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