LLVM ignores everything inside the if statement and doesn't generate
errors, but GCC does, resulting in the following:
drivers/perf/arm_pmuv3.c: In function armv8pmu_set_event_filter:
include/linux/bits.h:34:29: error: left shift count >= width of type [-Werror=shift-count-overflow]
34 | (((~UL(0)) - (UL(1) << (l)) + 1) & \
Fix it by changing the if to #if. This results in an unused function
warning for armv8pmu_event_threshold_control(), so suppress that too.
Fixes: 816c26754447 ("arm64: perf: Add support for event counting threshold")
Signed-off-by: James Clark <james.clark@xxxxxxx>
---
drivers/perf/arm_pmuv3.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c
index 3ed2086cefc3..8aa23878019a 100644
--- a/drivers/perf/arm_pmuv3.c
+++ b/drivers/perf/arm_pmuv3.c
@@ -338,7 +338,7 @@ static bool armv8pmu_event_want_user_access(struct perf_event *event)
return ATTR_CFG_GET_FLD(&event->attr, rdpmc);
}
-static u8 armv8pmu_event_threshold_control(struct perf_event_attr *attr)
+static __maybe_unused u8 armv8pmu_event_threshold_control(struct perf_event_attr *attr)
{
u8 th_compare = ATTR_CFG_GET_FLD(attr, threshold_compare);
u8 th_count = ATTR_CFG_GET_FLD(attr, threshold_count);
@@ -1040,11 +1040,13 @@ static int armv8pmu_set_event_filter(struct hw_perf_event *event,
return -EINVAL;
}
- if (IS_ENABLED(CONFIG_ARM64) && th) {
+#if IS_ENABLED(CONFIG_ARM64)
+ if (th) {
config_base |= FIELD_PREP(ARMV8_PMU_EVTYPE_TH, th);
config_base |= FIELD_PREP(ARMV8_PMU_EVTYPE_TC,
armv8pmu_event_threshold_control(attr));
}
+#endif
/*
* Install the filter into config_base as this is used to
--
2.34.1
