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Groups > linux.kernel > #1294094

[PATCH v4 01/12] arm-cci: Define CCI counter period

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Instead of hard coding the period we program on the PMU
counters, define a symbol.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
---
 drivers/bus/arm-cci.c |   19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
index ee47e6b..3786879 100644
--- a/drivers/bus/arm-cci.c
+++ b/drivers/bus/arm-cci.c
@@ -85,6 +85,14 @@ static const struct of_device_id arm_cci_matches[] = {
 #define CCI_PMU_CNTR_MASK		((1ULL << 32) -1)
 #define CCI_PMU_CNTR_LAST(cci_pmu)	(cci_pmu->num_cntrs - 1)
 
+/*
+ * The CCI PMU counters have a period of 2^32. To account for the
+ * possiblity of extreme interrupt latency we program for a period of
+ * half that. Hopefully we can handle the interrupt before another 2^31
+ * events occur and the counter overtakes its previous value.
+ */
+#define CCI_CNTR_PERIOD		(1UL << 31)
+
 #define CCI_PMU_MAX_HW_CNTRS(model) \
 	((model)->num_hw_cntrs + (model)->fixed_hw_cntrs)
 
@@ -797,15 +805,8 @@ static void pmu_read(struct perf_event *event)
 void pmu_event_set_period(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
-	/*
-	 * The CCI PMU counters have a period of 2^32. To account for the
-	 * possiblity of extreme interrupt latency we program for a period of
-	 * half that. Hopefully we can handle the interrupt before another 2^31
-	 * events occur and the counter overtakes its previous value.
-	 */
-	u64 val = 1ULL << 31;
-	local64_set(&hwc->prev_count, val);
-	pmu_write_counter(event, val);
+	local64_set(&hwc->prev_count, CCI_CNTR_PERIOD);
+	pmu_write_counter(event, CCI_CNTR_PERIOD);
 }
 
 static irqreturn_t pmu_handle_irq(int irq_num, void *dev)
-- 
1.7.9.5

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[PATCHv4 00/12] arm-cci: PMU updates "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-12-17 18:50 +0100
  [PATCH v4 09/12] arm-cci: Provide hook for writing to PMU counters "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-12-17 18:50 +0100
  [PATCH v4 08/12] arm-cci: Add routines to save/restore all counters "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-12-17 18:50 +0100
  [PATCH v4 11/12] arm-cci500: Rearrange PMU driver for code sharing with CCI-550 PMU "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-12-17 18:50 +0100
  [PATCH v4 10/12] arm-cci: CCI-500: Work around PMU counter writes "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-12-17 19:00 +0100
  [PATCH v4 02/12] arm-cci: Refactor pmu_write_counter "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-12-17 19:00 +0100
  [PATCH v4 01/12] arm-cci: Define CCI counter period "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-12-17 19:00 +0100
  [PATCH v4 06/12] arm-cci: Refactor CCI PMU enable/disable methods "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-12-17 19:00 +0100
  [PATCH v4 05/12] arm-cci: PMU: Add support for transactions "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-12-17 19:00 +0100
    Re: [PATCH v4 05/12] arm-cci: PMU: Add support for transactions Peter Zijlstra <peterz@infradead.org> - 2015-12-17 19:50 +0100
      Re: [PATCH v4 05/12] arm-cci: PMU: Add support for transactions "Suzuki K. Poulose" <Suzuki.Poulose@arm.com> - 2015-12-18 11:30 +0100
        Re: [PATCH v4 05/12] arm-cci: PMU: Add support for transactions Peter Zijlstra <peterz@infradead.org> - 2015-12-18 11:50 +0100
          Re: [PATCH v4 05/12] arm-cci: PMU: Add support for transactions "Suzuki K. Poulose" <Suzuki.Poulose@arm.com> - 2015-12-18 12:00 +0100
            Re: [PATCH v4 05/12] arm-cci: PMU: Add support for transactions Peter Zijlstra <peterz@infradead.org> - 2015-12-18 12:50 +0100
  [PATCH v4 07/12] arm-cci: Get the status of a counter "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-12-17 19:00 +0100
  [PATCH v4 03/12] arm-cci: Group writes to counter "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-12-17 19:00 +0100
  [PATCH v4 04/12] arm-cci: Fix the flags for pmu_start called from pmu_add "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-12-17 19:00 +0100
  [PATCH v4 12/12] arm-cci: CoreLink CCI-550 PMU driver "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-12-17 19:00 +0100

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