From 7d16196a8e63cd714d6f3c44d558f645a78ec201 Mon Sep 17 00:00:00 2001 From: Ionela Voinescu Date: Tue, 10 Feb 2015 18:41:47 +0000 Subject: [PATCH] pistachio: modify timer to account for CPU counter overflow Extended the 32bit CPU counter to 64bit by adding a static variable that takes into account CPU counter overflow. The varibale is updated everythime the timer_raw_value function is called so I assume that the function is called often enought to not miss an overflow of the CPU counter. BUG=chrome-os-partner:31438 TEST=tested on Pistachio bring up board; works as expected BRANCH=none Change-Id: I98bcc56e600dcff0c6da7c140dd34faec5e00885 Signed-off-by: Stefan Reinauer Original-Commit-Id: 972b105f950d800fa44f27bce090f6b89a5a84b9 Original-Change-Id: Id67b14e9d9c2354bc417b6587b615d466690c9b7 Original-Signed-off-by: Ionela Voinescu Original-Reviewed-on: https://chromium-review.googlesource.com/247642 Original-Reviewed-by: Daniel Ehrenberg Reviewed-on: http://review.coreboot.org/9672 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi --- payloads/libpayload/drivers/timer/img_pistachio.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/payloads/libpayload/drivers/timer/img_pistachio.c b/payloads/libpayload/drivers/timer/img_pistachio.c index ae53a9d0b1..9257bfef4c 100644 --- a/payloads/libpayload/drivers/timer/img_pistachio.c +++ b/payloads/libpayload/drivers/timer/img_pistachio.c @@ -27,5 +27,16 @@ uint64_t timer_hz(void) uint64_t timer_raw_value(void) { - return read_c0_count() * 2; + static uint64_t total_ticks = 0; + uint8_t overflow = 0; + uint32_t current_ticks = read_c0_count() * 2; + + /* It assumes only one overflow happened since the last call */ + if (current_ticks <= (uint32_t)total_ticks) + overflow = 1; + /* The least significant part(32 bits) of total_ticks will always + * become equal to current ticks */ + total_ticks = (((total_ticks >> 32) + overflow) << 32) + + current_ticks; + return total_ticks; }