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

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>

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 1ee46f4922676e02abe76a62866d5fe73532da84..acf5e8df3504fc347cc1bdac552c4f631c55a6dd 100644 (file)
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -104,6 +104,14 @@
  * 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 a42eff7e8c48bd81dd3db841a1e04f1672980b91..5b476d8414be43cc449fe27e3ecac7f2c047ceec 100644 (file)
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -13,6 +13,7 @@
 #include <linux/bitops.h>
 #include <linux/bug.h>
 #include <linux/kernel.h>
+#include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/uaccess.h>
 
@@ -1128,6 +1129,25 @@ 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);
+
 #if BITS_PER_LONG == 64
 /**
  * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap