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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;
139
    bool cond;
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
     */
159
    for (cond = true; cond; ) {
160
        btree_node_t *node;
161
 
162
        ASSERT(!list_empty(&as->as_area_btree.leaf_head));
163
        node = list_get_instance(&as->as_area_btree.leaf_head.next, btree_node_t, leaf_link);
164
        if ((cond = node->keys)) {
165
            as_area_destroy(as, node->key[0]);
166
            btree_remove(&as->as_area_btree, node->key[0], node);
167
        }
168
    }
169
 
170
    page_table_destroy(as->page_table);
171
 
172
    interrupts_restore(ipl);
173
 
973 palkovsky 174
    free(as);
175
}
176
 
703 jermar 177
/** Create address space area of common attributes.
178
 *
179
 * The created address space area is added to the target address space.
180
 *
181
 * @param as Target address space.
1239 jermar 182
 * @param flags Flags of the area memory.
1048 jermar 183
 * @param size Size of area.
703 jermar 184
 * @param base Base address of area.
1239 jermar 185
 * @param attrs Attributes of the area.
1409 jermar 186
 * @param backend Address space area backend. NULL if no backend is used.
187
 * @param backend_data NULL or a pointer to an array holding two void *.
703 jermar 188
 *
189
 * @return Address space area on success or NULL on failure.
190
 */
1409 jermar 191
as_area_t *as_area_create(as_t *as, int flags, size_t size, __address base, int attrs,
1424 jermar 192
           mem_backend_t *backend, mem_backend_data_t *backend_data)
703 jermar 193
{
194
    ipl_t ipl;
195
    as_area_t *a;
196
 
197
    if (base % PAGE_SIZE)
1048 jermar 198
        return NULL;
199
 
1233 jermar 200
    if (!size)
201
        return NULL;
202
 
1048 jermar 203
    /* Writeable executable areas are not supported. */
204
    if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
205
        return NULL;
703 jermar 206
 
207
    ipl = interrupts_disable();
1380 jermar 208
    mutex_lock(&as->lock);
703 jermar 209
 
1048 jermar 210
    if (!check_area_conflicts(as, base, size, NULL)) {
1380 jermar 211
        mutex_unlock(&as->lock);
1048 jermar 212
        interrupts_restore(ipl);
213
        return NULL;
214
    }
703 jermar 215
 
822 palkovsky 216
    a = (as_area_t *) malloc(sizeof(as_area_t), 0);
703 jermar 217
 
1380 jermar 218
    mutex_initialize(&a->lock);
822 palkovsky 219
 
1424 jermar 220
    a->as = as;
1026 jermar 221
    a->flags = flags;
1239 jermar 222
    a->attributes = attrs;
1048 jermar 223
    a->pages = SIZE2FRAMES(size);
822 palkovsky 224
    a->base = base;
1409 jermar 225
    a->sh_info = NULL;
226
    a->backend = backend;
1424 jermar 227
    if (backend_data)
228
        a->backend_data = *backend_data;
229
    else
230
        memsetb((__address) &a->backend_data, sizeof(a->backend_data), 0);
231
 
1387 jermar 232
    btree_create(&a->used_space);
822 palkovsky 233
 
1147 jermar 234
    btree_insert(&as->as_area_btree, base, (void *) a, NULL);
822 palkovsky 235
 
1380 jermar 236
    mutex_unlock(&as->lock);
703 jermar 237
    interrupts_restore(ipl);
704 jermar 238
 
703 jermar 239
    return a;
240
}
241
 
1235 jermar 242
/** Find address space area and change it.
243
 *
244
 * @param as Address space.
245
 * @param address Virtual address belonging to the area to be changed. Must be page-aligned.
246
 * @param size New size of the virtual memory block starting at address.
247
 * @param flags Flags influencing the remap operation. Currently unused.
248
 *
1306 jermar 249
 * @return Zero on success or a value from @ref errno.h otherwise.
1235 jermar 250
 */
1306 jermar 251
int as_area_resize(as_t *as, __address address, size_t size, int flags)
1235 jermar 252
{
1306 jermar 253
    as_area_t *area;
1235 jermar 254
    ipl_t ipl;
255
    size_t pages;
256
 
257
    ipl = interrupts_disable();
1380 jermar 258
    mutex_lock(&as->lock);
1235 jermar 259
 
260
    /*
261
     * Locate the area.
262
     */
263
    area = find_area_and_lock(as, address);
264
    if (!area) {
1380 jermar 265
        mutex_unlock(&as->lock);
1235 jermar 266
        interrupts_restore(ipl);
1306 jermar 267
        return ENOENT;
1235 jermar 268
    }
269
 
1424 jermar 270
    if (area->backend == &phys_backend) {
1235 jermar 271
        /*
272
         * Remapping of address space areas associated
273
         * with memory mapped devices is not supported.
274
         */
1380 jermar 275
        mutex_unlock(&area->lock);
276
        mutex_unlock(&as->lock);
1235 jermar 277
        interrupts_restore(ipl);
1306 jermar 278
        return ENOTSUP;
1235 jermar 279
    }
1409 jermar 280
    if (area->sh_info) {
281
        /*
282
         * Remapping of shared address space areas
283
         * is not supported.
284
         */
285
        mutex_unlock(&area->lock);
286
        mutex_unlock(&as->lock);
287
        interrupts_restore(ipl);
288
        return ENOTSUP;
289
    }
1235 jermar 290
 
291
    pages = SIZE2FRAMES((address - area->base) + size);
292
    if (!pages) {
293
        /*
294
         * Zero size address space areas are not allowed.
295
         */
1380 jermar 296
        mutex_unlock(&area->lock);
297
        mutex_unlock(&as->lock);
1235 jermar 298
        interrupts_restore(ipl);
1306 jermar 299
        return EPERM;
1235 jermar 300
    }
301
 
302
    if (pages < area->pages) {
1403 jermar 303
        bool cond;
304
        __address start_free = area->base + pages*PAGE_SIZE;
1235 jermar 305
 
306
        /*
307
         * Shrinking the area.
308
         * No need to check for overlaps.
309
         */
1403 jermar 310
 
311
        /*
1436 jermar 312
         * Start TLB shootdown sequence.
313
         */
314
        tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
315
 
316
        /*
1403 jermar 317
         * Remove frames belonging to used space starting from
318
         * the highest addresses downwards until an overlap with
319
         * the resized address space area is found. Note that this
320
         * is also the right way to remove part of the used_space
321
         * B+tree leaf list.
322
         */    
323
        for (cond = true; cond;) {
324
            btree_node_t *node;
325
 
326
            ASSERT(!list_empty(&area->used_space.leaf_head));
327
            node = list_get_instance(area->used_space.leaf_head.prev, btree_node_t, leaf_link);
328
            if ((cond = (bool) node->keys)) {
329
                __address b = node->key[node->keys - 1];
330
                count_t c = (count_t) node->value[node->keys - 1];
331
                int i = 0;
1235 jermar 332
 
1403 jermar 333
                if (overlaps(b, c*PAGE_SIZE, area->base, pages*PAGE_SIZE)) {
334
 
335
                    if (b + c*PAGE_SIZE <= start_free) {
336
                        /*
337
                         * The whole interval fits completely
338
                         * in the resized address space area.
339
                         */
340
                        break;
341
                    }
342
 
343
                    /*
344
                     * Part of the interval corresponding to b and c
345
                     * overlaps with the resized address space area.
346
                     */
347
 
348
                    cond = false;   /* we are almost done */
349
                    i = (start_free - b) >> PAGE_WIDTH;
350
                    if (!used_space_remove(area, start_free, c - i))
351
                        panic("Could not remove used space.");
352
                } else {
353
                    /*
354
                     * The interval of used space can be completely removed.
355
                     */
356
                    if (!used_space_remove(area, b, c))
357
                        panic("Could not remove used space.\n");
358
                }
359
 
360
                for (; i < c; i++) {
361
                    pte_t *pte;
362
 
363
                    page_table_lock(as, false);
364
                    pte = page_mapping_find(as, b + i*PAGE_SIZE);
365
                    ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424 jermar 366
                    if (area->backend && area->backend->frame_free) {
367
                        area->backend->frame_free(area,
1409 jermar 368
                            b + i*PAGE_SIZE, PTE_GET_FRAME(pte));
369
                    }
1403 jermar 370
                    page_mapping_remove(as, b + i*PAGE_SIZE);
371
                    page_table_unlock(as, false);
372
                }
1235 jermar 373
            }
374
        }
1436 jermar 375
 
1235 jermar 376
        /*
1436 jermar 377
         * Finish TLB shootdown sequence.
1235 jermar 378
         */
379
        tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
380
        tlb_shootdown_finalize();
381
    } else {
382
        /*
383
         * Growing the area.
384
         * Check for overlaps with other address space areas.
385
         */
386
        if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
1380 jermar 387
            mutex_unlock(&area->lock);
388
            mutex_unlock(&as->lock);       
1235 jermar 389
            interrupts_restore(ipl);
1306 jermar 390
            return EADDRNOTAVAIL;
1235 jermar 391
        }
392
    }
393
 
394
    area->pages = pages;
395
 
1380 jermar 396
    mutex_unlock(&area->lock);
397
    mutex_unlock(&as->lock);
1235 jermar 398
    interrupts_restore(ipl);
399
 
1306 jermar 400
    return 0;
1235 jermar 401
}
402
 
1306 jermar 403
/** Destroy address space area.
404
 *
405
 * @param as Address space.
406
 * @param address Address withing the area to be deleted.
407
 *
408
 * @return Zero on success or a value from @ref errno.h on failure.
409
 */
410
int as_area_destroy(as_t *as, __address address)
411
{
412
    as_area_t *area;
413
    __address base;
414
    ipl_t ipl;
1411 jermar 415
    bool cond;
1306 jermar 416
 
417
    ipl = interrupts_disable();
1380 jermar 418
    mutex_lock(&as->lock);
1306 jermar 419
 
420
    area = find_area_and_lock(as, address);
421
    if (!area) {
1380 jermar 422
        mutex_unlock(&as->lock);
1306 jermar 423
        interrupts_restore(ipl);
424
        return ENOENT;
425
    }
426
 
1403 jermar 427
    base = area->base;
428
 
1411 jermar 429
    /*
1436 jermar 430
     * Start TLB shootdown sequence.
431
     */
432
    tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages);
433
 
434
    /*
1411 jermar 435
     * Visit only the pages mapped by used_space B+tree.
436
     * Note that we must be very careful when walking the tree
437
     * leaf list and removing used space as the leaf list changes
438
     * unpredictibly after each remove. The solution is to actually
439
     * not walk the tree at all, but to remove items from the head
440
     * of the leaf list until there are some keys left.
441
     */
442
    for (cond = true; cond;) {
443
        btree_node_t *node;
1403 jermar 444
 
1411 jermar 445
        ASSERT(!list_empty(&area->used_space.leaf_head));
446
        node = list_get_instance(area->used_space.leaf_head.next, btree_node_t, leaf_link);
447
        if ((cond = (bool) node->keys)) {
448
            __address b = node->key[0];
449
            count_t i;
450
            pte_t *pte;
1403 jermar 451
 
1411 jermar 452
            for (i = 0; i < (count_t) node->value[0]; i++) {
453
                page_table_lock(as, false);
454
                pte = page_mapping_find(as, b + i*PAGE_SIZE);
455
                ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424 jermar 456
                if (area->backend && area->backend->frame_free) {
457
                    area->backend->frame_free(area,
1411 jermar 458
                        b + i*PAGE_SIZE, PTE_GET_FRAME(pte));
1403 jermar 459
                }
1411 jermar 460
                page_mapping_remove(as, b + i*PAGE_SIZE);
461
                page_table_unlock(as, false);
1306 jermar 462
            }
1411 jermar 463
            if (!used_space_remove(area, b, i))
464
                panic("Could not remove used space.\n");
1306 jermar 465
        }
466
    }
1403 jermar 467
 
1306 jermar 468
    /*
1436 jermar 469
     * Finish TLB shootdown sequence.
1306 jermar 470
     */
471
    tlb_invalidate_pages(AS->asid, area->base, area->pages);
472
    tlb_shootdown_finalize();
1436 jermar 473
 
474
    btree_destroy(&area->used_space);
1306 jermar 475
 
1309 jermar 476
    area->attributes |= AS_AREA_ATTR_PARTIAL;
1409 jermar 477
 
478
    if (area->sh_info)
479
        sh_info_remove_reference(area->sh_info);
480
 
1380 jermar 481
    mutex_unlock(&area->lock);
1306 jermar 482
 
483
    /*
484
     * Remove the empty area from address space.
485
     */
486
    btree_remove(&AS->as_area_btree, base, NULL);
487
 
1309 jermar 488
    free(area);
489
 
1380 jermar 490
    mutex_unlock(&AS->lock);
1306 jermar 491
    interrupts_restore(ipl);
492
    return 0;
493
}
494
 
1413 jermar 495
/** Share address space area with another or the same address space.
1235 jermar 496
 *
1424 jermar 497
 * Address space area mapping is shared with a new address space area.
498
 * If the source address space area has not been shared so far,
499
 * a new sh_info is created. The new address space area simply gets the
500
 * sh_info of the source area. The process of duplicating the
501
 * mapping is done through the backend share function.
1413 jermar 502
 *
1417 jermar 503
 * @param src_as Pointer to source address space.
1239 jermar 504
 * @param src_base Base address of the source address space area.
1417 jermar 505
 * @param acc_size Expected size of the source area.
1428 palkovsky 506
 * @param dst_as Pointer to destination address space.
1417 jermar 507
 * @param dst_base Target base address.
508
 * @param dst_flags_mask Destination address space area flags mask.
1235 jermar 509
 *
1306 jermar 510
 * @return Zero on success or ENOENT if there is no such task or
1235 jermar 511
 *     if there is no such address space area,
512
 *     EPERM if there was a problem in accepting the area or
513
 *     ENOMEM if there was a problem in allocating destination
1413 jermar 514
 *     address space area. ENOTSUP is returned if an attempt
515
 *     to share non-anonymous address space area is detected.
1235 jermar 516
 */
1413 jermar 517
int as_area_share(as_t *src_as, __address src_base, size_t acc_size,
1428 palkovsky 518
          as_t *dst_as, __address dst_base, int dst_flags_mask)
1235 jermar 519
{
520
    ipl_t ipl;
1239 jermar 521
    int src_flags;
522
    size_t src_size;
523
    as_area_t *src_area, *dst_area;
1413 jermar 524
    share_info_t *sh_info;
1424 jermar 525
    mem_backend_t *src_backend;
526
    mem_backend_data_t src_backend_data;
1434 palkovsky 527
 
1235 jermar 528
    ipl = interrupts_disable();
1380 jermar 529
    mutex_lock(&src_as->lock);
1329 palkovsky 530
    src_area = find_area_and_lock(src_as, src_base);
1239 jermar 531
    if (!src_area) {
1238 jermar 532
        /*
533
         * Could not find the source address space area.
534
         */
1380 jermar 535
        mutex_unlock(&src_as->lock);
1238 jermar 536
        interrupts_restore(ipl);
537
        return ENOENT;
538
    }
1413 jermar 539
 
1424 jermar 540
    if (!src_area->backend || !src_area->backend->share) {
1413 jermar 541
        /*
1424 jermar 542
         * There is now backend or the backend does not
543
         * know how to share the area.
1413 jermar 544
         */
545
        mutex_unlock(&src_area->lock);
546
        mutex_unlock(&src_as->lock);
547
        interrupts_restore(ipl);
548
        return ENOTSUP;
549
    }
550
 
1239 jermar 551
    src_size = src_area->pages * PAGE_SIZE;
552
    src_flags = src_area->flags;
1424 jermar 553
    src_backend = src_area->backend;
554
    src_backend_data = src_area->backend_data;
1413 jermar 555
 
1461 palkovsky 556
    if (src_size != acc_size || (src_flags & dst_flags_mask) != dst_flags_mask) {
1413 jermar 557
        mutex_unlock(&src_area->lock);
558
        mutex_unlock(&src_as->lock);
1235 jermar 559
        interrupts_restore(ipl);
560
        return EPERM;
561
    }
1413 jermar 562
 
1235 jermar 563
    /*
1413 jermar 564
     * Now we are committed to sharing the area.
565
     * First prepare the area for sharing.
566
     * Then it will be safe to unlock it.
567
     */
568
    sh_info = src_area->sh_info;
569
    if (!sh_info) {
570
        sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0);
571
        mutex_initialize(&sh_info->lock);
572
        sh_info->refcount = 2;
573
        btree_create(&sh_info->pagemap);
574
        src_area->sh_info = sh_info;
575
    } else {
576
        mutex_lock(&sh_info->lock);
577
        sh_info->refcount++;
578
        mutex_unlock(&sh_info->lock);
579
    }
580
 
1424 jermar 581
    src_area->backend->share(src_area);
1413 jermar 582
 
583
    mutex_unlock(&src_area->lock);
584
    mutex_unlock(&src_as->lock);
585
 
586
    /*
1239 jermar 587
     * Create copy of the source address space area.
588
     * The destination area is created with AS_AREA_ATTR_PARTIAL
589
     * attribute set which prevents race condition with
590
     * preliminary as_page_fault() calls.
1417 jermar 591
     * The flags of the source area are masked against dst_flags_mask
592
     * to support sharing in less privileged mode.
1235 jermar 593
     */
1461 palkovsky 594
    dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base,
1424 jermar 595
                  AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data);
1239 jermar 596
    if (!dst_area) {
1235 jermar 597
        /*
598
         * Destination address space area could not be created.
599
         */
1413 jermar 600
        sh_info_remove_reference(sh_info);
601
 
1235 jermar 602
        interrupts_restore(ipl);
603
        return ENOMEM;
604
    }
605
 
606
    /*
1239 jermar 607
     * Now the destination address space area has been
608
     * fully initialized. Clear the AS_AREA_ATTR_PARTIAL
1413 jermar 609
     * attribute and set the sh_info.
1239 jermar 610
     */
1380 jermar 611
    mutex_lock(&dst_area->lock);
1239 jermar 612
    dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
1413 jermar 613
    dst_area->sh_info = sh_info;
1380 jermar 614
    mutex_unlock(&dst_area->lock);
1235 jermar 615
 
616
    interrupts_restore(ipl);
617
 
618
    return 0;
619
}
620
 
1423 jermar 621
/** Check access mode for address space area.
622
 *
623
 * The address space area must be locked prior to this call.
624
 *
625
 * @param area Address space area.
626
 * @param access Access mode.
627
 *
628
 * @return False if access violates area's permissions, true otherwise.
629
 */
630
bool as_area_check_access(as_area_t *area, pf_access_t access)
631
{
632
    int flagmap[] = {
633
        [PF_ACCESS_READ] = AS_AREA_READ,
634
        [PF_ACCESS_WRITE] = AS_AREA_WRITE,
635
        [PF_ACCESS_EXEC] = AS_AREA_EXEC
636
    };
637
 
638
    if (!(area->flags & flagmap[access]))
639
        return false;
640
 
641
    return true;
642
}
643
 
703 jermar 644
/** Handle page fault within the current address space.
645
 *
1409 jermar 646
 * This is the high-level page fault handler. It decides
647
 * whether the page fault can be resolved by any backend
648
 * and if so, it invokes the backend to resolve the page
649
 * fault.
650
 *
703 jermar 651
 * Interrupts are assumed disabled.
652
 *
653
 * @param page Faulting page.
1411 jermar 654
 * @param access Access mode that caused the fault (i.e. read/write/exec).
1288 jermar 655
 * @param istate Pointer to interrupted state.
703 jermar 656
 *
1409 jermar 657
 * @return AS_PF_FAULT on page fault, AS_PF_OK on success or AS_PF_DEFER if the
658
 *     fault was caused by copy_to_uspace() or copy_from_uspace().
703 jermar 659
 */
1411 jermar 660
int as_page_fault(__address page, pf_access_t access, istate_t *istate)
703 jermar 661
{
1044 jermar 662
    pte_t *pte;
977 jermar 663
    as_area_t *area;
703 jermar 664
 
1380 jermar 665
    if (!THREAD)
1409 jermar 666
        return AS_PF_FAULT;
1380 jermar 667
 
703 jermar 668
    ASSERT(AS);
1044 jermar 669
 
1380 jermar 670
    mutex_lock(&AS->lock);
977 jermar 671
    area = find_area_and_lock(AS, page);   
703 jermar 672
    if (!area) {
673
        /*
674
         * No area contained mapping for 'page'.
675
         * Signal page fault to low-level handler.
676
         */
1380 jermar 677
        mutex_unlock(&AS->lock);
1288 jermar 678
        goto page_fault;
703 jermar 679
    }
680
 
1239 jermar 681
    if (area->attributes & AS_AREA_ATTR_PARTIAL) {
682
        /*
683
         * The address space area is not fully initialized.
684
         * Avoid possible race by returning error.
685
         */
1380 jermar 686
        mutex_unlock(&area->lock);
687
        mutex_unlock(&AS->lock);
1288 jermar 688
        goto page_fault;       
1239 jermar 689
    }
690
 
1424 jermar 691
    if (!area->backend || !area->backend->page_fault) {
1409 jermar 692
        /*
693
         * The address space area is not backed by any backend
694
         * or the backend cannot handle page faults.
695
         */
696
        mutex_unlock(&area->lock);
697
        mutex_unlock(&AS->lock);
698
        goto page_fault;       
699
    }
1179 jermar 700
 
1044 jermar 701
    page_table_lock(AS, false);
702
 
703 jermar 703
    /*
1044 jermar 704
     * To avoid race condition between two page faults
705
     * on the same address, we need to make sure
706
     * the mapping has not been already inserted.
707
     */
708
    if ((pte = page_mapping_find(AS, page))) {
709
        if (PTE_PRESENT(pte)) {
1423 jermar 710
            if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) ||
711
                (access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) ||
712
                (access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) {
713
                page_table_unlock(AS, false);
714
                mutex_unlock(&area->lock);
715
                mutex_unlock(&AS->lock);
716
                return AS_PF_OK;
717
            }
1044 jermar 718
        }
719
    }
1409 jermar 720
 
1044 jermar 721
    /*
1409 jermar 722
     * Resort to the backend page fault handler.
703 jermar 723
     */
1424 jermar 724
    if (area->backend->page_fault(area, page, access) != AS_PF_OK) {
1409 jermar 725
        page_table_unlock(AS, false);
726
        mutex_unlock(&area->lock);
727
        mutex_unlock(&AS->lock);
728
        goto page_fault;
729
    }
703 jermar 730
 
1044 jermar 731
    page_table_unlock(AS, false);
1380 jermar 732
    mutex_unlock(&area->lock);
733
    mutex_unlock(&AS->lock);
1288 jermar 734
    return AS_PF_OK;
735
 
736
page_fault:
737
    if (THREAD->in_copy_from_uspace) {
738
        THREAD->in_copy_from_uspace = false;
739
        istate_set_retaddr(istate, (__address) &memcpy_from_uspace_failover_address);
740
    } else if (THREAD->in_copy_to_uspace) {
741
        THREAD->in_copy_to_uspace = false;
742
        istate_set_retaddr(istate, (__address) &memcpy_to_uspace_failover_address);
743
    } else {
744
        return AS_PF_FAULT;
745
    }
746
 
747
    return AS_PF_DEFER;
703 jermar 748
}
749
 
823 jermar 750
/** Switch address spaces.
703 jermar 751
 *
1380 jermar 752
 * Note that this function cannot sleep as it is essentially a part of
1415 jermar 753
 * scheduling. Sleeping here would lead to deadlock on wakeup.
1380 jermar 754
 *
823 jermar 755
 * @param old Old address space or NULL.
756
 * @param new New address space.
703 jermar 757
 */
823 jermar 758
void as_switch(as_t *old, as_t *new)
703 jermar 759
{
760
    ipl_t ipl;
823 jermar 761
    bool needs_asid = false;
703 jermar 762
 
763
    ipl = interrupts_disable();
1415 jermar 764
    spinlock_lock(&inactive_as_with_asid_lock);
703 jermar 765
 
766
    /*
823 jermar 767
     * First, take care of the old address space.
768
     */
769
    if (old) {
1380 jermar 770
        mutex_lock_active(&old->lock);
1415 jermar 771
        ASSERT(old->cpu_refcount);
772
        if((--old->cpu_refcount == 0) && (old != AS_KERNEL)) {
823 jermar 773
            /*
774
             * The old address space is no longer active on
775
             * any processor. It can be appended to the
776
             * list of inactive address spaces with assigned
777
             * ASID.
778
             */
779
             ASSERT(old->asid != ASID_INVALID);
780
             list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head);
781
        }
1380 jermar 782
        mutex_unlock(&old->lock);
823 jermar 783
    }
784
 
785
    /*
786
     * Second, prepare the new address space.
787
     */
1380 jermar 788
    mutex_lock_active(&new->lock);
1415 jermar 789
    if ((new->cpu_refcount++ == 0) && (new != AS_KERNEL)) {
823 jermar 790
        if (new->asid != ASID_INVALID)
791
            list_remove(&new->inactive_as_with_asid_link);
792
        else
793
            needs_asid = true;  /* defer call to asid_get() until new->lock is released */
794
    }
795
    SET_PTL0_ADDRESS(new->page_table);
1380 jermar 796
    mutex_unlock(&new->lock);
823 jermar 797
 
798
    if (needs_asid) {
799
        /*
800
         * Allocation of new ASID was deferred
801
         * until now in order to avoid deadlock.
802
         */
803
        asid_t asid;
804
 
805
        asid = asid_get();
1380 jermar 806
        mutex_lock_active(&new->lock);
823 jermar 807
        new->asid = asid;
1380 jermar 808
        mutex_unlock(&new->lock);
823 jermar 809
    }
1415 jermar 810
    spinlock_unlock(&inactive_as_with_asid_lock);
823 jermar 811
    interrupts_restore(ipl);
812
 
813
    /*
703 jermar 814
     * Perform architecture-specific steps.
727 jermar 815
     * (e.g. write ASID to hardware register etc.)
703 jermar 816
     */
823 jermar 817
    as_install_arch(new);
703 jermar 818
 
823 jermar 819
    AS = new;
703 jermar 820
}
754 jermar 821
 
1235 jermar 822
/** Convert address space area flags to page flags.
754 jermar 823
 *
1235 jermar 824
 * @param aflags Flags of some address space area.
754 jermar 825
 *
1235 jermar 826
 * @return Flags to be passed to page_mapping_insert().
754 jermar 827
 */
1235 jermar 828
int area_flags_to_page_flags(int aflags)
754 jermar 829
{
830
    int flags;
831
 
1178 jermar 832
    flags = PAGE_USER | PAGE_PRESENT;
754 jermar 833
 
1235 jermar 834
    if (aflags & AS_AREA_READ)
1026 jermar 835
        flags |= PAGE_READ;
836
 
1235 jermar 837
    if (aflags & AS_AREA_WRITE)
1026 jermar 838
        flags |= PAGE_WRITE;
839
 
1235 jermar 840
    if (aflags & AS_AREA_EXEC)
1026 jermar 841
        flags |= PAGE_EXEC;
842
 
1424 jermar 843
    if (aflags & AS_AREA_CACHEABLE)
1178 jermar 844
        flags |= PAGE_CACHEABLE;
845
 
754 jermar 846
    return flags;
847
}
756 jermar 848
 
1235 jermar 849
/** Compute flags for virtual address translation subsytem.
850
 *
851
 * The address space area must be locked.
852
 * Interrupts must be disabled.
853
 *
854
 * @param a Address space area.
855
 *
856
 * @return Flags to be used in page_mapping_insert().
857
 */
1409 jermar 858
int as_area_get_flags(as_area_t *a)
1235 jermar 859
{
860
    return area_flags_to_page_flags(a->flags);
861
}
862
 
756 jermar 863
/** Create page table.
864
 *
865
 * Depending on architecture, create either address space
866
 * private or global page table.
867
 *
868
 * @param flags Flags saying whether the page table is for kernel address space.
869
 *
870
 * @return First entry of the page table.
871
 */
872
pte_t *page_table_create(int flags)
873
{
874
        ASSERT(as_operations);
875
        ASSERT(as_operations->page_table_create);
876
 
877
        return as_operations->page_table_create(flags);
878
}
977 jermar 879
 
1468 jermar 880
/** Destroy page table.
881
 *
882
 * Destroy page table in architecture specific way.
883
 *
884
 * @param page_table Physical address of PTL0.
885
 */
886
void page_table_destroy(pte_t *page_table)
887
{
888
        ASSERT(as_operations);
889
        ASSERT(as_operations->page_table_destroy);
890
 
891
        as_operations->page_table_destroy(page_table);
892
}
893
 
1044 jermar 894
/** Lock page table.
895
 *
896
 * This function should be called before any page_mapping_insert(),
897
 * page_mapping_remove() and page_mapping_find().
898
 *
899
 * Locking order is such that address space areas must be locked
900
 * prior to this call. Address space can be locked prior to this
901
 * call in which case the lock argument is false.
902
 *
903
 * @param as Address space.
1248 jermar 904
 * @param lock If false, do not attempt to lock as->lock.
1044 jermar 905
 */
906
void page_table_lock(as_t *as, bool lock)
907
{
908
    ASSERT(as_operations);
909
    ASSERT(as_operations->page_table_lock);
910
 
911
    as_operations->page_table_lock(as, lock);
912
}
913
 
914
/** Unlock page table.
915
 *
916
 * @param as Address space.
1248 jermar 917
 * @param unlock If false, do not attempt to unlock as->lock.
1044 jermar 918
 */
919
void page_table_unlock(as_t *as, bool unlock)
920
{
921
    ASSERT(as_operations);
922
    ASSERT(as_operations->page_table_unlock);
923
 
924
    as_operations->page_table_unlock(as, unlock);
925
}
926
 
977 jermar 927
 
928
/** Find address space area and lock it.
929
 *
930
 * The address space must be locked and interrupts must be disabled.
931
 *
932
 * @param as Address space.
933
 * @param va Virtual address.
934
 *
935
 * @return Locked address space area containing va on success or NULL on failure.
936
 */
937
as_area_t *find_area_and_lock(as_t *as, __address va)
938
{
939
    as_area_t *a;
1147 jermar 940
    btree_node_t *leaf, *lnode;
941
    int i;
977 jermar 942
 
1147 jermar 943
    a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
944
    if (a) {
945
        /* va is the base address of an address space area */
1380 jermar 946
        mutex_lock(&a->lock);
1147 jermar 947
        return a;
948
    }
949
 
950
    /*
1150 jermar 951
     * Search the leaf node and the righmost record of its left neighbour
1147 jermar 952
     * to find out whether this is a miss or va belongs to an address
953
     * space area found there.
954
     */
955
 
956
    /* First, search the leaf node itself. */
957
    for (i = 0; i < leaf->keys; i++) {
958
        a = (as_area_t *) leaf->value[i];
1380 jermar 959
        mutex_lock(&a->lock);
1147 jermar 960
        if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
961
            return a;
962
        }
1380 jermar 963
        mutex_unlock(&a->lock);
1147 jermar 964
    }
977 jermar 965
 
1147 jermar 966
    /*
1150 jermar 967
     * Second, locate the left neighbour and test its last record.
1148 jermar 968
     * Because of its position in the B+tree, it must have base < va.
1147 jermar 969
     */
1150 jermar 970
    if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 971
        a = (as_area_t *) lnode->value[lnode->keys - 1];
1380 jermar 972
        mutex_lock(&a->lock);
1147 jermar 973
        if (va < a->base + a->pages * PAGE_SIZE) {
1048 jermar 974
            return a;
1147 jermar 975
        }
1380 jermar 976
        mutex_unlock(&a->lock);
977 jermar 977
    }
978
 
979
    return NULL;
980
}
1048 jermar 981
 
982
/** Check area conflicts with other areas.
983
 *
984
 * The address space must be locked and interrupts must be disabled.
985
 *
986
 * @param as Address space.
987
 * @param va Starting virtual address of the area being tested.
988
 * @param size Size of the area being tested.
989
 * @param avoid_area Do not touch this area.
990
 *
991
 * @return True if there is no conflict, false otherwise.
992
 */
993
bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area)
994
{
995
    as_area_t *a;
1147 jermar 996
    btree_node_t *leaf, *node;
997
    int i;
1048 jermar 998
 
1070 jermar 999
    /*
1000
     * We don't want any area to have conflicts with NULL page.
1001
     */
1002
    if (overlaps(va, size, NULL, PAGE_SIZE))
1003
        return false;
1004
 
1147 jermar 1005
    /*
1006
     * The leaf node is found in O(log n), where n is proportional to
1007
     * the number of address space areas belonging to as.
1008
     * The check for conflicts is then attempted on the rightmost
1150 jermar 1009
     * record in the left neighbour, the leftmost record in the right
1010
     * neighbour and all records in the leaf node itself.
1147 jermar 1011
     */
1048 jermar 1012
 
1147 jermar 1013
    if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
1014
        if (a != avoid_area)
1015
            return false;
1016
    }
1017
 
1018
    /* First, check the two border cases. */
1150 jermar 1019
    if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 1020
        a = (as_area_t *) node->value[node->keys - 1];
1380 jermar 1021
        mutex_lock(&a->lock);
1147 jermar 1022
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 1023
            mutex_unlock(&a->lock);
1147 jermar 1024
            return false;
1025
        }
1380 jermar 1026
        mutex_unlock(&a->lock);
1147 jermar 1027
    }
1150 jermar 1028
    if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 1029
        a = (as_area_t *) node->value[0];
1380 jermar 1030
        mutex_lock(&a->lock);
1147 jermar 1031
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 1032
            mutex_unlock(&a->lock);
1147 jermar 1033
            return false;
1034
        }
1380 jermar 1035
        mutex_unlock(&a->lock);
1147 jermar 1036
    }
1037
 
1038
    /* Second, check the leaf node. */
1039
    for (i = 0; i < leaf->keys; i++) {
1040
        a = (as_area_t *) leaf->value[i];
1041
 
1048 jermar 1042
        if (a == avoid_area)
1043
            continue;
1147 jermar 1044
 
1380 jermar 1045
        mutex_lock(&a->lock);
1147 jermar 1046
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 1047
            mutex_unlock(&a->lock);
1147 jermar 1048
            return false;
1049
        }
1380 jermar 1050
        mutex_unlock(&a->lock);
1048 jermar 1051
    }
1052
 
1070 jermar 1053
    /*
1054
     * So far, the area does not conflict with other areas.
1055
     * Check if it doesn't conflict with kernel address space.
1056
     */  
1057
    if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
1058
        return !overlaps(va, size,
1059
            KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START);
1060
    }
1061
 
1048 jermar 1062
    return true;
1063
}
1235 jermar 1064
 
1380 jermar 1065
/** Return size of the address space area with given base.  */
1329 palkovsky 1066
size_t as_get_size(__address base)
1067
{
1068
    ipl_t ipl;
1069
    as_area_t *src_area;
1070
    size_t size;
1071
 
1072
    ipl = interrupts_disable();
1073
    src_area = find_area_and_lock(AS, base);
1074
    if (src_area){
1075
        size = src_area->pages * PAGE_SIZE;
1380 jermar 1076
        mutex_unlock(&src_area->lock);
1329 palkovsky 1077
    } else {
1078
        size = 0;
1079
    }
1080
    interrupts_restore(ipl);
1081
    return size;
1082
}
1083
 
1387 jermar 1084
/** Mark portion of address space area as used.
1085
 *
1086
 * The address space area must be already locked.
1087
 *
1088
 * @param a Address space area.
1089
 * @param page First page to be marked.
1090
 * @param count Number of page to be marked.
1091
 *
1092
 * @return 0 on failure and 1 on success.
1093
 */
1094
int used_space_insert(as_area_t *a, __address page, count_t count)
1095
{
1096
    btree_node_t *leaf, *node;
1097
    count_t pages;
1098
    int i;
1099
 
1100
    ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
1101
    ASSERT(count);
1102
 
1103
    pages = (count_t) btree_search(&a->used_space, page, &leaf);
1104
    if (pages) {
1105
        /*
1106
         * We hit the beginning of some used space.
1107
         */
1108
        return 0;
1109
    }
1110
 
1437 jermar 1111
    if (!leaf->keys) {
1112
        btree_insert(&a->used_space, page, (void *) count, leaf);
1113
        return 1;
1114
    }
1115
 
1387 jermar 1116
    node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
1117
    if (node) {
1118
        __address left_pg = node->key[node->keys - 1], right_pg = leaf->key[0];
1119
        count_t left_cnt = (count_t) node->value[node->keys - 1], right_cnt = (count_t) leaf->value[0];
1120
 
1121
        /*
1122
         * Examine the possibility that the interval fits
1123
         * somewhere between the rightmost interval of
1124
         * the left neigbour and the first interval of the leaf.
1125
         */
1126
 
1127
        if (page >= right_pg) {
1128
            /* Do nothing. */
1129
        } else if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1130
            /* The interval intersects with the left interval. */
1131
            return 0;
1132
        } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1133
            /* The interval intersects with the right interval. */
1134
            return 0;          
1135
        } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
1136
            /* The interval can be added by merging the two already present intervals. */
1403 jermar 1137
            node->value[node->keys - 1] += count + right_cnt;
1387 jermar 1138
            btree_remove(&a->used_space, right_pg, leaf);
1139
            return 1;
1140
        } else if (page == left_pg + left_cnt*PAGE_SIZE) {
1141
            /* The interval can be added by simply growing the left interval. */
1403 jermar 1142
            node->value[node->keys - 1] += count;
1387 jermar 1143
            return 1;
1144
        } else if (page + count*PAGE_SIZE == right_pg) {
1145
            /*
1146
             * The interval can be addded by simply moving base of the right
1147
             * interval down and increasing its size accordingly.
1148
             */
1403 jermar 1149
            leaf->value[0] += count;
1387 jermar 1150
            leaf->key[0] = page;
1151
            return 1;
1152
        } else {
1153
            /*
1154
             * The interval is between both neigbouring intervals,
1155
             * but cannot be merged with any of them.
1156
             */
1157
            btree_insert(&a->used_space, page, (void *) count, leaf);
1158
            return 1;
1159
        }
1160
    } else if (page < leaf->key[0]) {
1161
        __address right_pg = leaf->key[0];
1162
        count_t right_cnt = (count_t) leaf->value[0];
1163
 
1164
        /*
1165
         * Investigate the border case in which the left neighbour does not
1166
         * exist but the interval fits from the left.
1167
         */
1168
 
1169
        if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1170
            /* The interval intersects with the right interval. */
1171
            return 0;
1172
        } else if (page + count*PAGE_SIZE == right_pg) {
1173
            /*
1174
             * The interval can be added by moving the base of the right interval down
1175
             * and increasing its size accordingly.
1176
             */
1177
            leaf->key[0] = page;
1403 jermar 1178
            leaf->value[0] += count;
1387 jermar 1179
            return 1;
1180
        } else {
1181
            /*
1182
             * The interval doesn't adjoin with the right interval.
1183
             * It must be added individually.
1184
             */
1185
            btree_insert(&a->used_space, page, (void *) count, leaf);
1186
            return 1;
1187
        }
1188
    }
1189
 
1190
    node = btree_leaf_node_right_neighbour(&a->used_space, leaf);
1191
    if (node) {
1192
        __address left_pg = leaf->key[leaf->keys - 1], right_pg = node->key[0];
1193
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1], right_cnt = (count_t) node->value[0];
1194
 
1195
        /*
1196
         * Examine the possibility that the interval fits
1197
         * somewhere between the leftmost interval of
1198
         * the right neigbour and the last interval of the leaf.
1199
         */
1200
 
1201
        if (page < left_pg) {
1202
            /* Do nothing. */
1203
        } else if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1204
            /* The interval intersects with the left interval. */
1205
            return 0;
1206
        } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1207
            /* The interval intersects with the right interval. */
1208
            return 0;          
1209
        } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
1210
            /* The interval can be added by merging the two already present intervals. */
1403 jermar 1211
            leaf->value[leaf->keys - 1] += count + right_cnt;
1387 jermar 1212
            btree_remove(&a->used_space, right_pg, node);
1213
            return 1;
1214
        } else if (page == left_pg + left_cnt*PAGE_SIZE) {
1215
            /* The interval can be added by simply growing the left interval. */
1403 jermar 1216
            leaf->value[leaf->keys - 1] +=  count;
1387 jermar 1217
            return 1;
1218
        } else if (page + count*PAGE_SIZE == right_pg) {
1219
            /*
1220
             * The interval can be addded by simply moving base of the right
1221
             * interval down and increasing its size accordingly.
1222
             */
1403 jermar 1223
            node->value[0] += count;
1387 jermar 1224
            node->key[0] = page;
1225
            return 1;
1226
        } else {
1227
            /*
1228
             * The interval is between both neigbouring intervals,
1229
             * but cannot be merged with any of them.
1230
             */
1231
            btree_insert(&a->used_space, page, (void *) count, leaf);
1232
            return 1;
1233
        }
1234
    } else if (page >= leaf->key[leaf->keys - 1]) {
1235
        __address left_pg = leaf->key[leaf->keys - 1];
1236
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
1237
 
1238
        /*
1239
         * Investigate the border case in which the right neighbour does not
1240
         * exist but the interval fits from the right.
1241
         */
1242
 
1243
        if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1403 jermar 1244
            /* The interval intersects with the left interval. */
1387 jermar 1245
            return 0;
1246
        } else if (left_pg + left_cnt*PAGE_SIZE == page) {
1247
            /* The interval can be added by growing the left interval. */
1403 jermar 1248
            leaf->value[leaf->keys - 1] += count;
1387 jermar 1249
            return 1;
1250
        } else {
1251
            /*
1252
             * The interval doesn't adjoin with the left interval.
1253
             * It must be added individually.
1254
             */
1255
            btree_insert(&a->used_space, page, (void *) count, leaf);
1256
            return 1;
1257
        }
1258
    }
1259
 
1260
    /*
1261
     * Note that if the algorithm made it thus far, the interval can fit only
1262
     * between two other intervals of the leaf. The two border cases were already
1263
     * resolved.
1264
     */
1265
    for (i = 1; i < leaf->keys; i++) {
1266
        if (page < leaf->key[i]) {
1267
            __address left_pg = leaf->key[i - 1], right_pg = leaf->key[i];
1268
            count_t left_cnt = (count_t) leaf->value[i - 1], right_cnt = (count_t) leaf->value[i];
1269
 
1270
            /*
1271
             * The interval fits between left_pg and right_pg.
1272
             */
1273
 
1274
            if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1275
                /* The interval intersects with the left interval. */
1276
                return 0;
1277
            } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1278
                /* The interval intersects with the right interval. */
1279
                return 0;          
1280
            } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
1281
                /* The interval can be added by merging the two already present intervals. */
1403 jermar 1282
                leaf->value[i - 1] += count + right_cnt;
1387 jermar 1283
                btree_remove(&a->used_space, right_pg, leaf);
1284
                return 1;
1285
            } else if (page == left_pg + left_cnt*PAGE_SIZE) {
1286
                /* The interval can be added by simply growing the left interval. */
1403 jermar 1287
                leaf->value[i - 1] += count;
1387 jermar 1288
                return 1;
1289
            } else if (page + count*PAGE_SIZE == right_pg) {
1290
                /*
1291
                     * The interval can be addded by simply moving base of the right
1292
                 * interval down and increasing its size accordingly.
1293
                 */
1403 jermar 1294
                leaf->value[i] += count;
1387 jermar 1295
                leaf->key[i] = page;
1296
                return 1;
1297
            } else {
1298
                /*
1299
                 * The interval is between both neigbouring intervals,
1300
                 * but cannot be merged with any of them.
1301
                 */
1302
                btree_insert(&a->used_space, page, (void *) count, leaf);
1303
                return 1;
1304
            }
1305
        }
1306
    }
1307
 
1308
    panic("Inconsistency detected while adding %d pages of used space at %P.\n", count, page);
1309
}
1310
 
1311
/** Mark portion of address space area as unused.
1312
 *
1313
 * The address space area must be already locked.
1314
 *
1315
 * @param a Address space area.
1316
 * @param page First page to be marked.
1317
 * @param count Number of page to be marked.
1318
 *
1319
 * @return 0 on failure and 1 on success.
1320
 */
1321
int used_space_remove(as_area_t *a, __address page, count_t count)
1322
{
1323
    btree_node_t *leaf, *node;
1324
    count_t pages;
1325
    int i;
1326
 
1327
    ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
1328
    ASSERT(count);
1329
 
1330
    pages = (count_t) btree_search(&a->used_space, page, &leaf);
1331
    if (pages) {
1332
        /*
1333
         * We are lucky, page is the beginning of some interval.
1334
         */
1335
        if (count > pages) {
1336
            return 0;
1337
        } else if (count == pages) {
1338
            btree_remove(&a->used_space, page, leaf);
1403 jermar 1339
            return 1;
1387 jermar 1340
        } else {
1341
            /*
1342
             * Find the respective interval.
1343
             * Decrease its size and relocate its start address.
1344
             */
1345
            for (i = 0; i < leaf->keys; i++) {
1346
                if (leaf->key[i] == page) {
1347
                    leaf->key[i] += count*PAGE_SIZE;
1403 jermar 1348
                    leaf->value[i] -= count;
1387 jermar 1349
                    return 1;
1350
                }
1351
            }
1352
            goto error;
1353
        }
1354
    }
1355
 
1356
    node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
1357
    if (node && page < leaf->key[0]) {
1358
        __address left_pg = node->key[node->keys - 1];
1359
        count_t left_cnt = (count_t) node->value[node->keys - 1];
1360
 
1361
        if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
1362
            if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
1363
                /*
1364
                 * The interval is contained in the rightmost interval
1365
                 * of the left neighbour and can be removed by
1366
                 * updating the size of the bigger interval.
1367
                 */
1403 jermar 1368
                node->value[node->keys - 1] -= count;
1387 jermar 1369
                return 1;
1370
            } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
1403 jermar 1371
                count_t new_cnt;
1387 jermar 1372
 
1373
                /*
1374
                 * The interval is contained in the rightmost interval
1375
                 * of the left neighbour but its removal requires
1376
                 * both updating the size of the original interval and
1377
                 * also inserting a new interval.
1378
                 */
1403 jermar 1379
                new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1380
                node->value[node->keys - 1] -= count + new_cnt;
1387 jermar 1381
                btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
1382
                return 1;
1383
            }
1384
        }
1385
        return 0;
1386
    } else if (page < leaf->key[0]) {
1387
        return 0;
1388
    }
1389
 
1390
    if (page > leaf->key[leaf->keys - 1]) {
1391
        __address left_pg = leaf->key[leaf->keys - 1];
1392
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
1393
 
1394
        if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
1395
            if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
1396
                /*
1397
                 * The interval is contained in the rightmost interval
1398
                 * of the leaf and can be removed by updating the size
1399
                 * of the bigger interval.
1400
                 */
1403 jermar 1401
                leaf->value[leaf->keys - 1] -= count;
1387 jermar 1402
                return 1;
1403
            } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
1403 jermar 1404
                count_t new_cnt;
1387 jermar 1405
 
1406
                /*
1407
                 * The interval is contained in the rightmost interval
1408
                 * of the leaf but its removal requires both updating
1409
                 * the size of the original interval and
1410
                 * also inserting a new interval.
1411
                 */
1403 jermar 1412
                new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1413
                leaf->value[leaf->keys - 1] -= count + new_cnt;
1387 jermar 1414
                btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
1415
                return 1;
1416
            }
1417
        }
1418
        return 0;
1419
    }  
1420
 
1421
    /*
1422
     * The border cases have been already resolved.
1423
     * Now the interval can be only between intervals of the leaf.
1424
     */
1425
    for (i = 1; i < leaf->keys - 1; i++) {
1426
        if (page < leaf->key[i]) {
1427
            __address left_pg = leaf->key[i - 1];
1428
            count_t left_cnt = (count_t) leaf->value[i - 1];
1429
 
1430
            /*
1431
             * Now the interval is between intervals corresponding to (i - 1) and i.
1432
             */
1433
            if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
1434
                if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
1435
                    /*
1436
                    * The interval is contained in the interval (i - 1)
1437
                     * of the leaf and can be removed by updating the size
1438
                     * of the bigger interval.
1439
                     */
1403 jermar 1440
                    leaf->value[i - 1] -= count;
1387 jermar 1441
                    return 1;
1442
                } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
1403 jermar 1443
                    count_t new_cnt;
1387 jermar 1444
 
1445
                    /*
1446
                     * The interval is contained in the interval (i - 1)
1447
                     * of the leaf but its removal requires both updating
1448
                     * the size of the original interval and
1449
                     * also inserting a new interval.
1450
                     */
1403 jermar 1451
                    new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1452
                    leaf->value[i - 1] -= count + new_cnt;
1387 jermar 1453
                    btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
1454
                    return 1;
1455
                }
1456
            }
1457
            return 0;
1458
        }
1459
    }
1460
 
1461
error:
1462
    panic("Inconsistency detected while removing %d pages of used space from %P.\n", count, page);
1463
}
1464
 
1409 jermar 1465
/** Remove reference to address space area share info.
1466
 *
1467
 * If the reference count drops to 0, the sh_info is deallocated.
1468
 *
1469
 * @param sh_info Pointer to address space area share info.
1470
 */
1471
void sh_info_remove_reference(share_info_t *sh_info)
1472
{
1473
    bool dealloc = false;
1474
 
1475
    mutex_lock(&sh_info->lock);
1476
    ASSERT(sh_info->refcount);
1477
    if (--sh_info->refcount == 0) {
1478
        dealloc = true;
1479
        bool cond;
1480
 
1481
        /*
1482
         * Now walk carefully the pagemap B+tree and free/remove
1483
         * reference from all frames found there.
1484
         */
1485
        for (cond = true; cond;) {
1486
            btree_node_t *node;
1487
 
1488
            ASSERT(!list_empty(&sh_info->pagemap.leaf_head));
1489
            node = list_get_instance(sh_info->pagemap.leaf_head.next, btree_node_t, leaf_link);
1490
            if ((cond = node->keys)) {
1491
                frame_free(ADDR2PFN((__address) node->value[0]));
1492
                btree_remove(&sh_info->pagemap, node->key[0], node);
1493
            }
1494
        }
1495
 
1496
    }
1497
    mutex_unlock(&sh_info->lock);
1498
 
1499
    if (dealloc) {
1500
        btree_destroy(&sh_info->pagemap);
1501
        free(sh_info);
1502
    }
1503
}
1504
 
1235 jermar 1505
/*
1506
 * Address space related syscalls.
1507
 */
1508
 
1509
/** Wrapper for as_area_create(). */
1510
__native sys_as_area_create(__address address, size_t size, int flags)
1511
{
1424 jermar 1512
    if (as_area_create(AS, flags | AS_AREA_CACHEABLE, size, address, AS_AREA_ATTR_NONE, &anon_backend, NULL))
1235 jermar 1513
        return (__native) address;
1514
    else
1515
        return (__native) -1;
1516
}
1517
 
1518
/** Wrapper for as_area_resize. */
1519
__native sys_as_area_resize(__address address, size_t size, int flags)
1520
{
1306 jermar 1521
    return (__native) as_area_resize(AS, address, size, 0);
1235 jermar 1522
}
1523
 
1306 jermar 1524
/** Wrapper for as_area_destroy. */
1525
__native sys_as_area_destroy(__address address)
1526
{
1527
    return (__native) as_area_destroy(AS, address);
1528
}