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703 jermar 1
/*
2
 * Copyright (C) 2001-2006 Jakub 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
 
1248 jermar 29
/**
30
 * @file    as.c
31
 * @brief   Address space related functions.
32
 *
703 jermar 33
 * This file contains address space manipulation functions.
34
 * Roughly speaking, this is a higher-level client of
35
 * Virtual Address Translation (VAT) subsystem.
1248 jermar 36
 *
37
 * Functionality provided by this file allows one to
38
 * create address space and create, resize and share
39
 * address space areas.
40
 *
41
 * @see page.c
42
 *
703 jermar 43
 */
44
 
45
#include <mm/as.h>
756 jermar 46
#include <arch/mm/as.h>
703 jermar 47
#include <mm/page.h>
48
#include <mm/frame.h>
814 palkovsky 49
#include <mm/slab.h>
703 jermar 50
#include <mm/tlb.h>
51
#include <arch/mm/page.h>
52
#include <genarch/mm/page_pt.h>
1108 jermar 53
#include <genarch/mm/page_ht.h>
727 jermar 54
#include <mm/asid.h>
703 jermar 55
#include <arch/mm/asid.h>
56
#include <synch/spinlock.h>
1380 jermar 57
#include <synch/mutex.h>
788 jermar 58
#include <adt/list.h>
1147 jermar 59
#include <adt/btree.h>
1235 jermar 60
#include <proc/task.h>
1288 jermar 61
#include <proc/thread.h>
1235 jermar 62
#include <arch/asm.h>
703 jermar 63
#include <panic.h>
64
#include <debug.h>
1235 jermar 65
#include <print.h>
703 jermar 66
#include <memstr.h>
1070 jermar 67
#include <macros.h>
703 jermar 68
#include <arch.h>
1235 jermar 69
#include <errno.h>
70
#include <config.h>
71
#include <arch/types.h>
72
#include <typedefs.h>
1288 jermar 73
#include <syscall/copy.h>
74
#include <arch/interrupt.h>
703 jermar 75
 
756 jermar 76
as_operations_t *as_operations = NULL;
703 jermar 77
 
1380 jermar 78
/** Address space lock. It protects inactive_as_with_asid_head. Must be acquired before as_t mutex. */
823 jermar 79
SPINLOCK_INITIALIZE(as_lock);
80
 
81
/**
82
 * This list contains address spaces that are not active on any
83
 * processor and that have valid ASID.
84
 */
85
LIST_INITIALIZE(inactive_as_with_asid_head);
86
 
757 jermar 87
/** Kernel address space. */
88
as_t *AS_KERNEL = NULL;
89
 
1235 jermar 90
static int area_flags_to_page_flags(int aflags);
754 jermar 91
static int get_area_flags(as_area_t *a);
977 jermar 92
static as_area_t *find_area_and_lock(as_t *as, __address va);
1048 jermar 93
static bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area);
703 jermar 94
 
756 jermar 95
/** Initialize address space subsystem. */
96
void as_init(void)
97
{
98
    as_arch_init();
789 palkovsky 99
    AS_KERNEL = as_create(FLAG_AS_KERNEL);
756 jermar 100
        if (!AS_KERNEL)
101
                panic("can't create kernel address space\n");
102
}
103
 
757 jermar 104
/** Create address space.
105
 *
106
 * @param flags Flags that influence way in wich the address space is created.
107
 */
756 jermar 108
as_t *as_create(int flags)
703 jermar 109
{
110
    as_t *as;
111
 
822 palkovsky 112
    as = (as_t *) malloc(sizeof(as_t), 0);
823 jermar 113
    link_initialize(&as->inactive_as_with_asid_link);
1380 jermar 114
    mutex_initialize(&as->lock);
1147 jermar 115
    btree_create(&as->as_area_btree);
822 palkovsky 116
 
117
    if (flags & FLAG_AS_KERNEL)
118
        as->asid = ASID_KERNEL;
119
    else
120
        as->asid = ASID_INVALID;
121
 
823 jermar 122
    as->refcount = 0;
822 palkovsky 123
    as->page_table = page_table_create(flags);
703 jermar 124
 
125
    return as;
126
}
127
 
973 palkovsky 128
/** Free Adress space */
129
void as_free(as_t *as)
130
{
131
    ASSERT(as->refcount == 0);
132
 
133
    /* TODO: free as_areas and other resources held by as */
134
    /* TODO: free page table */
135
    free(as);
136
}
137
 
703 jermar 138
/** Create address space area of common attributes.
139
 *
140
 * The created address space area is added to the target address space.
141
 *
142
 * @param as Target address space.
1239 jermar 143
 * @param flags Flags of the area memory.
1048 jermar 144
 * @param size Size of area.
703 jermar 145
 * @param base Base address of area.
1239 jermar 146
 * @param attrs Attributes of the area.
703 jermar 147
 *
148
 * @return Address space area on success or NULL on failure.
149
 */
1239 jermar 150
as_area_t *as_area_create(as_t *as, int flags, size_t size, __address base, int attrs)
703 jermar 151
{
152
    ipl_t ipl;
153
    as_area_t *a;
154
 
155
    if (base % PAGE_SIZE)
1048 jermar 156
        return NULL;
157
 
1233 jermar 158
    if (!size)
159
        return NULL;
160
 
1048 jermar 161
    /* Writeable executable areas are not supported. */
162
    if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
163
        return NULL;
703 jermar 164
 
165
    ipl = interrupts_disable();
1380 jermar 166
    mutex_lock(&as->lock);
703 jermar 167
 
1048 jermar 168
    if (!check_area_conflicts(as, base, size, NULL)) {
1380 jermar 169
        mutex_unlock(&as->lock);
1048 jermar 170
        interrupts_restore(ipl);
171
        return NULL;
172
    }
703 jermar 173
 
822 palkovsky 174
    a = (as_area_t *) malloc(sizeof(as_area_t), 0);
703 jermar 175
 
1380 jermar 176
    mutex_initialize(&a->lock);
822 palkovsky 177
 
1026 jermar 178
    a->flags = flags;
1239 jermar 179
    a->attributes = attrs;
1048 jermar 180
    a->pages = SIZE2FRAMES(size);
822 palkovsky 181
    a->base = base;
182
 
1147 jermar 183
    btree_insert(&as->as_area_btree, base, (void *) a, NULL);
822 palkovsky 184
 
1380 jermar 185
    mutex_unlock(&as->lock);
703 jermar 186
    interrupts_restore(ipl);
704 jermar 187
 
703 jermar 188
    return a;
189
}
190
 
1235 jermar 191
/** Find address space area and change it.
192
 *
193
 * @param as Address space.
194
 * @param address Virtual address belonging to the area to be changed. Must be page-aligned.
195
 * @param size New size of the virtual memory block starting at address.
196
 * @param flags Flags influencing the remap operation. Currently unused.
197
 *
1306 jermar 198
 * @return Zero on success or a value from @ref errno.h otherwise.
1235 jermar 199
 */
1306 jermar 200
int as_area_resize(as_t *as, __address address, size_t size, int flags)
1235 jermar 201
{
1306 jermar 202
    as_area_t *area;
1235 jermar 203
    ipl_t ipl;
204
    size_t pages;
205
 
206
    ipl = interrupts_disable();
1380 jermar 207
    mutex_lock(&as->lock);
1235 jermar 208
 
209
    /*
210
     * Locate the area.
211
     */
212
    area = find_area_and_lock(as, address);
213
    if (!area) {
1380 jermar 214
        mutex_unlock(&as->lock);
1235 jermar 215
        interrupts_restore(ipl);
1306 jermar 216
        return ENOENT;
1235 jermar 217
    }
218
 
219
    if (area->flags & AS_AREA_DEVICE) {
220
        /*
221
         * Remapping of address space areas associated
222
         * with memory mapped devices is not supported.
223
         */
1380 jermar 224
        mutex_unlock(&area->lock);
225
        mutex_unlock(&as->lock);
1235 jermar 226
        interrupts_restore(ipl);
1306 jermar 227
        return ENOTSUP;
1235 jermar 228
    }
229
 
230
    pages = SIZE2FRAMES((address - area->base) + size);
231
    if (!pages) {
232
        /*
233
         * Zero size address space areas are not allowed.
234
         */
1380 jermar 235
        mutex_unlock(&area->lock);
236
        mutex_unlock(&as->lock);
1235 jermar 237
        interrupts_restore(ipl);
1306 jermar 238
        return EPERM;
1235 jermar 239
    }
240
 
241
    if (pages < area->pages) {
242
        int i;
243
 
244
        /*
245
         * Shrinking the area.
246
         * No need to check for overlaps.
247
         */
248
        for (i = pages; i < area->pages; i++) {
249
            pte_t *pte;
250
 
251
            /*
252
             * Releasing physical memory.
253
             * This depends on the fact that the memory was allocated using frame_alloc().
254
             */
255
            page_table_lock(as, false);
256
            pte = page_mapping_find(as, area->base + i*PAGE_SIZE);
257
            if (pte && PTE_VALID(pte)) {
258
                __address frame;
259
 
260
                ASSERT(PTE_PRESENT(pte));
261
                frame = PTE_GET_FRAME(pte);
262
                page_mapping_remove(as, area->base + i*PAGE_SIZE);
263
                page_table_unlock(as, false);
264
 
265
                frame_free(ADDR2PFN(frame));
266
            } else {
267
                page_table_unlock(as, false);
268
            }
269
        }
270
        /*
271
         * Invalidate TLB's.
272
         */
273
        tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
274
        tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
275
        tlb_shootdown_finalize();
276
    } else {
277
        /*
278
         * Growing the area.
279
         * Check for overlaps with other address space areas.
280
         */
281
        if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
1380 jermar 282
            mutex_unlock(&area->lock);
283
            mutex_unlock(&as->lock);       
1235 jermar 284
            interrupts_restore(ipl);
1306 jermar 285
            return EADDRNOTAVAIL;
1235 jermar 286
        }
287
    }
288
 
289
    area->pages = pages;
290
 
1380 jermar 291
    mutex_unlock(&area->lock);
292
    mutex_unlock(&as->lock);
1235 jermar 293
    interrupts_restore(ipl);
294
 
1306 jermar 295
    return 0;
1235 jermar 296
}
297
 
1306 jermar 298
/** Destroy address space area.
299
 *
300
 * @param as Address space.
301
 * @param address Address withing the area to be deleted.
302
 *
303
 * @return Zero on success or a value from @ref errno.h on failure.
304
 */
305
int as_area_destroy(as_t *as, __address address)
306
{
307
    as_area_t *area;
308
    __address base;
309
    ipl_t ipl;
310
    int i;
311
 
312
    ipl = interrupts_disable();
1380 jermar 313
    mutex_lock(&as->lock);
1306 jermar 314
 
315
    area = find_area_and_lock(as, address);
316
    if (!area) {
1380 jermar 317
        mutex_unlock(&as->lock);
1306 jermar 318
        interrupts_restore(ipl);
319
        return ENOENT;
320
    }
321
 
322
    base = area->base; 
323
    for (i = 0; i < area->pages; i++) {
324
        pte_t *pte;
325
 
326
        /*
327
         * Releasing physical memory.
328
         * Areas mapping memory-mapped devices are treated differently than
329
         * areas backing frame_alloc()'ed memory.
330
         */
331
        page_table_lock(as, false);
332
        pte = page_mapping_find(as, area->base + i*PAGE_SIZE);
333
        if (pte && PTE_VALID(pte)) {
334
            ASSERT(PTE_PRESENT(pte));
335
            page_mapping_remove(as, area->base + i*PAGE_SIZE);
336
            if (area->flags & AS_AREA_DEVICE) {
337
                __address frame;
338
                frame = PTE_GET_FRAME(pte);
339
                frame_free(ADDR2PFN(frame));
340
            }
341
            page_table_unlock(as, false);
342
        } else {
343
            page_table_unlock(as, false);
344
        }
345
    }
346
    /*
347
     * Invalidate TLB's.
348
     */
349
    tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages);
350
    tlb_invalidate_pages(AS->asid, area->base, area->pages);
351
    tlb_shootdown_finalize();
352
 
1309 jermar 353
    area->attributes |= AS_AREA_ATTR_PARTIAL;
1380 jermar 354
    mutex_unlock(&area->lock);
1306 jermar 355
 
356
    /*
357
     * Remove the empty area from address space.
358
     */
359
    btree_remove(&AS->as_area_btree, base, NULL);
360
 
1309 jermar 361
    free(area);
362
 
1380 jermar 363
    mutex_unlock(&AS->lock);
1306 jermar 364
    interrupts_restore(ipl);
365
    return 0;
366
}
367
 
1329 palkovsky 368
/** Steal address space area from another task.
1235 jermar 369
 *
1329 palkovsky 370
 * Address space area is stolen from another task
371
 * Moreover, any existing mapping
1235 jermar 372
 * is copied as well, providing thus a mechanism
373
 * for sharing group of pages. The source address
374
 * space area and any associated mapping is preserved.
375
 *
1329 palkovsky 376
 * @param src_task Pointer of source task
1239 jermar 377
 * @param src_base Base address of the source address space area.
1329 palkovsky 378
 * @param acc_size Expected size of the source area
379
 * @param dst_base Target base address
1235 jermar 380
 *
1306 jermar 381
 * @return Zero on success or ENOENT if there is no such task or
1235 jermar 382
 *     if there is no such address space area,
383
 *     EPERM if there was a problem in accepting the area or
384
 *     ENOMEM if there was a problem in allocating destination
385
 *     address space area.
386
 */
1329 palkovsky 387
int as_area_steal(task_t *src_task, __address src_base, size_t acc_size,
388
          __address dst_base)
1235 jermar 389
{
390
    ipl_t ipl;
391
    count_t i;
1329 palkovsky 392
    as_t *src_as;      
1239 jermar 393
    int src_flags;
394
    size_t src_size;
395
    as_area_t *src_area, *dst_area;
1329 palkovsky 396
 
1235 jermar 397
    ipl = interrupts_disable();
1329 palkovsky 398
    spinlock_lock(&src_task->lock);
399
    src_as = src_task->as;
1235 jermar 400
 
1380 jermar 401
    mutex_lock(&src_as->lock);
1329 palkovsky 402
    src_area = find_area_and_lock(src_as, src_base);
1239 jermar 403
    if (!src_area) {
1238 jermar 404
        /*
405
         * Could not find the source address space area.
406
         */
1329 palkovsky 407
        spinlock_unlock(&src_task->lock);
1380 jermar 408
        mutex_unlock(&src_as->lock);
1238 jermar 409
        interrupts_restore(ipl);
410
        return ENOENT;
411
    }
1239 jermar 412
    src_size = src_area->pages * PAGE_SIZE;
413
    src_flags = src_area->flags;
1380 jermar 414
    mutex_unlock(&src_area->lock);
415
    mutex_unlock(&src_as->lock);
1235 jermar 416
 
1329 palkovsky 417
 
418
    if (src_size != acc_size) {
419
        spinlock_unlock(&src_task->lock);
1235 jermar 420
        interrupts_restore(ipl);
421
        return EPERM;
422
    }
423
    /*
1239 jermar 424
     * Create copy of the source address space area.
425
     * The destination area is created with AS_AREA_ATTR_PARTIAL
426
     * attribute set which prevents race condition with
427
     * preliminary as_page_fault() calls.
1235 jermar 428
     */
1329 palkovsky 429
    dst_area = as_area_create(AS, src_flags, src_size, dst_base, AS_AREA_ATTR_PARTIAL);
1239 jermar 430
    if (!dst_area) {
1235 jermar 431
        /*
432
         * Destination address space area could not be created.
433
         */
1329 palkovsky 434
        spinlock_unlock(&src_task->lock);
1235 jermar 435
        interrupts_restore(ipl);
436
        return ENOMEM;
437
    }
438
 
1329 palkovsky 439
    spinlock_unlock(&src_task->lock);
1235 jermar 440
 
441
    /*
442
     * Avoid deadlock by first locking the address space with lower address.
443
     */
1329 palkovsky 444
    if (AS < src_as) {
1380 jermar 445
        mutex_lock(&AS->lock);
446
        mutex_lock(&src_as->lock);
1235 jermar 447
    } else {
1380 jermar 448
        mutex_lock(&AS->lock);
449
        mutex_lock(&src_as->lock);
1235 jermar 450
    }
451
 
1239 jermar 452
    for (i = 0; i < SIZE2FRAMES(src_size); i++) {
1235 jermar 453
        pte_t *pte;
454
        __address frame;
455
 
1329 palkovsky 456
        page_table_lock(src_as, false);
457
        pte = page_mapping_find(src_as, src_base + i*PAGE_SIZE);
1235 jermar 458
        if (pte && PTE_VALID(pte)) {
459
            ASSERT(PTE_PRESENT(pte));
460
            frame = PTE_GET_FRAME(pte);
1239 jermar 461
            if (!(src_flags & AS_AREA_DEVICE))
1236 jermar 462
                frame_reference_add(ADDR2PFN(frame));
1329 palkovsky 463
            page_table_unlock(src_as, false);
1235 jermar 464
        } else {
1329 palkovsky 465
            page_table_unlock(src_as, false);
1235 jermar 466
            continue;
467
        }
468
 
1329 palkovsky 469
        page_table_lock(AS, false);
470
        page_mapping_insert(AS, dst_base + i*PAGE_SIZE, frame, area_flags_to_page_flags(src_flags));
471
        page_table_unlock(AS, false);
1235 jermar 472
    }
1239 jermar 473
 
474
    /*
475
     * Now the destination address space area has been
476
     * fully initialized. Clear the AS_AREA_ATTR_PARTIAL
477
     * attribute.
478
     */
1380 jermar 479
    mutex_lock(&dst_area->lock);
1239 jermar 480
    dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
1380 jermar 481
    mutex_unlock(&dst_area->lock);
1235 jermar 482
 
1380 jermar 483
    mutex_unlock(&AS->lock);
484
    mutex_unlock(&src_as->lock);
1235 jermar 485
    interrupts_restore(ipl);
486
 
487
    return 0;
488
}
489
 
754 jermar 490
/** Initialize mapping for one page of address space.
703 jermar 491
 *
754 jermar 492
 * This functions maps 'page' to 'frame' according
493
 * to attributes of the address space area to
494
 * wich 'page' belongs.
703 jermar 495
 *
840 jermar 496
 * @param as Target address space.
754 jermar 497
 * @param page Virtual page within the area.
498
 * @param frame Physical frame to which page will be mapped.
703 jermar 499
 */
754 jermar 500
void as_set_mapping(as_t *as, __address page, __address frame)
703 jermar 501
{
977 jermar 502
    as_area_t *area;
703 jermar 503
    ipl_t ipl;
504
 
505
    ipl = interrupts_disable();
1044 jermar 506
    page_table_lock(as, true);
703 jermar 507
 
977 jermar 508
    area = find_area_and_lock(as, page);
754 jermar 509
    if (!area) {
510
        panic("page not part of any as_area\n");
511
    }
512
 
756 jermar 513
    page_mapping_insert(as, page, frame, get_area_flags(area));
754 jermar 514
 
1380 jermar 515
    mutex_unlock(&area->lock);
1044 jermar 516
    page_table_unlock(as, true);
703 jermar 517
    interrupts_restore(ipl);
518
}
519
 
520
/** Handle page fault within the current address space.
521
 *
522
 * This is the high-level page fault handler.
523
 * Interrupts are assumed disabled.
524
 *
525
 * @param page Faulting page.
1288 jermar 526
 * @param istate Pointer to interrupted state.
703 jermar 527
 *
1288 jermar 528
 * @return 0 on page fault, 1 on success or 2 if the fault was caused by copy_to_uspace() or copy_from_uspace().
703 jermar 529
 */
1288 jermar 530
int as_page_fault(__address page, istate_t *istate)
703 jermar 531
{
1044 jermar 532
    pte_t *pte;
977 jermar 533
    as_area_t *area;
703 jermar 534
    __address frame;
535
 
1380 jermar 536
    if (!THREAD)
537
        return 0;
538
 
703 jermar 539
    ASSERT(AS);
1044 jermar 540
 
1380 jermar 541
    mutex_lock(&AS->lock);
977 jermar 542
    area = find_area_and_lock(AS, page);   
703 jermar 543
    if (!area) {
544
        /*
545
         * No area contained mapping for 'page'.
546
         * Signal page fault to low-level handler.
547
         */
1380 jermar 548
        mutex_unlock(&AS->lock);
1288 jermar 549
        goto page_fault;
703 jermar 550
    }
551
 
1239 jermar 552
    if (area->attributes & AS_AREA_ATTR_PARTIAL) {
553
        /*
554
         * The address space area is not fully initialized.
555
         * Avoid possible race by returning error.
556
         */
1380 jermar 557
        mutex_unlock(&area->lock);
558
        mutex_unlock(&AS->lock);
1288 jermar 559
        goto page_fault;       
1239 jermar 560
    }
561
 
1179 jermar 562
    ASSERT(!(area->flags & AS_AREA_DEVICE));
563
 
1044 jermar 564
    page_table_lock(AS, false);
565
 
703 jermar 566
    /*
1044 jermar 567
     * To avoid race condition between two page faults
568
     * on the same address, we need to make sure
569
     * the mapping has not been already inserted.
570
     */
571
    if ((pte = page_mapping_find(AS, page))) {
572
        if (PTE_PRESENT(pte)) {
573
            page_table_unlock(AS, false);
1380 jermar 574
            mutex_unlock(&area->lock);
575
            mutex_unlock(&AS->lock);
1044 jermar 576
            return 1;
577
        }
578
    }
579
 
580
    /*
754 jermar 581
     * In general, there can be several reasons that
582
     * can have caused this fault.
583
     *
584
     * - non-existent mapping: the area is a scratch
585
     *   area (e.g. stack) and so far has not been
586
     *   allocated a frame for the faulting page
587
     *
588
     * - non-present mapping: another possibility,
589
     *   currently not implemented, would be frame
590
     *   reuse; when this becomes a possibility,
591
     *   do not forget to distinguish between
592
     *   the different causes
703 jermar 593
     */
814 palkovsky 594
    frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
754 jermar 595
    memsetb(PA2KA(frame), FRAME_SIZE, 0);
703 jermar 596
 
597
    /*
598
     * Map 'page' to 'frame'.
599
     * Note that TLB shootdown is not attempted as only new information is being
600
     * inserted into page tables.
601
     */
756 jermar 602
    page_mapping_insert(AS, page, frame, get_area_flags(area));
1044 jermar 603
    page_table_unlock(AS, false);
703 jermar 604
 
1380 jermar 605
    mutex_unlock(&area->lock);
606
    mutex_unlock(&AS->lock);
1288 jermar 607
    return AS_PF_OK;
608
 
609
page_fault:
610
    if (!THREAD)
611
        return AS_PF_FAULT;
612
 
613
    if (THREAD->in_copy_from_uspace) {
614
        THREAD->in_copy_from_uspace = false;
615
        istate_set_retaddr(istate, (__address) &memcpy_from_uspace_failover_address);
616
    } else if (THREAD->in_copy_to_uspace) {
617
        THREAD->in_copy_to_uspace = false;
618
        istate_set_retaddr(istate, (__address) &memcpy_to_uspace_failover_address);
619
    } else {
620
        return AS_PF_FAULT;
621
    }
622
 
623
    return AS_PF_DEFER;
703 jermar 624
}
625
 
823 jermar 626
/** Switch address spaces.
703 jermar 627
 *
1380 jermar 628
 * Note that this function cannot sleep as it is essentially a part of
629
 * the scheduling. Sleeping here would lead to deadlock on wakeup.
630
 *
823 jermar 631
 * @param old Old address space or NULL.
632
 * @param new New address space.
703 jermar 633
 */
823 jermar 634
void as_switch(as_t *old, as_t *new)
703 jermar 635
{
636
    ipl_t ipl;
823 jermar 637
    bool needs_asid = false;
703 jermar 638
 
639
    ipl = interrupts_disable();
823 jermar 640
    spinlock_lock(&as_lock);
703 jermar 641
 
642
    /*
823 jermar 643
     * First, take care of the old address space.
644
     */
645
    if (old) {
1380 jermar 646
        mutex_lock_active(&old->lock);
823 jermar 647
        ASSERT(old->refcount);
648
        if((--old->refcount == 0) && (old != AS_KERNEL)) {
649
            /*
650
             * The old address space is no longer active on
651
             * any processor. It can be appended to the
652
             * list of inactive address spaces with assigned
653
             * ASID.
654
             */
655
             ASSERT(old->asid != ASID_INVALID);
656
             list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head);
657
        }
1380 jermar 658
        mutex_unlock(&old->lock);
823 jermar 659
    }
660
 
661
    /*
662
     * Second, prepare the new address space.
663
     */
1380 jermar 664
    mutex_lock_active(&new->lock);
823 jermar 665
    if ((new->refcount++ == 0) && (new != AS_KERNEL)) {
666
        if (new->asid != ASID_INVALID)
667
            list_remove(&new->inactive_as_with_asid_link);
668
        else
669
            needs_asid = true;  /* defer call to asid_get() until new->lock is released */
670
    }
671
    SET_PTL0_ADDRESS(new->page_table);
1380 jermar 672
    mutex_unlock(&new->lock);
823 jermar 673
 
674
    if (needs_asid) {
675
        /*
676
         * Allocation of new ASID was deferred
677
         * until now in order to avoid deadlock.
678
         */
679
        asid_t asid;
680
 
681
        asid = asid_get();
1380 jermar 682
        mutex_lock_active(&new->lock);
823 jermar 683
        new->asid = asid;
1380 jermar 684
        mutex_unlock(&new->lock);
823 jermar 685
    }
686
    spinlock_unlock(&as_lock);
687
    interrupts_restore(ipl);
688
 
689
    /*
703 jermar 690
     * Perform architecture-specific steps.
727 jermar 691
     * (e.g. write ASID to hardware register etc.)
703 jermar 692
     */
823 jermar 693
    as_install_arch(new);
703 jermar 694
 
823 jermar 695
    AS = new;
703 jermar 696
}
754 jermar 697
 
1235 jermar 698
/** Convert address space area flags to page flags.
754 jermar 699
 *
1235 jermar 700
 * @param aflags Flags of some address space area.
754 jermar 701
 *
1235 jermar 702
 * @return Flags to be passed to page_mapping_insert().
754 jermar 703
 */
1235 jermar 704
int area_flags_to_page_flags(int aflags)
754 jermar 705
{
706
    int flags;
707
 
1178 jermar 708
    flags = PAGE_USER | PAGE_PRESENT;
754 jermar 709
 
1235 jermar 710
    if (aflags & AS_AREA_READ)
1026 jermar 711
        flags |= PAGE_READ;
712
 
1235 jermar 713
    if (aflags & AS_AREA_WRITE)
1026 jermar 714
        flags |= PAGE_WRITE;
715
 
1235 jermar 716
    if (aflags & AS_AREA_EXEC)
1026 jermar 717
        flags |= PAGE_EXEC;
718
 
1235 jermar 719
    if (!(aflags & AS_AREA_DEVICE))
1178 jermar 720
        flags |= PAGE_CACHEABLE;
721
 
754 jermar 722
    return flags;
723
}
756 jermar 724
 
1235 jermar 725
/** Compute flags for virtual address translation subsytem.
726
 *
727
 * The address space area must be locked.
728
 * Interrupts must be disabled.
729
 *
730
 * @param a Address space area.
731
 *
732
 * @return Flags to be used in page_mapping_insert().
733
 */
734
int get_area_flags(as_area_t *a)
735
{
736
    return area_flags_to_page_flags(a->flags);
737
}
738
 
756 jermar 739
/** Create page table.
740
 *
741
 * Depending on architecture, create either address space
742
 * private or global page table.
743
 *
744
 * @param flags Flags saying whether the page table is for kernel address space.
745
 *
746
 * @return First entry of the page table.
747
 */
748
pte_t *page_table_create(int flags)
749
{
750
        ASSERT(as_operations);
751
        ASSERT(as_operations->page_table_create);
752
 
753
        return as_operations->page_table_create(flags);
754
}
977 jermar 755
 
1044 jermar 756
/** Lock page table.
757
 *
758
 * This function should be called before any page_mapping_insert(),
759
 * page_mapping_remove() and page_mapping_find().
760
 *
761
 * Locking order is such that address space areas must be locked
762
 * prior to this call. Address space can be locked prior to this
763
 * call in which case the lock argument is false.
764
 *
765
 * @param as Address space.
1248 jermar 766
 * @param lock If false, do not attempt to lock as->lock.
1044 jermar 767
 */
768
void page_table_lock(as_t *as, bool lock)
769
{
770
    ASSERT(as_operations);
771
    ASSERT(as_operations->page_table_lock);
772
 
773
    as_operations->page_table_lock(as, lock);
774
}
775
 
776
/** Unlock page table.
777
 *
778
 * @param as Address space.
1248 jermar 779
 * @param unlock If false, do not attempt to unlock as->lock.
1044 jermar 780
 */
781
void page_table_unlock(as_t *as, bool unlock)
782
{
783
    ASSERT(as_operations);
784
    ASSERT(as_operations->page_table_unlock);
785
 
786
    as_operations->page_table_unlock(as, unlock);
787
}
788
 
977 jermar 789
 
790
/** Find address space area and lock it.
791
 *
792
 * The address space must be locked and interrupts must be disabled.
793
 *
794
 * @param as Address space.
795
 * @param va Virtual address.
796
 *
797
 * @return Locked address space area containing va on success or NULL on failure.
798
 */
799
as_area_t *find_area_and_lock(as_t *as, __address va)
800
{
801
    as_area_t *a;
1147 jermar 802
    btree_node_t *leaf, *lnode;
803
    int i;
977 jermar 804
 
1147 jermar 805
    a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
806
    if (a) {
807
        /* va is the base address of an address space area */
1380 jermar 808
        mutex_lock(&a->lock);
1147 jermar 809
        return a;
810
    }
811
 
812
    /*
1150 jermar 813
     * Search the leaf node and the righmost record of its left neighbour
1147 jermar 814
     * to find out whether this is a miss or va belongs to an address
815
     * space area found there.
816
     */
817
 
818
    /* First, search the leaf node itself. */
819
    for (i = 0; i < leaf->keys; i++) {
820
        a = (as_area_t *) leaf->value[i];
1380 jermar 821
        mutex_lock(&a->lock);
1147 jermar 822
        if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
823
            return a;
824
        }
1380 jermar 825
        mutex_unlock(&a->lock);
1147 jermar 826
    }
977 jermar 827
 
1147 jermar 828
    /*
1150 jermar 829
     * Second, locate the left neighbour and test its last record.
1148 jermar 830
     * Because of its position in the B+tree, it must have base < va.
1147 jermar 831
     */
1150 jermar 832
    if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 833
        a = (as_area_t *) lnode->value[lnode->keys - 1];
1380 jermar 834
        mutex_lock(&a->lock);
1147 jermar 835
        if (va < a->base + a->pages * PAGE_SIZE) {
1048 jermar 836
            return a;
1147 jermar 837
        }
1380 jermar 838
        mutex_unlock(&a->lock);
977 jermar 839
    }
840
 
841
    return NULL;
842
}
1048 jermar 843
 
844
/** Check area conflicts with other areas.
845
 *
846
 * The address space must be locked and interrupts must be disabled.
847
 *
848
 * @param as Address space.
849
 * @param va Starting virtual address of the area being tested.
850
 * @param size Size of the area being tested.
851
 * @param avoid_area Do not touch this area.
852
 *
853
 * @return True if there is no conflict, false otherwise.
854
 */
855
bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area)
856
{
857
    as_area_t *a;
1147 jermar 858
    btree_node_t *leaf, *node;
859
    int i;
1048 jermar 860
 
1070 jermar 861
    /*
862
     * We don't want any area to have conflicts with NULL page.
863
     */
864
    if (overlaps(va, size, NULL, PAGE_SIZE))
865
        return false;
866
 
1147 jermar 867
    /*
868
     * The leaf node is found in O(log n), where n is proportional to
869
     * the number of address space areas belonging to as.
870
     * The check for conflicts is then attempted on the rightmost
1150 jermar 871
     * record in the left neighbour, the leftmost record in the right
872
     * neighbour and all records in the leaf node itself.
1147 jermar 873
     */
1048 jermar 874
 
1147 jermar 875
    if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
876
        if (a != avoid_area)
877
            return false;
878
    }
879
 
880
    /* First, check the two border cases. */
1150 jermar 881
    if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 882
        a = (as_area_t *) node->value[node->keys - 1];
1380 jermar 883
        mutex_lock(&a->lock);
1147 jermar 884
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 885
            mutex_unlock(&a->lock);
1147 jermar 886
            return false;
887
        }
1380 jermar 888
        mutex_unlock(&a->lock);
1147 jermar 889
    }
1150 jermar 890
    if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 891
        a = (as_area_t *) node->value[0];
1380 jermar 892
        mutex_lock(&a->lock);
1147 jermar 893
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 894
            mutex_unlock(&a->lock);
1147 jermar 895
            return false;
896
        }
1380 jermar 897
        mutex_unlock(&a->lock);
1147 jermar 898
    }
899
 
900
    /* Second, check the leaf node. */
901
    for (i = 0; i < leaf->keys; i++) {
902
        a = (as_area_t *) leaf->value[i];
903
 
1048 jermar 904
        if (a == avoid_area)
905
            continue;
1147 jermar 906
 
1380 jermar 907
        mutex_lock(&a->lock);
1147 jermar 908
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 909
            mutex_unlock(&a->lock);
1147 jermar 910
            return false;
911
        }
1380 jermar 912
        mutex_unlock(&a->lock);
1048 jermar 913
    }
914
 
1070 jermar 915
    /*
916
     * So far, the area does not conflict with other areas.
917
     * Check if it doesn't conflict with kernel address space.
918
     */  
919
    if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
920
        return !overlaps(va, size,
921
            KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START);
922
    }
923
 
1048 jermar 924
    return true;
925
}
1235 jermar 926
 
1380 jermar 927
/** Return size of the address space area with given base.  */
1329 palkovsky 928
size_t as_get_size(__address base)
929
{
930
    ipl_t ipl;
931
    as_area_t *src_area;
932
    size_t size;
933
 
934
    ipl = interrupts_disable();
935
    src_area = find_area_and_lock(AS, base);
936
    if (src_area){
937
        size = src_area->pages * PAGE_SIZE;
1380 jermar 938
        mutex_unlock(&src_area->lock);
1329 palkovsky 939
    } else {
940
        size = 0;
941
    }
942
    interrupts_restore(ipl);
943
    return size;
944
}
945
 
1235 jermar 946
/*
947
 * Address space related syscalls.
948
 */
949
 
950
/** Wrapper for as_area_create(). */
951
__native sys_as_area_create(__address address, size_t size, int flags)
952
{
1239 jermar 953
    if (as_area_create(AS, flags, size, address, AS_AREA_ATTR_NONE))
1235 jermar 954
        return (__native) address;
955
    else
956
        return (__native) -1;
957
}
958
 
959
/** Wrapper for as_area_resize. */
960
__native sys_as_area_resize(__address address, size_t size, int flags)
961
{
1306 jermar 962
    return (__native) as_area_resize(AS, address, size, 0);
1235 jermar 963
}
964
 
1306 jermar 965
/** Wrapper for as_area_destroy. */
966
__native sys_as_area_destroy(__address address)
967
{
968
    return (__native) as_area_destroy(AS, address);
969
}