1 /* $NetBSD: kvm_aarch64.c,v 1.11 2022/01/10 19:51:30 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2014, 2018 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Matt Thomas of 3am Software Foundry.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/param.h>
33 #include <sys/proc.h>
34 #include <sys/stat.h>
35 #include <sys/kcore.h>
36 #include <sys/types.h>
37 #include <unistd.h>
38 #include <nlist.h>
39 #include <kvm.h>
40
41 #include <machine/kcore.h>
42 #include <machine/armreg.h>
43 #include <machine/pte.h>
44 #include <machine/vmparam.h>
45
46 #include <limits.h>
47 #include <db.h>
48 #include <stdlib.h>
49
50 #include "kvm_private.h"
51
52 __RCSID("$NetBSD: kvm_aarch64.c,v 1.11 2022/01/10 19:51:30 christos Exp $");
53
54 /*ARGSUSED*/
55 void
_kvm_freevtop(kvm_t * kd)56 _kvm_freevtop(kvm_t *kd)
57 {
58 return;
59 }
60
61 /*ARGSUSED*/
62 int
_kvm_initvtop(kvm_t * kd)63 _kvm_initvtop(kvm_t *kd)
64 {
65 return (0);
66 }
67
68 int
_kvm_kvatop(kvm_t * kd,vaddr_t va,paddr_t * pa)69 _kvm_kvatop(kvm_t *kd, vaddr_t va, paddr_t *pa)
70 {
71 if (ISALIVE(kd)) {
72 _kvm_err(kd, 0, "vatop called in live kernel!");
73 return(0);
74 }
75
76 if ((va & AARCH64_DIRECTMAP_MASK) != AARCH64_DIRECTMAP_START) {
77 /*
78 * Bogus address (not in KV space): punt.
79 */
80 _kvm_err(kd, 0, "invalid kernel virtual address");
81 lose:
82 *pa = -1;
83 return 0;
84 }
85
86 const cpu_kcore_hdr_t * const cpu_kh = kd->cpu_data;
87 const uint64_t tg1 = cpu_kh->kh_tcr1 & TCR_TG1;
88 const u_int t1siz = __SHIFTOUT(cpu_kh->kh_tcr1, TCR_T1SZ);
89 const u_int inputsz = 64 - t1siz;
90
91 /*
92 * Real kernel virtual address: do the translation.
93 */
94
95 u_int page_shift;
96
97 switch (tg1) {
98 case TCR_TG1_4KB:
99 page_shift = 12;
100 break;
101 case TCR_TG1_16KB:
102 page_shift = 14;
103 break;
104 case TCR_TG1_64KB:
105 page_shift = 16;
106 break;
107 default:
108 goto lose;
109 }
110
111 const size_t page_size = 1 << page_shift;
112 const uint64_t page_mask = __BITS(page_shift - 1, 0);
113 const uint64_t page_addr = __BITS(47, page_shift);
114 const u_int pte_shift = page_shift - 3;
115
116 /* how many levels of page tables do we have? */
117 u_int levels = howmany(inputsz - page_shift, pte_shift);
118
119 /* restrict va to the valid VA bits */
120 va &= __BITS(inputsz - 1, 0);
121
122 u_int addr_shift = page_shift + (levels - 1) * pte_shift;
123
124 /* clear out the unused low bits of the table address */
125 paddr_t pte_addr = cpu_kh->kh_ttbr1 & TTBR_BADDR;
126
127 for (;;) {
128 pt_entry_t pte;
129
130 /* now index into the pte table */
131 const uint64_t idx_mask = __BITS(addr_shift + pte_shift - 1,
132 addr_shift);
133 pte_addr += 8 * __SHIFTOUT(va, idx_mask);
134
135 /* Find and read the PTE. */
136 if (_kvm_pread(kd, kd->pmfd, &pte, sizeof(pte),
137 _kvm_pa2off(kd, pte_addr)) != sizeof(pte)) {
138 _kvm_syserr(kd, 0, "could not read pte");
139 goto lose;
140 }
141
142 /* Find and read the L2 PTE. */
143 if ((pte & LX_VALID) == 0) {
144 _kvm_err(kd, 0, "invalid translation (invalid pte)");
145 goto lose;
146 }
147
148 if ((pte & LX_TYPE) == LX_TYPE_BLK) {
149 const size_t blk_size = 1 << addr_shift;
150 const uint64_t blk_mask = __BITS(addr_shift - 1, 0);
151
152 *pa = (pte & page_addr & ~blk_mask) | (va & blk_mask);
153 return blk_size - (va & blk_mask);
154 }
155 if (--levels == 0) {
156 *pa = (pte & page_addr) | (va & page_mask);
157 return page_size - (va & page_mask);
158 }
159
160 /*
161 * Read next level of page table
162 */
163
164 pte_addr = pte & page_addr;
165 addr_shift -= pte_shift;
166 }
167 }
168
169 /*
170 * Translate a physical address to a file-offset in the crash dump.
171 */
172 off_t
_kvm_pa2off(kvm_t * kd,paddr_t pa)173 _kvm_pa2off(kvm_t *kd, paddr_t pa)
174 {
175 const cpu_kcore_hdr_t * const cpu_kh = kd->cpu_data;
176 off_t off = 0;
177
178 for (const phys_ram_seg_t *ramsegs = cpu_kh->kh_ramsegs;
179 ramsegs->size != 0; ramsegs++) {
180 if (pa >= ramsegs->start
181 && pa < ramsegs->start + ramsegs->size) {
182 off += pa - ramsegs->start;
183 break;
184 }
185 off += ramsegs->size;
186 }
187
188 return kd->dump_off + off;
189 }
190
191 /*
192 * Machine-dependent initialization for ALL open kvm descriptors,
193 * not just those for a kernel crash dump. Some architectures
194 * have to deal with these NOT being constants! (i.e. m68k)
195 */
196 int
_kvm_mdopen(kvm_t * kd)197 _kvm_mdopen(kvm_t *kd)
198 {
199
200 kd->min_uva = VM_MIN_ADDRESS;
201 kd->max_uva = VM_MAXUSER_ADDRESS;
202
203 return (0);
204 }
205