1/*	$NetBSD: pcb.h,v 1.16 2009/10/13 22:41:57 pooka Exp $ */
  2
  3/*
  4 * Copyright (c) 1992, 1993
  5 *	The Regents of the University of California.  All rights reserved.
  6 *
  7 * This software was developed by the Computer Systems Engineering group
  8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
  9 * contributed to Berkeley.
 10 *
 11 * All advertising materials mentioning features or use of this software
 12 * must display the following acknowledgement:
 13 *	This product includes software developed by the University of
 14 *	California, Lawrence Berkeley Laboratory.
 15 *
 16 * Redistribution and use in source and binary forms, with or without
 17 * modification, are permitted provided that the following conditions
 18 * are met:
 19 * 1. Redistributions of source code must retain the above copyright
 20 *    notice, this list of conditions and the following disclaimer.
 21 * 2. Redistributions in binary form must reproduce the above copyright
 22 *    notice, this list of conditions and the following disclaimer in the
 23 *    documentation and/or other materials provided with the distribution.
 24 * 3. Neither the name of the University nor the names of its contributors
 25 *    may be used to endorse or promote products derived from this software
 26 *    without specific prior written permission.
 27 *
 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 31 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 38 * SUCH DAMAGE.
 39 *
 40 *	@(#)pcb.h	8.1 (Berkeley) 6/11/93
 41 */
 42
 43/*
 44 * Copyright (c) 1996-2002 Eduardo Horvath.  All rights reserved.
 45 *
 46 * Redistribution and use in source and binary forms, with or without
 47 * modification, are permitted provided that the following conditions
 48 * are met:
 49 * 1. Redistributions of source code must retain the above copyright
 50 *    notice, this list of conditions and the following disclaimer.
 51 * 2. Redistributions in binary form must reproduce the above copyright
 52 *    notice, this list of conditions and the following disclaimer in the
 53 *    documentation and/or other materials provided with the distribution.
 54 * 3. Neither the name of the author nor the names of its contributors
 55 *    may be used to endorse or promote products derived from this software
 56 *    without specific prior written permission.
 57 *
 58 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 59 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 60 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 61 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 62 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 63 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 64 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 65 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 66 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 67 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 68 * SUCH DAMAGE.
 69 *
 70 *	@(#)pcb.h	8.1 (Berkeley) 6/11/93
 71 */
 72
 73#ifndef _SPARC64_PCB_H_
 74#define _SPARC64_PCB_H_
 75
 76#include <machine/reg.h>
 77
 78#ifdef notyet
 79#define	PCB_MAXWIN	32	/* architectural limit */
 80#else
 81#define	PCB_MAXWIN	8	/* worried about u area sizes ... */
 82#endif
 83
 84/*
 85 * SPARC Process Control Block.
 86 *
 87 * pcb_uw is positive if there are any user windows that are
 88 * are currently in the CPU windows rather than on the user
 89 * stack.  Whenever we are running in the kernel with traps
 90 * enabled, we decrement pcb_uw for each ``push'' of a CPU
 91 * register window into the stack, and we increment it for
 92 * each ``pull'' from the stack into the CPU.  (If traps are
 93 * disabled, or if we are in user mode, pcb_uw is junk.)
 94 *
 95 * To ease computing pcb_uw on traps from user mode, we keep track
 96 * of the log base 2 of the single bit that is set in %wim.
 97 *
 98 * If an overflow occurs while the associated user stack pages
 99 * are invalid (paged out), we have to store the registers
100 * in a page that is locked in core while the process runs,
101 * i.e., right here in the pcb.  We also need the stack pointer
102 * for the last such window (but only the last, as the others
103 * are in each window) and the count of windows saved.  We
104 * cheat by having a whole window structure for that one %sp.
105 * Thus, to save window pcb_rw[i] to memory, we write it at
106 * pcb_rw[i + 1].rw_in[6].
107 *
108 * pcb_nsaved has three `kinds' of values.  If 0, it means no
109 * registers are in the PCB (though if pcb_uw is positive,
110 * there may be the next time you look).  If positive, it means
111 * there are no user registers in the CPU, but there are some
112 * saved in pcb_rw[].  As a special case, traps that needed
113 * assistance to pull user registers from the stack also store
114 * the registers in pcb_rw[], and set pcb_nsaved to -1.  This
115 * special state is normally short-term: it can only last until the
116 * trap returns, and it can never persist across entry to user code.
117 */
118/*
119 * v9 addendum:
120 *
121 * Window handling between v8 and v9 has changed somewhat.  There
122 * is no %wim.  Instead, we have a %cwp, %cansave, %canrestore,
123 * %cleanwin, and %otherwin.  By definition:
124 *
125 *	 %cansave + %canrestore + %otherwin = NWINDOWS - 2
126 *
127 * In addition, %cleanwin >= %canrestore since restorable windows
128 * are considered clean.  This means that by storing %canrestore
129 * and %otherwin, we should be able to compute the values of all
130 * the other registers.
131 *
132 * The only other register we need to save is %cwp because it cannot
133 * be trivially computed from the other registers.  The %cwp is
134 * stored in the %tstate register, but if the machine was in a register
135 * window spill/fill handler, the value of that %cwp may be off by 
136 * as much as 2 register windows.  We will also store %cwp.  [We will
137 * try to steal pcb_uw or pcb_nsaved for this purpose eventually.]
138 *
139 * To calculate what registers are in the pcb, start with pcb_cwp
140 * and proceed to (pcb_cwp - pcb_canrestore) % NWINDOWS.  These should
141 * be saved to their appropriate register windows.  The client routine
142 * (trap handler) is responsible for saving pcb_cwp + 1 [%o1-%o7] in
143 * the trap frame or on the stack.
144 *
145 *
146 * Even more addendum:
147 *
148 * With the new system for keeping track of register windows we don't
149 * care about anything other than pcb_uw which keeps track of how many
150 * full windows we have.  As soon as a flush traps, we dump all user
151 * windows to the pcb, handle the fault, then restore all user windows.
152 *
153 * XXX we are using pcb_nsaved as the counter.  pcb_uw is still a mask.  
154 * change this as soon as the new scheme is debugged.
155 */
156struct pcb {
157	uint64_t	pcb_sp;		/* sp (%o6) when switch() was called */
158	uint64_t	pcb_pc;		/* pc (%o7) when switch() was called */
159	void *	pcb_onfault;	/* for copyin/out */
160	short	pcb_pstate;	/* %pstate when switch() was called -- may be useful if we support multiple memory models */
161	char	pcb_nsaved;	/* number of windows saved in pcb */
162
163	/* The rest is probably not needed except for pcb_rw */
164	char	pcb_cwp;	/* %cwp when switch() was called */
165	char	pcb_pil;	/* %pil when switch() was called -- prolly not needed */
166
167	const char *lastcall;	/* DEBUG -- name of last system call */
168	/* the following MUST be aligned on a 64-bit boundary */
169	struct	rwindow64 pcb_rw[PCB_MAXWIN];	/* saved windows */
170};
171
172/*
173 * The pcb is augmented with machine-dependent additional data for
174 * core dumps.  Note that the trapframe here is a copy of the one
175 * from the top of the kernel stack (included here so that the kernel
176 * stack itself need not be dumped).
177 */
178struct md_coredump32 {
179	struct	trapframe32 md_tf;
180	struct	fpstate32 md_fpstate;
181};
182
183struct md_coredump {
184	struct	trapframe64 md_tf;
185	struct	fpstate64 md_fpstate;
186};
187
188#ifndef _KERNEL
189/* Let gdb compile.  We need fancier macros to make these make sense. */
190#define pcb_psr	pcb_pstate
191#define pcb_wim	pcb_cwp
192#endif /* _KERNEL */
193
194#endif /* _SPARC64_PCB_H_ */