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703 jermar 1
/*
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 * Copyright (C) 2001-2006 Jakub Jermar
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *
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 * - Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright
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 *   notice, this list of conditions and the following disclaimer in the
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 *   documentation and/or other materials provided with the distribution.
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 * - The name of the author may not be used to endorse or promote products
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 *   derived from this software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
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/*
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 * This file contains address space manipulation functions.
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 * Roughly speaking, this is a higher-level client of
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 * Virtual Address Translation (VAT) subsystem.
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 */
34
 
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#include <mm/as.h>
756 jermar 36
#include <arch/mm/as.h>
703 jermar 37
#include <mm/page.h>
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#include <mm/frame.h>
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#include <mm/tlb.h>
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#include <mm/heap.h>
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#include <arch/mm/page.h>
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#include <genarch/mm/page_pt.h>
727 jermar 43
#include <mm/asid.h>
703 jermar 44
#include <arch/mm/asid.h>
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#include <arch/types.h>
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#include <typedefs.h>
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#include <synch/spinlock.h>
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#include <config.h>
788 jermar 49
#include <adt/list.h>
703 jermar 50
#include <panic.h>
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#include <arch/asm.h>
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#include <debug.h>
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#include <memstr.h>
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#include <arch.h>
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#include <print.h>
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756 jermar 57
as_operations_t *as_operations = NULL;
703 jermar 58
 
757 jermar 59
/** Kernel address space. */
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as_t *AS_KERNEL = NULL;
61
 
754 jermar 62
static int get_area_flags(as_area_t *a);
703 jermar 63
 
756 jermar 64
/** Initialize address space subsystem. */
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void as_init(void)
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{
67
    as_arch_init();
778 palkovsky 68
    AS_KERNEL = as_create(FLAG_AS_KERNEL | FLAG_AS_EARLYMALLOC);
756 jermar 69
        if (!AS_KERNEL)
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                panic("can't create kernel address space\n");
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}
72
 
757 jermar 73
/** Create address space.
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 *
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 * @param flags Flags that influence way in wich the address space is created.
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 */
756 jermar 77
as_t *as_create(int flags)
703 jermar 78
{
79
    as_t *as;
80
 
778 palkovsky 81
    if (flags & FLAG_AS_EARLYMALLOC)
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        as = (as_t *) early_malloc(sizeof(as_t));
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    else
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        as = (as_t *) malloc(sizeof(as_t));
703 jermar 85
    if (as) {
727 jermar 86
        list_initialize(&as->as_with_asid_link);
703 jermar 87
        spinlock_initialize(&as->lock, "as_lock");
88
        list_initialize(&as->as_area_head);
89
 
755 jermar 90
        if (flags & FLAG_AS_KERNEL)
727 jermar 91
            as->asid = ASID_KERNEL;
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        else
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            as->asid = ASID_INVALID;
703 jermar 94
 
756 jermar 95
        as->page_table = page_table_create(flags);
703 jermar 96
    }
97
 
98
    return as;
99
}
100
 
101
/** Create address space area of common attributes.
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 *
103
 * The created address space area is added to the target address space.
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 *
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 * @param as Target address space.
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 * @param type Type of area.
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 * @param size Size of area in multiples of PAGE_SIZE.
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 * @param base Base address of area.
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 *
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 * @return Address space area on success or NULL on failure.
111
 */
112
as_area_t *as_area_create(as_t *as, as_area_type_t type, size_t size, __address base)
113
{
114
    ipl_t ipl;
115
    as_area_t *a;
116
 
117
    if (base % PAGE_SIZE)
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        panic("addr not aligned to a page boundary");
119
 
120
    ipl = interrupts_disable();
121
    spinlock_lock(&as->lock);
122
 
123
    /*
124
     * TODO: test as_area which is to be created doesn't overlap with an existing one.
125
     */
126
 
127
    a = (as_area_t *) malloc(sizeof(as_area_t));
754 jermar 128
    if (a) {   
703 jermar 129
        spinlock_initialize(&a->lock, "as_area_lock");
130
 
131
        link_initialize(&a->link);         
132
        a->type = type;
133
        a->size = size;
134
        a->base = base;
135
 
136
        list_append(&a->link, &as->as_area_head);
137
    }
138
 
139
    spinlock_unlock(&as->lock);
140
    interrupts_restore(ipl);
704 jermar 141
 
703 jermar 142
    return a;
143
}
144
 
754 jermar 145
/** Initialize mapping for one page of address space.
703 jermar 146
 *
754 jermar 147
 * This functions maps 'page' to 'frame' according
148
 * to attributes of the address space area to
149
 * wich 'page' belongs.
703 jermar 150
 *
754 jermar 151
 * @param a Target address space.
152
 * @param page Virtual page within the area.
153
 * @param frame Physical frame to which page will be mapped.
703 jermar 154
 */
754 jermar 155
void as_set_mapping(as_t *as, __address page, __address frame)
703 jermar 156
{
754 jermar 157
    as_area_t *a, *area = NULL;
158
    link_t *cur;
703 jermar 159
    ipl_t ipl;
160
 
161
    ipl = interrupts_disable();
754 jermar 162
    spinlock_lock(&as->lock);
703 jermar 163
 
754 jermar 164
    /*
165
     * First, try locate an area.
166
     */
167
    for (cur = as->as_area_head.next; cur != &as->as_area_head; cur = cur->next) {
168
        a = list_get_instance(cur, as_area_t, link);
169
        spinlock_lock(&a->lock);
170
 
171
        if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {
172
            area = a;
173
            break;
174
        }
175
 
176
        spinlock_unlock(&a->lock);
177
    }
718 decky 178
 
754 jermar 179
    if (!area) {
180
        panic("page not part of any as_area\n");
181
    }
182
 
183
    /*
184
     * Note: area->lock is held.
185
     */
186
 
756 jermar 187
    page_mapping_insert(as, page, frame, get_area_flags(area));
754 jermar 188
 
189
    spinlock_unlock(&area->lock);
190
    spinlock_unlock(&as->lock);
703 jermar 191
    interrupts_restore(ipl);
192
}
193
 
194
/** Handle page fault within the current address space.
195
 *
196
 * This is the high-level page fault handler.
197
 * Interrupts are assumed disabled.
198
 *
199
 * @param page Faulting page.
200
 *
704 jermar 201
 * @return 0 on page fault, 1 on success.
703 jermar 202
 */
203
int as_page_fault(__address page)
204
{
205
    link_t *cur;
206
    as_area_t *a, *area = NULL;
207
    __address frame;
208
 
209
    ASSERT(AS);
210
    spinlock_lock(&AS->lock);
211
 
212
    /*
213
     * Search this areas of this address space for presence of 'page'.
214
     */
215
    for (cur = AS->as_area_head.next; cur != &AS->as_area_head; cur = cur->next) {
216
        a = list_get_instance(cur, as_area_t, link);
217
        spinlock_lock(&a->lock);
218
 
219
        if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {
220
 
221
            /*
222
             * We found the area containing 'page'.
223
             * TODO: access checking
224
             */
225
            area = a;
226
            break;
227
        }
228
 
229
        spinlock_unlock(&a->lock);
230
    }
231
 
232
    if (!area) {
233
        /*
234
         * No area contained mapping for 'page'.
235
         * Signal page fault to low-level handler.
236
         */
237
        spinlock_unlock(&AS->lock);
238
        return 0;
239
    }
240
 
241
    /*
242
     * Note: area->lock is held.
243
     */
244
 
245
    /*
754 jermar 246
     * In general, there can be several reasons that
247
     * can have caused this fault.
248
     *
249
     * - non-existent mapping: the area is a scratch
250
     *   area (e.g. stack) and so far has not been
251
     *   allocated a frame for the faulting page
252
     *
253
     * - non-present mapping: another possibility,
254
     *   currently not implemented, would be frame
255
     *   reuse; when this becomes a possibility,
256
     *   do not forget to distinguish between
257
     *   the different causes
703 jermar 258
     */
786 bondari 259
    frame = frame_alloc(ONE_FRAME, 0);
754 jermar 260
    memsetb(PA2KA(frame), FRAME_SIZE, 0);
703 jermar 261
 
262
    /*
263
     * Map 'page' to 'frame'.
264
     * Note that TLB shootdown is not attempted as only new information is being
265
     * inserted into page tables.
266
     */
756 jermar 267
    page_mapping_insert(AS, page, frame, get_area_flags(area));
703 jermar 268
 
269
    spinlock_unlock(&area->lock);
270
    spinlock_unlock(&AS->lock);
271
 
272
    return 1;
273
}
274
 
275
/** Install address space on CPU.
276
 *
277
 * @param as Address space.
278
 */
279
void as_install(as_t *as)
280
{
281
    ipl_t ipl;
282
 
727 jermar 283
    asid_install(as);
284
 
703 jermar 285
    ipl = interrupts_disable();
286
    spinlock_lock(&as->lock);
756 jermar 287
    ASSERT(as->page_table);
288
    SET_PTL0_ADDRESS(as->page_table);
703 jermar 289
    spinlock_unlock(&as->lock);
290
    interrupts_restore(ipl);
291
 
292
    /*
293
     * Perform architecture-specific steps.
727 jermar 294
     * (e.g. write ASID to hardware register etc.)
703 jermar 295
     */
296
    as_install_arch(as);
297
 
298
    AS = as;
299
}
754 jermar 300
 
301
/** Compute flags for virtual address translation subsytem.
302
 *
303
 * The address space area must be locked.
304
 * Interrupts must be disabled.
305
 *
306
 * @param a Address space area.
307
 *
308
 * @return Flags to be used in page_mapping_insert().
309
 */
310
int get_area_flags(as_area_t *a)
311
{
312
    int flags;
313
 
314
    switch (a->type) {
315
        case AS_AREA_TEXT:
316
            flags = PAGE_EXEC | PAGE_READ | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
317
            break;
318
        case AS_AREA_DATA:
319
        case AS_AREA_STACK:
320
            flags = PAGE_READ | PAGE_WRITE | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
321
            break;
322
        default:
323
            panic("unexpected as_area_type_t %d", a->type);
324
    }
325
 
326
    return flags;
327
}
756 jermar 328
 
329
/** Create page table.
330
 *
331
 * Depending on architecture, create either address space
332
 * private or global page table.
333
 *
334
 * @param flags Flags saying whether the page table is for kernel address space.
335
 *
336
 * @return First entry of the page table.
337
 */
338
pte_t *page_table_create(int flags)
339
{
340
        ASSERT(as_operations);
341
        ASSERT(as_operations->page_table_create);
342
 
343
        return as_operations->page_table_create(flags);
344
}