preparation for merging Haswell and Broadwell,
also enable timed MWAIT on Haswell code, but only if it is supported.

Change-Id: I1d11d62f1801d65ae4d5623994fd55fd35e8f34a
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46916
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Angel Pons 2020-10-28 22:23:02 +01:00 committed by Patrick Georgi
parent 8199b88222
commit c89d2a2890
2 changed files with 8 additions and 1 deletions
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1
src/cpu/intel/haswell/haswell.h
View File

@ -36,6 +36,7 @@
#define MSR_CORE_THREAD_COUNT 0x35 #define MSR_CORE_THREAD_COUNT 0x35
#define MSR_PLATFORM_INFO 0xce #define MSR_PLATFORM_INFO 0xce
#define PLATFORM_INFO_SET_TDP (1 << 29) #define PLATFORM_INFO_SET_TDP (1 << 29)
#define TIMED_MWAIT_SUPPORTED (1 << (37 - 32))
#define MSR_PKG_CST_CONFIG_CONTROL 0xe2 #define MSR_PKG_CST_CONFIG_CONTROL 0xe2
#define MSR_PMG_IO_CAPTURE_BASE 0xe4 #define MSR_PMG_IO_CAPTURE_BASE 0xe4
#define MSR_FEATURE_CONFIG 0x13c #define MSR_FEATURE_CONFIG 0x13c

8
src/cpu/intel/haswell/haswell_init.c
View File

@ -431,7 +431,9 @@ void set_power_limits(u8 power_limit_1_time)
static void configure_c_states(void) static void configure_c_states(void)
{ {
msr_t msr; msr_t msr = rdmsr(MSR_PLATFORM_INFO);
const bool timed_mwait_capable = !!(msr.hi & TIMED_MWAIT_SUPPORTED);
msr = rdmsr(MSR_PKG_CST_CONFIG_CONTROL); msr = rdmsr(MSR_PKG_CST_CONFIG_CONTROL);
msr.lo |= (1 << 30); // Package c-state Undemotion Enable msr.lo |= (1 << 30); // Package c-state Undemotion Enable
@ -441,6 +443,10 @@ static void configure_c_states(void)
msr.lo |= (1 << 26); // C1 Auto Demotion Enable msr.lo |= (1 << 26); // C1 Auto Demotion Enable
msr.lo |= (1 << 25); // C3 Auto Demotion Enable msr.lo |= (1 << 25); // C3 Auto Demotion Enable
msr.lo &= ~(1 << 10); // Disable IO MWAIT redirection msr.lo &= ~(1 << 10); // Disable IO MWAIT redirection
if (timed_mwait_capable)
msr.lo |= (1 << 31); // Timed MWAIT Enable
/* The deepest package c-state defaults to factory-configured value. */ /* The deepest package c-state defaults to factory-configured value. */
wrmsr(MSR_PKG_CST_CONFIG_CONTROL, msr); wrmsr(MSR_PKG_CST_CONFIG_CONTROL, msr);