/*      $OpenBSD: pcb.h,v 1.11 2015/05/05 02:13:46 guenther Exp $       */
/*      $NetBSD: pcb.h,v 1.5 1996/11/13 22:21:00 cgd Exp $      */

/*
 * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Author: Chris G. Demetriou
 * 
 * Permission to use, copy, modify and distribute this software and
 * its documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 
 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */

#ifndef _MACHINE_PCB_H_
#define _MACHINE_PCB_H_

#include <machine/frame.h>
#include <machine/reg.h>

#include <machine/alpha_cpu.h>

/*
 * PCB: process control block
 *
 * In this case, the hardware structure that is the defining element
 * for a process, and the additional state that must be saved by software
 * on a context switch.  Fields marked [HW] are mandated by hardware; fields
 * marked [SW] are for the software.
 *
 * It's said in the VMS PALcode section of the AARM that the pcb address
 * passed to the swpctx PALcode call has to be a physical address.  Not
 * knowing this (and trying a virtual) address proved this correct.
 * So we cache the physical address of the pcb in the md_proc struct.
 */
struct pcb {
        struct alpha_pcb pcb_hw;                /* PALcode defined */
        unsigned long   pcb_context[9];         /* s[0-6], ra, ps       [SW] */
        struct fpreg    pcb_fp;                 /* FP registers         [SW] */
        unsigned long   pcb_onfault;            /* for copy faults      [SW] */
        struct cpu_info *volatile pcb_fpcpu;    /* CPU with our FP state[SW] */
};

#ifdef _KERNEL
void savectx(struct pcb *);
#endif

#endif /* _MACHINE_PCB_H_ */