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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>
1387 jermar 71
#include <align.h>
1235 jermar 72
#include <arch/types.h>
73
#include <typedefs.h>
1288 jermar 74
#include <syscall/copy.h>
75
#include <arch/interrupt.h>
703 jermar 76
 
756 jermar 77
as_operations_t *as_operations = NULL;
703 jermar 78
 
1415 jermar 79
/** This lock protects inactive_as_with_asid_head list. It must be acquired before as_t mutex. */
80
SPINLOCK_INITIALIZE(inactive_as_with_asid_lock);
823 jermar 81
 
82
/**
83
 * This list contains address spaces that are not active on any
84
 * processor and that have valid ASID.
85
 */
86
LIST_INITIALIZE(inactive_as_with_asid_head);
87
 
757 jermar 88
/** Kernel address space. */
89
as_t *AS_KERNEL = NULL;
90
 
1235 jermar 91
static int area_flags_to_page_flags(int aflags);
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);
1409 jermar 94
static void sh_info_remove_reference(share_info_t *sh_info);
703 jermar 95
 
756 jermar 96
/** Initialize address space subsystem. */
97
void as_init(void)
98
{
99
    as_arch_init();
789 palkovsky 100
    AS_KERNEL = as_create(FLAG_AS_KERNEL);
1383 decky 101
    if (!AS_KERNEL)
102
        panic("can't create kernel address space\n");
103
 
756 jermar 104
}
105
 
757 jermar 106
/** Create address space.
107
 *
108
 * @param flags Flags that influence way in wich the address space is created.
109
 */
756 jermar 110
as_t *as_create(int flags)
703 jermar 111
{
112
    as_t *as;
113
 
822 palkovsky 114
    as = (as_t *) malloc(sizeof(as_t), 0);
823 jermar 115
    link_initialize(&as->inactive_as_with_asid_link);
1380 jermar 116
    mutex_initialize(&as->lock);
1147 jermar 117
    btree_create(&as->as_area_btree);
822 palkovsky 118
 
119
    if (flags & FLAG_AS_KERNEL)
120
        as->asid = ASID_KERNEL;
121
    else
122
        as->asid = ASID_INVALID;
123
 
1468 jermar 124
    as->refcount = 0;
1415 jermar 125
    as->cpu_refcount = 0;
822 palkovsky 126
    as->page_table = page_table_create(flags);
703 jermar 127
 
128
    return as;
129
}
130
 
1468 jermar 131
/** Destroy adress space.
132
 *
133
 * When there are no tasks referencing this address space (i.e. its refcount is zero),
134
 * the address space can be destroyed.
135
 */
136
void as_destroy(as_t *as)
973 palkovsky 137
{
1468 jermar 138
    ipl_t ipl;
1495 jermar 139
    link_t *cur;
973 palkovsky 140
 
1468 jermar 141
    ASSERT(as->refcount == 0);
142
 
143
    /*
144
     * Since there is no reference to this area,
145
     * it is safe not to lock its mutex.
146
     */
147
 
148
    ipl = interrupts_disable();
149
    spinlock_lock(&inactive_as_with_asid_lock);
150
    if (as->asid != ASID_INVALID && as->asid != ASID_KERNEL) {
151
        list_remove(&as->inactive_as_with_asid_link);
152
        asid_put(as->asid);
153
    }
154
    spinlock_unlock(&inactive_as_with_asid_lock);
155
 
156
    /*
157
     * Destroy address space areas of the address space.
158
     */
1495 jermar 159
    for (cur = as->as_area_btree.leaf_head.next; cur != &as->as_area_btree.leaf_head; cur = cur->next) {
1468 jermar 160
        btree_node_t *node;
1495 jermar 161
        int i;
1468 jermar 162
 
1495 jermar 163
        node = list_get_instance(cur, btree_node_t, leaf_link);
164
        for (i = 0; i < node->keys; i++)
165
            as_area_destroy(as, node->key[i]);
1468 jermar 166
    }
1495 jermar 167
 
1483 jermar 168
    btree_destroy(&as->as_area_btree);
1468 jermar 169
    page_table_destroy(as->page_table);
170
 
171
    interrupts_restore(ipl);
172
 
973 palkovsky 173
    free(as);
174
}
175
 
703 jermar 176
/** Create address space area of common attributes.
177
 *
178
 * The created address space area is added to the target address space.
179
 *
180
 * @param as Target address space.
1239 jermar 181
 * @param flags Flags of the area memory.
1048 jermar 182
 * @param size Size of area.
703 jermar 183
 * @param base Base address of area.
1239 jermar 184
 * @param attrs Attributes of the area.
1409 jermar 185
 * @param backend Address space area backend. NULL if no backend is used.
186
 * @param backend_data NULL or a pointer to an array holding two void *.
703 jermar 187
 *
188
 * @return Address space area on success or NULL on failure.
189
 */
1409 jermar 190
as_area_t *as_area_create(as_t *as, int flags, size_t size, __address base, int attrs,
1424 jermar 191
           mem_backend_t *backend, mem_backend_data_t *backend_data)
703 jermar 192
{
193
    ipl_t ipl;
194
    as_area_t *a;
195
 
196
    if (base % PAGE_SIZE)
1048 jermar 197
        return NULL;
198
 
1233 jermar 199
    if (!size)
200
        return NULL;
201
 
1048 jermar 202
    /* Writeable executable areas are not supported. */
203
    if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
204
        return NULL;
703 jermar 205
 
206
    ipl = interrupts_disable();
1380 jermar 207
    mutex_lock(&as->lock);
703 jermar 208
 
1048 jermar 209
    if (!check_area_conflicts(as, base, size, NULL)) {
1380 jermar 210
        mutex_unlock(&as->lock);
1048 jermar 211
        interrupts_restore(ipl);
212
        return NULL;
213
    }
703 jermar 214
 
822 palkovsky 215
    a = (as_area_t *) malloc(sizeof(as_area_t), 0);
703 jermar 216
 
1380 jermar 217
    mutex_initialize(&a->lock);
822 palkovsky 218
 
1424 jermar 219
    a->as = as;
1026 jermar 220
    a->flags = flags;
1239 jermar 221
    a->attributes = attrs;
1048 jermar 222
    a->pages = SIZE2FRAMES(size);
822 palkovsky 223
    a->base = base;
1409 jermar 224
    a->sh_info = NULL;
225
    a->backend = backend;
1424 jermar 226
    if (backend_data)
227
        a->backend_data = *backend_data;
228
    else
229
        memsetb((__address) &a->backend_data, sizeof(a->backend_data), 0);
230
 
1387 jermar 231
    btree_create(&a->used_space);
822 palkovsky 232
 
1147 jermar 233
    btree_insert(&as->as_area_btree, base, (void *) a, NULL);
822 palkovsky 234
 
1380 jermar 235
    mutex_unlock(&as->lock);
703 jermar 236
    interrupts_restore(ipl);
704 jermar 237
 
703 jermar 238
    return a;
239
}
240
 
1235 jermar 241
/** Find address space area and change it.
242
 *
243
 * @param as Address space.
244
 * @param address Virtual address belonging to the area to be changed. Must be page-aligned.
245
 * @param size New size of the virtual memory block starting at address.
246
 * @param flags Flags influencing the remap operation. Currently unused.
247
 *
1306 jermar 248
 * @return Zero on success or a value from @ref errno.h otherwise.
1235 jermar 249
 */
1306 jermar 250
int as_area_resize(as_t *as, __address address, size_t size, int flags)
1235 jermar 251
{
1306 jermar 252
    as_area_t *area;
1235 jermar 253
    ipl_t ipl;
254
    size_t pages;
255
 
256
    ipl = interrupts_disable();
1380 jermar 257
    mutex_lock(&as->lock);
1235 jermar 258
 
259
    /*
260
     * Locate the area.
261
     */
262
    area = find_area_and_lock(as, address);
263
    if (!area) {
1380 jermar 264
        mutex_unlock(&as->lock);
1235 jermar 265
        interrupts_restore(ipl);
1306 jermar 266
        return ENOENT;
1235 jermar 267
    }
268
 
1424 jermar 269
    if (area->backend == &phys_backend) {
1235 jermar 270
        /*
271
         * Remapping of address space areas associated
272
         * with memory mapped devices is not supported.
273
         */
1380 jermar 274
        mutex_unlock(&area->lock);
275
        mutex_unlock(&as->lock);
1235 jermar 276
        interrupts_restore(ipl);
1306 jermar 277
        return ENOTSUP;
1235 jermar 278
    }
1409 jermar 279
    if (area->sh_info) {
280
        /*
281
         * Remapping of shared address space areas
282
         * is not supported.
283
         */
284
        mutex_unlock(&area->lock);
285
        mutex_unlock(&as->lock);
286
        interrupts_restore(ipl);
287
        return ENOTSUP;
288
    }
1235 jermar 289
 
290
    pages = SIZE2FRAMES((address - area->base) + size);
291
    if (!pages) {
292
        /*
293
         * Zero size address space areas are not allowed.
294
         */
1380 jermar 295
        mutex_unlock(&area->lock);
296
        mutex_unlock(&as->lock);
1235 jermar 297
        interrupts_restore(ipl);
1306 jermar 298
        return EPERM;
1235 jermar 299
    }
300
 
301
    if (pages < area->pages) {
1403 jermar 302
        bool cond;
303
        __address start_free = area->base + pages*PAGE_SIZE;
1235 jermar 304
 
305
        /*
306
         * Shrinking the area.
307
         * No need to check for overlaps.
308
         */
1403 jermar 309
 
310
        /*
1436 jermar 311
         * Start TLB shootdown sequence.
312
         */
313
        tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
314
 
315
        /*
1403 jermar 316
         * Remove frames belonging to used space starting from
317
         * the highest addresses downwards until an overlap with
318
         * the resized address space area is found. Note that this
319
         * is also the right way to remove part of the used_space
320
         * B+tree leaf list.
321
         */    
322
        for (cond = true; cond;) {
323
            btree_node_t *node;
324
 
325
            ASSERT(!list_empty(&area->used_space.leaf_head));
326
            node = list_get_instance(area->used_space.leaf_head.prev, btree_node_t, leaf_link);
327
            if ((cond = (bool) node->keys)) {
328
                __address b = node->key[node->keys - 1];
329
                count_t c = (count_t) node->value[node->keys - 1];
330
                int i = 0;
1235 jermar 331
 
1403 jermar 332
                if (overlaps(b, c*PAGE_SIZE, area->base, pages*PAGE_SIZE)) {
333
 
334
                    if (b + c*PAGE_SIZE <= start_free) {
335
                        /*
336
                         * The whole interval fits completely
337
                         * in the resized address space area.
338
                         */
339
                        break;
340
                    }
341
 
342
                    /*
343
                     * Part of the interval corresponding to b and c
344
                     * overlaps with the resized address space area.
345
                     */
346
 
347
                    cond = false;   /* we are almost done */
348
                    i = (start_free - b) >> PAGE_WIDTH;
349
                    if (!used_space_remove(area, start_free, c - i))
350
                        panic("Could not remove used space.");
351
                } else {
352
                    /*
353
                     * The interval of used space can be completely removed.
354
                     */
355
                    if (!used_space_remove(area, b, c))
356
                        panic("Could not remove used space.\n");
357
                }
358
 
359
                for (; i < c; i++) {
360
                    pte_t *pte;
361
 
362
                    page_table_lock(as, false);
363
                    pte = page_mapping_find(as, b + i*PAGE_SIZE);
364
                    ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424 jermar 365
                    if (area->backend && area->backend->frame_free) {
366
                        area->backend->frame_free(area,
1409 jermar 367
                            b + i*PAGE_SIZE, PTE_GET_FRAME(pte));
368
                    }
1403 jermar 369
                    page_mapping_remove(as, b + i*PAGE_SIZE);
370
                    page_table_unlock(as, false);
371
                }
1235 jermar 372
            }
373
        }
1436 jermar 374
 
1235 jermar 375
        /*
1436 jermar 376
         * Finish TLB shootdown sequence.
1235 jermar 377
         */
378
        tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
379
        tlb_shootdown_finalize();
380
    } else {
381
        /*
382
         * Growing the area.
383
         * Check for overlaps with other address space areas.
384
         */
385
        if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
1380 jermar 386
            mutex_unlock(&area->lock);
387
            mutex_unlock(&as->lock);       
1235 jermar 388
            interrupts_restore(ipl);
1306 jermar 389
            return EADDRNOTAVAIL;
1235 jermar 390
        }
391
    }
392
 
393
    area->pages = pages;
394
 
1380 jermar 395
    mutex_unlock(&area->lock);
396
    mutex_unlock(&as->lock);
1235 jermar 397
    interrupts_restore(ipl);
398
 
1306 jermar 399
    return 0;
1235 jermar 400
}
401
 
1306 jermar 402
/** Destroy address space area.
403
 *
404
 * @param as Address space.
405
 * @param address Address withing the area to be deleted.
406
 *
407
 * @return Zero on success or a value from @ref errno.h on failure.
408
 */
409
int as_area_destroy(as_t *as, __address address)
410
{
411
    as_area_t *area;
412
    __address base;
1495 jermar 413
    link_t *cur;
1306 jermar 414
    ipl_t ipl;
415
 
416
    ipl = interrupts_disable();
1380 jermar 417
    mutex_lock(&as->lock);
1306 jermar 418
 
419
    area = find_area_and_lock(as, address);
420
    if (!area) {
1380 jermar 421
        mutex_unlock(&as->lock);
1306 jermar 422
        interrupts_restore(ipl);
423
        return ENOENT;
424
    }
425
 
1403 jermar 426
    base = area->base;
427
 
1411 jermar 428
    /*
1436 jermar 429
     * Start TLB shootdown sequence.
430
     */
431
    tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages);
432
 
433
    /*
1411 jermar 434
     * Visit only the pages mapped by used_space B+tree.
435
     */
1495 jermar 436
    for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {
1411 jermar 437
        btree_node_t *node;
1495 jermar 438
        int i;
1403 jermar 439
 
1495 jermar 440
        node = list_get_instance(cur, btree_node_t, leaf_link);
441
        for (i = 0; i < node->keys; i++) {
442
            __address b = node->key[i];
443
            count_t j;
1411 jermar 444
            pte_t *pte;
1403 jermar 445
 
1495 jermar 446
            for (j = 0; j < (count_t) node->value[i]; j++) {
1411 jermar 447
                page_table_lock(as, false);
1495 jermar 448
                pte = page_mapping_find(as, b + j*PAGE_SIZE);
1411 jermar 449
                ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424 jermar 450
                if (area->backend && area->backend->frame_free) {
451
                    area->backend->frame_free(area,
1495 jermar 452
                        b + j*PAGE_SIZE, PTE_GET_FRAME(pte));
1403 jermar 453
                }
1495 jermar 454
                page_mapping_remove(as, b + j*PAGE_SIZE);
1411 jermar 455
                page_table_unlock(as, false);
1306 jermar 456
            }
457
        }
458
    }
1403 jermar 459
 
1306 jermar 460
    /*
1436 jermar 461
     * Finish TLB shootdown sequence.
1306 jermar 462
     */
463
    tlb_invalidate_pages(AS->asid, area->base, area->pages);
464
    tlb_shootdown_finalize();
1436 jermar 465
 
466
    btree_destroy(&area->used_space);
1306 jermar 467
 
1309 jermar 468
    area->attributes |= AS_AREA_ATTR_PARTIAL;
1409 jermar 469
 
470
    if (area->sh_info)
471
        sh_info_remove_reference(area->sh_info);
472
 
1380 jermar 473
    mutex_unlock(&area->lock);
1306 jermar 474
 
475
    /*
476
     * Remove the empty area from address space.
477
     */
478
    btree_remove(&AS->as_area_btree, base, NULL);
479
 
1309 jermar 480
    free(area);
481
 
1380 jermar 482
    mutex_unlock(&AS->lock);
1306 jermar 483
    interrupts_restore(ipl);
484
    return 0;
485
}
486
 
1413 jermar 487
/** Share address space area with another or the same address space.
1235 jermar 488
 *
1424 jermar 489
 * Address space area mapping is shared with a new address space area.
490
 * If the source address space area has not been shared so far,
491
 * a new sh_info is created. The new address space area simply gets the
492
 * sh_info of the source area. The process of duplicating the
493
 * mapping is done through the backend share function.
1413 jermar 494
 *
1417 jermar 495
 * @param src_as Pointer to source address space.
1239 jermar 496
 * @param src_base Base address of the source address space area.
1417 jermar 497
 * @param acc_size Expected size of the source area.
1428 palkovsky 498
 * @param dst_as Pointer to destination address space.
1417 jermar 499
 * @param dst_base Target base address.
500
 * @param dst_flags_mask Destination address space area flags mask.
1235 jermar 501
 *
1306 jermar 502
 * @return Zero on success or ENOENT if there is no such task or
1235 jermar 503
 *     if there is no such address space area,
504
 *     EPERM if there was a problem in accepting the area or
505
 *     ENOMEM if there was a problem in allocating destination
1413 jermar 506
 *     address space area. ENOTSUP is returned if an attempt
507
 *     to share non-anonymous address space area is detected.
1235 jermar 508
 */
1413 jermar 509
int as_area_share(as_t *src_as, __address src_base, size_t acc_size,
1428 palkovsky 510
          as_t *dst_as, __address dst_base, int dst_flags_mask)
1235 jermar 511
{
512
    ipl_t ipl;
1239 jermar 513
    int src_flags;
514
    size_t src_size;
515
    as_area_t *src_area, *dst_area;
1413 jermar 516
    share_info_t *sh_info;
1424 jermar 517
    mem_backend_t *src_backend;
518
    mem_backend_data_t src_backend_data;
1434 palkovsky 519
 
1235 jermar 520
    ipl = interrupts_disable();
1380 jermar 521
    mutex_lock(&src_as->lock);
1329 palkovsky 522
    src_area = find_area_and_lock(src_as, src_base);
1239 jermar 523
    if (!src_area) {
1238 jermar 524
        /*
525
         * Could not find the source address space area.
526
         */
1380 jermar 527
        mutex_unlock(&src_as->lock);
1238 jermar 528
        interrupts_restore(ipl);
529
        return ENOENT;
530
    }
1413 jermar 531
 
1424 jermar 532
    if (!src_area->backend || !src_area->backend->share) {
1413 jermar 533
        /*
1424 jermar 534
         * There is now backend or the backend does not
535
         * know how to share the area.
1413 jermar 536
         */
537
        mutex_unlock(&src_area->lock);
538
        mutex_unlock(&src_as->lock);
539
        interrupts_restore(ipl);
540
        return ENOTSUP;
541
    }
542
 
1239 jermar 543
    src_size = src_area->pages * PAGE_SIZE;
544
    src_flags = src_area->flags;
1424 jermar 545
    src_backend = src_area->backend;
546
    src_backend_data = src_area->backend_data;
1413 jermar 547
 
1461 palkovsky 548
    if (src_size != acc_size || (src_flags & dst_flags_mask) != dst_flags_mask) {
1413 jermar 549
        mutex_unlock(&src_area->lock);
550
        mutex_unlock(&src_as->lock);
1235 jermar 551
        interrupts_restore(ipl);
552
        return EPERM;
553
    }
1413 jermar 554
 
1235 jermar 555
    /*
1413 jermar 556
     * Now we are committed to sharing the area.
557
     * First prepare the area for sharing.
558
     * Then it will be safe to unlock it.
559
     */
560
    sh_info = src_area->sh_info;
561
    if (!sh_info) {
562
        sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0);
563
        mutex_initialize(&sh_info->lock);
564
        sh_info->refcount = 2;
565
        btree_create(&sh_info->pagemap);
566
        src_area->sh_info = sh_info;
567
    } else {
568
        mutex_lock(&sh_info->lock);
569
        sh_info->refcount++;
570
        mutex_unlock(&sh_info->lock);
571
    }
572
 
1424 jermar 573
    src_area->backend->share(src_area);
1413 jermar 574
 
575
    mutex_unlock(&src_area->lock);
576
    mutex_unlock(&src_as->lock);
577
 
578
    /*
1239 jermar 579
     * Create copy of the source address space area.
580
     * The destination area is created with AS_AREA_ATTR_PARTIAL
581
     * attribute set which prevents race condition with
582
     * preliminary as_page_fault() calls.
1417 jermar 583
     * The flags of the source area are masked against dst_flags_mask
584
     * to support sharing in less privileged mode.
1235 jermar 585
     */
1461 palkovsky 586
    dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base,
1424 jermar 587
                  AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data);
1239 jermar 588
    if (!dst_area) {
1235 jermar 589
        /*
590
         * Destination address space area could not be created.
591
         */
1413 jermar 592
        sh_info_remove_reference(sh_info);
593
 
1235 jermar 594
        interrupts_restore(ipl);
595
        return ENOMEM;
596
    }
597
 
598
    /*
1239 jermar 599
     * Now the destination address space area has been
600
     * fully initialized. Clear the AS_AREA_ATTR_PARTIAL
1413 jermar 601
     * attribute and set the sh_info.
1239 jermar 602
     */
1380 jermar 603
    mutex_lock(&dst_area->lock);
1239 jermar 604
    dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
1413 jermar 605
    dst_area->sh_info = sh_info;
1380 jermar 606
    mutex_unlock(&dst_area->lock);
1235 jermar 607
 
608
    interrupts_restore(ipl);
609
 
610
    return 0;
611
}
612
 
1423 jermar 613
/** Check access mode for address space area.
614
 *
615
 * The address space area must be locked prior to this call.
616
 *
617
 * @param area Address space area.
618
 * @param access Access mode.
619
 *
620
 * @return False if access violates area's permissions, true otherwise.
621
 */
622
bool as_area_check_access(as_area_t *area, pf_access_t access)
623
{
624
    int flagmap[] = {
625
        [PF_ACCESS_READ] = AS_AREA_READ,
626
        [PF_ACCESS_WRITE] = AS_AREA_WRITE,
627
        [PF_ACCESS_EXEC] = AS_AREA_EXEC
628
    };
629
 
630
    if (!(area->flags & flagmap[access]))
631
        return false;
632
 
633
    return true;
634
}
635
 
703 jermar 636
/** Handle page fault within the current address space.
637
 *
1409 jermar 638
 * This is the high-level page fault handler. It decides
639
 * whether the page fault can be resolved by any backend
640
 * and if so, it invokes the backend to resolve the page
641
 * fault.
642
 *
703 jermar 643
 * Interrupts are assumed disabled.
644
 *
645
 * @param page Faulting page.
1411 jermar 646
 * @param access Access mode that caused the fault (i.e. read/write/exec).
1288 jermar 647
 * @param istate Pointer to interrupted state.
703 jermar 648
 *
1409 jermar 649
 * @return AS_PF_FAULT on page fault, AS_PF_OK on success or AS_PF_DEFER if the
650
 *     fault was caused by copy_to_uspace() or copy_from_uspace().
703 jermar 651
 */
1411 jermar 652
int as_page_fault(__address page, pf_access_t access, istate_t *istate)
703 jermar 653
{
1044 jermar 654
    pte_t *pte;
977 jermar 655
    as_area_t *area;
703 jermar 656
 
1380 jermar 657
    if (!THREAD)
1409 jermar 658
        return AS_PF_FAULT;
1380 jermar 659
 
703 jermar 660
    ASSERT(AS);
1044 jermar 661
 
1380 jermar 662
    mutex_lock(&AS->lock);
977 jermar 663
    area = find_area_and_lock(AS, page);   
703 jermar 664
    if (!area) {
665
        /*
666
         * No area contained mapping for 'page'.
667
         * Signal page fault to low-level handler.
668
         */
1380 jermar 669
        mutex_unlock(&AS->lock);
1288 jermar 670
        goto page_fault;
703 jermar 671
    }
672
 
1239 jermar 673
    if (area->attributes & AS_AREA_ATTR_PARTIAL) {
674
        /*
675
         * The address space area is not fully initialized.
676
         * Avoid possible race by returning error.
677
         */
1380 jermar 678
        mutex_unlock(&area->lock);
679
        mutex_unlock(&AS->lock);
1288 jermar 680
        goto page_fault;       
1239 jermar 681
    }
682
 
1424 jermar 683
    if (!area->backend || !area->backend->page_fault) {
1409 jermar 684
        /*
685
         * The address space area is not backed by any backend
686
         * or the backend cannot handle page faults.
687
         */
688
        mutex_unlock(&area->lock);
689
        mutex_unlock(&AS->lock);
690
        goto page_fault;       
691
    }
1179 jermar 692
 
1044 jermar 693
    page_table_lock(AS, false);
694
 
703 jermar 695
    /*
1044 jermar 696
     * To avoid race condition between two page faults
697
     * on the same address, we need to make sure
698
     * the mapping has not been already inserted.
699
     */
700
    if ((pte = page_mapping_find(AS, page))) {
701
        if (PTE_PRESENT(pte)) {
1423 jermar 702
            if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) ||
703
                (access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) ||
704
                (access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) {
705
                page_table_unlock(AS, false);
706
                mutex_unlock(&area->lock);
707
                mutex_unlock(&AS->lock);
708
                return AS_PF_OK;
709
            }
1044 jermar 710
        }
711
    }
1409 jermar 712
 
1044 jermar 713
    /*
1409 jermar 714
     * Resort to the backend page fault handler.
703 jermar 715
     */
1424 jermar 716
    if (area->backend->page_fault(area, page, access) != AS_PF_OK) {
1409 jermar 717
        page_table_unlock(AS, false);
718
        mutex_unlock(&area->lock);
719
        mutex_unlock(&AS->lock);
720
        goto page_fault;
721
    }
703 jermar 722
 
1044 jermar 723
    page_table_unlock(AS, false);
1380 jermar 724
    mutex_unlock(&area->lock);
725
    mutex_unlock(&AS->lock);
1288 jermar 726
    return AS_PF_OK;
727
 
728
page_fault:
729
    if (THREAD->in_copy_from_uspace) {
730
        THREAD->in_copy_from_uspace = false;
731
        istate_set_retaddr(istate, (__address) &memcpy_from_uspace_failover_address);
732
    } else if (THREAD->in_copy_to_uspace) {
733
        THREAD->in_copy_to_uspace = false;
734
        istate_set_retaddr(istate, (__address) &memcpy_to_uspace_failover_address);
735
    } else {
736
        return AS_PF_FAULT;
737
    }
738
 
739
    return AS_PF_DEFER;
703 jermar 740
}
741
 
823 jermar 742
/** Switch address spaces.
703 jermar 743
 *
1380 jermar 744
 * Note that this function cannot sleep as it is essentially a part of
1415 jermar 745
 * scheduling. Sleeping here would lead to deadlock on wakeup.
1380 jermar 746
 *
823 jermar 747
 * @param old Old address space or NULL.
748
 * @param new New address space.
703 jermar 749
 */
823 jermar 750
void as_switch(as_t *old, as_t *new)
703 jermar 751
{
752
    ipl_t ipl;
823 jermar 753
    bool needs_asid = false;
703 jermar 754
 
755
    ipl = interrupts_disable();
1415 jermar 756
    spinlock_lock(&inactive_as_with_asid_lock);
703 jermar 757
 
758
    /*
823 jermar 759
     * First, take care of the old address space.
760
     */
761
    if (old) {
1380 jermar 762
        mutex_lock_active(&old->lock);
1415 jermar 763
        ASSERT(old->cpu_refcount);
764
        if((--old->cpu_refcount == 0) && (old != AS_KERNEL)) {
823 jermar 765
            /*
766
             * The old address space is no longer active on
767
             * any processor. It can be appended to the
768
             * list of inactive address spaces with assigned
769
             * ASID.
770
             */
771
             ASSERT(old->asid != ASID_INVALID);
772
             list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head);
773
        }
1380 jermar 774
        mutex_unlock(&old->lock);
823 jermar 775
    }
776
 
777
    /*
778
     * Second, prepare the new address space.
779
     */
1380 jermar 780
    mutex_lock_active(&new->lock);
1415 jermar 781
    if ((new->cpu_refcount++ == 0) && (new != AS_KERNEL)) {
823 jermar 782
        if (new->asid != ASID_INVALID)
783
            list_remove(&new->inactive_as_with_asid_link);
784
        else
785
            needs_asid = true;  /* defer call to asid_get() until new->lock is released */
786
    }
787
    SET_PTL0_ADDRESS(new->page_table);
1380 jermar 788
    mutex_unlock(&new->lock);
823 jermar 789
 
790
    if (needs_asid) {
791
        /*
792
         * Allocation of new ASID was deferred
793
         * until now in order to avoid deadlock.
794
         */
795
        asid_t asid;
796
 
797
        asid = asid_get();
1380 jermar 798
        mutex_lock_active(&new->lock);
823 jermar 799
        new->asid = asid;
1380 jermar 800
        mutex_unlock(&new->lock);
823 jermar 801
    }
1415 jermar 802
    spinlock_unlock(&inactive_as_with_asid_lock);
823 jermar 803
    interrupts_restore(ipl);
804
 
805
    /*
703 jermar 806
     * Perform architecture-specific steps.
727 jermar 807
     * (e.g. write ASID to hardware register etc.)
703 jermar 808
     */
823 jermar 809
    as_install_arch(new);
703 jermar 810
 
823 jermar 811
    AS = new;
703 jermar 812
}
754 jermar 813
 
1235 jermar 814
/** Convert address space area flags to page flags.
754 jermar 815
 *
1235 jermar 816
 * @param aflags Flags of some address space area.
754 jermar 817
 *
1235 jermar 818
 * @return Flags to be passed to page_mapping_insert().
754 jermar 819
 */
1235 jermar 820
int area_flags_to_page_flags(int aflags)
754 jermar 821
{
822
    int flags;
823
 
1178 jermar 824
    flags = PAGE_USER | PAGE_PRESENT;
754 jermar 825
 
1235 jermar 826
    if (aflags & AS_AREA_READ)
1026 jermar 827
        flags |= PAGE_READ;
828
 
1235 jermar 829
    if (aflags & AS_AREA_WRITE)
1026 jermar 830
        flags |= PAGE_WRITE;
831
 
1235 jermar 832
    if (aflags & AS_AREA_EXEC)
1026 jermar 833
        flags |= PAGE_EXEC;
834
 
1424 jermar 835
    if (aflags & AS_AREA_CACHEABLE)
1178 jermar 836
        flags |= PAGE_CACHEABLE;
837
 
754 jermar 838
    return flags;
839
}
756 jermar 840
 
1235 jermar 841
/** Compute flags for virtual address translation subsytem.
842
 *
843
 * The address space area must be locked.
844
 * Interrupts must be disabled.
845
 *
846
 * @param a Address space area.
847
 *
848
 * @return Flags to be used in page_mapping_insert().
849
 */
1409 jermar 850
int as_area_get_flags(as_area_t *a)
1235 jermar 851
{
852
    return area_flags_to_page_flags(a->flags);
853
}
854
 
756 jermar 855
/** Create page table.
856
 *
857
 * Depending on architecture, create either address space
858
 * private or global page table.
859
 *
860
 * @param flags Flags saying whether the page table is for kernel address space.
861
 *
862
 * @return First entry of the page table.
863
 */
864
pte_t *page_table_create(int flags)
865
{
866
        ASSERT(as_operations);
867
        ASSERT(as_operations->page_table_create);
868
 
869
        return as_operations->page_table_create(flags);
870
}
977 jermar 871
 
1468 jermar 872
/** Destroy page table.
873
 *
874
 * Destroy page table in architecture specific way.
875
 *
876
 * @param page_table Physical address of PTL0.
877
 */
878
void page_table_destroy(pte_t *page_table)
879
{
880
        ASSERT(as_operations);
881
        ASSERT(as_operations->page_table_destroy);
882
 
883
        as_operations->page_table_destroy(page_table);
884
}
885
 
1044 jermar 886
/** Lock page table.
887
 *
888
 * This function should be called before any page_mapping_insert(),
889
 * page_mapping_remove() and page_mapping_find().
890
 *
891
 * Locking order is such that address space areas must be locked
892
 * prior to this call. Address space can be locked prior to this
893
 * call in which case the lock argument is false.
894
 *
895
 * @param as Address space.
1248 jermar 896
 * @param lock If false, do not attempt to lock as->lock.
1044 jermar 897
 */
898
void page_table_lock(as_t *as, bool lock)
899
{
900
    ASSERT(as_operations);
901
    ASSERT(as_operations->page_table_lock);
902
 
903
    as_operations->page_table_lock(as, lock);
904
}
905
 
906
/** Unlock page table.
907
 *
908
 * @param as Address space.
1248 jermar 909
 * @param unlock If false, do not attempt to unlock as->lock.
1044 jermar 910
 */
911
void page_table_unlock(as_t *as, bool unlock)
912
{
913
    ASSERT(as_operations);
914
    ASSERT(as_operations->page_table_unlock);
915
 
916
    as_operations->page_table_unlock(as, unlock);
917
}
918
 
977 jermar 919
 
920
/** Find address space area and lock it.
921
 *
922
 * The address space must be locked and interrupts must be disabled.
923
 *
924
 * @param as Address space.
925
 * @param va Virtual address.
926
 *
927
 * @return Locked address space area containing va on success or NULL on failure.
928
 */
929
as_area_t *find_area_and_lock(as_t *as, __address va)
930
{
931
    as_area_t *a;
1147 jermar 932
    btree_node_t *leaf, *lnode;
933
    int i;
977 jermar 934
 
1147 jermar 935
    a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
936
    if (a) {
937
        /* va is the base address of an address space area */
1380 jermar 938
        mutex_lock(&a->lock);
1147 jermar 939
        return a;
940
    }
941
 
942
    /*
1150 jermar 943
     * Search the leaf node and the righmost record of its left neighbour
1147 jermar 944
     * to find out whether this is a miss or va belongs to an address
945
     * space area found there.
946
     */
947
 
948
    /* First, search the leaf node itself. */
949
    for (i = 0; i < leaf->keys; i++) {
950
        a = (as_area_t *) leaf->value[i];
1380 jermar 951
        mutex_lock(&a->lock);
1147 jermar 952
        if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
953
            return a;
954
        }
1380 jermar 955
        mutex_unlock(&a->lock);
1147 jermar 956
    }
977 jermar 957
 
1147 jermar 958
    /*
1150 jermar 959
     * Second, locate the left neighbour and test its last record.
1148 jermar 960
     * Because of its position in the B+tree, it must have base < va.
1147 jermar 961
     */
1150 jermar 962
    if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 963
        a = (as_area_t *) lnode->value[lnode->keys - 1];
1380 jermar 964
        mutex_lock(&a->lock);
1147 jermar 965
        if (va < a->base + a->pages * PAGE_SIZE) {
1048 jermar 966
            return a;
1147 jermar 967
        }
1380 jermar 968
        mutex_unlock(&a->lock);
977 jermar 969
    }
970
 
971
    return NULL;
972
}
1048 jermar 973
 
974
/** Check area conflicts with other areas.
975
 *
976
 * The address space must be locked and interrupts must be disabled.
977
 *
978
 * @param as Address space.
979
 * @param va Starting virtual address of the area being tested.
980
 * @param size Size of the area being tested.
981
 * @param avoid_area Do not touch this area.
982
 *
983
 * @return True if there is no conflict, false otherwise.
984
 */
985
bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area)
986
{
987
    as_area_t *a;
1147 jermar 988
    btree_node_t *leaf, *node;
989
    int i;
1048 jermar 990
 
1070 jermar 991
    /*
992
     * We don't want any area to have conflicts with NULL page.
993
     */
994
    if (overlaps(va, size, NULL, PAGE_SIZE))
995
        return false;
996
 
1147 jermar 997
    /*
998
     * The leaf node is found in O(log n), where n is proportional to
999
     * the number of address space areas belonging to as.
1000
     * The check for conflicts is then attempted on the rightmost
1150 jermar 1001
     * record in the left neighbour, the leftmost record in the right
1002
     * neighbour and all records in the leaf node itself.
1147 jermar 1003
     */
1048 jermar 1004
 
1147 jermar 1005
    if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
1006
        if (a != avoid_area)
1007
            return false;
1008
    }
1009
 
1010
    /* First, check the two border cases. */
1150 jermar 1011
    if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 1012
        a = (as_area_t *) node->value[node->keys - 1];
1380 jermar 1013
        mutex_lock(&a->lock);
1147 jermar 1014
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 1015
            mutex_unlock(&a->lock);
1147 jermar 1016
            return false;
1017
        }
1380 jermar 1018
        mutex_unlock(&a->lock);
1147 jermar 1019
    }
1150 jermar 1020
    if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 1021
        a = (as_area_t *) node->value[0];
1380 jermar 1022
        mutex_lock(&a->lock);
1147 jermar 1023
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 1024
            mutex_unlock(&a->lock);
1147 jermar 1025
            return false;
1026
        }
1380 jermar 1027
        mutex_unlock(&a->lock);
1147 jermar 1028
    }
1029
 
1030
    /* Second, check the leaf node. */
1031
    for (i = 0; i < leaf->keys; i++) {
1032
        a = (as_area_t *) leaf->value[i];
1033
 
1048 jermar 1034
        if (a == avoid_area)
1035
            continue;
1147 jermar 1036
 
1380 jermar 1037
        mutex_lock(&a->lock);
1147 jermar 1038
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 1039
            mutex_unlock(&a->lock);
1147 jermar 1040
            return false;
1041
        }
1380 jermar 1042
        mutex_unlock(&a->lock);
1048 jermar 1043
    }
1044
 
1070 jermar 1045
    /*
1046
     * So far, the area does not conflict with other areas.
1047
     * Check if it doesn't conflict with kernel address space.
1048
     */  
1049
    if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
1050
        return !overlaps(va, size,
1051
            KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START);
1052
    }
1053
 
1048 jermar 1054
    return true;
1055
}
1235 jermar 1056
 
1380 jermar 1057
/** Return size of the address space area with given base.  */
1329 palkovsky 1058
size_t as_get_size(__address base)
1059
{
1060
    ipl_t ipl;
1061
    as_area_t *src_area;
1062
    size_t size;
1063
 
1064
    ipl = interrupts_disable();
1065
    src_area = find_area_and_lock(AS, base);
1066
    if (src_area){
1067
        size = src_area->pages * PAGE_SIZE;
1380 jermar 1068
        mutex_unlock(&src_area->lock);
1329 palkovsky 1069
    } else {
1070
        size = 0;
1071
    }
1072
    interrupts_restore(ipl);
1073
    return size;
1074
}
1075
 
1387 jermar 1076
/** Mark portion of address space area as used.
1077
 *
1078
 * The address space area must be already locked.
1079
 *
1080
 * @param a Address space area.
1081
 * @param page First page to be marked.
1082
 * @param count Number of page to be marked.
1083
 *
1084
 * @return 0 on failure and 1 on success.
1085
 */
1086
int used_space_insert(as_area_t *a, __address page, count_t count)
1087
{
1088
    btree_node_t *leaf, *node;
1089
    count_t pages;
1090
    int i;
1091
 
1092
    ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
1093
    ASSERT(count);
1094
 
1095
    pages = (count_t) btree_search(&a->used_space, page, &leaf);
1096
    if (pages) {
1097
        /*
1098
         * We hit the beginning of some used space.
1099
         */
1100
        return 0;
1101
    }
1102
 
1437 jermar 1103
    if (!leaf->keys) {
1104
        btree_insert(&a->used_space, page, (void *) count, leaf);
1105
        return 1;
1106
    }
1107
 
1387 jermar 1108
    node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
1109
    if (node) {
1110
        __address left_pg = node->key[node->keys - 1], right_pg = leaf->key[0];
1111
        count_t left_cnt = (count_t) node->value[node->keys - 1], right_cnt = (count_t) leaf->value[0];
1112
 
1113
        /*
1114
         * Examine the possibility that the interval fits
1115
         * somewhere between the rightmost interval of
1116
         * the left neigbour and the first interval of the leaf.
1117
         */
1118
 
1119
        if (page >= right_pg) {
1120
            /* Do nothing. */
1121
        } else if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1122
            /* The interval intersects with the left interval. */
1123
            return 0;
1124
        } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1125
            /* The interval intersects with the right interval. */
1126
            return 0;          
1127
        } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
1128
            /* The interval can be added by merging the two already present intervals. */
1403 jermar 1129
            node->value[node->keys - 1] += count + right_cnt;
1387 jermar 1130
            btree_remove(&a->used_space, right_pg, leaf);
1131
            return 1;
1132
        } else if (page == left_pg + left_cnt*PAGE_SIZE) {
1133
            /* The interval can be added by simply growing the left interval. */
1403 jermar 1134
            node->value[node->keys - 1] += count;
1387 jermar 1135
            return 1;
1136
        } else if (page + count*PAGE_SIZE == right_pg) {
1137
            /*
1138
             * The interval can be addded by simply moving base of the right
1139
             * interval down and increasing its size accordingly.
1140
             */
1403 jermar 1141
            leaf->value[0] += count;
1387 jermar 1142
            leaf->key[0] = page;
1143
            return 1;
1144
        } else {
1145
            /*
1146
             * The interval is between both neigbouring intervals,
1147
             * but cannot be merged with any of them.
1148
             */
1149
            btree_insert(&a->used_space, page, (void *) count, leaf);
1150
            return 1;
1151
        }
1152
    } else if (page < leaf->key[0]) {
1153
        __address right_pg = leaf->key[0];
1154
        count_t right_cnt = (count_t) leaf->value[0];
1155
 
1156
        /*
1157
         * Investigate the border case in which the left neighbour does not
1158
         * exist but the interval fits from the left.
1159
         */
1160
 
1161
        if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1162
            /* The interval intersects with the right interval. */
1163
            return 0;
1164
        } else if (page + count*PAGE_SIZE == right_pg) {
1165
            /*
1166
             * The interval can be added by moving the base of the right interval down
1167
             * and increasing its size accordingly.
1168
             */
1169
            leaf->key[0] = page;
1403 jermar 1170
            leaf->value[0] += count;
1387 jermar 1171
            return 1;
1172
        } else {
1173
            /*
1174
             * The interval doesn't adjoin with the right interval.
1175
             * It must be added individually.
1176
             */
1177
            btree_insert(&a->used_space, page, (void *) count, leaf);
1178
            return 1;
1179
        }
1180
    }
1181
 
1182
    node = btree_leaf_node_right_neighbour(&a->used_space, leaf);
1183
    if (node) {
1184
        __address left_pg = leaf->key[leaf->keys - 1], right_pg = node->key[0];
1185
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1], right_cnt = (count_t) node->value[0];
1186
 
1187
        /*
1188
         * Examine the possibility that the interval fits
1189
         * somewhere between the leftmost interval of
1190
         * the right neigbour and the last interval of the leaf.
1191
         */
1192
 
1193
        if (page < left_pg) {
1194
            /* Do nothing. */
1195
        } else if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1196
            /* The interval intersects with the left interval. */
1197
            return 0;
1198
        } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1199
            /* The interval intersects with the right interval. */
1200
            return 0;          
1201
        } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
1202
            /* The interval can be added by merging the two already present intervals. */
1403 jermar 1203
            leaf->value[leaf->keys - 1] += count + right_cnt;
1387 jermar 1204
            btree_remove(&a->used_space, right_pg, node);
1205
            return 1;
1206
        } else if (page == left_pg + left_cnt*PAGE_SIZE) {
1207
            /* The interval can be added by simply growing the left interval. */
1403 jermar 1208
            leaf->value[leaf->keys - 1] +=  count;
1387 jermar 1209
            return 1;
1210
        } else if (page + count*PAGE_SIZE == right_pg) {
1211
            /*
1212
             * The interval can be addded by simply moving base of the right
1213
             * interval down and increasing its size accordingly.
1214
             */
1403 jermar 1215
            node->value[0] += count;
1387 jermar 1216
            node->key[0] = page;
1217
            return 1;
1218
        } else {
1219
            /*
1220
             * The interval is between both neigbouring intervals,
1221
             * but cannot be merged with any of them.
1222
             */
1223
            btree_insert(&a->used_space, page, (void *) count, leaf);
1224
            return 1;
1225
        }
1226
    } else if (page >= leaf->key[leaf->keys - 1]) {
1227
        __address left_pg = leaf->key[leaf->keys - 1];
1228
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
1229
 
1230
        /*
1231
         * Investigate the border case in which the right neighbour does not
1232
         * exist but the interval fits from the right.
1233
         */
1234
 
1235
        if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1403 jermar 1236
            /* The interval intersects with the left interval. */
1387 jermar 1237
            return 0;
1238
        } else if (left_pg + left_cnt*PAGE_SIZE == page) {
1239
            /* The interval can be added by growing the left interval. */
1403 jermar 1240
            leaf->value[leaf->keys - 1] += count;
1387 jermar 1241
            return 1;
1242
        } else {
1243
            /*
1244
             * The interval doesn't adjoin with the left interval.
1245
             * It must be added individually.
1246
             */
1247
            btree_insert(&a->used_space, page, (void *) count, leaf);
1248
            return 1;
1249
        }
1250
    }
1251
 
1252
    /*
1253
     * Note that if the algorithm made it thus far, the interval can fit only
1254
     * between two other intervals of the leaf. The two border cases were already
1255
     * resolved.
1256
     */
1257
    for (i = 1; i < leaf->keys; i++) {
1258
        if (page < leaf->key[i]) {
1259
            __address left_pg = leaf->key[i - 1], right_pg = leaf->key[i];
1260
            count_t left_cnt = (count_t) leaf->value[i - 1], right_cnt = (count_t) leaf->value[i];
1261
 
1262
            /*
1263
             * The interval fits between left_pg and right_pg.
1264
             */
1265
 
1266
            if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1267
                /* The interval intersects with the left interval. */
1268
                return 0;
1269
            } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1270
                /* The interval intersects with the right interval. */
1271
                return 0;          
1272
            } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
1273
                /* The interval can be added by merging the two already present intervals. */
1403 jermar 1274
                leaf->value[i - 1] += count + right_cnt;
1387 jermar 1275
                btree_remove(&a->used_space, right_pg, leaf);
1276
                return 1;
1277
            } else if (page == left_pg + left_cnt*PAGE_SIZE) {
1278
                /* The interval can be added by simply growing the left interval. */
1403 jermar 1279
                leaf->value[i - 1] += count;
1387 jermar 1280
                return 1;
1281
            } else if (page + count*PAGE_SIZE == right_pg) {
1282
                /*
1283
                     * The interval can be addded by simply moving base of the right
1284
                 * interval down and increasing its size accordingly.
1285
                 */
1403 jermar 1286
                leaf->value[i] += count;
1387 jermar 1287
                leaf->key[i] = page;
1288
                return 1;
1289
            } else {
1290
                /*
1291
                 * The interval is between both neigbouring intervals,
1292
                 * but cannot be merged with any of them.
1293
                 */
1294
                btree_insert(&a->used_space, page, (void *) count, leaf);
1295
                return 1;
1296
            }
1297
        }
1298
    }
1299
 
1300
    panic("Inconsistency detected while adding %d pages of used space at %P.\n", count, page);
1301
}
1302
 
1303
/** Mark portion of address space area as unused.
1304
 *
1305
 * The address space area must be already locked.
1306
 *
1307
 * @param a Address space area.
1308
 * @param page First page to be marked.
1309
 * @param count Number of page to be marked.
1310
 *
1311
 * @return 0 on failure and 1 on success.
1312
 */
1313
int used_space_remove(as_area_t *a, __address page, count_t count)
1314
{
1315
    btree_node_t *leaf, *node;
1316
    count_t pages;
1317
    int i;
1318
 
1319
    ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
1320
    ASSERT(count);
1321
 
1322
    pages = (count_t) btree_search(&a->used_space, page, &leaf);
1323
    if (pages) {
1324
        /*
1325
         * We are lucky, page is the beginning of some interval.
1326
         */
1327
        if (count > pages) {
1328
            return 0;
1329
        } else if (count == pages) {
1330
            btree_remove(&a->used_space, page, leaf);
1403 jermar 1331
            return 1;
1387 jermar 1332
        } else {
1333
            /*
1334
             * Find the respective interval.
1335
             * Decrease its size and relocate its start address.
1336
             */
1337
            for (i = 0; i < leaf->keys; i++) {
1338
                if (leaf->key[i] == page) {
1339
                    leaf->key[i] += count*PAGE_SIZE;
1403 jermar 1340
                    leaf->value[i] -= count;
1387 jermar 1341
                    return 1;
1342
                }
1343
            }
1344
            goto error;
1345
        }
1346
    }
1347
 
1348
    node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
1349
    if (node && page < leaf->key[0]) {
1350
        __address left_pg = node->key[node->keys - 1];
1351
        count_t left_cnt = (count_t) node->value[node->keys - 1];
1352
 
1353
        if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
1354
            if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
1355
                /*
1356
                 * The interval is contained in the rightmost interval
1357
                 * of the left neighbour and can be removed by
1358
                 * updating the size of the bigger interval.
1359
                 */
1403 jermar 1360
                node->value[node->keys - 1] -= count;
1387 jermar 1361
                return 1;
1362
            } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
1403 jermar 1363
                count_t new_cnt;
1387 jermar 1364
 
1365
                /*
1366
                 * The interval is contained in the rightmost interval
1367
                 * of the left neighbour but its removal requires
1368
                 * both updating the size of the original interval and
1369
                 * also inserting a new interval.
1370
                 */
1403 jermar 1371
                new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1372
                node->value[node->keys - 1] -= count + new_cnt;
1387 jermar 1373
                btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
1374
                return 1;
1375
            }
1376
        }
1377
        return 0;
1378
    } else if (page < leaf->key[0]) {
1379
        return 0;
1380
    }
1381
 
1382
    if (page > leaf->key[leaf->keys - 1]) {
1383
        __address left_pg = leaf->key[leaf->keys - 1];
1384
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
1385
 
1386
        if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
1387
            if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
1388
                /*
1389
                 * The interval is contained in the rightmost interval
1390
                 * of the leaf and can be removed by updating the size
1391
                 * of the bigger interval.
1392
                 */
1403 jermar 1393
                leaf->value[leaf->keys - 1] -= count;
1387 jermar 1394
                return 1;
1395
            } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
1403 jermar 1396
                count_t new_cnt;
1387 jermar 1397
 
1398
                /*
1399
                 * The interval is contained in the rightmost interval
1400
                 * of the leaf but its removal requires both updating
1401
                 * the size of the original interval and
1402
                 * also inserting a new interval.
1403
                 */
1403 jermar 1404
                new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1405
                leaf->value[leaf->keys - 1] -= count + new_cnt;
1387 jermar 1406
                btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
1407
                return 1;
1408
            }
1409
        }
1410
        return 0;
1411
    }  
1412
 
1413
    /*
1414
     * The border cases have been already resolved.
1415
     * Now the interval can be only between intervals of the leaf.
1416
     */
1417
    for (i = 1; i < leaf->keys - 1; i++) {
1418
        if (page < leaf->key[i]) {
1419
            __address left_pg = leaf->key[i - 1];
1420
            count_t left_cnt = (count_t) leaf->value[i - 1];
1421
 
1422
            /*
1423
             * Now the interval is between intervals corresponding to (i - 1) and i.
1424
             */
1425
            if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
1426
                if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
1427
                    /*
1428
                    * The interval is contained in the interval (i - 1)
1429
                     * of the leaf and can be removed by updating the size
1430
                     * of the bigger interval.
1431
                     */
1403 jermar 1432
                    leaf->value[i - 1] -= count;
1387 jermar 1433
                    return 1;
1434
                } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
1403 jermar 1435
                    count_t new_cnt;
1387 jermar 1436
 
1437
                    /*
1438
                     * The interval is contained in the interval (i - 1)
1439
                     * of the leaf but its removal requires both updating
1440
                     * the size of the original interval and
1441
                     * also inserting a new interval.
1442
                     */
1403 jermar 1443
                    new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1444
                    leaf->value[i - 1] -= count + new_cnt;
1387 jermar 1445
                    btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
1446
                    return 1;
1447
                }
1448
            }
1449
            return 0;
1450
        }
1451
    }
1452
 
1453
error:
1454
    panic("Inconsistency detected while removing %d pages of used space from %P.\n", count, page);
1455
}
1456
 
1409 jermar 1457
/** Remove reference to address space area share info.
1458
 *
1459
 * If the reference count drops to 0, the sh_info is deallocated.
1460
 *
1461
 * @param sh_info Pointer to address space area share info.
1462
 */
1463
void sh_info_remove_reference(share_info_t *sh_info)
1464
{
1465
    bool dealloc = false;
1466
 
1467
    mutex_lock(&sh_info->lock);
1468
    ASSERT(sh_info->refcount);
1469
    if (--sh_info->refcount == 0) {
1470
        dealloc = true;
1495 jermar 1471
        link_t *cur;
1409 jermar 1472
 
1473
        /*
1474
         * Now walk carefully the pagemap B+tree and free/remove
1475
         * reference from all frames found there.
1476
         */
1495 jermar 1477
        for (cur = sh_info->pagemap.leaf_head.next; cur != &sh_info->pagemap.leaf_head; cur = cur->next) {
1409 jermar 1478
            btree_node_t *node;
1495 jermar 1479
            int i;
1409 jermar 1480
 
1495 jermar 1481
            node = list_get_instance(cur, btree_node_t, leaf_link);
1482
            for (i = 0; i < node->keys; i++)
1483
                frame_free(ADDR2PFN((__address) node->value[i]));
1409 jermar 1484
        }
1485
 
1486
    }
1487
    mutex_unlock(&sh_info->lock);
1488
 
1489
    if (dealloc) {
1490
        btree_destroy(&sh_info->pagemap);
1491
        free(sh_info);
1492
    }
1493
}
1494
 
1235 jermar 1495
/*
1496
 * Address space related syscalls.
1497
 */
1498
 
1499
/** Wrapper for as_area_create(). */
1500
__native sys_as_area_create(__address address, size_t size, int flags)
1501
{
1424 jermar 1502
    if (as_area_create(AS, flags | AS_AREA_CACHEABLE, size, address, AS_AREA_ATTR_NONE, &anon_backend, NULL))
1235 jermar 1503
        return (__native) address;
1504
    else
1505
        return (__native) -1;
1506
}
1507
 
1508
/** Wrapper for as_area_resize. */
1509
__native sys_as_area_resize(__address address, size_t size, int flags)
1510
{
1306 jermar 1511
    return (__native) as_area_resize(AS, address, size, 0);
1235 jermar 1512
}
1513
 
1306 jermar 1514
/** Wrapper for as_area_destroy. */
1515
__native sys_as_area_destroy(__address address)
1516
{
1517
    return (__native) as_area_destroy(AS, address);
1518
}