libperf: Add 'struct perf_mmap_param'

Add libperf's version of mmap params 'struct perf_mmap_param' object
with the basics: 'prot' and 'mask'.  Encapsulate it in the current
'struct mmap_params' object.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20191007125344.14268-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/lib/include/internal/mmap.h

@@ -29,6 +29,11 @@ struct perf_mmap {
 	char		 event_copy[PERF_SAMPLE_MAX_SIZE] __aligned(8);
 };
 
+struct perf_mmap_param {
+	int	prot;
+	int	mask;
+};
+
 void perf_mmap__init(struct perf_mmap *map, bool overwrite);
 
 #endif /* __LIBPERF_INTERNAL_MMAP_H */

tools/perf/util/evlist.c

@@ -667,7 +667,7 @@ static int evlist__mmap_per_evsel(struct evlist *evlist, int idx,
 		int fd;
 		int cpu;
 
-		mp->prot = PROT_READ | PROT_WRITE;
+		mp->core.prot = PROT_READ | PROT_WRITE;
 		if (evsel->core.attr.write_backward) {
 			output = _output_overwrite;
 			maps = evlist->overwrite_mmap;
@@ -680,7 +680,7 @@ static int evlist__mmap_per_evsel(struct evlist *evlist, int idx,
 				if (evlist->bkw_mmap_state == BKW_MMAP_NOTREADY)
 					perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_RUNNING);
 			}
-			mp->prot &= ~PROT_WRITE;
+			mp->core.prot &= ~PROT_WRITE;
 		}
 
 		if (evsel->core.system_wide && thread)
@@ -921,8 +921,12 @@ int evlist__mmap_ex(struct evlist *evlist, unsigned int pages,
 	 * Its value is decided by evsel's write_backward.
 	 * So &mp should not be passed through const pointer.
 	 */
-	struct mmap_params mp = { .nr_cblocks = nr_cblocks, .affinity = affinity, .flush = flush,
-				  .comp_level = comp_level };
+	struct mmap_params mp = {
+		.nr_cblocks	= nr_cblocks,
+		.affinity	= affinity,
+		.flush		= flush,
+		.comp_level	= comp_level
+	};
 
 	if (!evlist->mmap)
 		evlist->mmap = evlist__alloc_mmap(evlist, false);
@@ -934,7 +938,7 @@ int evlist__mmap_ex(struct evlist *evlist, unsigned int pages,
 
 	evlist->core.mmap_len = evlist__mmap_size(pages);
 	pr_debug("mmap size %zuB\n", evlist->core.mmap_len);
-	mp.mask = evlist->core.mmap_len - page_size - 1;
+	mp.core.mask = evlist->core.mmap_len - page_size - 1;
 
 	auxtrace_mmap_params__init(&mp.auxtrace_mp, evlist->core.mmap_len,
 				   auxtrace_pages, auxtrace_overwrite);

tools/perf/util/mmap.c

@@ -370,8 +370,8 @@ int perf_mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, int cpu)
 	 */
 	refcount_set(&map->core.refcnt, 2);
 	map->core.prev = 0;
-	map->core.mask = mp->mask;
-	map->core.base = mmap(NULL, perf_mmap__mmap_len(map), mp->prot,
+	map->core.mask = mp->core.mask;
+	map->core.base = mmap(NULL, perf_mmap__mmap_len(map), mp->core.prot,
 			 MAP_SHARED, fd, 0);
 	if (map->core.base == MAP_FAILED) {
 		pr_debug2("failed to mmap perf event ring buffer, error %d\n",

tools/perf/util/mmap.h

@@ -37,7 +37,8 @@ struct mmap {
 };
 
 struct mmap_params {
-	int prot, mask, nr_cblocks, affinity, flush, comp_level;
+	struct perf_mmap_param core;
+	int nr_cblocks, affinity, flush, comp_level;
 	struct auxtrace_mmap_params auxtrace_mp;
 };