xref: /netbsd/sys/arch/sparc64/include/pcb.h (revision 5e8ba6d4)
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  */
156 struct 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  */
178 struct md_coredump32 {
179 	struct	trapframe32 md_tf;
180 	struct	fpstate32 md_fpstate;
181 };
182 
183 struct 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_ */
195