perf auxtrace: Add auxtrace_cache__remove()

Add auxtrace_cache__remove(). Intel PT uses an auxtrace_cache to store
the results of code-walking, so that the same block of instructions does
not have to be decoded repeatedly. However, when there are text poke
events, the associated cache entries need to be removed.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org
Link: http://lore.kernel.org/lkml/20191025130000.13032-6-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/auxtrace.c

@@ -1457,6 +1457,34 @@ int auxtrace_cache__add(struct auxtrace_cache *c, u32 key,
 	return 0;
 }
 
+static struct auxtrace_cache_entry *auxtrace_cache__rm(struct auxtrace_cache *c,
+						       u32 key)
+{
+	struct auxtrace_cache_entry *entry;
+	struct hlist_head *hlist;
+	struct hlist_node *n;
+
+	if (!c)
+		return NULL;
+
+	hlist = &c->hashtable[hash_32(key, c->bits)];
+	hlist_for_each_entry_safe(entry, n, hlist, hash) {
+		if (entry->key == key) {
+			hlist_del(&entry->hash);
+			return entry;
+		}
+	}
+
+	return NULL;
+}
+
+void auxtrace_cache__remove(struct auxtrace_cache *c, u32 key)
+{
+	struct auxtrace_cache_entry *entry = auxtrace_cache__rm(c, key);
+
+	auxtrace_cache__free_entry(c, entry);
+}
+
 void *auxtrace_cache__lookup(struct auxtrace_cache *c, u32 key)
 {
 	struct auxtrace_cache_entry *entry;

tools/perf/util/auxtrace.h

@@ -489,6 +489,7 @@ void *auxtrace_cache__alloc_entry(struct auxtrace_cache *c);
 void auxtrace_cache__free_entry(struct auxtrace_cache *c, void *entry);
 int auxtrace_cache__add(struct auxtrace_cache *c, u32 key,
 			struct auxtrace_cache_entry *entry);
+void auxtrace_cache__remove(struct auxtrace_cache *c, u32 key);
 void *auxtrace_cache__lookup(struct auxtrace_cache *c, u32 key);
 
 struct auxtrace_record *auxtrace_record__init(struct evlist *evlist,