xref: /openbsd-src/lib/libkvm/kvm_alpha.c (revision 0e64ee4c2b175b1ffc335440a90100bf53ad4596)
1 /*	$OpenBSD: kvm_alpha.c,v 1.17 2021/12/01 16:53:28 deraadt Exp $	*/
2 /*	$NetBSD: kvm_alpha.c,v 1.5 1996/10/01 21:12:05 cgd Exp $	*/
3 
4 /*
5  * Copyright (c) 1994, 1995 Carnegie-Mellon University.
6  * All rights reserved.
7  *
8  * Author: Chris G. Demetriou
9  *
10  * Permission to use, copy, modify and distribute this software and
11  * its documentation is hereby granted, provided that both the copyright
12  * notice and this permission notice appear in all copies of the
13  * software, derivative works or modified versions, and any portions
14  * thereof, and that both notices appear in supporting documentation.
15  *
16  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
17  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
18  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
19  *
20  * Carnegie Mellon requests users of this software to return to
21  *
22  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
23  *  School of Computer Science
24  *  Carnegie Mellon University
25  *  Pittsburgh PA 15213-3890
26  *
27  * any improvements or extensions that they make and grant Carnegie the
28  * rights to redistribute these changes.
29  */
30 
31 #define __KVM_ALPHA_PRIVATE	     /* see <machine/pte.h> */
32 
33 #include <sys/types.h>
34 #include <sys/signal.h>
35 #include <sys/proc.h>
36 #include <sys/stat.h>
37 #include <sys/kcore.h>
38 #include <machine/kcore.h>
39 #include <unistd.h>
40 #include <stdlib.h>
41 #include <nlist.h>
42 #include <kvm.h>
43 
44 #include <uvm/uvm_extern.h>
45 #include <machine/vmparam.h>
46 #include <machine/pmap.h>
47 
48 #include <limits.h>
49 #include <db.h>
50 
51 #include "kvm_private.h"
52 
53 struct vmstate {
54 	vsize_t	page_shift;
55 };
56 
57 void
_kvm_freevtop(kvm_t * kd)58 _kvm_freevtop(kvm_t *kd)
59 {
60 
61 	/* Not actually used for anything right now, but safe. */
62 	free(kd->vmst);
63 	kd->vmst = NULL;
64 }
65 
66 int
_kvm_initvtop(kvm_t * kd)67 _kvm_initvtop(kvm_t *kd)
68 {
69 	cpu_kcore_hdr_t *cpu_kh;
70 	struct vmstate *vm;
71 
72 	vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm));
73 	if (vm == NULL)
74 		return (-1);
75 
76 	cpu_kh = kd->cpu_data;
77 
78 	/* Compute page_shift. */
79 	for (vm->page_shift = 0; (1L << vm->page_shift) < cpu_kh->page_size;
80 	    vm->page_shift++)
81 		/* nothing */ ;
82 	if ((1L << vm->page_shift) != cpu_kh->page_size) {
83 		free(vm);
84 		return (-1);
85 	}
86 
87 	kd->vmst = vm;
88 	return (0);
89 }
90 
91 int
_kvm_kvatop(kvm_t * kd,u_long va,paddr_t * pa)92 _kvm_kvatop(kvm_t *kd, u_long va, paddr_t *pa)
93 {
94 	cpu_kcore_hdr_t *cpu_kh;
95 	struct vmstate *vm;
96 	int rv, page_off;
97 	alpha_pt_entry_t pte;
98 	off_t pteoff;
99 
100 	if (!kd->vmst) {
101 		_kvm_err(kd, 0, "vatop called before initvtop");
102 		return (0);
103 	}
104 
105 	if (ISALIVE(kd)) {
106 		_kvm_err(kd, 0, "vatop called in live kernel!");
107 		return (0);
108 	}
109 
110 	cpu_kh = kd->cpu_data;
111 	vm = kd->vmst;
112 	page_off = va & (cpu_kh->page_size - 1);
113 
114 #ifndef PAGE_SHIFT
115 #define	PAGE_SHIFT      vm->page_shift
116 #endif
117 
118 	if (va >= ALPHA_K0SEG_BASE && va <= ALPHA_K0SEG_END) {
119 		/*
120 		 * Direct-mapped address: just convert it.
121 		 */
122 
123 		*pa = ALPHA_K0SEG_TO_PHYS(va);
124 		rv = cpu_kh->page_size - page_off;
125 	} else if (va >= ALPHA_K1SEG_BASE && va <= ALPHA_K1SEG_END) {
126 		/*
127 		 * Real kernel virtual address: do the translation.
128 		 */
129 
130 		/* Find and read the L1 PTE. */
131 		pteoff = cpu_kh->lev1map_pa +
132 		    l1pte_index(va) * sizeof(alpha_pt_entry_t);
133 		if (_kvm_pread(kd, kd->pmfd, (char *)&pte, sizeof(pte),
134 		    (off_t)_kvm_pa2off(kd, pteoff)) != sizeof(pte)) {
135 			_kvm_syserr(kd, 0, "could not read L1 PTE");
136 			goto lose;
137 		}
138 
139 		/* Find and read the L2 PTE. */
140 		if ((pte & ALPHA_PTE_VALID) == 0) {
141 			_kvm_err(kd, 0, "invalid translation (invalid L1 PTE)");
142 			goto lose;
143 		}
144 		pteoff = ALPHA_PTE_TO_PFN(pte) * cpu_kh->page_size +
145 		    l2pte_index(va) * sizeof(alpha_pt_entry_t);
146 		if (_kvm_pread(kd, kd->pmfd, (char *)&pte, sizeof(pte),
147 		    (off_t)_kvm_pa2off(kd, pteoff)) != sizeof(pte)) {
148 			_kvm_syserr(kd, 0, "could not read L2 PTE");
149 			goto lose;
150 		}
151 
152 		/* Find and read the L3 PTE. */
153 		if ((pte & ALPHA_PTE_VALID) == 0) {
154 			_kvm_err(kd, 0, "invalid translation (invalid L2 PTE)");
155 			goto lose;
156 		}
157 		pteoff = ALPHA_PTE_TO_PFN(pte) * cpu_kh->page_size +
158 		    l3pte_index(va) * sizeof(alpha_pt_entry_t);
159 		if (_kvm_pread(kd, kd->pmfd, (char *)&pte, sizeof(pte),
160 		    (off_t)_kvm_pa2off(kd, pteoff)) != sizeof(pte)) {
161 			_kvm_syserr(kd, 0, "could not read L3 PTE");
162 			goto lose;
163 		}
164 
165 		/* Fill in the PA. */
166 		if ((pte & ALPHA_PTE_VALID) == 0) {
167 			_kvm_err(kd, 0, "invalid translation (invalid L3 PTE)");
168 			goto lose;
169 		}
170 		*pa = ALPHA_PTE_TO_PFN(pte) * cpu_kh->page_size + page_off;
171 		rv = cpu_kh->page_size - page_off;
172 	} else {
173 		/*
174 		 * Bogus address (not in KV space): punt.
175 		 */
176 
177 		_kvm_err(kd, 0, "invalid kernel virtual address");
178 lose:
179 		*pa = -1;
180 		rv = 0;
181 	}
182 
183 	return (rv);
184 }
185 
186 /*
187  * Translate a physical address to a file-offset in the crash-dump.
188  */
189 off_t
_kvm_pa2off(kvm_t * kd,paddr_t pa)190 _kvm_pa2off(kvm_t *kd, paddr_t pa)
191 {
192 	cpu_kcore_hdr_t *cpu_kh;
193 	phys_ram_seg_t *ramsegs;
194 	off_t off;
195 	int i;
196 
197 	cpu_kh = kd->cpu_data;
198 	ramsegs = (phys_ram_seg_t *)((char *)cpu_kh + _ALIGN(sizeof *cpu_kh));
199 
200 	off = 0;
201 	for (i = 0; i < cpu_kh->nmemsegs; i++) {
202 		if (pa >= ramsegs[i].start &&
203 		   (pa - ramsegs[i].start) < ramsegs[i].size) {
204 			off += (pa - ramsegs[i].start);
205 			break;
206 		}
207 		off += ramsegs[i].size;
208 	}
209 	return (kd->dump_off + off);
210 }
211