kvm_aarch64.c revision 1.5 
1/* $NetBSD: kvm_aarch64.c,v 1.5 2018/11/09 04:06:40 mrg Exp $ */
2
3/*-
4 * Copyright (c) 2014 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/pte.h>
43#include <machine/vmparam.h>
44
45#include <limits.h>
46#include <db.h>
47#include <stdlib.h>
48
49#include "kvm_private.h"
50
51__RCSID("$NetBSD: kvm_aarch64.c,v 1.5 2018/11/09 04:06:40 mrg Exp $");
52
53/*ARGSUSED*/
54void
55_kvm_freevtop(kvm_t *kd)
56{
57	return;
58}
59
60/*ARGSUSED*/
61int
62_kvm_initvtop(kvm_t *kd)
63{
64	return (0);
65}
66
67int
68_kvm_kvatop(kvm_t *kd, vaddr_t va, paddr_t *pa)
69{
70        if (ISALIVE(kd)) {
71                _kvm_err(kd, 0, "vatop called in live kernel!");
72                return(0);
73        }
74
75	if ((va & AARCH64_KSEG_MASK) != AARCH64_KSEG_START) {
76		/*
77		 * Bogus address (not in KV space): punt.
78		 */
79		_kvm_err(kd, 0, "invalid kernel virtual address");
80lose:
81		*pa = -1;
82		return 0;
83	}
84
85	const cpu_kcore_hdr_t * const cpu_kh = kd->cpu_data;
86	const uint64_t tg1 = cpu_kh->kh_tcr1 & TCR_TG1;
87	const u_int t1siz = __SHIFTOUT(cpu_kh->kh_tcr1, TCR_T1SZ);
88
89	/*
90	 * Real kernel virtual address: do the translation.
91	 */
92
93	u_int va_bits;
94	u_int page_shift;
95
96	switch (tg1) {
97	case TCR_TG1_4KB:
98		va_bits = t1siz + 36;
99		page_shift = 12;
100		break;
101	case TCR_TG1_16KB:
102		va_bits = 48;
103		page_shift = 14;
104		break;
105	case TCR_TG1_64KB:
106		va_bits = t1siz + 38;
107		page_shift = 16;
108		break;
109	default:
110		goto lose;
111	}
112
113	const size_t page_size = 1 << page_shift;
114	const uint64_t page_mask = (page_size - 1);
115	const uint64_t page_addr = __BITS(47, 0) & ~page_mask;
116	const uint64_t pte_mask = page_mask >> 3;
117	const u_int pte_shift = page_shift - 3;
118
119	/* how many level of page tables do we have? */
120	u_int level = (48 + page_shift - 1) / page_shift;
121
122	/* restrict va to the valid VA bits */
123	va &= (1LL << va_bits) - 1;
124
125	u_int addr_shift = page_shift + (level - 1) * pte_shift;
126
127	/* clear out the unused low bits of the table address */
128	paddr_t pte_addr = (cpu_kh->kh_ttbr1 & TTBR_BADDR);
129	pte_addr &= ~((8L << (va_bits - addr_shift)) - 1);
130
131	for (;;) {
132		pt_entry_t pte;
133
134		/* now index into the pte table */
135		pte_addr += 8 * ((va >> addr_shift) & pte_mask);
136
137		/* Find and read the PTE. */
138		if (_kvm_pread(kd, kd->pmfd, &pte, sizeof(pte),
139		    _kvm_pa2off(kd, pte_addr)) != sizeof(pte)) {
140			_kvm_syserr(kd, 0, "could not read pte");
141			goto lose;
142		}
143
144		/* Find and read the L2 PTE. */
145		if ((pte & LX_VALID) == 0) {
146			_kvm_err(kd, 0, "invalid translation (invalid pte)");
147			goto lose;
148		}
149
150		if ((pte & LX_TYPE) == LX_TYPE_BLK) {
151			const paddr_t blk_mask = ((1L << addr_shift) - 1);
152
153			*pa = (pte & page_addr & ~blk_mask) | (va & blk_mask);
154			return 0;
155		}
156
157		if (level == page_shift) {
158			*pa = (pte & page_addr) | (va & page_mask);
159			return 0;
160		}
161
162		/*
163		 * Read next level of page table
164		 */
165
166		pte_addr = pte & page_addr;
167		addr_shift -= pte_shift;
168	}
169}
170
171/*
172 * Translate a physical address to a file-offset in the crash dump.
173 */
174off_t
175_kvm_pa2off(kvm_t *kd, paddr_t pa)
176{
177	const cpu_kcore_hdr_t * const cpu_kh = kd->cpu_data;
178	off_t off = 0;
179
180	for (const phys_ram_seg_t *ramsegs = cpu_kh->kh_ramsegs;
181	     ramsegs->size != 0; ramsegs++) {
182		if (pa >= ramsegs->start
183		    && pa < ramsegs->start + ramsegs->size) {
184			off += pa - ramsegs->start;
185			break;
186		}
187		off += ramsegs->size;
188	}
189
190	return kd->dump_off + off;
191}
192
193/*
194 * Machine-dependent initialization for ALL open kvm descriptors,
195 * not just those for a kernel crash dump.  Some architectures
196 * have to deal with these NOT being constants!  (i.e. m68k)
197 */
198int
199_kvm_mdopen(kvm_t *kd)
200{
201
202	kd->usrstack = USRSTACK;
203	kd->min_uva = VM_MIN_ADDRESS;
204	kd->max_uva = VM_MAXUSER_ADDRESS;
205
206	return (0);
207}
208