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kvm_i386pae.c revision 1.1 
      1 /* $NetBSD: kvm_i386pae.c,v 1.1 2010/10/05 23:48:16 jym 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 1.1 2010/10/05 23:48:16 jym 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/user.h>
     40 #include <sys/stat.h>
     41 #include <sys/kcore.h>
     42 #include <sys/types.h>
     43 
     44 #include <stdlib.h>
     45 #include <unistd.h>
     46 #include <nlist.h>
     47 #include <kvm.h>
     48 
     49 #include <uvm/uvm_extern.h>
     50 
     51 #include <limits.h>
     52 #include <db.h>
     53 
     54 #include "kvm_private.h"
     55 
     56 #include <i386/kcore.h>
     57 #include <i386/pmap.h>
     58 #include <i386/pte.h>
     59 #include <i386/vmparam.h>
     60 
     61 int _kvm_kvatop_i386pae(kvm_t *, vaddr_t, paddr_t *);
     62 
     63 /*
     64  * Used to translate a virtual address to a physical address for systems
     65  * running under PAE mode. Three levels of virtual memory pages are handled
     66  * here: the per-CPU L3 page, the 4 L2 PDs and the PTs.
     67  */
     68 int
     69 _kvm_kvatop_i386pae(kvm_t *kd, vaddr_t va, paddr_t *pa)
     70 {
     71 	cpu_kcore_hdr_t *cpu_kh;
     72 	u_long page_off;
     73 	pd_entry_t pde;
     74 	pt_entry_t pte;
     75 	paddr_t pde_pa, pte_pa;
     76 
     77 	cpu_kh = kd->cpu_data;
     78 	page_off = va & PGOFSET;
     79 
     80 	/*
     81 	 * Find and read the PDE. Ignore the L3, as it is only a per-CPU
     82 	 * page, not needed for kernel VA => PA translations.
     83 	 * Remember that the 4 L2 pages are contiguous, so it is safe
     84 	 * to increment pdppaddr to compute the address of the PDE.
     85 	 * pdppaddr being PAGE_SIZE aligned, we mask the option bits.
     86 	 */
     87 	pde_pa = (cpu_kh->pdppaddr & PG_FRAME) + (pl2_pi(va) * sizeof(pde));
     88 	if (_kvm_pread(kd, kd->pmfd, (void *)&pde, sizeof(pde),
     89 	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
     90 		_kvm_syserr(kd, 0, "could not read PDE");
     91 		goto lose;
     92 	}
     93 
     94 	/*
     95 	 * Find and read the page table entry.
     96 	 */
     97 	if ((pde & PG_V) == 0) {
     98 		_kvm_err(kd, 0, "invalid translation (invalid PDE)");
     99 		goto lose;
    100 	}
    101 	if ((pde & PG_PS) != 0) {
    102 		/*
    103 		 * This is a 2MB page.
    104 		 */
    105 		page_off = va & ((vaddr_t)~PG_LGFRAME);
    106 		*pa = (pde & PG_LGFRAME) + page_off;
    107 		return (int)(NBPD_L2 - page_off);
    108 	}
    109 
    110 	pte_pa = (pde & PG_FRAME) + (pl1_pi(va) * sizeof(pt_entry_t));
    111 	if (_kvm_pread(kd, kd->pmfd, (void *) &pte, sizeof(pte),
    112 	    _kvm_pa2off(kd, pte_pa)) != sizeof(pte)) {
    113 		_kvm_syserr(kd, 0, "could not read PTE");
    114 		goto lose;
    115 	}
    116 
    117 	/*
    118 	 * Validate the PTE and return the physical address.
    119 	 */
    120 	if ((pte & PG_V) == 0) {
    121 		_kvm_err(kd, 0, "invalid translation (invalid PTE)");
    122 		goto lose;
    123 	}
    124 	*pa = (pte & PG_FRAME) + page_off;
    125 	return (int)(NBPG - page_off);
    126 
    127 lose:
    128 	*pa = (paddr_t)~0L;
    129 	return 0;
    130 
    131 }
    132