Annotation of sys/arch/sparc64/include/pcb.h, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: pcb.h,v 1.7 2007/05/26 00:36:03 krw Exp $ */
2: /* $NetBSD: pcb.h,v 1.7 2000/12/29 17:12:05 eeh Exp $ */
3:
4: /*
5: * Copyright (c) 1992, 1993
6: * The Regents of the University of California. All rights reserved.
7: *
8: * This software was developed by the Computer Systems Engineering group
9: * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
10: * contributed to Berkeley.
11: *
12: * All advertising materials mentioning features or use of this software
13: * must display the following acknowledgement:
14: * This product includes software developed by the University of
15: * California, Lawrence Berkeley Laboratory.
16: *
17: * Redistribution and use in source and binary forms, with or without
18: * modification, are permitted provided that the following conditions
19: * are met:
20: * 1. Redistributions of source code must retain the above copyright
21: * notice, this list of conditions and the following disclaimer.
22: * 2. Redistributions in binary form must reproduce the above copyright
23: * notice, this list of conditions and the following disclaimer in the
24: * documentation and/or other materials provided with the distribution.
25: * 3. Neither the name of the University nor the names of its contributors
26: * may be used to endorse or promote products derived from this software
27: * without specific prior written permission.
28: *
29: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39: * SUCH DAMAGE.
40: *
41: * @(#)pcb.h 8.1 (Berkeley) 6/11/93
42: */
43:
44: #ifndef _SPARC64_PCB_H_
45: #define _SPARC64_PCB_H_
46:
47: #include <machine/reg.h>
48:
49: #ifdef notyet
50: #define PCB_MAXWIN 32 /* architectural limit */
51: #else
52: #define PCB_MAXWIN 8 /* worried about u area sizes ... */
53: #endif
54:
55: /*
56: * SPARC Process Control Block.
57: *
58: * pcb_uw is positive if there are any user windows that are
59: * are currently in the CPU windows rather than on the user
60: * stack. Whenever we are running in the kernel with traps
61: * enabled, we decrement pcb_uw for each ``push'' of a CPU
62: * register window into the stack, and we increment it for
63: * each ``pull'' from the stack into the CPU. (If traps are
64: * disabled, or if we are in user mode, pcb_uw is junk.)
65: *
66: * To ease computing pcb_uw on traps from user mode, we keep track
67: * of the log base 2 of the single bit that is set in %wim.
68: *
69: * If an overflow occurs while the associated user stack pages
70: * are invalid (paged out), we have to store the registers
71: * in a page that is locked in core while the process runs,
72: * i.e., right here in the pcb. We also need the stack pointer
73: * for the last such window (but only the last, as the others
74: * are in each window) and the count of windows saved. We
75: * cheat by having a whole window structure for that one %sp.
76: * Thus, to save window pcb_rw[i] to memory, we write it at
77: * pcb_rw[i + 1].rw_in[6].
78: *
79: * pcb_nsaved has three `kinds' of values. If 0, it means no
80: * registers are in the PCB (though if pcb_uw is positive,
81: * there may be the next time you look). If positive, it means
82: * there are no user registers in the CPU, but there are some
83: * saved in pcb_rw[]. As a special case, traps that needed
84: * assistance to pull user registers from the stack also store
85: * the registers in pcb_rw[], and set pcb_nsaved to -1. This
86: * special state is normally short-term: it can only last until the
87: * trap returns, and it can never persist across entry to user code.
88: */
89: /*
90: * v9 addendum:
91: *
92: * Window handling between v8 and v9 has changed somewhat. There
93: * is no %wim. Instead, we have a %cwp, %cansave, %canrestore,
94: * %cleanwin, and %otherwin. By definition:
95: *
96: * %cansave + %canrestore + %otherwin = NWINDOWS - 2
97: *
98: * In addition, %cleanwin >= %canrestore since restorable windows
99: * are considered clean. This means that by storing %canrestore
100: * and %otherwin, we should be able to compute the values of all
101: * the other registers.
102: *
103: * The only other register we need to save is %cwp because it cannot
104: * be trivially computed from the other registers. The %cwp is
105: * stored in the %tstate register, but if the machine was in a register
106: * window spill/fill handler, the value of that %cwp may be off by
107: * as much as 2 register windows. We will also store %cwp. [We will
108: * try to steal pcb_uw or pcb_nsaved for this purpose eventually.]
109: *
110: * To calculate what registers are in the pcb, start with pcb_cwp
111: * and proceed to (pcb_cwp - pcb_canrestore) % NWINDOWS. These should
112: * be saved to their appropriate register windows. The client routine
113: * (trap handler) is responsible for saving pcb_cwp + 1 [%o1-%o7] in
114: * the trap frame or on the stack.
115: *
116: *
117: * Even more addendum:
118: *
119: * With the new system for keeping track of register windows we don't
120: * care about anything other than pcb_uw which keeps track of how many
121: * full windows we have. As soon as a flush traps, we dump all user
122: * windows to the pcb, handle the fault, then restore all user windows.
123: *
124: * XXX we are using pcb_nsaved as the counter. pcb_uw is still a mask.
125: * change this as soon as the new scheme is debugged.
126: */
127: struct pcb {
128: u_int64_t pcb_sp; /* sp (%o6) when switch() was called */
129: u_int64_t pcb_pc; /* pc (%o7) when switch() was called */
130: caddr_t pcb_onfault; /* for copyin/out */
131: short pcb_pstate; /* %pstate when switch() was called -- may be useful if we support multiple memory models */
132: char pcb_nsaved; /* number of windows saved in pcb */
133:
134: /* The rest is probably not needed except for pcb_rw */
135: char pcb_cwp; /* %cwp when switch() was called */
136: char pcb_pil; /* %pil when switch() was called -- probably not needed */
137:
138: const char *lastcall; /* DEBUG -- name of last system call */
139: u_int64_t pcb_wcookie;
140:
141: /* the following MUST be aligned on a 64-bit boundary */
142: struct rwindow64 pcb_rw[PCB_MAXWIN]; /* saved windows */
143: };
144:
145: /*
146: * The pcb is augmented with machine-dependent additional data for
147: * core dumps. Note that the trapframe here is a copy of the one
148: * from the top of the kernel stack (included here so that the kernel
149: * stack itself need not be dumped).
150: */
151: struct md_coredump {
152: struct trapframe64 md_tf;
153: struct fpstate64 md_fpstate;
154: u_int64_t md_wcookie;
155: };
156:
157: #ifndef _KERNEL
158: /* Let gdb compile. We need fancier macros to make these make sense. */
159: #define pcb_psr pcb_pstate
160: #define pcb_wim pcb_cwp
161: #endif /* _KERNEL */
162:
163: #endif /* _SPARC64_PCB_H_ */
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