pcb.h revision 1.2
1 /* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This software was developed by the Computer Systems Engineering group 6 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 7 * contributed to Berkeley. 8 * 9 * All advertising materials mentioning features or use of this software 10 * must display the following acknowledgement: 11 * This product includes software developed by the University of 12 * California, Lawrence Berkeley Laboratory. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. All advertising materials mentioning features or use of this software 23 * must display the following acknowledgement: 24 * This product includes software developed by the University of 25 * California, Berkeley and its contributors. 26 * 4. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * @(#)pcb.h 8.1 (Berkeley) 6/11/93 43 * 44 * from: Header: pcb.h,v 1.6 92/11/26 02:04:39 torek Exp 45 * $Id: pcb.h,v 1.2 1994/05/19 08:23:36 deraadt Exp $ 46 */ 47 48 #include <machine/reg.h> 49 50 #ifdef notyet 51 #define PCB_MAXWIN 32 /* architectural limit */ 52 #else 53 #define PCB_MAXWIN 8 /* worried about u area sizes ... */ 54 #endif 55 56 /* 57 * SPARC Process Control Block. 58 * 59 * pcb_uw is positive if there are any user windows that are 60 * are currently in the CPU windows rather than on the user 61 * stack. Whenever we are running in the kernel with traps 62 * enabled, we decrement pcb_uw for each ``push'' of a CPU 63 * register window into the stack, and we increment it for 64 * each ``pull'' from the stack into the CPU. (If traps are 65 * disabled, or if we are in user mode, pcb_uw is junk.) 66 * 67 * To ease computing pcb_uw on traps from user mode, we keep track 68 * of the log base 2 of the single bit that is set in %wim. 69 * 70 * If an overflow occurs while the associated user stack pages 71 * are invalid (paged out), we have to store the registers 72 * in a page that is locked in core while the process runs, 73 * i.e., right here in the pcb. We also need the stack pointer 74 * for the last such window (but only the last, as the others 75 * are in each window) and the count of windows saved. We 76 * cheat by having a whole window structure for that one %sp. 77 * Thus, to save window pcb_rw[i] to memory, we write it at 78 * pcb_rw[i + 1].rw_in[6]. 79 * 80 * pcb_nsaved has three `kinds' of values. If 0, it means no 81 * registers are in the PCB (though if pcb_uw is positive, 82 * there may be the next time you look). If positive, it means 83 * there are no user registers in the CPU, but there are some 84 * saved in pcb_rw[]. As a special case, traps that needed 85 * assistance to pull user registers from the stack also store 86 * the registers in pcb_rw[], and set pcb_nsaved to -1. This 87 * special state is normally short-term: it can only last until the 88 * trap returns, and it can never persist across entry to user code. 89 */ 90 struct pcb { 91 int pcb_sp; /* sp (%o6) when switch() was called */ 92 int pcb_pc; /* pc (%o7) when switch() was called */ 93 int pcb_psr; /* %psr when switch() was called */ 94 95 caddr_t pcb_onfault; /* for copyin/out */ 96 97 int pcb_uw; /* user windows inside CPU */ 98 int pcb_wim; /* log2(%wim) */ 99 int pcb_nsaved; /* number of windows saved in pcb */ 100 101 #ifdef notdef 102 int pcb_winof; /* number of window overflow traps */ 103 int pcb_winuf; /* number of window underflow traps */ 104 #endif 105 int pcb_pad; /* pad to doubleword boundary */ 106 107 /* the following MUST be aligned on a doubleword boundary */ 108 struct rwindow pcb_rw[PCB_MAXWIN]; /* saved windows */ 109 }; 110 111 /* 112 * The pcb is augmented with machine-dependent additional data for 113 * core dumps. Note that the trapframe here is a copy of the one 114 * from the top of the kernel stack (included here so that the kernel 115 * stack itself need not be dumped). 116 */ 117 struct md_coredump { 118 struct trapframe md_tf; 119 struct fpstate md_fpstate; 120 }; 121 122 #ifdef KERNEL 123 extern struct pcb *cpcb; 124 #endif /* KERNEL */ 125
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