bitmap: Add bitmap_alloc(), bitmap_zalloc() and bitmap_free()

commit c42b65e363ce97a828f81b59033c3558f8fa7f70 upstream.

A lot of code become ugly because of open coding allocations for bitmaps.

Introduce three helpers to allow users be more clear of intention
and keep their code neat.

Note, due to multiple circular dependencies we may not provide
the helpers as inliners. For now we keep them exported and, perhaps,
at some point in the future we will sort out header inclusion and
inheritance.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 714ce4a5e31fd3ada68f0b15c2813cc07bfef3e5..39d47af6ca7bd3b08332b680e8b67a74ca81a4d3 100644 (file)
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -83,6 +83,14 @@
  * contain all bit positions from 0 to 'bits' - 1.
  */
 
+/*
+ * Allocation and deallocation of bitmap.
+ * Provided in lib/bitmap.c to avoid circular dependency.
+ */
+extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
+extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
+extern void bitmap_free(const unsigned long *bitmap);
+
 /*
  * lib/bitmap.c provides these functions:
  */

diff --git a/lib/bitmap.c b/lib/bitmap.c
index 814814397cce39b5b0a4aafa3571062a6468e8cf..bdf572d09b8fbfecf5098a654671410a0b6374e5 100644 (file)
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -12,6 +12,7 @@
 #include <linux/bitmap.h>
 #include <linux/bitops.h>
 #include <linux/bug.h>
+#include <linux/slab.h>
 
 #include <asm/page.h>
 #include <asm/uaccess.h>
@@ -1081,3 +1082,22 @@ void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int n
 }
 EXPORT_SYMBOL(bitmap_copy_le);
 #endif
+
+unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)
+{
+       return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long),
+                            flags);
+}
+EXPORT_SYMBOL(bitmap_alloc);
+
+unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)
+{
+       return bitmap_alloc(nbits, flags | __GFP_ZERO);
+}
+EXPORT_SYMBOL(bitmap_zalloc);
+
+void bitmap_free(const unsigned long *bitmap)
+{
+       kfree(bitmap);
+}
+EXPORT_SYMBOL(bitmap_free);