perf/x86: Fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
by explicitly adding a fallthrough pseudo-keyword as a replacement for
a /* fall through */ comment, instead of letting the code fall through
to the next case.

Notice that Clang doesn't recognize /* fall through */ comments as
implicit fall-through markings.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://github.com/KSPP/linux/issues/115

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index a88c94d6569315a7bd33a85cda5f0cff212d448f..550c5e7002b90bd787b556228b6d1e6f28b3490a 100644 (file)
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1174,7 +1174,7 @@ static inline void x86_assign_hw_event(struct perf_event *event,
        case INTEL_PMC_IDX_METRIC_BASE ... INTEL_PMC_IDX_METRIC_END:
                /* All the metric events are mapped onto the fixed counter 3. */
                idx = INTEL_PMC_IDX_FIXED_SLOTS;
-               /* fall through */
+               fallthrough;
        case INTEL_PMC_IDX_FIXED ... INTEL_PMC_IDX_FIXED_BTS-1:
                hwc->config_base = MSR_ARCH_PERFMON_FIXED_CTR_CTRL;
                hwc->event_base = MSR_ARCH_PERFMON_FIXED_CTR0 +