2 files changed, 18 insertions, 1 deletions

diff --git a/Documentation/arm/CCN.txt b/Documentation/arm/CCN.txt
index 3a7604874762..ffca443a19b4 100644
--- a/Documentation/arm/CCN.txt
+++ b/Documentation/arm/CCN.txt
@@ -45,7 +45,7 @@ Example of perf tool use:
 / # perf list | grep ccn
   ccn/cycles/                                        [Kernel PMU event]
 <...>
-  ccn/xp_valid_flit/                                 [Kernel PMU event]
+  ccn/xp_valid_flit,xp=?,port=?,vc=?,dir=?/          [Kernel PMU event]
 <...>
 
 / # perf stat -a -e ccn/cycles/,ccn/xp_valid_flit,xp=1,port=0,vc=1,dir=1/ \
diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c
index 3374dcb12f1e..572360f1f493 100644
--- a/drivers/bus/arm-ccn.c
+++ b/drivers/bus/arm-ccn.c
@@ -340,6 +340,23 @@ static ssize_t arm_ccn_pmu_event_show(struct device *dev,
         if (event->mask)
                 res += snprintf(buf + res, PAGE_SIZE - res, ",mask=0x%x",
                                 event->mask);
+
+        /* Arguments required by an event */
+        switch (event->type) {
+        case CCN_TYPE_CYCLES:
+                break;
+        case CCN_TYPE_XP:
+                res += snprintf(buf + res, PAGE_SIZE - res,
+                                ",xp=?,port=?,vc=?,dir=?");
+                if (event->event == CCN_EVENT_WATCHPOINT)
+                        res += snprintf(buf + res, PAGE_SIZE - res,
+                                        ",cmp_l=?,cmp_h=?,mask=?");
+                break;
+        default:
+                res += snprintf(buf + res, PAGE_SIZE - res, ",node=?");
+                break;
+        }
+
         res += snprintf(buf + res, PAGE_SIZE - res, "\n");
 
         return res;