the following patch was just integrated into master: commit 703aa978aa6db915fbc7fa42e5ca79cf31f57505 Author: Aaron Durbin adurbin@chromium.org Date: Wed May 1 15:55:14 2013 -0500
x86: harden tsc udelay() function
Since the TSC udelay() function can be used in SMM that means the TSC can count up to whatever value. The current loop was not handling TSC rollover properly. In most cases this should not matter as the TSC typically starts ticking at value 0, and it would take a very long time to roll it over. However, it is my understanding that this behavior is not guaranteed. Theoretically the TSC could start or be be written to with a large value that would cause the rollover.
Change-Id: I2f11a5bc4f27d5543e74f8224811fa91e4a55484 Signed-off-by: Aaron Durbin adurbin@chromium.org Reviewed-on: http://review.coreboot.org/3171 Reviewed-by: Stefan Reinauer stefan.reinauer@coreboot.org Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel paulepanter@users.sourceforge.net
Build-Tested: build bot (Jenkins) at Tue May 7 22:25:15 2013, giving +1 Reviewed-By: Stefan Reinauer stefan.reinauer@coreboot.org at Tue May 7 20:02:01 2013, giving +2 See http://review.coreboot.org/3171 for details.
-gerrit