4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Len Brown <len.brown@xxxxxxxxx> [ Upstream commit 71616c8e936a6dd541f0627d7bf4ff09971d8ccb ] with --debug, see: cpu0: MSR_CC6_DEMOTION_POLICY_CONFIG: 0x00000000 (DISable-CC6-Demotion) cpu0: MSR_MC6_DEMOTION_POLICY_CONFIG: 0x00000000 (DISable-MC6-Demotion) Note that the hardware default is to enable demotion, and Linux started clearing these registers in 3.17. Signed-off-by: Len Brown <len.brown@xxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/power/x86/turbostat/turbostat.c | 42 ++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) --- a/tools/power/x86/turbostat/turbostat.c +++ b/tools/power/x86/turbostat/turbostat.c @@ -2951,6 +2951,27 @@ int has_snb_msrs(unsigned int family, un } /* + * SLV client has supporet for unique MSRs: + * + * MSR_CC6_DEMOTION_POLICY_CONFIG + * MSR_MC6_DEMOTION_POLICY_CONFIG + */ + +int has_slv_msrs(unsigned int family, unsigned int model) +{ + if (!genuine_intel) + return 0; + + switch (model) { + case INTEL_FAM6_ATOM_SILVERMONT1: + case INTEL_FAM6_ATOM_MERRIFIELD: + case INTEL_FAM6_ATOM_MOOREFIELD: + return 1; + } + return 0; +} + +/* * HSW adds support for additional MSRs: * * MSR_PKG_C8_RESIDENCY 0x00000630 @@ -3179,6 +3200,24 @@ void decode_misc_pwr_mgmt_msr(void) msr & (1 << 0) ? "DIS" : "EN", msr & (1 << 1) ? "EN" : "DIS"); } +/* + * Decode MSR_CC6_DEMOTION_POLICY_CONFIG, MSR_MC6_DEMOTION_POLICY_CONFIG + * + * This MSRs are present on Silvermont processors, + * Intel Atom processor E3000 series (Baytrail), and friends. + */ +void decode_c6_demotion_policy_msr(void) +{ + unsigned long long msr; + + if (!get_msr(base_cpu, MSR_CC6_DEMOTION_POLICY_CONFIG, &msr)) + fprintf(outf, "cpu%d: MSR_CC6_DEMOTION_POLICY_CONFIG: 0x%08llx (%sable-CC6-Demotion)\n", + base_cpu, msr, msr & (1 << 0) ? "EN" : "DIS"); + + if (!get_msr(base_cpu, MSR_MC6_DEMOTION_POLICY_CONFIG, &msr)) + fprintf(outf, "cpu%d: MSR_MC6_DEMOTION_POLICY_CONFIG: 0x%08llx (%sable-MC6-Demotion)\n", + base_cpu, msr, msr & (1 << 0) ? "EN" : "DIS"); +} void process_cpuid() { @@ -3360,6 +3399,9 @@ void process_cpuid() if (debug) decode_misc_pwr_mgmt_msr(); + if (debug && has_slv_msrs(family, model)) + decode_c6_demotion_policy_msr(); + rapl_probe(family, model); perf_limit_reasons_probe(family, model);