perf/x86/pt, coresight: Clean up address filter structure

This is a cosmetic patch that deals with the address filter structure's
ambiguous fields 'filter' and 'range'. The former stands to mean that the
filter's *action* should be to filter the traces to its address range if
it's set or stop tracing if it's unset. This is confusing and hard on the
eyes, so this patch replaces it with 'action' enum. The 'range' field is
completely redundant (meaning that the filter is an address range as
opposed to a single address trigger), as we can use zero size to mean the
same thing.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20180329120648.11902-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 26 insertions, 33 deletions

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 8a0ad77..4e5ed65 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -393,35 +393,26 @@ static int etm_addr_filters_validate(struct list_head *filters)
 		if (++index > ETM_ADDR_CMP_MAX)
 			return -EOPNOTSUPP;
 
+		/* filter::size==0 means single address trigger */
+		if (filter->size) {
+			/*
+			 * The existing code relies on START/STOP filters
+			 * being address filters.
+			 */
+			if (filter->action == PERF_ADDR_FILTER_ACTION_START ||
+			    filter->action == PERF_ADDR_FILTER_ACTION_STOP)
+				return -EOPNOTSUPP;
+
+			range = true;
+		} else
+			address = true;
+
 		/*
-		 * As taken from the struct perf_addr_filter documentation:
-		 *	@range:	1: range, 0: address
-		 *
 		 * At this time we don't allow range and start/stop filtering
 		 * to cohabitate, they have to be mutually exclusive.
 		 */
-		if ((filter->range == 1) && address)
+		if (range && address)
 			return -EOPNOTSUPP;
-
-		if ((filter->range == 0) && range)
-			return -EOPNOTSUPP;
-
-		/*
-		 * For range filtering, the second address in the address
-		 * range comparator needs to be higher than the first.
-		 * Invalid otherwise.
-		 */
-		if (filter->range && filter->size == 0)
-			return -EINVAL;
-
-		/*
-		 * Everything checks out with this filter, record what we've
-		 * received before moving on to the next one.
-		 */
-		if (filter->range)
-			range = true;
-		else
-			address = true;
 	}
 
 	return 0;
@@ -441,18 +432,20 @@ static void etm_addr_filters_sync(struct perf_event *event)
 		stop = start + filter->size;
 		etm_filter = &filters->etm_filter[i];
 
-		if (filter->range == 1) {
+		switch (filter->action) {
+		case PERF_ADDR_FILTER_ACTION_FILTER:
 			etm_filter->start_addr = start;
 			etm_filter->stop_addr = stop;
 			etm_filter->type = ETM_ADDR_TYPE_RANGE;
-		} else {
-			if (filter->filter == 1) {
-				etm_filter->start_addr = start;
-				etm_filter->type = ETM_ADDR_TYPE_START;
-			} else {
-				etm_filter->stop_addr = stop;
-				etm_filter->type = ETM_ADDR_TYPE_STOP;
-			}
+			break;
+		case PERF_ADDR_FILTER_ACTION_START:
+			etm_filter->start_addr = start;
+			etm_filter->type = ETM_ADDR_TYPE_START;
+			break;
+		case PERF_ADDR_FILTER_ACTION_STOP:
+			etm_filter->stop_addr = stop;
+			etm_filter->type = ETM_ADDR_TYPE_STOP;
+			break;
 		}
 		i++;
 	}