xref: /freebsd-10.0-release/sys/sys/cpuset.h

/*-
 * Copyright (c) 2008,	Jeffrey Roberson <jeff@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 unmodified, 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 ``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 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: head/sys/sys/cpuset.h 176730 2008-03-02 07:39:22Z jeff $
 */

#ifndef _SYS_CPUSET_H_
#define	_SYS_CPUSET_H_

#ifdef _KERNEL
#define	CPU_SETSIZE	MAXCPU
#endif

#define	CPU_MAXSIZE	128

#ifndef	CPU_SETSIZE
#define	CPU_SETSIZE	CPU_MAXSIZE
#endif

#define	_NCPUBITS	(sizeof(long) * NBBY)	/* bits per mask */
#define	_NCPUWORDS	howmany(CPU_SETSIZE, _NCPUBITS)

typedef	struct _cpuset {
	long	__bits[howmany(CPU_SETSIZE, _NCPUBITS)];
} cpuset_t;

#define	__cpuset_mask(n)	((long)1 << ((n) % _NCPUBITS))
#define	CPU_CLR(n, p)	((p)->__bits[(n)/_NCPUBITS] &= ~__cpuset_mask(n))
#define	CPU_COPY(f, t)	(void)(*(t) = *(f))
#define	CPU_ISSET(n, p)	(((p)->__bits[(n)/_NCPUBITS] & __cpuset_mask(n)) != 0)
#define	CPU_SET(n, p)	((p)->__bits[(n)/_NCPUBITS] |= __cpuset_mask(n))
#define	CPU_ZERO(p) do {				\
	__size_t __i;					\
	for (__i = 0; __i < _NCPUWORDS; __i++)		\
		(p)->__bits[__i] = 0;			\
} while (0)

#define	CPU_EMPTY(p) __extension__ ({			\
	__size_t __i;					\
	for (__i = 0; __i < _NCPUWORDS; __i++)		\
		if ((p)->__bits[__i])			\
			break;				\
	__i == _NCPUWORDS;				\
})

#define	CPU_OR(d, s) do {				\
	__size_t __i;					\
	for (__i = 0; __i < _NCPUWORDS; __i++)		\
		(d)->__bits[__i] |= (s)->__bits[__i];	\
} while (0)

#define	CPU_AND(d, s) do {				\
	__size_t __i;					\
	for (__i = 0; __i < _NCPUWORDS; __i++)		\
		(d)->__bits[__i] &= (s)->__bits[__i];	\
} while (0)

#define	CPU_NAND(d, s) do {				\
	__size_t __i;					\
	for (__i = 0; __i < _NCPUWORDS; __i++)		\
		(d)->__bits[__i] &= ~(s)->__bits[__i];	\
} while (0)

/*
 * Valid cpulevel_t values.
 */
#define	CPU_LEVEL_ROOT		1	/* All system cpus. */
#define	CPU_LEVEL_CPUSET	2	/* Available cpus for which. */
#define	CPU_LEVEL_WHICH		3	/* Actual mask/id for which. */

/*
 * Valid cpuwhich_t values.
 */
#define	CPU_WHICH_TID		1	/* Specifies a thread id. */
#define	CPU_WHICH_PID		2	/* Specifies a process id. */
#define	CPU_WHICH_CPUSET	3	/* Specifies a set id. */

/*
 * Reserved cpuset identifiers.
 */
#define	CPUSET_INVALID	-1
#define	CPUSET_DEFAULT	0

#ifdef _KERNEL
LIST_HEAD(setlist, cpuset);

/*
 * cpusets encapsulate cpu binding information for one or more threads.
 *
 * 	a - Accessed with atomics.
 *	s - Set at creation, never modified.  Only a ref required to read.
 *	c - Locked internally by a cpuset lock.
 *
 * The bitmask is only modified while holding the cpuset lock.  It may be
 * read while only a reference is held but the consumer must be prepared
 * to deal with inconsistent results.
 */
struct cpuset {
	cpuset_t		cs_mask;	/* bitmask of valid cpus. */
	volatile u_int		cs_ref;		/* (a) Reference count. */
	int			cs_flags;	/* (s) Flags from below. */
	cpusetid_t		cs_id;		/* (s) Id or INVALID. */
	struct cpuset		*cs_parent;	/* (s) Pointer to our parent. */
	LIST_ENTRY(cpuset)	cs_link;	/* (c) All identified sets. */
	LIST_ENTRY(cpuset)	cs_siblings;	/* (c) Sibling set link. */
	struct setlist		cs_children;	/* (c) List of children. */
};

#define CPU_SET_ROOT    0x0001  /* Set is a root set. */
#define CPU_SET_RDONLY  0x0002  /* No modification allowed. */

struct cpuset *cpuset_thread0(void);
struct cpuset *cpuset_ref(struct cpuset *);
void cpuset_rel(struct cpuset *);
#else
__BEGIN_DECLS
int	cpuset(cpusetid_t *);
int	cpuset_setid(cpuwhich_t, id_t, cpusetid_t);
int	cpuset_getid(cpulevel_t, cpuwhich_t, id_t, cpusetid_t *);
int	cpuset_getaffinity(cpulevel_t, cpuwhich_t, id_t, int, cpuset_t *);
int	cpuset_setaffinity(cpulevel_t, cpuwhich_t, id_t, int, cpuset_t *);
__END_DECLS
#endif
#endif /* !_SYS_CPUSET_H_ */