1/* $NetBSD: kvm_aarch64.c,v 1.12 2023/08/23 14:00:11 rin 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 1.12 2023/08/23 14:00:11 rin Exp $");
53
54/*ARGSUSED*/
55void
56_kvm_freevtop(kvm_t *kd)
57{
58	return;
59}
60
61/*ARGSUSED*/
62int
63_kvm_initvtop(kvm_t *kd)
64{
65	return (0);
66}
67
68int
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");
81lose:
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 */
172off_t
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 */
196int
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