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exynos: Simplify the monotonic timer implementation.

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The previous implementation was overly complicated, and when used in the
timestamp implementation produced some weird and broken results.

BUG=chrome-os-partner:19420
TEST=Built and booted on pit. Used cbmem to check the timestamps and saw that
they were now monotonically ascending and within reasonable bounds.
BRANCH=None

Change-Id: I3048028ddea0657b01b0c94f312764b38d1397e4
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://gerrit.chromium.org/gerrit/65302
Reviewed-by: Ronald G. Minnich <rminnich@chromium.org>
Commit-Queue: Stefan Reinauer <reinauer@google.com>
Reviewed-by: Stefan Reinauer <reinauer@google.com>
Tested-by: Stefan Reinauer <reinauer@google.com>
This commit is contained in:
Gabe Black 2013-08-09 00:56:40 -07:00 • committed by ChromeBot
commit 6a3fde9a5b
2 changed files with 8 additions and 48 deletions
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28
src/cpu/samsung/exynos5250/monotonic_timer.c
View file

@ -18,40 +18,20 @@
*/
#include <stdint.h>
#include <delay.h>
#include <timer.h>
#include "clk.h"
static struct monotonic_counter {
int initialized;
struct mono_time time;
uint64_t last_value;
} mono_counter;
static int initialized;
static const uint32_t clocks_per_usec = MCT_HZ/1000000;
void timer_monotonic_get(struct mono_time *mt)
{
uint64_t current_tick;
uint64_t usecs_elapsed;
if (!mono_counter.initialized) {
if (!initialized) {
mct_start();
mono_counter.last_value = mct_raw_value();
mono_counter.initialized = 1;
initialized = 1;
}
current_tick = mct_raw_value();
usecs_elapsed = (current_tick - mono_counter.last_value) /
clocks_per_usec;
/* Update current time and tick values only if a full tick occurred. */
if (usecs_elapsed) {
mono_time_add_usecs(&mono_counter.time, usecs_elapsed);
mono_counter.last_value = current_tick;
}
/* Save result. */
*mt = mono_counter.time;
mono_time_set_usecs(mt, mct_raw_value() / clocks_per_usec);
}

28
src/cpu/samsung/exynos5420/monotonic_timer.c
View file

@ -18,40 +18,20 @@
*/
#include <stdint.h>
#include <delay.h>
#include <timer.h>
#include "clk.h"
static struct monotonic_counter {
int initialized;
struct mono_time time;
uint64_t last_value;
} mono_counter;
static int initialized;
static const uint32_t clocks_per_usec = MCT_HZ/1000000;
void timer_monotonic_get(struct mono_time *mt)
{
uint64_t current_tick;
uint64_t usecs_elapsed;
if (!mono_counter.initialized) {
if (!initialized) {
mct_start();
mono_counter.last_value = mct_raw_value();
mono_counter.initialized = 1;
initialized = 1;
}
current_tick = mct_raw_value();
usecs_elapsed = (current_tick - mono_counter.last_value) /
clocks_per_usec;
/* Update current time and tick values only if a full tick occurred. */
if (usecs_elapsed) {
mono_time_add_usecs(&mono_counter.time, usecs_elapsed);
mono_counter.last_value = current_tick;
}
/* Save result. */
*mt = mono_counter.time;
mono_time_set_usecs(mt, mct_raw_value() / clocks_per_usec);
}