queue/arm64-perf-Correct-the-event-index-in-sysfs.patch

From fabef2fc9a81373331ccfb2556aba99e99035f2f Mon Sep 17 00:00:00 2001
From: Shaokun Zhang <zhangshaokun@hisilicon.com>
Date: Thu, 18 Jun 2020 21:35:44 +0800
Subject: [PATCH] arm64: perf: Correct the event index in sysfs

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@hisilicon.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1592487344-30555-3-git-send-email-zhangshaokun@hisilicon.com
[will: fixed formatting of 'if' condition]
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index 96e90e270042..1439cff99a28 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -154,7 +154,7 @@ armv8pmu_events_sysfs_show(struct device *dev,
 
 	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_RESOLVE(m) #m
@@ -303,10 +303,13 @@ armv8pmu_event_attr_is_visible(struct kobject *kobj,
 	    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;
 }
-- 
2.27.0