xref: /netbsd-src/lib/libkvm/kvm_mips.c (revision 6a9b3088d8d2341ca1454531d365c15fe9c1c589)
1 /* $NetBSD: kvm_mips.c,v 1.20 2010/09/20 23:23:16 jym Exp $ */
2 
3 /*
4  * Copyright (c) 1994, 1995 Carnegie-Mellon University.
5  * All rights reserved.
6  *
7  * Author: Chris G. Demetriou
8  *
9  * Permission to use, copy, modify and distribute this software and
10  * its documentation is hereby granted, provided that both the copyright
11  * notice and this permission notice appear in all copies of the
12  * software, derivative works or modified versions, and any portions
13  * thereof, and that both notices appear in supporting documentation.
14  *
15  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
16  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
17  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
18  *
19  * Carnegie Mellon requests users of this software to return to
20  *
21  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
22  *  School of Computer Science
23  *  Carnegie Mellon University
24  *  Pittsburgh PA 15213-3890
25  *
26  * any improvements or extensions that they make and grant Carnegie the
27  * rights to redistribute these changes.
28  */
29 
30 /*
31  * Modified for NetBSD/mips by Jason R. Thorpe, Numerical Aerospace
32  * Simulation Facility, NASA Ames Research Center.
33  */
34 
35 #include <sys/cdefs.h>
36 #if defined(LIBC_SCCS) && !defined(lint)
37 __RCSID("$NetBSD: kvm_mips.c,v 1.20 2010/09/20 23:23:16 jym Exp $");
38 #endif /* LIBC_SCCS and not lint */
39 
40 /*
41  * MIPS machine dependent routines for kvm.
42  */
43 
44 #include <sys/param.h>
45 #include <sys/user.h>
46 #include <sys/proc.h>
47 #include <sys/stat.h>
48 #include <sys/kcore.h>
49 #include <sys/types.h>
50 
51 #include <machine/kcore.h>
52 
53 #include <stdlib.h>
54 #include <unistd.h>
55 #include <nlist.h>
56 #include <kvm.h>
57 
58 #include <uvm/uvm_extern.h>
59 
60 #include <limits.h>
61 #include <db.h>
62 
63 #include "kvm_private.h"
64 
65 #include <mips/cpuregs.h>
66 #include <mips/vmparam.h>
67 
68 void
69 _kvm_freevtop(kvm_t *kd)
70 {
71 
72 	/* Not actually used for anything right now, but safe. */
73 	if (kd->vmst != 0)
74 		free(kd->vmst);
75 }
76 
77 int
78 _kvm_initvtop(kvm_t *kd)
79 {
80 
81 	return (0);
82 }
83 
84 /*
85  * Translate a kernel virtual address to a physical address.
86  */
87 int
88 _kvm_kvatop(kvm_t *kd, vaddr_t va, paddr_t *pa)
89 {
90 	cpu_kcore_hdr_t *cpu_kh;
91 	int page_off;
92 	u_int pte;
93 	paddr_t pte_pa;
94 
95 	if (ISALIVE(kd)) {
96 		_kvm_err(kd, 0, "vatop called in live kernel!");
97 		return((off_t)0);
98 	}
99 
100 	cpu_kh = kd->cpu_data;
101 	page_off = va & PGOFSET;
102 
103 	if (va < MIPS_KSEG0_START) {
104 		/*
105 		 * KUSEG (user virtual address space) - invalid.
106 		 */
107 		_kvm_err(kd, 0, "invalid kernel virtual address");
108 		goto lose;
109 	}
110 
111 	if (va >= MIPS_KSEG0_START && va < MIPS_KSEG1_START) {
112 		/*
113 		 * Direct-mapped cached address: just convert it.
114 		 */
115 		*pa = MIPS_KSEG0_TO_PHYS(va);
116 		return (NBPG - page_off);
117 	}
118 
119 	if (va >= MIPS_KSEG1_START && va < MIPS_KSEG2_START) {
120 		/*
121 		 * Direct-mapped uncached address: just convert it.
122 		 */
123 		*pa = MIPS_KSEG1_TO_PHYS(va);
124 		return (NBPG - page_off);
125 	}
126 
127 	/*
128 	 * We now know that we're a KSEG2 (kernel virtually mapped)
129 	 * address.  Translate the address using the pmap's kernel
130 	 * page table.
131 	 */
132 
133 	/*
134 	 * Step 1: Make sure the kernel page table has a translation
135 	 * for the address.
136 	 */
137 	if (va >= (MIPS_KSEG2_START + (cpu_kh->sysmapsize * NBPG))) {
138 		_kvm_err(kd, 0, "invalid KSEG2 address");
139 		goto lose;
140 	}
141 
142 	/*
143 	 * Step 2: Locate and read the PTE.
144 	 */
145 	pte_pa = cpu_kh->sysmappa +
146 	    (((va - MIPS_KSEG2_START) >> PGSHIFT) * sizeof(u_int));
147 	if (_kvm_pread(kd, kd->pmfd, &pte, sizeof(pte),
148 	    _kvm_pa2off(kd, pte_pa)) != sizeof(pte)) {
149 		_kvm_syserr(kd, 0, "could not read PTE");
150 		goto lose;
151 	}
152 
153 	/*
154 	 * Step 3: Validate the PTE and return the physical address.
155 	 */
156 	if ((pte & cpu_kh->pg_v) == 0) {
157 		_kvm_err(kd, 0, "invalid translation (invalid PTE)");
158 		goto lose;
159 	}
160 	*pa = (((pte & cpu_kh->pg_frame) >> cpu_kh->pg_shift) << PGSHIFT) +
161 	    page_off;
162 	return (NBPG - page_off);
163 
164  lose:
165 	*pa = -1;
166 	return (0);
167 }
168 
169 /*
170  * Translate a physical address to a file-offset in the crash dump.
171  */
172 off_t
173 _kvm_pa2off(kvm_t *kd, paddr_t pa)
174 {
175 	cpu_kcore_hdr_t *cpu_kh;
176 	phys_ram_seg_t *ramsegs;
177 	off_t off;
178 	int i;
179 
180 	cpu_kh = kd->cpu_data;
181 	ramsegs = (phys_ram_seg_t *)((char *)cpu_kh + ALIGN(sizeof *cpu_kh));
182 
183 	off = 0;
184 	for (i = 0; i < cpu_kh->nmemsegs; i++) {
185 		if (pa >= ramsegs[i].start &&
186 		    (pa - ramsegs[i].start) < ramsegs[i].size) {
187 			off += (pa - ramsegs[i].start);
188 			break;
189 		}
190 		off += ramsegs[i].size;
191 	}
192 
193 	return (kd->dump_off + off);
194 }
195 
196 /*
197  * Machine-dependent initialization for ALL open kvm descriptors,
198  * not just those for a kernel crash dump.  Some architectures
199  * have to deal with these NOT being constants!  (i.e. m68k)
200  */
201 int
202 _kvm_mdopen(kvm_t *kd)
203 {
204 
205 	kd->usrstack = USRSTACK;
206 	kd->min_uva = VM_MIN_ADDRESS;
207 	kd->max_uva = VM_MAXUSER_ADDRESS;
208 
209 	return (0);
210 }
211