Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
tools/power x86_energy_perf_policy: Enhance HWP enable
On enabling HWP, preserve the reserved bits in MSR_PM_ENABLE.
Also, skip writing the MSR_PM_ENABLE if HWP is already enabled.
Signed-off-by: Len Brown <len.brown@intel.com>
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tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c
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tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c
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int enable_hwp_on_cpu(int cpu)
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{
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unsigned long long msr;
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unsigned long long old_msr, new_msr;
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get_msr(cpu, MSR_PM_ENABLE, &msr);
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put_msr(cpu, MSR_PM_ENABLE, 1);
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get_msr(cpu, MSR_PM_ENABLE, &old_msr);
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if (old_msr & 1)
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return 0; /* already enabled */
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new_msr = old_msr | 1;
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put_msr(cpu, MSR_PM_ENABLE, new_msr);
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if (verbose)
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printf("cpu%d: MSR_PM_ENABLE old: %d new: %d\n", cpu, (unsigned int) msr, 1);
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printf("cpu%d: MSR_PM_ENABLE old: %llX new: %llX\n", cpu, old_msr, new_msr);
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return 0;
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}