linux-kernel - [PATCH v6 08/12] __cci_pmu_enable: Make counter sync optional

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Date:	Mon, 25 Jan 2016 11:21:13 +0000
From:	"Suzuki K. Poulose" <suzuki.poulose@....com>
To:	linux-arm-kernel@...ts.infradead.org
Cc:	mark.rutland@....com, punit.agrawal@....com, arm@...nel.org,
	linux-kernel@...r.kernel.org,
	"Suzuki K. Poulose" <suzuki.poulose@....com>
Subject: [PATCH v6 08/12] __cci_pmu_enable: Make counter sync optional

On CCI-500 writing to a counter requires turning the PMU on. So,
syncing the counter state should not be performed for such special cases,
while turning the PMU on. This patch makes the 'sync' operation based
on an input parameter to allow reuse of the __cci_pmu_enable() function,
rather than definig a new helper (and a corresponding helper for pmu_disable
to match the new helper for the sake of readability).

Cc: Mark Rutland <mark.rutland@....com>
Cc: Punit Agrawal <punit.agrawal@....com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@....com>
---
 drivers/bus/arm-cci.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
index 997ad36..9d700e1 100644
--- a/drivers/bus/arm-cci.c
+++ b/drivers/bus/arm-cci.c
@@ -88,6 +88,9 @@ static const struct of_device_id arm_cci_matches[] = {
 #define CCI_PMU_MAX_HW_CNTRS(model) \
 	((model)->num_hw_cntrs + (model)->fixed_hw_cntrs)
 
+#define CCI_CNTRS_SYNC		true
+#define CCI_CNTRS_NOSYNC	false
+
 /* Types of interfaces that can generate events */
 enum {
 	CCI_IF_SLAVE,
@@ -640,11 +643,12 @@ 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(struct cci_pmu *cci_pmu, bool sync)
 {
 	u32 val;
 
-	cci_pmu_sync_counters(cci_pmu);
+	if (sync)
+		cci_pmu_sync_counters(cci_pmu);
 
 	/* Enable all the PMU counters. */
 	val = readl_relaxed(cci_ctrl_base + CCI_PMCR) | CCI_PMCR_CEN;
@@ -960,7 +964,7 @@ 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(cci_pmu, CCI_CNTRS_SYNC);
 	raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
 
 	return IRQ_RETVAL(handled);
@@ -1004,7 +1008,7 @@ 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(cci_pmu, CCI_CNTRS_SYNC);
 	raw_spin_unlock_irqrestore(&hw_events->pmu_lock, flags);
 
 }
-- 
1.7.9.5