[S] Change in coreboot[main]: arch/arm64/arch_timer: Fix possible overflow in multiplication

[Yidi Lin (Code Review)]

Attention is currently required from: Julius Werner, Yu-Ping Wu.

Hello Julius Werner, Yu-Ping Wu,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/78800?usp=email

to look at the new patch set (#2).

Change subject: arch/arm64/arch_timer: Fix possible overflow in multiplication
......................................................................

arch/arm64/arch_timer: Fix possible overflow in multiplication

The value from raw_read_cntfrq_el0() could be large enough to cause
overflow when multiplied by 1000000. To prevent this, both 1000000 and
tfreq can be reduced by dividing them by their GCD.

BUG=b:307790895
TEST=emerge-geralt coreboot
TEST=boot to kernel and check the timestamps from `cbmem`

Change-Id: I366667de05392913150414f0fa9058725be71c52
Signed-off-by: Yidi Lin 
---
M src/arch/arm64/arch_timer.c
1 file changed, 15 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/00/78800/2