1/* $NetBSD: pcb.h,v 1.9 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#ifndef _SPARC_PCB_H_
44#define _SPARC_PCB_H_
45
46#include <machine/reg.h>
47
48#ifdef notyet
49#define PCB_MAXWIN 32 /* architectural limit */
50#else
51#define PCB_MAXWIN 8 /* worried about u area sizes ... */
52#endif
53
54/*
55 * SPARC Process Control Block.
56 *
57 * pcb_uw is positive if there are any user windows that are
58 * are currently in the CPU windows rather than on the user
59 * stack. Whenever we are running in the kernel with traps
60 * enabled, we decrement pcb_uw for each ``push'' of a CPU
61 * register window into the stack, and we increment it for
62 * each ``pull'' from the stack into the CPU. (If traps are
63 * disabled, or if we are in user mode, pcb_uw is junk.)
64 *
65 * To ease computing pcb_uw on traps from user mode, we keep track
66 * of the log base 2 of the single bit that is set in %wim.
67 *
68 * If an overflow occurs while the associated user stack pages
69 * are invalid (paged out), we have to store the registers
70 * in a page that is locked in core while the process runs,
71 * i.e., right here in the pcb. We also need the stack pointer
72 * for the last such window (but only the last, as the others
73 * are in each window) and the count of windows saved. We
74 * cheat by having a whole window structure for that one %sp.
75 * Thus, to save window pcb_rw[i] to memory, we write it at
76 * pcb_rw[i + 1].rw_in[6].
77 *
78 * pcb_nsaved has three `kinds' of values. If 0, it means no
79 * registers are in the PCB (though if pcb_uw is positive,
80 * there may be the next time you look). If positive, it means
81 * there are no user registers in the CPU, but there are some
82 * saved in pcb_rw[]. As a special case, traps that needed
83 * assistance to pull user registers from the stack also store
84 * the registers in pcb_rw[], and set pcb_nsaved to -1. This
85 * special state is normally short-term: it can only last until the
86 * trap returns, and it can never persist across entry to user code.
87 */
88struct pcb {
89 int pcb_sp; /* sp (%o6) when switch() was called */
90 int pcb_pc; /* pc (%o7) when switch() was called */
91 int pcb_psr; /* %psr when switch() was called */
92
93 void * pcb_onfault; /* for copyin/out */
94
95 int pcb_uw; /* user windows inside CPU */
96 int pcb_wim; /* log2(%wim) */
97 int pcb_nsaved; /* number of windows saved in pcb */
98
99#ifdef notdef
100 int pcb_winof; /* number of window overflow traps */
101 int pcb_winuf; /* number of window underflow traps */
102#endif
103 int pcb_pad; /* pad to doubleword boundary */
104
105 /* the following MUST be aligned on a doubleword boundary */
106 struct rwindow pcb_rw[PCB_MAXWIN]; /* saved windows */
107};
108
109/*
110 * The pcb is augmented with machine-dependent additional data for
111 * core dumps. Note that the trapframe here is a copy of the one
112 * from the top of the kernel stack (included here so that the kernel
113 * stack itself need not be dumped).
114 */
115struct md_coredump {
116 struct trapframe md_tf;
117 struct fpstate md_fpstate;
118};
119
120#endif /* _SPARC_PCB_H_ */