This patch add a test to measure the precise vtimer firing time.
Signed-off-by: Jingyi Wang <wangjingyi11@xxxxxxxxxx>
---
arm/timer.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arm/timer.c b/arm/timer.c
index f390e8e..1d5b3dc 100644
--- a/arm/timer.c
+++ b/arm/timer.c
@@ -16,6 +16,9 @@
#define ARCH_TIMER_CTL_IMASK (1 << 1)
#define ARCH_TIMER_CTL_ISTATUS (1 << 2)
+static u64 inject_time;
+static u64 receive_time;
+
static void *gic_ispendr;
static void *gic_isenabler;
static void *gic_icenabler;
@@ -149,6 +152,8 @@ static void irq_handler(struct pt_regs *regs)
u32 irqstat = gic_read_iar();
u32 irqnr = gic_iar_irqnr(irqstat);
+ receive_time = get_cntvct();
+
if (irqnr != GICC_INT_SPURIOUS)
gic_write_eoir(irqstat);
@@ -163,6 +168,11 @@ static void irq_handler(struct pt_regs *regs)
info->write_ctl(ARCH_TIMER_CTL_IMASK | ARCH_TIMER_CTL_ENABLE);
info->irq_received = true;
+
+ if (inject_time != 0)
+ report_info("vtimer latency: %ld cycles/10ms\n",
+ receive_time - inject_time);
+ inject_time = 0;
}
static bool gic_timer_pending(struct timer_info *info)
@@ -179,6 +189,7 @@ static bool test_cval_10msec(struct timer_info *info)
/* Program timer to fire in 10 ms */
before_timer = info->read_counter();
+ inject_time = get_cntvct();
info->write_cval(before_timer + time_10ms);
info->write_ctl(ARCH_TIMER_CTL_ENABLE);
isb();
--
2.19.1
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