/*
 * ----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
 * can do whatever you want with this stuff. If we meet some day, and you think
 * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
 * ----------------------------------------------------------------------------
 *
 * $FreeBSD: src/sys/sys/smp.h,v 1.77 2004/03/27 18:21:24 marcel Exp $
 */

#ifndef _SYS_SMP_H_
#define _SYS_SMP_H_

#ifdef _KERNEL

#ifndef LOCORE

#ifdef SMP

/*
 * Topology of a NUMA or HTT system.
 *
 * The top level topology is an array of pointers to groups.  Each group
 * contains a bitmask of cpus in its group or subgroups.  It may also
 * contain a pointer to an array of child groups.
 *
 * The bitmasks at non leaf groups may be used by consumers who support
 * a smaller depth than the hardware provides.
 *
 * The topology may be omitted by systems where all CPUs are equal.
 */

struct cpu_group {
	cpumask_t cg_mask;		/* Mask of cpus in this group. */
	int	cg_count;		/* Count of cpus in this group. */
	int	cg_children;		/* Number of children groups. */
	struct cpu_group *cg_child;	/* Optional child group. */
};

struct cpu_top {
	int	ct_count;		/* Count of groups. */
	struct cpu_group *ct_group;	/* Array of pointers to cpu groups. */
};

extern struct cpu_top *smp_topology;
extern void (*cpustop_restartfunc)(void);
extern int smp_active;
extern int smp_cpus;
extern volatile cpumask_t started_cpus;
extern volatile cpumask_t stopped_cpus;
#endif /* SMP */

extern cpumask_t all_cpus;
extern u_int mp_maxid;
extern int mp_ncpus;
extern volatile int smp_started;

/*
 * Macro allowing us to determine whether a CPU is absent at any given
 * time, thus permitting us to configure sparse maps of cpuid-dependent
 * (per-CPU) structures.
 */
#define	CPU_ABSENT(x_cpu)	((all_cpus & (1 << (x_cpu))) == 0)

#ifdef SMP
/*
 * Machine dependent functions used to initialize MP support.
 *
 * The cpu_mp_probe() should check to see if MP support is present and return
 * zero if it is not or non-zero if it is.  If MP support is present, then
 * cpu_mp_start() will be called so that MP can be enabled.  This function
 * should do things such as startup secondary processors.  It should also
 * setup mp_ncpus, all_cpus, and smp_cpus.  It should also ensure that
 * smp_active and smp_started are initialized at the appropriate time.
 * Once cpu_mp_start() returns, machine independent MP startup code will be
 * executed and a simple message will be output to the console.  Finally,
 * cpu_mp_announce() will be called so that machine dependent messages about
 * the MP support may be output to the console if desired.
 *
 * The cpu_setmaxid() function is called very early during the boot process
 * so that the MD code may set mp_maxid to provide an upper bound on CPU IDs
 * that other subsystems may use.  If a platform is not able to determine
 * the exact maximum ID that early, then it may set mp_maxid to MAXCPU - 1.
 */
struct thread;

void	cpu_mp_announce(void);
int	cpu_mp_probe(void);
void	cpu_mp_setmaxid(void);
void	cpu_mp_start(void);

void	forward_signal(struct thread *);
void	forward_roundrobin(void);
int	restart_cpus(cpumask_t);
int	stop_cpus(cpumask_t);
void	smp_rendezvous_action(void);
#endif /* SMP */
void	smp_rendezvous(void (*)(void *), 
		       void (*)(void *),
		       void (*)(void *),
		       void *arg);
#endif /* !LOCORE */
#endif /* _KERNEL */
#endif /* _SYS_SMP_H_ */
