xref: /netbsd-src/lib/libkvm/kvm_aarch64.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* $NetBSD: kvm_aarch64.c,v 1.3 2018/04/01 04:35:02 ryo 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 1.3 2018/04/01 04:35:02 ryo Exp $");
52 
53 /*ARGSUSED*/
54 void
55 _kvm_freevtop(kvm_t *kd)
56 {
57 	return;
58 }
59 
60 /*ARGSUSED*/
61 int
62 _kvm_initvtop(kvm_t *kd)
63 {
64 	return (0);
65 }
66 
67 int
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");
80 lose:
81 		*pa = -1;
82 		return 0;
83 	}
84 
85 	const cpu_kcore_hdr_t * const cpu_kh = kd->cpu_data;
86 	const u_int tg1 =__SHIFTOUT(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  */
174 off_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  */
198 int
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