[PATCH v1 2/3] perf mmap: declare type for cpu mask of arbitrary length

[Alexey Budankov]

Declare a dedicated struct map_cpu_mask type for cpu masks of 
arbitrary length. Mask is available thru bits pointer and the 
mask length is kept in nbits field. mmap_cpu_mask_bytes() macro 
returns mask storage size in bytes.

Signed-off-by: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx>
---
 tools/perf/util/mmap.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
index bee4e83f7109..a218a0eb1466 100644
--- a/tools/perf/util/mmap.h
+++ b/tools/perf/util/mmap.h
@@ -15,6 +15,15 @@
 #include "event.h"
 
 struct aiocb;
+
+struct mmap_cpu_mask {
+	unsigned long *bits;
+	size_t nbits;
+};
+
+#define mmap_cpu_mask_bytes(m) \
+	(BITS_TO_LONGS(((struct mmap_cpu_mask *)m)->nbits) * sizeof(unsigned long))
+
 /**
  * struct mmap - perf's ring buffer mmap details
  *
-- 
2.20.1