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Subject[PATCH 09/13] arm-cci: Add helper to enable PMU without synchornising counters
Date
On CCI-500 writing to a counter requires turning the PMU on. So,
synchronising the counter state should not be performed for such special cases,
while turning the PMU on. This patch adds a helper, __cci_pmu_enable_nosync(),
without flushing the counter states.

Cc: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
drivers/bus/arm-cci.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
index 7ce7da0..bcc4c59 100644
--- a/drivers/bus/arm-cci.c
+++ b/drivers/bus/arm-cci.c
@@ -640,18 +640,23 @@ void cci_pmu_sync_counters(struct cci_pmu *cci_pmu)
}

/* Should be called with cci_pmu->hw_events->pmu_lock held */
-static void __cci_pmu_enable(struct cci_pmu *cci_pmu)
+static void __cci_pmu_enable_nosync(struct cci_pmu *cci_pmu)
{
u32 val;

- cci_pmu_sync_counters(cci_pmu);
-
/* Enable all the PMU counters. */
val = readl_relaxed(cci_ctrl_base + CCI_PMCR) | CCI_PMCR_CEN;
writel(val, cci_ctrl_base + CCI_PMCR);
}

/* Should be called with cci_pmu->hw_events->pmu_lock held */
+static void __cci_pmu_enable_sync(struct cci_pmu *cci_pmu)
+{
+ cci_pmu_sync_counters(cci_pmu);
+ __cci_pmu_enable_nosync(cci_pmu);
+}
+
+/* Should be called with cci_pmu->hw_events->pmu_lock held */
static void __cci_pmu_disable(void)
{
u32 val;
@@ -960,7 +965,7 @@ static irqreturn_t pmu_handle_irq(int irq_num, void *dev)
}

/* Enable the PMU and sync possibly overflowed counters */
- __cci_pmu_enable(cci_pmu);
+ __cci_pmu_enable_sync(cci_pmu);
raw_spin_unlock_irqrestore(&events->pmu_lock, flags);

return IRQ_RETVAL(handled);
@@ -1004,7 +1009,7 @@ static void cci_pmu_enable(struct pmu *pmu)
return;

raw_spin_lock_irqsave(&hw_events->pmu_lock, flags);
- __cci_pmu_enable(cci_pmu);
+ __cci_pmu_enable_sync(cci_pmu);
raw_spin_unlock_irqrestore(&hw_events->pmu_lock, flags);

}
--
1.7.9.5
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