Nico Weber 8a01be4849 Kernel: Add some CPU feature flags related to TSC ... In case we want to rely more on TSC in time keeping in the future, idk This adds: - RDTSCP, for when the RDTSCP instruction is available - CONSTANT_TSC, for when the TSC has a constant frequency, invariant under things like the CPU boosting its frequency. - NONSTOP_TSC, for when the TSC doesn't pause when the CPU enters sleep states. AMD cpus and newer intel cpus set the INVSTC bit (bit 8 in edx of extended cpuid 0x8000000008), which implies both CONSTANT_TSC and NONSTOP_TSC. Some older intel processors have CONSTANT_TSC but not NONSTOP_TSC; this is set based on cpu model checks. There isn't a ton of documentation on this, so this follows Linux terminology and http://blog.tinola.com/?e=54 CONSTANT_TSC: 39b3a79105 NONSTOP_TSC: 40fb17152c qemu disables invtsc (bit 8 in edx of extended cpuid 0x8000000008) by default even if the host cpu supports it. It can be enabled by running with `SERENITY_QEMU_CPU=host,migratable=off` set.		2020-10-08 10:00:39 +02:00
..
Boot	Kernel: Tell the bootloader to put us into graphics mode	2020-08-01 07:57:29 +02:00
CPU.cpp	Kernel: Add some CPU feature flags related to TSC	2020-10-08 10:00:39 +02:00
CPU.h	Kernel: Add some CPU feature flags related to TSC	2020-10-08 10:00:39 +02:00
Interrupts.h	Meta+Kernel: Make clang-format-10 clean	2020-09-25 21:18:17 +02:00
ISRStubs.h	Kernel: Add SMP IPI support	2020-07-06 17:07:44 +02:00
ProcessorInfo.cpp	Kernel: Add some CPU feature flags related to TSC	2020-10-08 10:00:39 +02:00
ProcessorInfo.h	Meta+Kernel: Make clang-format-10 clean	2020-09-25 21:18:17 +02:00