1/* $NetBSD: kvm_i386.c,v 1.30 2014/02/19 20:21:22 dsl Exp $ */
2
3/*-
4 * Copyright (c) 1989, 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software developed by the Computer Systems
8 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
9 * BG 91-66 and contributed to Berkeley.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <sys/cdefs.h>
37#if defined(LIBC_SCCS) && !defined(lint)
38#if 0
39static char sccsid[] = "@(#)kvm_hp300.c 8.1 (Berkeley) 6/4/93";
40#else
41__RCSID("$NetBSD: kvm_i386.c,v 1.30 2014/02/19 20:21:22 dsl Exp $");
42#endif
43#endif /* LIBC_SCCS and not lint */
44
45/*
46 * i386 machine dependent routines for kvm.
47 */
48
49#include <sys/param.h>
50#include <sys/stat.h>
51#include <sys/kcore.h>
52#include <sys/types.h>
53
54#include <stdlib.h>
55#include <unistd.h>
56#include <nlist.h>
57#include <kvm.h>
58
59#include <uvm/uvm_extern.h>
60
61#include <limits.h>
62#include <db.h>
63
64#include "kvm_private.h"
65
66#include <i386/kcore.h>
67#include <i386/pmap.h>
68#include <i386/pte.h>
69#include <i386/vmparam.h>
70
71#ifndef btop
72#define btop(x) (((unsigned)(x)) >> PGSHIFT) /* XXX */
73#define ptob(x) ((caddr_t)((x) << PGSHIFT)) /* XXX */
74#endif
75
76/*
77 * Indicates whether PAE is in use for the kernel image
78 * 0: native i386 memory mappings
79 * 1: i386 PAE mappings
80 */
81static int i386_use_pae;
82
83int _kvm_kvatop_i386(kvm_t *, vaddr_t, paddr_t *);
84int _kvm_kvatop_i386pae(kvm_t *, vaddr_t, paddr_t *);
85
86void
87_kvm_freevtop(kvm_t *kd)
88{
89
90 /* Not actually used for anything right now, but safe. */
91 if (kd->vmst != 0)
92 free(kd->vmst);
93}
94
95/*ARGSUSED*/
96int
97_kvm_initvtop(kvm_t *kd)
98{
99 cpu_kcore_hdr_t *cpu_kh = kd->cpu_data;
100
101 i386_use_pae = 0; /* default: non PAE mode */
102 if ((cpu_kh->pdppaddr & I386_KCORE_PAE) == I386_KCORE_PAE)
103 i386_use_pae = 1;
104
105 return 0;
106}
107
108/*
109 * Translate a kernel virtual address to a physical address.
110 */
111int
112_kvm_kvatop(kvm_t *kd, vaddr_t va, paddr_t *pa)
113{
114
115 if (ISALIVE(kd)) {
116 _kvm_err(kd, 0, "vatop called in live kernel!");
117 return 0;
118 }
119
120 switch (i386_use_pae) {
121 default:
122 case 0:
123 return _kvm_kvatop_i386(kd, va, pa);
124 case 1:
125 return _kvm_kvatop_i386pae(kd, va, pa);
126 }
127
128}
129
130/*
131 * Used to translate a virtual address to a physical address for systems
132 * with PAE mode disabled. Only two levels of virtual memory pages are
133 * dereferenced (L2 PDEs, then L1 PTEs).
134 */
135int
136_kvm_kvatop_i386(kvm_t *kd, vaddr_t va, paddr_t *pa)
137{
138 cpu_kcore_hdr_t *cpu_kh;
139 u_long page_off;
140 pd_entry_t pde;
141 pt_entry_t pte;
142 paddr_t pde_pa, pte_pa;
143
144 cpu_kh = kd->cpu_data;
145 page_off = va & PGOFSET;
146
147 /*
148 * Find and read the page directory entry.
149 * pdppaddr being PAGE_SIZE aligned, we mask the option bits.
150 */
151 pde_pa = (cpu_kh->pdppaddr & PG_FRAME) + (pl2_pi(va) * sizeof(pde));
152 if (_kvm_pread(kd, kd->pmfd, (void *)&pde, sizeof(pde),
153 _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
154 _kvm_syserr(kd, 0, "could not read PDE");
155 goto lose;
156 }
157
158 /*
159 * Find and read the page table entry.
160 */
161 if ((pde & PG_V) == 0) {
162 _kvm_err(kd, 0, "invalid translation (invalid PDE)");
163 goto lose;
164 }
165 if ((pde & PG_PS) != 0) {
166 /*
167 * This is a 4MB page.
168 */
169 page_off = va & ~PG_LGFRAME;
170 *pa = (pde & PG_LGFRAME) + page_off;
171 return (int)(NBPD_L2 - page_off);
172 }
173 pte_pa = (pde & PG_FRAME) + (pl1_pi(va) * sizeof(pt_entry_t));
174 if (_kvm_pread(kd, kd->pmfd, (void *) &pte, sizeof(pte),
175 _kvm_pa2off(kd, pte_pa)) != sizeof(pte)) {
176 _kvm_syserr(kd, 0, "could not read PTE");
177 goto lose;
178 }
179
180 /*
181 * Validate the PTE and return the physical address.
182 */
183 if ((pte & PG_V) == 0) {
184 _kvm_err(kd, 0, "invalid translation (invalid PTE)");
185 goto lose;
186 }
187 *pa = (pte & PG_FRAME) + page_off;
188 return (int)(NBPG - page_off);
189
190 lose:
191 *pa = (paddr_t)~0L;
192 return 0;
193}
194
195/*
196 * Translate a physical address to a file-offset in the crash dump.
197 */
198off_t
199_kvm_pa2off(kvm_t *kd, paddr_t pa)
200{
201 cpu_kcore_hdr_t *cpu_kh;
202 phys_ram_seg_t *ramsegs;
203 off_t off;
204 int i;
205
206 cpu_kh = kd->cpu_data;
207 ramsegs = (void *)((char *)(void *)cpu_kh + ALIGN(sizeof *cpu_kh));
208
209 off = 0;
210 for (i = 0; i < cpu_kh->nmemsegs; i++) {
211 if (pa >= ramsegs[i].start &&
212 (pa - ramsegs[i].start) < ramsegs[i].size) {
213 off += (pa - ramsegs[i].start);
214 break;
215 }
216 off += ramsegs[i].size;
217 }
218
219 return (kd->dump_off + off);
220}
221
222/*
223 * Machine-dependent initialization for ALL open kvm descriptors,
224 * not just those for a kernel crash dump. Some architectures
225 * have to deal with these NOT being constants! (i.e. m68k)
226 */
227int
228_kvm_mdopen(kvm_t *kd)
229{
230
231 kd->usrstack = USRSTACK;
232 kd->min_uva = VM_MIN_ADDRESS;
233 kd->max_uva = VM_MAXUSER_ADDRESS;
234
235 return 0;
236}
237