lib/libkvm/kvm_i386pae.c

   1 /* $NetBSD: kvm_i386pae.c,v 1.2 2014/02/19 20:21:22 dsl Exp $ */
   2
   3 /*
   4  * Copyright (c) 2010 Jean-Yves Migeon.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  16  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  17  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  19  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  24  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  25  * POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include <sys/cdefs.h>
  29 __RCSID("$NetBSD: kvm_i386pae.c,v 1.2 2014/02/19 20:21:22 dsl Exp $");
  30
  31 /*
  32  * This will expose PAE functions, macros, definitions and constants.
  33  * Note: this affects all virtual memory related functions. Only their
  34  * PAE versions can be used below.
  35  */
  36 #define PAE
  37
  38 #include <sys/param.h>
  39 #include <sys/stat.h>
  40 #include <sys/kcore.h>
  41 #include <sys/types.h>
  42
  43 #include <stdlib.h>
  44 #include <unistd.h>
  45 #include <nlist.h>
  46 #include <kvm.h>
  47
  48 #include <uvm/uvm_extern.h>
  49
  50 #include <limits.h>
  51 #include <db.h>
  52
  53 #include "kvm_private.h"
  54
  55 #include <i386/kcore.h>
  56 #include <i386/pmap.h>
  57 #include <i386/pte.h>
  58 #include <i386/vmparam.h>
  59
  60 int _kvm_kvatop_i386pae(kvm_t *, vaddr_t, paddr_t *);
  61
  62 /*
  63  * Used to translate a virtual address to a physical address for systems
  64  * running under PAE mode. Three levels of virtual memory pages are handled
  65  * here: the per-CPU L3 page, the 4 L2 PDs and the PTs.
  66  */
  67 int
  68 _kvm_kvatop_i386pae(kvm_t *kd, vaddr_t va, paddr_t *pa)
  69 {
  70         cpu_kcore_hdr_t *cpu_kh;
  71         u_long page_off;
  72         pd_entry_t pde;
  73         pt_entry_t pte;
  74         paddr_t pde_pa, pte_pa;
  75
  76         cpu_kh = kd->cpu_data;
  77         page_off = va & PGOFSET;
  78
  79         /*
  80          * Find and read the PDE. Ignore the L3, as it is only a per-CPU
  81          * page, not needed for kernel VA => PA translations.
  82          * Remember that the 4 L2 pages are contiguous, so it is safe
  83          * to increment pdppaddr to compute the address of the PDE.
  84          * pdppaddr being PAGE_SIZE aligned, we mask the option bits.
  85          */
  86         pde_pa = (cpu_kh->pdppaddr & PG_FRAME) + (pl2_pi(va) * sizeof(pde));
  87         if (_kvm_pread(kd, kd->pmfd, (void *)&pde, sizeof(pde),
  88             _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
  89                 _kvm_syserr(kd, 0, "could not read PDE");
  90                 goto lose;
  91         }
  92
  93         /*
  94          * Find and read the page table entry.
  95          */
  96         if ((pde & PG_V) == 0) {
  97                 _kvm_err(kd, 0, "invalid translation (invalid PDE)");
  98                 goto lose;
  99         }
 100         if ((pde & PG_PS) != 0) {
 101                 /*
 102                  * This is a 2MB page.
 103                  */
 104                 page_off = va & ((vaddr_t)~PG_LGFRAME);
 105                 *pa = (pde & PG_LGFRAME) + page_off;
 106                 return (int)(NBPD_L2 - page_off);
 107         }
 108
 109         pte_pa = (pde & PG_FRAME) + (pl1_pi(va) * sizeof(pt_entry_t));
 110         if (_kvm_pread(kd, kd->pmfd, (void *) &pte, sizeof(pte),
 111             _kvm_pa2off(kd, pte_pa)) != sizeof(pte)) {
 112                 _kvm_syserr(kd, 0, "could not read PTE");
 113                 goto lose;
 114         }
 115
 116         /*
 117          * Validate the PTE and return the physical address.
 118          */
 119         if ((pte & PG_V) == 0) {
 120                 _kvm_err(kd, 0, "invalid translation (invalid PTE)");
 121                 goto lose;
 122         }
 123         *pa = (pte & PG_FRAME) + page_off;
 124         return (int)(NBPG - page_off);
 125
 126 lose:
 127         *pa = (paddr_t)~0L;
 128         return 0;
 129
 130 }