[PATCH v2 7/7] clocksource: mips-gic-timer: Correct sched_clock width

From: Jiaxun Yang
Date: Wed Jun 12 2024 - 04:56:32 EST


Counter width of GIC is configurable and can be read from a
register.

Use width value from the register for sched_clock.

Reviewed-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>
Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
---
drivers/clocksource/mips-gic-timer.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c
index 7a03d94c028a..110347707ff9 100644
--- a/drivers/clocksource/mips-gic-timer.c
+++ b/drivers/clocksource/mips-gic-timer.c
@@ -19,6 +19,7 @@
static DEFINE_PER_CPU(struct clock_event_device, gic_clockevent_device);
static int gic_timer_irq;
static unsigned int gic_frequency;
+static unsigned int gic_count_width;
static bool __read_mostly gic_clock_unstable;

static void gic_clocksource_unstable(char *reason);
@@ -186,15 +187,14 @@ static void gic_clocksource_unstable(char *reason)

static int __init __gic_clocksource_init(void)
{
- unsigned int count_width;
int ret;

/* Set clocksource mask. */
- count_width = read_gic_config() & GIC_CONFIG_COUNTBITS;
- count_width >>= __ffs(GIC_CONFIG_COUNTBITS);
- count_width *= 4;
- count_width += 32;
- gic_clocksource.mask = CLOCKSOURCE_MASK(count_width);
+ gic_count_width = read_gic_config() & GIC_CONFIG_COUNTBITS;
+ gic_count_width >>= __ffs(GIC_CONFIG_COUNTBITS);
+ gic_count_width *= 4;
+ gic_count_width += 32;
+ gic_clocksource.mask = CLOCKSOURCE_MASK(gic_count_width);

/* Calculate a somewhat reasonable rating value. */
if (mips_cm_revision() >= CM_REV_CM3 || !IS_ENABLED(CONFIG_CPU_FREQ))
@@ -264,7 +264,7 @@ static int __init gic_clocksource_of_init(struct device_node *node)
if (mips_cm_revision() >= CM_REV_CM3 || !IS_ENABLED(CONFIG_CPU_FREQ)) {
sched_clock_register(mips_cm_is64 ?
gic_read_count_64 : gic_read_count_2x32,
- 64, gic_frequency);
+ gic_count_width, gic_frequency);
}

return 0;

--
2.43.0