1 /* $NetBSD: pcb.h,v 1.9 2002/05/16 23:29:42 eeh Exp $ */ 2 3 /* 4 * Copyright (c) 1996-2002 Eduardo Horvath. All rights reserved. 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. All advertising materials mentioning features or use of this software 26 * must display the following acknowledgement: 27 * This product includes software developed by the University of 28 * California, Berkeley and its contributors. 29 * 4. Neither the name of the University nor the names of its contributors 30 * may be used to endorse or promote products derived from this software 31 * without specific prior written permission. 32 * 33 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 34 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 35 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 36 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 37 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 38 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 39 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 41 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 42 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 43 * SUCH DAMAGE. 44 * 45 * @(#)pcb.h 8.1 (Berkeley) 6/11/93 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 /* 91 * v9 addendum: 92 * 93 * Window handling between v8 and v9 has changed somewhat. There 94 * is no %wim. Instead, we have a %cwp, %cansave, %canrestore, 95 * %cleanwin, and %otherwin. By definition: 96 * 97 * %cansave + %canrestore + %otherwin = NWINDOWS - 2 98 * 99 * In addition, %cleanwin >= %canrestore since restorable windows 100 * are considered clean. This means that by storing %canrestore 101 * and %otherwin, we should be able to compute the values of all 102 * the other registers. 103 * 104 * The only other register we need to save is %cwp because it cannot 105 * be trivially computed from the other registers. The %cwp is 106 * stored in the %tstate register, but if the machine was in a register 107 * window spill/fill handler, the value of that %cwp may be off by 108 * as much as 2 register windows. We will also store %cwp. [We will 109 * try to steal pcb_uw or pcb_nsaved for this purpose eventually.] 110 * 111 * To calculate what registers are in the pcb, start with pcb_cwp 112 * and proceed to (pcb_cwp - pcb_canrestore) % NWINDOWS. These should 113 * be saved to their appropriate register windows. The client routine 114 * (trap handler) is responsible for saving pcb_cwp + 1 [%o1-%o7] in 115 * the trap frame or on the stack. 116 * 117 * 118 * Even more addendum: 119 * 120 * With the new system for keeping track of register windows we don't 121 * care about anything other than pcb_uw which keeps track of how many 122 * full windows we have. As soon as a flush traps, we dump all user 123 * windows to the pcb, handle the fault, then restore all user windows. 124 * 125 * XXX we are using pcb_nsaved as the counter. pcb_uw is still a mask. 126 * change this as soon as the new scheme is debugged. 127 */ 128 struct pcb { 129 u_int64_t pcb_sp; /* sp (%o6) when switch() was called */ 130 u_int64_t pcb_pc; /* pc (%o7) when switch() was called */ 131 caddr_t pcb_onfault; /* for copyin/out */ 132 short pcb_pstate; /* %pstate when switch() was called -- may be useful if we support multiple memory models */ 133 char pcb_nsaved; /* number of windows saved in pcb */ 134 135 /* The rest is probably not needed except for pcb_rw */ 136 char pcb_cwp; /* %cwp when switch() was called */ 137 char pcb_pil; /* %pil when switch() was called -- prolly not needed */ 138 139 const char *lastcall; /* DEBUG -- name of last system call */ 140 /* the following MUST be aligned on a 64-bit boundary */ 141 struct rwindow64 pcb_rw[PCB_MAXWIN]; /* saved windows */ 142 }; 143 144 /* 145 * The pcb is augmented with machine-dependent additional data for 146 * core dumps. Note that the trapframe here is a copy of the one 147 * from the top of the kernel stack (included here so that the kernel 148 * stack itself need not be dumped). 149 */ 150 struct md_coredump32 { 151 struct trapframe32 md_tf; 152 struct fpstate32 md_fpstate; 153 }; 154 155 struct md_coredump { 156 struct trapframe64 md_tf; 157 struct fpstate64 md_fpstate; 158 }; 159 160 #ifdef _KERNEL 161 extern struct pcb *cpcb; 162 #else 163 /* Let gdb compile. We need fancier macros to make these make sense. */ 164 #define pcb_psr pcb_pstate 165 #define pcb_wim pcb_cwp 166 #endif /* _KERNEL */ 167