diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index 99aba3c964cb..39cb10ec596e 100644
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -346,11 +346,15 @@ static u64 get_ibs_op_count(u64 config)
 {
 	u64 count = 0;
 
+	/*
+	 * If the internal 27-bit counter rolled over, the count is MaxCnt
+	 * and the lower 7 bits of CurCnt are randomized.
+	 * Otherwise CurCnt has the full 27-bit current counter value.
+	 */
 	if (config & IBS_OP_VAL)
-		count += (config & IBS_OP_MAX_CNT) << 4; /* cnt rolled over */
-
-	if (ibs_caps & IBS_CAPS_RDWROPCNT)
-		count += (config & IBS_OP_CUR_CNT) >> 32;
+		count = (config & IBS_OP_MAX_CNT) << 4;
+	else if (ibs_caps & IBS_CAPS_RDWROPCNT)
+		count = (config & IBS_OP_CUR_CNT) >> 32;
 
 	return count;
 }