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