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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
 *
197
 * @return address on success, (__address) -1 otherwise.
198
 */
199
__address as_area_resize(as_t *as, __address address, size_t size, int flags)
200
{
201
    as_area_t *area = NULL;
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);
215
        return (__address) -1;
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);
226
        return (__address) -1;
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);
237
        return (__address) -1;
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);
284
            return (__address) -1;
285
        }
286
    }
287
 
288
    area->pages = pages;
289
 
290
    spinlock_unlock(&area->lock);
291
    spinlock_unlock(&as->lock);
292
    interrupts_restore(ipl);
293
 
294
    return address;
295
}
296
 
297
/** Send address space area to another task.
298
 *
299
 * Address space area is sent to the specified task.
300
 * If the destination task is willing to accept the
301
 * area, a new area is created according to the
302
 * source area. Moreover, any existing mapping
303
 * is copied as well, providing thus a mechanism
304
 * for sharing group of pages. The source address
305
 * space area and any associated mapping is preserved.
306
 *
1239 jermar 307
 * @param dst_id Task ID of the accepting task.
308
 * @param src_base Base address of the source address space area.
1235 jermar 309
 *
310
 * @return 0 on success or ENOENT if there is no such task or
311
 *     if there is no such address space area,
312
 *     EPERM if there was a problem in accepting the area or
313
 *     ENOMEM if there was a problem in allocating destination
314
 *     address space area.
315
 */
1239 jermar 316
int as_area_send(task_id_t dst_id, __address src_base)
1235 jermar 317
{
318
    ipl_t ipl;
319
    task_t *t;
320
    count_t i;
1239 jermar 321
    as_t *dst_as;
1235 jermar 322
    __address dst_base;
1239 jermar 323
    int src_flags;
324
    size_t src_size;
325
    as_area_t *src_area, *dst_area;
1235 jermar 326
 
327
    ipl = interrupts_disable();
328
    spinlock_lock(&tasks_lock);
329
 
1239 jermar 330
    t = task_find_by_id(dst_id);
1235 jermar 331
    if (!NULL) {
332
        spinlock_unlock(&tasks_lock);
333
        interrupts_restore(ipl);
334
        return ENOENT;
335
    }
336
 
337
    spinlock_lock(&t->lock);
338
    spinlock_unlock(&tasks_lock);
339
 
1239 jermar 340
    dst_as = t->as;
1235 jermar 341
    dst_base = (__address) t->accept_arg.base;
342
 
1239 jermar 343
    if (dst_as == AS) {
1235 jermar 344
        /*
345
         * The two tasks share the entire address space.
346
         * Return error since there is no point in continuing.
347
         */
348
        spinlock_unlock(&t->lock);
349
        interrupts_restore(ipl);
350
        return EPERM;
351
    }
1238 jermar 352
 
353
    spinlock_lock(&AS->lock);
1239 jermar 354
    src_area = find_area_and_lock(AS, src_base);
355
    if (!src_area) {
1238 jermar 356
        /*
357
         * Could not find the source address space area.
358
         */
359
        spinlock_unlock(&t->lock);
360
        spinlock_unlock(&AS->lock);
361
        interrupts_restore(ipl);
362
        return ENOENT;
363
    }
1239 jermar 364
    src_size = src_area->pages * PAGE_SIZE;
365
    src_flags = src_area->flags;
366
    spinlock_unlock(&src_area->lock);
1238 jermar 367
    spinlock_unlock(&AS->lock);
1235 jermar 368
 
1239 jermar 369
    if ((t->accept_arg.task_id != TASK->taskid) || (t->accept_arg.size != src_size) ||
370
        (t->accept_arg.flags != src_flags)) {
1235 jermar 371
        /*
372
         * Discrepancy in either task ID, size or flags.
373
         */
374
        spinlock_unlock(&t->lock);
375
        interrupts_restore(ipl);
376
        return EPERM;
377
    }
378
 
379
    /*
1239 jermar 380
     * Create copy of the source address space area.
381
     * The destination area is created with AS_AREA_ATTR_PARTIAL
382
     * attribute set which prevents race condition with
383
     * preliminary as_page_fault() calls.
1235 jermar 384
     */
1239 jermar 385
    dst_area = as_area_create(dst_as, src_flags, src_size, dst_base, AS_AREA_ATTR_PARTIAL);
386
    if (!dst_area) {
1235 jermar 387
        /*
388
         * Destination address space area could not be created.
389
         */
390
        spinlock_unlock(&t->lock);
391
        interrupts_restore(ipl);
392
        return ENOMEM;
393
    }
394
 
395
    memsetb((__address) &t->accept_arg, sizeof(as_area_acptsnd_arg_t), 0);
396
    spinlock_unlock(&t->lock);
397
 
398
    /*
399
     * Avoid deadlock by first locking the address space with lower address.
400
     */
1239 jermar 401
    if (dst_as < AS) {
402
        spinlock_lock(&dst_as->lock);
1235 jermar 403
        spinlock_lock(&AS->lock);
404
    } else {
405
        spinlock_lock(&AS->lock);
1239 jermar 406
        spinlock_lock(&dst_as->lock);
1235 jermar 407
    }
408
 
1239 jermar 409
    for (i = 0; i < SIZE2FRAMES(src_size); i++) {
1235 jermar 410
        pte_t *pte;
411
        __address frame;
412
 
413
        page_table_lock(AS, false);
1239 jermar 414
        pte = page_mapping_find(AS, src_base + i*PAGE_SIZE);
1235 jermar 415
        if (pte && PTE_VALID(pte)) {
416
            ASSERT(PTE_PRESENT(pte));
417
            frame = PTE_GET_FRAME(pte);
1239 jermar 418
            if (!(src_flags & AS_AREA_DEVICE))
1236 jermar 419
                frame_reference_add(ADDR2PFN(frame));
1235 jermar 420
            page_table_unlock(AS, false);
421
        } else {
422
            page_table_unlock(AS, false);
423
            continue;
424
        }
425
 
1239 jermar 426
        page_table_lock(dst_as, false);
427
        page_mapping_insert(dst_as, dst_base + i*PAGE_SIZE, frame, area_flags_to_page_flags(src_flags));
428
        page_table_unlock(dst_as, false);
1235 jermar 429
    }
1239 jermar 430
 
431
    /*
432
     * Now the destination address space area has been
433
     * fully initialized. Clear the AS_AREA_ATTR_PARTIAL
434
     * attribute.
435
     */
436
    spinlock_lock(&dst_area->lock);
437
    dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
438
    spinlock_unlock(&dst_area->lock);
1235 jermar 439
 
440
    spinlock_unlock(&AS->lock);
1239 jermar 441
    spinlock_unlock(&dst_as->lock);
1235 jermar 442
    interrupts_restore(ipl);
443
 
444
    return 0;
445
}
446
 
754 jermar 447
/** Initialize mapping for one page of address space.
703 jermar 448
 *
754 jermar 449
 * This functions maps 'page' to 'frame' according
450
 * to attributes of the address space area to
451
 * wich 'page' belongs.
703 jermar 452
 *
840 jermar 453
 * @param as Target address space.
754 jermar 454
 * @param page Virtual page within the area.
455
 * @param frame Physical frame to which page will be mapped.
703 jermar 456
 */
754 jermar 457
void as_set_mapping(as_t *as, __address page, __address frame)
703 jermar 458
{
977 jermar 459
    as_area_t *area;
703 jermar 460
    ipl_t ipl;
461
 
462
    ipl = interrupts_disable();
1044 jermar 463
    page_table_lock(as, true);
703 jermar 464
 
977 jermar 465
    area = find_area_and_lock(as, page);
754 jermar 466
    if (!area) {
467
        panic("page not part of any as_area\n");
468
    }
469
 
756 jermar 470
    page_mapping_insert(as, page, frame, get_area_flags(area));
754 jermar 471
 
472
    spinlock_unlock(&area->lock);
1044 jermar 473
    page_table_unlock(as, true);
703 jermar 474
    interrupts_restore(ipl);
475
}
476
 
477
/** Handle page fault within the current address space.
478
 *
479
 * This is the high-level page fault handler.
480
 * Interrupts are assumed disabled.
481
 *
482
 * @param page Faulting page.
1288 jermar 483
 * @param istate Pointer to interrupted state.
703 jermar 484
 *
1288 jermar 485
 * @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 486
 */
1288 jermar 487
int as_page_fault(__address page, istate_t *istate)
703 jermar 488
{
1044 jermar 489
    pte_t *pte;
977 jermar 490
    as_area_t *area;
703 jermar 491
    __address frame;
492
 
493
    ASSERT(AS);
1044 jermar 494
 
703 jermar 495
    spinlock_lock(&AS->lock);
977 jermar 496
    area = find_area_and_lock(AS, page);   
703 jermar 497
    if (!area) {
498
        /*
499
         * No area contained mapping for 'page'.
500
         * Signal page fault to low-level handler.
501
         */
502
        spinlock_unlock(&AS->lock);
1288 jermar 503
        goto page_fault;
703 jermar 504
    }
505
 
1239 jermar 506
    if (area->attributes & AS_AREA_ATTR_PARTIAL) {
507
        /*
508
         * The address space area is not fully initialized.
509
         * Avoid possible race by returning error.
510
         */
511
        spinlock_unlock(&area->lock);
512
        spinlock_unlock(&AS->lock);
1288 jermar 513
        goto page_fault;       
1239 jermar 514
    }
515
 
1179 jermar 516
    ASSERT(!(area->flags & AS_AREA_DEVICE));
517
 
1044 jermar 518
    page_table_lock(AS, false);
519
 
703 jermar 520
    /*
1044 jermar 521
     * To avoid race condition between two page faults
522
     * on the same address, we need to make sure
523
     * the mapping has not been already inserted.
524
     */
525
    if ((pte = page_mapping_find(AS, page))) {
526
        if (PTE_PRESENT(pte)) {
527
            page_table_unlock(AS, false);
528
            spinlock_unlock(&area->lock);
529
            spinlock_unlock(&AS->lock);
530
            return 1;
531
        }
532
    }
533
 
534
    /*
754 jermar 535
     * In general, there can be several reasons that
536
     * can have caused this fault.
537
     *
538
     * - non-existent mapping: the area is a scratch
539
     *   area (e.g. stack) and so far has not been
540
     *   allocated a frame for the faulting page
541
     *
542
     * - non-present mapping: another possibility,
543
     *   currently not implemented, would be frame
544
     *   reuse; when this becomes a possibility,
545
     *   do not forget to distinguish between
546
     *   the different causes
703 jermar 547
     */
814 palkovsky 548
    frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
754 jermar 549
    memsetb(PA2KA(frame), FRAME_SIZE, 0);
703 jermar 550
 
551
    /*
552
     * Map 'page' to 'frame'.
553
     * Note that TLB shootdown is not attempted as only new information is being
554
     * inserted into page tables.
555
     */
756 jermar 556
    page_mapping_insert(AS, page, frame, get_area_flags(area));
1044 jermar 557
    page_table_unlock(AS, false);
703 jermar 558
 
559
    spinlock_unlock(&area->lock);
560
    spinlock_unlock(&AS->lock);
1288 jermar 561
    return AS_PF_OK;
562
 
563
page_fault:
564
    if (!THREAD)
565
        return AS_PF_FAULT;
566
 
567
    if (THREAD->in_copy_from_uspace) {
568
        THREAD->in_copy_from_uspace = false;
569
        istate_set_retaddr(istate, (__address) &memcpy_from_uspace_failover_address);
570
    } else if (THREAD->in_copy_to_uspace) {
571
        THREAD->in_copy_to_uspace = false;
572
        istate_set_retaddr(istate, (__address) &memcpy_to_uspace_failover_address);
573
    } else {
574
        return AS_PF_FAULT;
575
    }
576
 
577
    return AS_PF_DEFER;
703 jermar 578
}
579
 
823 jermar 580
/** Switch address spaces.
703 jermar 581
 *
823 jermar 582
 * @param old Old address space or NULL.
583
 * @param new New address space.
703 jermar 584
 */
823 jermar 585
void as_switch(as_t *old, as_t *new)
703 jermar 586
{
587
    ipl_t ipl;
823 jermar 588
    bool needs_asid = false;
703 jermar 589
 
590
    ipl = interrupts_disable();
823 jermar 591
    spinlock_lock(&as_lock);
703 jermar 592
 
593
    /*
823 jermar 594
     * First, take care of the old address space.
595
     */
596
    if (old) {
597
        spinlock_lock(&old->lock);
598
        ASSERT(old->refcount);
599
        if((--old->refcount == 0) && (old != AS_KERNEL)) {
600
            /*
601
             * The old address space is no longer active on
602
             * any processor. It can be appended to the
603
             * list of inactive address spaces with assigned
604
             * ASID.
605
             */
606
             ASSERT(old->asid != ASID_INVALID);
607
             list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head);
608
        }
609
        spinlock_unlock(&old->lock);
610
    }
611
 
612
    /*
613
     * Second, prepare the new address space.
614
     */
615
    spinlock_lock(&new->lock);
616
    if ((new->refcount++ == 0) && (new != AS_KERNEL)) {
617
        if (new->asid != ASID_INVALID)
618
            list_remove(&new->inactive_as_with_asid_link);
619
        else
620
            needs_asid = true;  /* defer call to asid_get() until new->lock is released */
621
    }
622
    SET_PTL0_ADDRESS(new->page_table);
623
    spinlock_unlock(&new->lock);
624
 
625
    if (needs_asid) {
626
        /*
627
         * Allocation of new ASID was deferred
628
         * until now in order to avoid deadlock.
629
         */
630
        asid_t asid;
631
 
632
        asid = asid_get();
633
        spinlock_lock(&new->lock);
634
        new->asid = asid;
635
        spinlock_unlock(&new->lock);
636
    }
637
    spinlock_unlock(&as_lock);
638
    interrupts_restore(ipl);
639
 
640
    /*
703 jermar 641
     * Perform architecture-specific steps.
727 jermar 642
     * (e.g. write ASID to hardware register etc.)
703 jermar 643
     */
823 jermar 644
    as_install_arch(new);
703 jermar 645
 
823 jermar 646
    AS = new;
703 jermar 647
}
754 jermar 648
 
1235 jermar 649
/** Convert address space area flags to page flags.
754 jermar 650
 *
1235 jermar 651
 * @param aflags Flags of some address space area.
754 jermar 652
 *
1235 jermar 653
 * @return Flags to be passed to page_mapping_insert().
754 jermar 654
 */
1235 jermar 655
int area_flags_to_page_flags(int aflags)
754 jermar 656
{
657
    int flags;
658
 
1178 jermar 659
    flags = PAGE_USER | PAGE_PRESENT;
754 jermar 660
 
1235 jermar 661
    if (aflags & AS_AREA_READ)
1026 jermar 662
        flags |= PAGE_READ;
663
 
1235 jermar 664
    if (aflags & AS_AREA_WRITE)
1026 jermar 665
        flags |= PAGE_WRITE;
666
 
1235 jermar 667
    if (aflags & AS_AREA_EXEC)
1026 jermar 668
        flags |= PAGE_EXEC;
669
 
1235 jermar 670
    if (!(aflags & AS_AREA_DEVICE))
1178 jermar 671
        flags |= PAGE_CACHEABLE;
672
 
754 jermar 673
    return flags;
674
}
756 jermar 675
 
1235 jermar 676
/** Compute flags for virtual address translation subsytem.
677
 *
678
 * The address space area must be locked.
679
 * Interrupts must be disabled.
680
 *
681
 * @param a Address space area.
682
 *
683
 * @return Flags to be used in page_mapping_insert().
684
 */
685
int get_area_flags(as_area_t *a)
686
{
687
    return area_flags_to_page_flags(a->flags);
688
}
689
 
756 jermar 690
/** Create page table.
691
 *
692
 * Depending on architecture, create either address space
693
 * private or global page table.
694
 *
695
 * @param flags Flags saying whether the page table is for kernel address space.
696
 *
697
 * @return First entry of the page table.
698
 */
699
pte_t *page_table_create(int flags)
700
{
701
        ASSERT(as_operations);
702
        ASSERT(as_operations->page_table_create);
703
 
704
        return as_operations->page_table_create(flags);
705
}
977 jermar 706
 
1044 jermar 707
/** Lock page table.
708
 *
709
 * This function should be called before any page_mapping_insert(),
710
 * page_mapping_remove() and page_mapping_find().
711
 *
712
 * Locking order is such that address space areas must be locked
713
 * prior to this call. Address space can be locked prior to this
714
 * call in which case the lock argument is false.
715
 *
716
 * @param as Address space.
1248 jermar 717
 * @param lock If false, do not attempt to lock as->lock.
1044 jermar 718
 */
719
void page_table_lock(as_t *as, bool lock)
720
{
721
    ASSERT(as_operations);
722
    ASSERT(as_operations->page_table_lock);
723
 
724
    as_operations->page_table_lock(as, lock);
725
}
726
 
727
/** Unlock page table.
728
 *
729
 * @param as Address space.
1248 jermar 730
 * @param unlock If false, do not attempt to unlock as->lock.
1044 jermar 731
 */
732
void page_table_unlock(as_t *as, bool unlock)
733
{
734
    ASSERT(as_operations);
735
    ASSERT(as_operations->page_table_unlock);
736
 
737
    as_operations->page_table_unlock(as, unlock);
738
}
739
 
977 jermar 740
 
741
/** Find address space area and lock it.
742
 *
743
 * The address space must be locked and interrupts must be disabled.
744
 *
745
 * @param as Address space.
746
 * @param va Virtual address.
747
 *
748
 * @return Locked address space area containing va on success or NULL on failure.
749
 */
750
as_area_t *find_area_and_lock(as_t *as, __address va)
751
{
752
    as_area_t *a;
1147 jermar 753
    btree_node_t *leaf, *lnode;
754
    int i;
977 jermar 755
 
1147 jermar 756
    a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
757
    if (a) {
758
        /* va is the base address of an address space area */
977 jermar 759
        spinlock_lock(&a->lock);
1147 jermar 760
        return a;
761
    }
762
 
763
    /*
1150 jermar 764
     * Search the leaf node and the righmost record of its left neighbour
1147 jermar 765
     * to find out whether this is a miss or va belongs to an address
766
     * space area found there.
767
     */
768
 
769
    /* First, search the leaf node itself. */
770
    for (i = 0; i < leaf->keys; i++) {
771
        a = (as_area_t *) leaf->value[i];
772
        spinlock_lock(&a->lock);
773
        if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
774
            return a;
775
        }
776
        spinlock_unlock(&a->lock);
777
    }
977 jermar 778
 
1147 jermar 779
    /*
1150 jermar 780
     * Second, locate the left neighbour and test its last record.
1148 jermar 781
     * Because of its position in the B+tree, it must have base < va.
1147 jermar 782
     */
1150 jermar 783
    if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 784
        a = (as_area_t *) lnode->value[lnode->keys - 1];
785
        spinlock_lock(&a->lock);
786
        if (va < a->base + a->pages * PAGE_SIZE) {
1048 jermar 787
            return a;
1147 jermar 788
        }
977 jermar 789
        spinlock_unlock(&a->lock);
790
    }
791
 
792
    return NULL;
793
}
1048 jermar 794
 
795
/** Check area conflicts with other areas.
796
 *
797
 * The address space must be locked and interrupts must be disabled.
798
 *
799
 * @param as Address space.
800
 * @param va Starting virtual address of the area being tested.
801
 * @param size Size of the area being tested.
802
 * @param avoid_area Do not touch this area.
803
 *
804
 * @return True if there is no conflict, false otherwise.
805
 */
806
bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area)
807
{
808
    as_area_t *a;
1147 jermar 809
    btree_node_t *leaf, *node;
810
    int i;
1048 jermar 811
 
1070 jermar 812
    /*
813
     * We don't want any area to have conflicts with NULL page.
814
     */
815
    if (overlaps(va, size, NULL, PAGE_SIZE))
816
        return false;
817
 
1147 jermar 818
    /*
819
     * The leaf node is found in O(log n), where n is proportional to
820
     * the number of address space areas belonging to as.
821
     * The check for conflicts is then attempted on the rightmost
1150 jermar 822
     * record in the left neighbour, the leftmost record in the right
823
     * neighbour and all records in the leaf node itself.
1147 jermar 824
     */
1048 jermar 825
 
1147 jermar 826
    if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
827
        if (a != avoid_area)
828
            return false;
829
    }
830
 
831
    /* First, check the two border cases. */
1150 jermar 832
    if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 833
        a = (as_area_t *) node->value[node->keys - 1];
834
        spinlock_lock(&a->lock);
835
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
836
            spinlock_unlock(&a->lock);
837
            return false;
838
        }
839
        spinlock_unlock(&a->lock);
840
    }
1150 jermar 841
    if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 842
        a = (as_area_t *) node->value[0];
843
        spinlock_lock(&a->lock);
844
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
845
            spinlock_unlock(&a->lock);
846
            return false;
847
        }
848
        spinlock_unlock(&a->lock);
849
    }
850
 
851
    /* Second, check the leaf node. */
852
    for (i = 0; i < leaf->keys; i++) {
853
        a = (as_area_t *) leaf->value[i];
854
 
1048 jermar 855
        if (a == avoid_area)
856
            continue;
1147 jermar 857
 
1048 jermar 858
        spinlock_lock(&a->lock);
1147 jermar 859
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
860
            spinlock_unlock(&a->lock);
861
            return false;
862
        }
1048 jermar 863
        spinlock_unlock(&a->lock);
864
    }
865
 
1070 jermar 866
    /*
867
     * So far, the area does not conflict with other areas.
868
     * Check if it doesn't conflict with kernel address space.
869
     */  
870
    if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
871
        return !overlaps(va, size,
872
            KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START);
873
    }
874
 
1048 jermar 875
    return true;
876
}
1235 jermar 877
 
878
/*
879
 * Address space related syscalls.
880
 */
881
 
882
/** Wrapper for as_area_create(). */
883
__native sys_as_area_create(__address address, size_t size, int flags)
884
{
1239 jermar 885
    if (as_area_create(AS, flags, size, address, AS_AREA_ATTR_NONE))
1235 jermar 886
        return (__native) address;
887
    else
888
        return (__native) -1;
889
}
890
 
891
/** Wrapper for as_area_resize. */
892
__native sys_as_area_resize(__address address, size_t size, int flags)
893
{
894
    return as_area_resize(AS, address, size, 0);
895
}
896
 
897
/** Prepare task for accepting address space area from another task.
898
 *
899
 * @param uspace_accept_arg Accept structure passed from userspace.
900
 *
901
 * @return EPERM if the task ID encapsulated in @uspace_accept_arg references
902
 *     TASK. Otherwise zero is returned.
903
 */
904
__native sys_as_area_accept(as_area_acptsnd_arg_t *uspace_accept_arg)
905
{
906
    as_area_acptsnd_arg_t arg;
1288 jermar 907
    int rc;
1235 jermar 908
 
1288 jermar 909
    rc = copy_from_uspace(&arg, uspace_accept_arg, sizeof(as_area_acptsnd_arg_t));
910
    if (rc != 0)
911
        return rc;
1235 jermar 912
 
913
    if (!arg.size)
914
        return (__native) EPERM;
915
 
916
    if (arg.task_id == TASK->taskid) {
917
        /*
918
         * Accepting from itself is not allowed.
919
         */
920
        return (__native) EPERM;
921
    }
922
 
923
    memcpy(&TASK->accept_arg, &arg, sizeof(as_area_acptsnd_arg_t));
924
 
925
        return 0;
926
}
927
 
928
/** Wrapper for as_area_send. */
929
__native sys_as_area_send(as_area_acptsnd_arg_t *uspace_send_arg)
930
{
931
    as_area_acptsnd_arg_t arg;
1288 jermar 932
    int rc;
1235 jermar 933
 
1288 jermar 934
    rc = copy_from_uspace(&arg, uspace_send_arg, sizeof(as_area_acptsnd_arg_t));
935
    if (rc != 0)
936
        return rc;
1235 jermar 937
 
938
    if (!arg.size)
939
        return (__native) EPERM;
940
 
941
    if (arg.task_id == TASK->taskid) {
942
        /*
943
         * Sending to itself is not allowed.
944
         */
945
        return (__native) EPERM;
946
    }
947
 
1238 jermar 948
    return (__native) as_area_send(arg.task_id, (__address) arg.base);
1235 jermar 949
}