mISDN: improve bitops usage

This improves bitops usages in several points:

- Convert u64 to a proper bitmap declaration.  This enables to remove
  superfluous typecasting from 'u64' to 'unsigned long *'.

- Convert superfluous atomic bitops to non atomic bitops.  The bitmap
  is allocated on the stack and it is not accessed by any other threads,
  so using atomic bitops is not necessary.

- Use find_next_zero_bit and find_next_zero_bit instead of calling
  test_bit() for each bit.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/isdn/mISDN/tei.c b/drivers/isdn/mISDN/tei.c
index be88728f110643dbaef2794b8ad64143a7224b08..592f597d895181d0ce1e5dd697a7d37ab09f2ef3 100644 (file)
--- a/drivers/isdn/mISDN/tei.c
+++ b/drivers/isdn/mISDN/tei.c
@@ -250,7 +250,7 @@ tei_debug(struct FsmInst *fi, char *fmt, ...)
 static int
 get_free_id(struct manager *mgr)
 {
-       u64             ids = 0;
+       DECLARE_BITMAP(ids, 64) = { [0 ... BITS_TO_LONGS(64) - 1] = 0 };
        int             i;
        struct layer2   *l2;
 
@@ -261,11 +261,11 @@ get_free_id(struct manager *mgr)
                               __func__);
                        return -EBUSY;
                }
-               test_and_set_bit(l2->ch.nr, (u_long *)&ids);
+               __set_bit(l2->ch.nr, ids);
        }
-       for (i = 1; i < 64; i++)
-               if (!test_bit(i, (u_long *)&ids))
-                       return i;
+       i = find_next_zero_bit(ids, 64, 1);
+       if (i < 64)
+               return i;
        printk(KERN_WARNING "%s: more as 63 layer2 for one device\n",
               __func__);
        return -EBUSY;
@@ -274,7 +274,7 @@ get_free_id(struct manager *mgr)
 static int
 get_free_tei(struct manager *mgr)
 {
-       u64             ids = 0;
+       DECLARE_BITMAP(ids, 64) = { [0 ... BITS_TO_LONGS(64) - 1] = 0 };
        int             i;
        struct layer2   *l2;
 
@@ -288,11 +288,11 @@ get_free_tei(struct manager *mgr)
                        continue;
                i -= 64;
 
-               test_and_set_bit(i, (u_long *)&ids);
+               __set_bit(i, ids);
        }
-       for (i = 0; i < 64; i++)
-               if (!test_bit(i, (u_long *)&ids))
-                       return i + 64;
+       i = find_first_zero_bit(ids, 64);
+       if (i < 64)
+               return i + 64;
        printk(KERN_WARNING "%s: more as 63 dynamic tei for one device\n",
               __func__);
        return -1;