Subversion Repositories HelenOS

Rev

Rev 2106 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
684 jermar 1
/*
2071 jermar 2
 * Copyright (c) 2006 Jakub Jermar
684 jermar 3
 * All rights reserved.
4
 *
5
 * Redistribution and use in source and binary forms, with or without
6
 * modification, are permitted provided that the following conditions
7
 * are met:
8
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - 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
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
1851 jermar 29
/** @addtogroup genarchmm
1702 cejka 30
 * @{
31
 */
32
 
1266 jermar 33
/**
1702 cejka 34
 * @file
1266 jermar 35
 * @brief   Virtual Address Translation for hierarchical 4-level page tables.
36
 */
37
 
684 jermar 38
#include <genarch/mm/page_pt.h>
39
#include <mm/page.h>
40
#include <mm/frame.h>
756 jermar 41
#include <mm/as.h>
684 jermar 42
#include <arch/mm/page.h>
755 jermar 43
#include <arch/mm/as.h>
684 jermar 44
#include <arch/types.h>
45
#include <arch/asm.h>
46
#include <memstr.h>
47
 
1780 jermar 48
static void pt_mapping_insert(as_t *as, uintptr_t page, uintptr_t frame, int flags);
49
static void pt_mapping_remove(as_t *as, uintptr_t page);
50
static pte_t *pt_mapping_find(as_t *as, uintptr_t page);
684 jermar 51
 
793 jermar 52
page_mapping_operations_t pt_mapping_operations = {
684 jermar 53
    .mapping_insert = pt_mapping_insert,
826 jermar 54
    .mapping_remove = pt_mapping_remove,
684 jermar 55
    .mapping_find = pt_mapping_find
56
};
57
 
58
/** Map page to frame using hierarchical page tables.
59
 *
1248 jermar 60
 * Map virtual address page to physical address frame
61
 * using flags.
684 jermar 62
 *
1044 jermar 63
 * The page table must be locked and interrupts must be disabled.
756 jermar 64
 *
65
 * @param as Address space to wich page belongs.
684 jermar 66
 * @param page Virtual address of the page to be mapped.
67
 * @param frame Physical address of memory frame to which the mapping is done.
68
 * @param flags Flags to be used for mapping.
69
 */
1780 jermar 70
void pt_mapping_insert(as_t *as, uintptr_t page, uintptr_t frame, int flags)
684 jermar 71
{
72
    pte_t *ptl0, *ptl1, *ptl2, *ptl3;
1760 palkovsky 73
    pte_t *newpt;
684 jermar 74
 
2106 jermar 75
    ptl0 = (pte_t *) PA2KA((uintptr_t) as->genarch.page_table);
684 jermar 76
 
77
    if (GET_PTL1_FLAGS(ptl0, PTL0_INDEX(page)) & PAGE_NOT_PRESENT) {
1760 palkovsky 78
        newpt = (pte_t *)frame_alloc(ONE_FRAME, FRAME_KA);
1780 jermar 79
        memsetb((uintptr_t)newpt, PAGE_SIZE, 0);
684 jermar 80
        SET_PTL1_ADDRESS(ptl0, PTL0_INDEX(page), KA2PA(newpt));
81
        SET_PTL1_FLAGS(ptl0, PTL0_INDEX(page), PAGE_PRESENT | PAGE_USER | PAGE_EXEC | PAGE_CACHEABLE | PAGE_WRITE);
82
    }
83
 
84
    ptl1 = (pte_t *) PA2KA(GET_PTL1_ADDRESS(ptl0, PTL0_INDEX(page)));
85
 
86
    if (GET_PTL2_FLAGS(ptl1, PTL1_INDEX(page)) & PAGE_NOT_PRESENT) {
1760 palkovsky 87
        newpt = (pte_t *)frame_alloc(ONE_FRAME, FRAME_KA);
1780 jermar 88
        memsetb((uintptr_t)newpt, PAGE_SIZE, 0);
684 jermar 89
        SET_PTL2_ADDRESS(ptl1, PTL1_INDEX(page), KA2PA(newpt));
90
        SET_PTL2_FLAGS(ptl1, PTL1_INDEX(page), PAGE_PRESENT | PAGE_USER | PAGE_EXEC | PAGE_CACHEABLE | PAGE_WRITE);
91
    }
92
 
93
    ptl2 = (pte_t *) PA2KA(GET_PTL2_ADDRESS(ptl1, PTL1_INDEX(page)));
94
 
95
    if (GET_PTL3_FLAGS(ptl2, PTL2_INDEX(page)) & PAGE_NOT_PRESENT) {
1760 palkovsky 96
        newpt = (pte_t *)frame_alloc(ONE_FRAME, FRAME_KA);
1780 jermar 97
        memsetb((uintptr_t)newpt, PAGE_SIZE, 0);
684 jermar 98
        SET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page), KA2PA(newpt));
99
        SET_PTL3_FLAGS(ptl2, PTL2_INDEX(page), PAGE_PRESENT | PAGE_USER | PAGE_EXEC | PAGE_CACHEABLE | PAGE_WRITE);
100
    }
101
 
102
    ptl3 = (pte_t *) PA2KA(GET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page)));
103
 
104
    SET_FRAME_ADDRESS(ptl3, PTL3_INDEX(page), frame);
105
    SET_FRAME_FLAGS(ptl3, PTL3_INDEX(page), flags);
106
}
107
 
826 jermar 108
/** Remove mapping of page from hierarchical page tables.
109
 *
1248 jermar 110
 * Remove any mapping of page within address space as.
826 jermar 111
 * TLB shootdown should follow in order to make effects of
112
 * this call visible.
113
 *
832 jermar 114
 * Empty page tables except PTL0 are freed.
115
 *
1044 jermar 116
 * The page table must be locked and interrupts must be disabled.
826 jermar 117
 *
1248 jermar 118
 * @param as Address space to wich page belongs.
826 jermar 119
 * @param page Virtual address of the page to be demapped.
120
 */
1780 jermar 121
void pt_mapping_remove(as_t *as, uintptr_t page)
826 jermar 122
{
123
    pte_t *ptl0, *ptl1, *ptl2, *ptl3;
832 jermar 124
    bool empty = true;
125
    int i;
826 jermar 126
 
832 jermar 127
    /*
128
     * First, remove the mapping, if it exists.
129
     */
130
 
2106 jermar 131
    ptl0 = (pte_t *) PA2KA((uintptr_t) as->genarch.page_table);
826 jermar 132
 
133
    if (GET_PTL1_FLAGS(ptl0, PTL0_INDEX(page)) & PAGE_NOT_PRESENT)
134
        return;
135
 
136
    ptl1 = (pte_t *) PA2KA(GET_PTL1_ADDRESS(ptl0, PTL0_INDEX(page)));
137
 
138
    if (GET_PTL2_FLAGS(ptl1, PTL1_INDEX(page)) & PAGE_NOT_PRESENT)
139
        return;
140
 
141
    ptl2 = (pte_t *) PA2KA(GET_PTL2_ADDRESS(ptl1, PTL1_INDEX(page)));
142
 
143
    if (GET_PTL3_FLAGS(ptl2, PTL2_INDEX(page)) & PAGE_NOT_PRESENT)
144
        return;
145
 
146
    ptl3 = (pte_t *) PA2KA(GET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page)));
147
 
148
    /* Destroy the mapping. Setting to PAGE_NOT_PRESENT is not sufficient. */
1780 jermar 149
    memsetb((uintptr_t) &ptl3[PTL3_INDEX(page)], sizeof(pte_t), 0);
832 jermar 150
 
151
    /*
152
     * Second, free all empty tables along the way from PTL3 down to PTL0.
153
     */
154
 
155
    /* check PTL3 */
156
    for (i = 0; i < PTL3_ENTRIES; i++) {
157
        if (PTE_VALID(&ptl3[i])) {
158
            empty = false;
159
            break;
160
        }
161
    }
162
    if (empty) {
163
        /*
164
         * PTL3 is empty.
165
         * Release the frame and remove PTL3 pointer from preceding table.
166
         */
1780 jermar 167
        frame_free(KA2PA((uintptr_t) ptl3));
832 jermar 168
        if (PTL2_ENTRIES)
1780 jermar 169
            memsetb((uintptr_t) &ptl2[PTL2_INDEX(page)], sizeof(pte_t), 0);
832 jermar 170
        else if (PTL1_ENTRIES)
1780 jermar 171
            memsetb((uintptr_t) &ptl1[PTL1_INDEX(page)], sizeof(pte_t), 0);
832 jermar 172
        else
1780 jermar 173
            memsetb((uintptr_t) &ptl0[PTL0_INDEX(page)], sizeof(pte_t), 0);
832 jermar 174
    } else {
175
        /*
176
         * PTL3 is not empty.
177
         * Therefore, there must be a path from PTL0 to PTL3 and
178
         * thus nothing to free in higher levels.
179
         */
180
        return;
181
    }
182
 
183
    /* check PTL2, empty is still true */
184
    if (PTL2_ENTRIES) {
185
        for (i = 0; i < PTL2_ENTRIES; i++) {
186
            if (PTE_VALID(&ptl2[i])) {
187
                empty = false;
188
                break;
189
            }
190
        }
191
        if (empty) {
192
            /*
193
             * PTL2 is empty.
194
             * Release the frame and remove PTL2 pointer from preceding table.
195
             */
1780 jermar 196
            frame_free(KA2PA((uintptr_t) ptl2));
832 jermar 197
            if (PTL1_ENTRIES)
1780 jermar 198
                memsetb((uintptr_t) &ptl1[PTL1_INDEX(page)], sizeof(pte_t), 0);
832 jermar 199
            else
1780 jermar 200
                memsetb((uintptr_t) &ptl0[PTL0_INDEX(page)], sizeof(pte_t), 0);
832 jermar 201
        }
202
        else {
203
            /*
204
             * PTL2 is not empty.
205
             * Therefore, there must be a path from PTL0 to PTL2 and
206
             * thus nothing to free in higher levels.
207
             */
208
            return;
209
        }
210
    }
211
 
212
    /* check PTL1, empty is still true */
213
    if (PTL1_ENTRIES) {
214
        for (i = 0; i < PTL1_ENTRIES; i++) {
215
            if (PTE_VALID(&ptl1[i])) {
216
                empty = false;
217
                break;
218
            }
219
        }
220
        if (empty) {
221
            /*
222
             * PTL1 is empty.
223
             * Release the frame and remove PTL1 pointer from preceding table.
224
             */
1780 jermar 225
            frame_free(KA2PA((uintptr_t) ptl1));
226
            memsetb((uintptr_t) &ptl0[PTL0_INDEX(page)], sizeof(pte_t), 0);
832 jermar 227
        }
228
    }
229
 
826 jermar 230
}
231
 
684 jermar 232
/** Find mapping for virtual page in hierarchical page tables.
233
 *
234
 * Find mapping for virtual page.
235
 *
1044 jermar 236
 * The page table must be locked and interrupts must be disabled.
756 jermar 237
 *
1248 jermar 238
 * @param as Address space to which page belongs.
684 jermar 239
 * @param page Virtual page.
240
 *
241
 * @return NULL if there is no such mapping; entry from PTL3 describing the mapping otherwise.
242
 */
1780 jermar 243
pte_t *pt_mapping_find(as_t *as, uintptr_t page)
684 jermar 244
{
245
    pte_t *ptl0, *ptl1, *ptl2, *ptl3;
246
 
2106 jermar 247
    ptl0 = (pte_t *) PA2KA((uintptr_t) as->genarch.page_table);
684 jermar 248
 
249
    if (GET_PTL1_FLAGS(ptl0, PTL0_INDEX(page)) & PAGE_NOT_PRESENT)
250
        return NULL;
251
 
252
    ptl1 = (pte_t *) PA2KA(GET_PTL1_ADDRESS(ptl0, PTL0_INDEX(page)));
253
 
254
    if (GET_PTL2_FLAGS(ptl1, PTL1_INDEX(page)) & PAGE_NOT_PRESENT)
255
        return NULL;
256
 
257
    ptl2 = (pte_t *) PA2KA(GET_PTL2_ADDRESS(ptl1, PTL1_INDEX(page)));
258
 
259
    if (GET_PTL3_FLAGS(ptl2, PTL2_INDEX(page)) & PAGE_NOT_PRESENT)
260
        return NULL;
261
 
262
    ptl3 = (pte_t *) PA2KA(GET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page)));
263
 
264
    return &ptl3[PTL3_INDEX(page)];
265
}
1702 cejka 266
 
1851 jermar 267
/** @}
1702 cejka 268
 */