idr: remove length restriction from idr_layer->bitmap

Currently, idr->bitmap is declared as an unsigned long which restricts
the number of bits an idr_layer can contain.  All bitops can handle
arbitrary positive integer bit number and there's no reason for this
restriction.

Declare idr_layer->bitmap using DECLARE_BITMAP() instead of a single
unsigned long.

* idr_layer->bitmap is now an array.  '&' dropped from params to
  bitops.

* Replaced "== IDR_FULL" tests with bitmap_full() and removed
  IDR_FULL.

* Replaced find_next_bit() on ~bitmap with find_next_zero_bit().

* Replaced "bitmap = 0" with bitmap_clear().

This patch doesn't (or at least shouldn't) introduce any behavior
changes.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 11 deletions

diff --git a/include/linux/idr.h b/include/linux/idr.h
index 99b0ce533f0e..63aa542da49b 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -19,18 +19,8 @@
 
 #if BITS_PER_LONG == 32
 # define IDR_BITS 5
-# define IDR_FULL 0xfffffffful
-/* We can only use two of the bits in the top level because there is
-   only one possible bit in the top level (5 bits * 7 levels = 35
-   bits, but you only use 31 bits in the id). */
-# define TOP_LEVEL_FULL (IDR_FULL >> 30)
 #elif BITS_PER_LONG == 64
 # define IDR_BITS 6
-# define IDR_FULL 0xfffffffffffffffful
-/* We can only use two of the bits in the top level because there is
-   only one possible bit in the top level (6 bits * 6 levels = 36
-   bits, but you only use 31 bits in the id). */
-# define TOP_LEVEL_FULL (IDR_FULL >> 62)
 #else
 # error "BITS_PER_LONG is not 32 or 64"
 #endif
@@ -39,7 +29,7 @@
 #define IDR_MASK ((1 << IDR_BITS)-1)
 
 struct idr_layer {
-        unsigned long           bitmap; /* A zero bit means "space here" */
+        DECLARE_BITMAP(bitmap, IDR_SIZE); /* A zero bit means "space here" */
         struct idr_layer __rcu  *ary[1<<IDR_BITS];
         int                     count;  /* When zero, we can release it */
         int                     layer;  /* distance from leaf */