| 1 | /* $OpenBSD: pcb.h,v 1.11 2022/10/21 18:55:42 miod 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 rwindow pcb_rw[PCB_MAXWIN]; /* saved windows */ |
| 143 | u_int64_t pcb_rwsp[PCB_MAXWIN]; |
| 144 | }; |
| 145 | |
| 146 | #ifndef _KERNEL |
| 147 | /* Let gdb compile. We need fancier macros to make these make sense. */ |
| 148 | #define pcb_psr pcb_pstate |
| 149 | #define pcb_wim pcb_cwp |
| 150 | #endif /* _KERNEL */ |
| 151 | |
| 152 | #endif /* _MACHINE_PCB_H_ */ |