bus: arm-ccn: Correct required arguments for XP PMU events

XP can provide events from two sources: watchpoints, observing traffic
on device ports and PMU looking at internal buses.

Unfortunately the sysfs definition of the PMU events was requiring
port number (instead of bus number) and direction (the buses are
unidirectional), as these fields were shared with the watchpoint event.

Although it does not introduce a major problem (port can be used as
bus alias and direction is simply ignored for XP PMU events), it's
better to fix it now, before external tools start depending on this
behaviour.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>

Documentation/arm/CCN.txt

@@ -18,13 +18,17 @@ and config2 fields of the perf_event_attr structure. The "events"
 directory provides configuration templates for all documented
 events, that can be used with perf tool. For example "xp_valid_flit"
 is an equivalent of "type=0x8,event=0x4". Other parameters must be
-explicitly specified. For events originating from device, "node"
-defines its index. All crosspoint events require "xp" (index),
-"port" (device port number) and "vc" (virtual channel ID) and
-"dir" (direction). Watchpoints (special "event" value 0xfe) also
-require comparator values ("cmp_l" and "cmp_h") and "mask", being
-index of the comparator mask.
+explicitly specified.
 
+For events originating from device, "node" defines its index.
+
+Crosspoint PMU events require "xp" (index), "bus" (bus number)
+and "vc" (virtual channel ID).
+
+Crosspoint watchpoint-based events (special "event" value 0xfe)
+require "xp" and "vc" as as above plus "port" (device port index),
+"dir" (transmit/receive direction), comparator values ("cmp_l"
+and "cmp_h") and "mask", being index of the comparator mask.
 Masks are defined separately from the event description
 (due to limited number of the config values) in the "cmp_mask"
 directory, with first 8 configurable by user and additional

drivers/bus/arm-ccn.c

@@ -213,6 +213,7 @@ static int arm_ccn_node_to_xp_port(int node)
 #define CCN_CONFIG_TYPE(_config)	(((_config) >> 8) & 0xff)
 #define CCN_CONFIG_EVENT(_config)	(((_config) >> 16) & 0xff)
 #define CCN_CONFIG_PORT(_config)	(((_config) >> 24) & 0x3)
+#define CCN_CONFIG_BUS(_config)		(((_config) >> 24) & 0x3)
 #define CCN_CONFIG_VC(_config)		(((_config) >> 26) & 0x7)
 #define CCN_CONFIG_DIR(_config)		(((_config) >> 29) & 0x1)
 #define CCN_CONFIG_MASK(_config)	(((_config) >> 30) & 0xf)
@@ -242,6 +243,7 @@ static CCN_FORMAT_ATTR(xp, "config:0-7");
 static CCN_FORMAT_ATTR(type, "config:8-15");
 static CCN_FORMAT_ATTR(event, "config:16-23");
 static CCN_FORMAT_ATTR(port, "config:24-25");
+static CCN_FORMAT_ATTR(bus, "config:24-25");
 static CCN_FORMAT_ATTR(vc, "config:26-28");
 static CCN_FORMAT_ATTR(dir, "config:29-29");
 static CCN_FORMAT_ATTR(mask, "config:30-33");
@@ -254,6 +256,7 @@ static struct attribute *arm_ccn_pmu_format_attrs[] = {
 	&arm_ccn_pmu_format_attr_type.attr.attr,
 	&arm_ccn_pmu_format_attr_event.attr.attr,
 	&arm_ccn_pmu_format_attr_port.attr.attr,
+	&arm_ccn_pmu_format_attr_bus.attr.attr,
 	&arm_ccn_pmu_format_attr_vc.attr.attr,
 	&arm_ccn_pmu_format_attr_dir.attr.attr,
 	&arm_ccn_pmu_format_attr_mask.attr.attr,
@@ -351,10 +354,14 @@ static ssize_t arm_ccn_pmu_event_show(struct device *dev,
 		break;
 	case CCN_TYPE_XP:
 		res += snprintf(buf + res, PAGE_SIZE - res,
-				",xp=?,port=?,vc=?,dir=?");
+				",xp=?,vc=?");
 		if (event->event == CCN_EVENT_WATCHPOINT)
 			res += snprintf(buf + res, PAGE_SIZE - res,
-					",cmp_l=?,cmp_h=?,mask=?");
+					",port=?,dir=?,cmp_l=?,cmp_h=?,mask=?");
+		else
+			res += snprintf(buf + res, PAGE_SIZE - res,
+					",bus=?");
+
 		break;
 	case CCN_TYPE_MN:
 		res += snprintf(buf + res, PAGE_SIZE - res, ",node=%d", ccn->mn_id);
@@ -1029,7 +1036,7 @@ static void arm_ccn_pmu_xp_event_config(struct perf_event *event)
 	hw->event_base = CCN_XP_DT_CONFIG__DT_CFG__XP_PMU_EVENT(hw->config_base);
 
 	id = (CCN_CONFIG_VC(event->attr.config) << 4) |
-			(CCN_CONFIG_PORT(event->attr.config) << 3) |
+			(CCN_CONFIG_BUS(event->attr.config) << 3) |
 			(CCN_CONFIG_EVENT(event->attr.config) << 0);
 
 	val = readl(source->base + CCN_XP_PMU_EVENT_SEL);