arch/x86/kernel/platform/i86pc/boot/boot_mmu.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*
  28  * WARNING: This file is used by both dboot and the kernel.
  29  */
  30
  31 #pragma ident   "%Z%%M% %I%     %E% SMI"
  32
  33 #include <sys/param.h>
  34 #include <sys/machparam.h>
  35 #include <sys/mach_mmu.h>
  36
  37 #ifdef _BOOT
  38 #include <dboot_printf.h>
  39 #define bop_panic dboot_panic
  40 #else
  41 #include <sys/bootconf.h>
  42 #endif
  43
  44 uint_t shift_amt_nopae[] = {12, 22};
  45 uint_t shift_amt_pae[] = {12, 21, 30, 39};
  46 uint_t *shift_amt;
  47 uint_t ptes_per_table;
  48 uint_t pte_size;
  49 uint32_t lpagesize;
  50 paddr_t top_page_table;
  51 uint_t top_level;
  52
  53 /*
  54  * Return the index corresponding to a virt address at a given page table level.
  55  */
  56 static uint_t
  57 vatoindex(uint64_t va, uint_t level)
  58 {
  59         return ((va >> shift_amt[level]) & (ptes_per_table - 1));
  60 }
  61
  62 /*
  63  * Return a pointer to the page table entry that maps a virtual address.
  64  * If there is no page table and probe_only is not set, one is created.
  65  */
  66 x86pte_t *
  67 find_pte(uint64_t va, paddr_t *pa, uint_t level, uint_t probe_only)
  68 {
  69         uint_t l;
  70         uint_t index;
  71         paddr_t table;
  72
  73         if (pa)
  74                 *pa = 0;
  75
  76 #ifndef _BOOT
  77         if (IN_HYPERVISOR_VA(va))
  78                 return (NULL);
  79 #endif
  80
  81         /*
  82          * Walk down the page tables creating any needed intermediate tables.
  83          */
  84         table = top_page_table;
  85         for (l = top_level; l != level; --l) {
  86                 uint64_t pteval;
  87                 paddr_t new_table;
  88
  89                 index = vatoindex(va, l);
  90                 pteval = get_pteval(table, index);
  91
  92                 /*
  93                  * Life is easy if we find the pagetable.  We just use it.
  94                  */
  95                 if (pteval & PT_VALID) {
  96                         table = ma_to_pa(pteval & MMU_PAGEMASK);
  97                         if (table == -1) {
  98                                 if (probe_only)
  99                                         return (NULL);
 100                                 bop_panic("find_pte(): phys not found!");
 101                         }
 102                         continue;
 103                 }
 104
 105                 if (probe_only)
 106                         return (NULL);
 107
 108                 new_table = make_ptable(&pteval, l);
 109                 set_pteval(table, index, l, pteval);
 110
 111                 table = new_table;
 112         }
 113
 114         /*
 115          * Return a pointer into the current pagetable.
 116          */
 117         index = vatoindex(va, l);
 118         if (pa)
 119                 *pa = table + index * pte_size;
 120         return (map_pte(table, index));
 121 }