pcb.h revision 1.3
1 /* $NetBSD: pcb.h,v 1.3 1994/11/20 20:53:20 deraadt 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. All advertising materials mentioning features or use of this software 25 * must display the following acknowledgement: 26 * This product includes software developed by the University of 27 * California, Berkeley and its contributors. 28 * 4. Neither the name of the University nor the names of its contributors 29 * may be used to endorse or promote products derived from this software 30 * without specific prior written permission. 31 * 32 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 33 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 34 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 35 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 36 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 40 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 41 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 42 * SUCH DAMAGE. 43 * 44 * @(#)pcb.h 8.1 (Berkeley) 6/11/93 45 */ 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 struct pcb { 90 int pcb_sp; /* sp (%o6) when switch() was called */ 91 int pcb_pc; /* pc (%o7) when switch() was called */ 92 int pcb_psr; /* %psr when switch() was called */ 93 94 caddr_t pcb_onfault; /* for copyin/out */ 95 96 int pcb_uw; /* user windows inside CPU */ 97 int pcb_wim; /* log2(%wim) */ 98 int pcb_nsaved; /* number of windows saved in pcb */ 99 100 #ifdef notdef 101 int pcb_winof; /* number of window overflow traps */ 102 int pcb_winuf; /* number of window underflow traps */ 103 #endif 104 int pcb_pad; /* pad to doubleword boundary */ 105 106 /* the following MUST be aligned on a doubleword boundary */ 107 struct rwindow pcb_rw[PCB_MAXWIN]; /* saved windows */ 108 }; 109 110 /* 111 * The pcb is augmented with machine-dependent additional data for 112 * core dumps. Note that the trapframe here is a copy of the one 113 * from the top of the kernel stack (included here so that the kernel 114 * stack itself need not be dumped). 115 */ 116 struct md_coredump { 117 struct trapframe md_tf; 118 struct fpstate md_fpstate; 119 }; 120 121 #ifdef KERNEL 122 extern struct pcb *cpcb; 123 #endif /* KERNEL */ 124
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