1 /*-
2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software developed by the Computer Systems
6 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
7 * BG 91-66 and contributed to Berkeley.
8 *
9 * %sccs.include.redist.c%
10 */
11
12 #if defined(LIBC_SCCS) && !defined(lint)
13 static char sccsid[] = "@(#)kvm_sparc.c 8.1 (Berkeley) 06/04/93";
14 #endif /* LIBC_SCCS and not lint */
15
16 /*
17 * Sparc machine dependent routines for kvm. Hopefully, the forthcoming
18 * vm code will one day obsolete this module.
19 */
20
21 #include <sys/param.h>
22 #include <sys/user.h>
23 #include <sys/proc.h>
24 #include <sys/stat.h>
25 #include <unistd.h>
26 #include <nlist.h>
27 #include <kvm.h>
28
29 #include <vm/vm.h>
30 #include <vm/vm_param.h>
31
32 #include <limits.h>
33 #include <db.h>
34
35 #include "kvm_private.h"
36
37 #define NPMEG 128
38
39 /* XXX from sparc/pmap.c */
40 #define MAXMEM (128 * 1024 * 1024) /* no more than 128 MB phys mem */
41 #define NPGBANK 16 /* 2^4 pages per bank (64K / bank) */
42 #define BSHIFT 4 /* log2(NPGBANK) */
43 #define BOFFSET (NPGBANK - 1)
44 #define BTSIZE (MAXMEM / NBPG / NPGBANK)
45 #define HWTOSW(pmap_stod, pg) (pmap_stod[(pg) >> BSHIFT] | ((pg) & BOFFSET))
46
47 struct vmstate {
48 pmeg_t segmap[NKSEG];
49 int pmeg[NPMEG][NPTESG];
50 int pmap_stod[BTSIZE]; /* dense to sparse */
51 };
52
53 void
_kvm_freevtop(kd)54 _kvm_freevtop(kd)
55 kvm_t *kd;
56 {
57 if (kd->vmst != 0)
58 free(kd->vmst);
59 }
60
61 int
_kvm_initvtop(kd)62 _kvm_initvtop(kd)
63 kvm_t *kd;
64 {
65 register int i;
66 register int off;
67 register struct vmstate *vm;
68 struct stat st;
69 struct nlist nlist[2];
70
71 vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm));
72 if (vm == 0)
73 return (-1);
74
75 kd->vmst = vm;
76
77 if (fstat(kd->pmfd, &st) < 0)
78 return (-1);
79 /*
80 * Read segment table.
81 */
82 off = st.st_size - ctob(btoc(sizeof(vm->segmap)));
83 errno = 0;
84 if (lseek(kd->pmfd, (off_t)off, 0) == -1 && errno != 0 ||
85 read(kd->pmfd, (char *)vm->segmap, sizeof(vm->segmap)) < 0) {
86 _kvm_err(kd, kd->program, "cannot read segment map");
87 return (-1);
88 }
89 /*
90 * Read PMEGs.
91 */
92 off = st.st_size - ctob(btoc(sizeof(vm->pmeg)) +
93 btoc(sizeof(vm->segmap)));
94 errno = 0;
95 if (lseek(kd->pmfd, (off_t)off, 0) == -1 && errno != 0 ||
96 read(kd->pmfd, (char *)vm->pmeg, sizeof(vm->pmeg)) < 0) {
97 _kvm_err(kd, kd->program, "cannot read PMEG table");
98 return (-1);
99 }
100 /*
101 * Make pmap_stod be an identity map so we can bootstrap it in.
102 * We assume it's in the first contiguous chunk of physical memory.
103 */
104 for (i = 0; i < BTSIZE; ++i)
105 vm->pmap_stod[i] = i << 4;
106
107 /*
108 * It's okay to do this nlist separately from the one kvm_getprocs()
109 * does, since the only time we could gain anything by combining
110 * them is if we do a kvm_getprocs() on a dead kernel, which is
111 * not too common.
112 */
113 nlist[0].n_name = "_pmap_stod";
114 nlist[1].n_name = 0;
115 if (kvm_nlist(kd, nlist) != 0) {
116 _kvm_err(kd, kd->program, "pmap_stod: no such symbol");
117 return (-1);
118 }
119 if (kvm_read(kd, (u_long)nlist[0].n_value,
120 (char *)vm->pmap_stod, sizeof(vm->pmap_stod))
121 != sizeof(vm->pmap_stod)) {
122 _kvm_err(kd, kd->program, "cannot read pmap_stod");
123 return (-1);
124 }
125 return (0);
126 }
127
128 #define VA_OFF(va) (va & (NBPG - 1))
129
130 /*
131 * Translate a user virtual address to a physical address.
132 */
133 int
_kvm_uvatop(kd,p,va,pa)134 _kvm_uvatop(kd, p, va, pa)
135 kvm_t *kd;
136 const struct proc *p;
137 u_long va;
138 u_long *pa;
139 {
140 int kva, pte;
141 register int off, frame;
142 register struct vmspace *vms = p->p_vmspace;
143
144 if ((u_long)vms < KERNBASE) {
145 _kvm_err(kd, kd->program, "_kvm_uvatop: corrupt proc");
146 return (0);
147 }
148 if (va >= KERNBASE)
149 return (0);
150 /*
151 * Get the PTE. This takes two steps. We read the
152 * base address of the table, then we index it.
153 * Note that the index pte table is indexed by
154 * virtual segment rather than physical segment.
155 */
156 kva = (u_long)&vms->vm_pmap.pm_rpte[VA_VSEG(va)];
157 if (kvm_read(kd, kva, (char *)&kva, 4) != 4 || kva == 0)
158 goto invalid;
159 kva += sizeof(vms->vm_pmap.pm_rpte[0]) * VA_VPG(va);
160 if (kvm_read(kd, kva, (char *)&pte, 4) == 4 && (pte & PG_V)) {
161 off = VA_OFF(va);
162 /*
163 * /dev/mem adheres to the hardware model of physical memory
164 * (with holes in the address space), while crashdumps
165 * adhere to the contiguous software model.
166 */
167 if (ISALIVE(kd))
168 frame = pte & PG_PFNUM;
169 else
170 frame = HWTOSW(kd->vmst->pmap_stod, pte & PG_PFNUM);
171 *pa = (frame << PGSHIFT) | off;
172 return (NBPG - off);
173 }
174 invalid:
175 _kvm_err(kd, 0, "invalid address (%x)", va);
176 return (0);
177 }
178
179 /*
180 * Translate a kernel virtual address to a physical address using the
181 * mapping information in kd->vm. Returns the result in pa, and returns
182 * the number of bytes that are contiguously available from this
183 * physical address. This routine is used only for crashdumps.
184 */
185 int
_kvm_kvatop(kd,va,pa)186 _kvm_kvatop(kd, va, pa)
187 kvm_t *kd;
188 u_long va;
189 u_long *pa;
190 {
191 register struct vmstate *vm;
192 register int s;
193 register int pte;
194 register int off;
195
196 if (va >= KERNBASE) {
197 vm = kd->vmst;
198 s = vm->segmap[VA_VSEG(va) - NUSEG];
199 pte = vm->pmeg[s][VA_VPG(va)];
200 if ((pte & PG_V) != 0) {
201 off = VA_OFF(va);
202 *pa = (HWTOSW(vm->pmap_stod, pte & PG_PFNUM)
203 << PGSHIFT) | off;
204
205 return (NBPG - off);
206 }
207 }
208 _kvm_err(kd, 0, "invalid address (%x)", va);
209 return (0);
210 }
211