lib/libkvm/kvm_aarch64.c

   1 /* $NetBSD: kvm_aarch64.c,v 1.1 2014/08/10 05:47:37 matt 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/user.h>
  34 #include <sys/proc.h>
  35 #include <sys/stat.h>
  36 #include <sys/kcore.h>
  37 #include <sys/types.h>
  38 #include <unistd.h>
  39 #include <nlist.h>
  40 #include <kvm.h>
  41
  42 #include <machine/kcore.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 1.1 2014/08/10 05:47:37 matt Exp $");
  53
  54 /*ARGSUSED*/
  55 void
  56 _kvm_freevtop(kvm_t *kd)
  57 {
  58         return;
  59 }
  60
  61 /*ARGSUSED*/
  62 int
  63 _kvm_initvtop(kvm_t *kd)
  64 {
  65         return (0);
  66 }
  67
  68 int
  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_KSEG_MASK) != AARCH64_KSEG_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 u_int tg1 =__SHIFTOUT(cpu_kh->kh_tcr1, TCR_TG1);
  88         const u_int t1siz = __SHIFTOUT(cpu_kh->kh_tcr1, TCR_T1SZ);
  89
  90         /*
  91          * Real kernel virtual address: do the translation.
  92          */
  93
  94         u_int va_bits;
  95         u_int page_shift;
  96
  97         switch (tg1) {
  98         case TCR_TG_4KB:
  99                 va_bits = t1siz + 36;
 100                 page_shift = 12;
 101                 break;
 102         case TCR_TG_16KB:
 103                 va_bits = 48;
 104                 page_shift = 14;
 105                 break;
 106         case TCR_TG_64KB:
 107                 va_bits = t1siz + 38;
 108                 page_shift = 16;
 109                 break;
 110         default:
 111                 goto lose;
 112         }
 113
 114         const size_t page_size = 1 << page_shift;
 115         const uint64_t page_mask = (page_size - 1);
 116         const uint64_t page_addr = __BITS(47, 0) & ~page_mask;
 117         const uint64_t pte_mask = page_mask >> 3;
 118         const u_int pte_shift = page_shift - 3;
 119
 120         /* how many level of page tables do we have? */
 121         u_int level = (48 + page_shift - 1) / page_shift;
 122
 123         /* restrict va to the valid VA bits */
 124         va &= (1LL << va_bits) - 1;
 125
 126         u_int addr_shift = page_shift + (level - 1) * pte_shift;
 127
 128         /* clear out the unused low bits of the table address */
 129         paddr_t pte_addr = (cpu_kh->kh_ttbr1 & TTBR_BADDR);
 130         pte_addr &= ~((8L << (va_bits - addr_shift)) - 1);
 131
 132         for (;;) {
 133                 pt_entry_t pte;
 134
 135                 /* now index into the pte table */
 136                 pte_addr += 8 * ((va >> addr_shift) & pte_mask);
 137
 138                 /* Find and read the PTE. */
 139                 if (_kvm_pread(kd, kd->pmfd, &pte, sizeof(pte),
 140                     _kvm_pa2off(kd, pte_addr)) != sizeof(pte)) {
 141                         _kvm_syserr(kd, 0, "could not read pte");
 142                         goto lose;
 143                 }
 144
 145                 /* Find and read the L2 PTE. */
 146                 if ((pte & LX_VALID) == 0) {
 147                         _kvm_err(kd, 0, "invalid translation (invalid pte)");
 148                         goto lose;
 149                 }
 150
 151                 if ((pte & LX_TYPE) == LX_TYPE_BLK) {
 152                         const paddr_t blk_mask = ((1L << addr_shift) - 1);
 153
 154                         *pa = (pte & page_addr & ~blk_mask) | (va & blk_mask);
 155                         return 0;
 156                 }
 157
 158                 if (level == page_shift) {
 159                         *pa = (pte & page_addr) | (va & page_mask);
 160                         return 0;
 161                 }
 162
 163                 /*
 164                  * Read next level of page table
 165                  */
 166
 167                 pte_addr = pte & page_addr;
 168                 addr_shift -= pte_shift;
 169         }
 170 }
 171
 172 /*
 173  * Translate a physical address to a file-offset in the crash dump.
 174  */
 175 off_t
 176 _kvm_pa2off(kvm_t *kd, paddr_t pa)
 177 {
 178         const cpu_kcore_hdr_t * const cpu_kh = kd->cpu_data;
 179         off_t off = 0;
 180
 181         for (const phys_ram_seg_t *ramsegs = cpu_kh->kh_ramsegs;
 182              ramsegs->size != 0; ramsegs++) {
 183                 if (pa >= ramsegs->start
 184                     && pa < ramsegs->start + ramsegs->size) {
 185                         off += pa - ramsegs->start;
 186                         break;
 187                 }
 188                 off += ramsegs->size;
 189         }
 190
 191         return kd->dump_off + off;
 192 }
 193
 194 /*
 195  * Machine-dependent initialization for ALL open kvm descriptors,
 196  * not just those for a kernel crash dump.  Some architectures
 197  * have to deal with these NOT being constants!  (i.e. m68k)
 198  */
 199 int
 200 _kvm_mdopen(kvm_t *kd)
 201 {
 202
 203         kd->usrstack = USRSTACK;
 204         kd->min_uva = VM_MIN_ADDRESS;
 205         kd->max_uva = VM_MAXUSER_ADDRESS;
 206
 207         return (0);
 208 }