[PATCH V4 3/8] perf/x86/intel/uncore: correct fixed counter index check in generic code

From: kan . liang
Date: Thu Nov 02 2017 - 16:33:06 EST


From: Kan Liang <Kan.liang@xxxxxxxxx>

There is no index which is bigger than UNCORE_PMC_IDX_FIXED. The only
exception is client IMC uncore. It has customized function to deal with
the 'UNCORE_PMC_IDX_FIXED + 1' case. It does not touch the generic code.
For generic code, it is not correct to use >= to check fixed counter.
The code quality issue will bring problem when new counter index is
introduced.

Signed-off-by: Kan Liang <Kan.liang@xxxxxxxxx>
---

Changes since V3:
- Split the patch for generic change

arch/x86/events/intel/uncore.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index 1c5390f..3b8cd88 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -218,7 +218,7 @@ void uncore_perf_event_update(struct intel_uncore_box *box, struct perf_event *e
u64 prev_count, new_count, delta;
int shift;

- if (event->hw.idx >= UNCORE_PMC_IDX_FIXED)
+ if (event->hw.idx == UNCORE_PMC_IDX_FIXED)
shift = 64 - uncore_fixed_ctr_bits(box);
else
shift = 64 - uncore_perf_ctr_bits(box);
--
2.7.4