1 /* $OpenBSD: pcb.h,v 1.9 2011/03/23 16:54:37 pirofti 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 _MACHINE_PCB_H_ 45 #define _MACHINE_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 u_int64_t pcb_rwsp[PCB_MAXWIN]; 144 }; 145 146 /* 147 * The pcb is augmented with machine-dependent additional data for 148 * core dumps. Note that the trapframe here is a copy of the one 149 * from the top of the kernel stack (included here so that the kernel 150 * stack itself need not be dumped). 151 */ 152 struct md_coredump { 153 struct trapframe64 md_tf; 154 struct fpstate64 md_fpstate; 155 u_int64_t md_wcookie; 156 }; 157 158 #ifndef _KERNEL 159 /* Let gdb compile. We need fancier macros to make these make sense. */ 160 #define pcb_psr pcb_pstate 161 #define pcb_wim pcb_cwp 162 #endif /* _KERNEL */ 163 164 #endif /* _MACHINE_PCB_H_ */ 165