4830c34648
implementations can provide a base zero ffs function if they wish. This changes #define RQB_FFS(mask) (ffs64(mask)) foo = RQB_FFS(mask) - 1; to #define RQB_FFS(mask) (ffs64(mask) - 1) foo = RQB_FFS(mask); On some platforms we can get the "- 1" for free, eg: those that use the C code for ffs64(). Reviewed by: jake (in principle)
59 lines
2.0 KiB
C
59 lines
2.0 KiB
C
/*
|
|
* Copyright (c) 2001 Jake Burkholder <jake@FreeBSD.org>
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#ifndef _MACHINE_RUNQ_H_
|
|
#define _MACHINE_RUNQ_H_
|
|
|
|
#define RQB_LEN (1UL) /* Number of priority status words. */
|
|
#define RQB_L2BPW (6UL) /* Log2(sizeof(rqb_word_t) * NBBY)). */
|
|
#define RQB_BPW (1UL<<RQB_L2BPW) /* Bits in an rqb_word_t. */
|
|
|
|
#define RQB_BIT(pri) (1UL << ((pri) & (RQB_BPW - 1)))
|
|
#define RQB_WORD(pri) ((pri) >> RQB_L2BPW)
|
|
|
|
#define RQB_FFS(word) (ffs64(word) - 1)
|
|
|
|
/*
|
|
* Type of run queue status word.
|
|
*/
|
|
typedef u_int64_t rqb_word_t;
|
|
|
|
static __inline u_long
|
|
ffs64(u_long mask)
|
|
{
|
|
u_long bit;
|
|
|
|
if (mask == 0)
|
|
return (0);
|
|
for (bit = 1; (mask & 1UL) == 0; bit++)
|
|
mask >>= 1UL;
|
|
return (bit);
|
|
}
|
|
|
|
#endif
|