[PATCH 2/8] ARC: perf: cap the number of counters to hardware max of 32

From: Vineet Gupta
Date: Tue Jun 09 2015 - 08:20:17 EST


The number of counters in PCT can never be more than 32 (while countable
conditions could be 100+) for both ARCompact and ARCv2

Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
---
arch/arc/include/asm/perf_event.h | 5 +++--
arch/arc/kernel/perf_event.c | 4 ++--
2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/arc/include/asm/perf_event.h b/arch/arc/include/asm/perf_event.h
index ea43477f8a59..ca8c414738de 100644
--- a/arch/arc/include/asm/perf_event.h
+++ b/arch/arc/include/asm/perf_event.h
@@ -1,6 +1,7 @@
/*
* Linux performance counter support for ARC
*
+ * Copyright (C) 2014-2015 Synopsys, Inc. (www.synopsys.com)
* Copyright (C) 2011-2013 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
@@ -12,8 +13,8 @@
#ifndef __ASM_PERF_EVENT_H
#define __ASM_PERF_EVENT_H

-/* real maximum varies per CPU, this is the maximum supported by the driver */
-#define ARC_PMU_MAX_HWEVENTS 64
+/* Max number of counters that PCT block may ever have */
+#define ARC_PERF_MAX_COUNTERS 32

/* Max number of countable events that CPU may have */
#define ARC_PERF_MAX_EVENTS 256
diff --git a/arch/arc/kernel/perf_event.c b/arch/arc/kernel/perf_event.c
index 400965973bb0..18b074f63cb6 100644
--- a/arch/arc/kernel/perf_event.c
+++ b/arch/arc/kernel/perf_event.c
@@ -23,7 +23,7 @@ struct arc_pmu {
int counter_size; /* in bits */
int n_counters;
int n_events;
- unsigned long used_mask[BITS_TO_LONGS(ARC_PMU_MAX_HWEVENTS)];
+ unsigned long used_mask[BITS_TO_LONGS(ARC_PERF_MAX_COUNTERS)];
int ev_hw_idx[PERF_COUNT_ARC_HW_MAX];
u64 raw_events[ARC_PERF_MAX_EVENTS];
};
@@ -333,7 +333,7 @@ static int arc_pmu_device_probe(struct platform_device *pdev)
pr_err("This core does not have performance counters!\n");
return -ENODEV;
}
- BUG_ON(pct_bcr.c > ARC_PMU_MAX_HWEVENTS);
+ BUG_ON(pct_bcr.c > ARC_PERF_MAX_COUNTERS);

READ_BCR(ARC_REG_CC_BUILD, cc_bcr);
BUG_ON(!cc_bcr.v); /* Counters exist but No countable conditions ? */
--
1.9.1

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