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authorIonela Voinescu <ionela.voinescu@imgtec.com>2015-02-10 18:41:47 +0000
committerPatrick Georgi <pgeorgi@google.com>2015-04-14 12:08:39 +0200
commit7d16196a8e63cd714d6f3c44d558f645a78ec201 (patch)
tree80f25ecfd5acfbee205a6a71a2e542c511383b79 /payloads
parent0f58d0b941559c627153943891737cf8fb0a7430 (diff)
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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')
-rw-r--r--payloads/libpayload/drivers/timer/img_pistachio.c13
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 ae53a9d0b..9257bfef4 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;
}