Compute the number of ticks to wait to measure TSC frequency.
Instead of (ACPI_TIMER_FREQUENCY / 10000) = 357 and 357 * 10000 = 3570000,
use 363 * 9861 = 3579543 Hz which is within 2 Hz of ACPI_TIMER_FREQUENCY.
363 counts is a calibration time of 101.4 uS.
The idea comes from Michael and Paolo.
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul A Lohr <paul.a.lohr@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Minimize the code overhead between the two TSC reads by adding
new internal API to calculate TSC Frequency instead of reusing
MicroSecondDelay ().
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Paul A Lohr <paul.a.lohr@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Two library instances are added to support BASE type and DXE type. Those libraries provides basic timer support using the ACPI timer hardware. The performance counter features are provided by the processors time stamp counter.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Gao, Liming <liming.gao@intel.com>
Reviewed-by: Kinney, Michael D <michael.d.kinney@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15803 6f19259b-4bc3-4df7-8a09-765794883524
Star Zeng
Gao, Liming