[PATCH 3.18 15/85] perf/x86/intel/uncore: Correct fixed counter index check for NHM

[Greg Kroah-Hartman]

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Kan Liang <kan.liang@xxxxxxxxx>

[ Upstream commit d71f11c076c420c4e2fceb4faefa144e055e0935 ]

For Nehalem and Westmere, there is only one fixed counter for W-Box.
There is no index which is bigger than UNCORE_PMC_IDX_FIXED.
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>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: acme@xxxxxxxxxx
Cc: eranian@xxxxxxxxxx
Link: http://lkml.kernel.org/r/1525371913-10597-2-git-send-email-kan.liang@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/x86/kernel/cpu/perf_event_intel_uncore_nhmex.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/perf_event_intel_uncore_nhmex.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore_nhmex.c
@@ -240,7 +240,7 @@ static void nhmex_uncore_msr_enable_even
 {
 	struct hw_perf_event *hwc = &event->hw;
 
-	if (hwc->idx >= UNCORE_PMC_IDX_FIXED)
+	if (hwc->idx == UNCORE_PMC_IDX_FIXED)
 		wrmsrl(hwc->config_base, NHMEX_PMON_CTL_EN_BIT0);
 	else if (box->pmu->type->event_mask & NHMEX_PMON_CTL_EN_BIT0)
 		wrmsrl(hwc->config_base, hwc->config | NHMEX_PMON_CTL_EN_BIT22);