1 /* $NetBSD: pcb.h,v 1.6 2003/08/07 16:29:40 agc 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 #include <machine/reg.h> 44 45 #ifdef notyet 46 #define PCB_MAXWIN 32 /* architectural limit */ 47 #else 48 #define PCB_MAXWIN 8 /* worried about u area sizes ... */ 49 #endif 50 51 /* 52 * SPARC Process Control Block. 53 * 54 * pcb_uw is positive if there are any user windows that are 55 * are currently in the CPU windows rather than on the user 56 * stack. Whenever we are running in the kernel with traps 57 * enabled, we decrement pcb_uw for each ``push'' of a CPU 58 * register window into the stack, and we increment it for 59 * each ``pull'' from the stack into the CPU. (If traps are 60 * disabled, or if we are in user mode, pcb_uw is junk.) 61 * 62 * To ease computing pcb_uw on traps from user mode, we keep track 63 * of the log base 2 of the single bit that is set in %wim. 64 * 65 * If an overflow occurs while the associated user stack pages 66 * are invalid (paged out), we have to store the registers 67 * in a page that is locked in core while the process runs, 68 * i.e., right here in the pcb. We also need the stack pointer 69 * for the last such window (but only the last, as the others 70 * are in each window) and the count of windows saved. We 71 * cheat by having a whole window structure for that one %sp. 72 * Thus, to save window pcb_rw[i] to memory, we write it at 73 * pcb_rw[i + 1].rw_in[6]. 74 * 75 * pcb_nsaved has three `kinds' of values. If 0, it means no 76 * registers are in the PCB (though if pcb_uw is positive, 77 * there may be the next time you look). If positive, it means 78 * there are no user registers in the CPU, but there are some 79 * saved in pcb_rw[]. As a special case, traps that needed 80 * assistance to pull user registers from the stack also store 81 * the registers in pcb_rw[], and set pcb_nsaved to -1. This 82 * special state is normally short-term: it can only last until the 83 * trap returns, and it can never persist across entry to user code. 84 */ 85 struct pcb { 86 int pcb_sp; /* sp (%o6) when switch() was called */ 87 int pcb_pc; /* pc (%o7) when switch() was called */ 88 int pcb_psr; /* %psr when switch() was called */ 89 90 caddr_t pcb_onfault; /* for copyin/out */ 91 92 int pcb_uw; /* user windows inside CPU */ 93 int pcb_wim; /* log2(%wim) */ 94 int pcb_nsaved; /* number of windows saved in pcb */ 95 96 #ifdef notdef 97 int pcb_winof; /* number of window overflow traps */ 98 int pcb_winuf; /* number of window underflow traps */ 99 #endif 100 int pcb_pad; /* pad to doubleword boundary */ 101 102 /* the following MUST be aligned on a doubleword boundary */ 103 struct rwindow pcb_rw[PCB_MAXWIN]; /* saved windows */ 104 }; 105 106 /* 107 * The pcb is augmented with machine-dependent additional data for 108 * core dumps. Note that the trapframe here is a copy of the one 109 * from the top of the kernel stack (included here so that the kernel 110 * stack itself need not be dumped). 111 */ 112 struct md_coredump { 113 struct trapframe md_tf; 114 struct fpstate md_fpstate; 115 }; 116