xref: /netbsd-src/lib/libkvm/kvm_i386pae.c (revision 5bbd2a12505d72a8177929a37b5cee489d0a1cfd)
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