[PATCH 5.8 043/232] arm64: perf: Correct the event index in sysfs

[Greg Kroah-Hartman]

From: Shaokun Zhang <zhangshaokun@xxxxxxxxxxxxx>

commit 539707caa1a89ee4efc57b4e4231c20c46575ccc upstream.

When PMU event ID is equal or greater than 0x4000, it will be reduced
by 0x4000 and it is not the raw number in the sysfs. Let's correct it
and obtain the raw event ID.

Before this patch:
cat /sys/bus/event_source/devices/armv8_pmuv3_0/events/sample_feed
event=0x001
After this patch:
cat /sys/bus/event_source/devices/armv8_pmuv3_0/events/sample_feed
event=0x4001

Signed-off-by: Shaokun Zhang <zhangshaokun@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1592487344-30555-3-git-send-email-zhangshaokun@xxxxxxxxxxxxx
[will: fixed formatting of 'if' condition]
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/arm64/kernel/perf_event.c |   13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -155,7 +155,7 @@ armv8pmu_events_sysfs_show(struct device
 
 	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
 
-	return sprintf(page, "event=0x%03llx\n", pmu_attr->id);
+	return sprintf(page, "event=0x%04llx\n", pmu_attr->id);
 }
 
 #define ARMV8_EVENT_ATTR(name, config)						\
@@ -244,10 +244,13 @@ armv8pmu_event_attr_is_visible(struct ko
 	    test_bit(pmu_attr->id, cpu_pmu->pmceid_bitmap))
 		return attr->mode;
 
-	pmu_attr->id -= ARMV8_PMUV3_EXT_COMMON_EVENT_BASE;
-	if (pmu_attr->id < ARMV8_PMUV3_MAX_COMMON_EVENTS &&
-	    test_bit(pmu_attr->id, cpu_pmu->pmceid_ext_bitmap))
-		return attr->mode;
+	if (pmu_attr->id >= ARMV8_PMUV3_EXT_COMMON_EVENT_BASE) {
+		u64 id = pmu_attr->id - ARMV8_PMUV3_EXT_COMMON_EVENT_BASE;
+
+		if (id < ARMV8_PMUV3_MAX_COMMON_EVENTS &&
+		    test_bit(id, cpu_pmu->pmceid_ext_bitmap))
+			return attr->mode;
+	}
 
 	return 0;
 }