diff options
| author | Ionela Voinescu <ionela.voinescu@imgtec.com> | 2015-02-10 18:41:47 +0000 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2015-04-14 12:08:39 +0200 |
| commit | 7d16196a8e63cd714d6f3c44d558f645a78ec201 (patch) | |
| tree | 80f25ecfd5acfbee205a6a71a2e542c511383b79 /payloads/libpayload/drivers/timer | |
| parent | 0f58d0b941559c627153943891737cf8fb0a7430 (diff) | |
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 <reinauer@chromium.org>
Original-Commit-Id: 972b105f950d800fa44f27bce090f6b89a5a84b9
Original-Change-Id: Id67b14e9d9c2354bc417b6587b615d466690c9b7
Original-Signed-off-by: Ionela Voinescu <ionela.voinescu@imgtec.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/247642
Original-Reviewed-by: Daniel Ehrenberg <dehrenberg@chromium.org>
Reviewed-on: http://review.coreboot.org/9672
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Diffstat (limited to 'payloads/libpayload/drivers/timer')
| -rw-r--r-- | payloads/libpayload/drivers/timer/img_pistachio.c | 13 |
1 files changed, 12 insertions, 1 deletions
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; } |