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703 jermar 1
/*
2
 * Copyright (C) 2001-2006 Jakub Jermar
3
 * All rights reserved.
4
 *
5
 * Redistribution and use in source and binary forms, with or without
6
 * modification, are permitted provided that the following conditions
7
 * are met:
8
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - Redistributions in binary form must reproduce the above copyright
12
 *   notice, this list of conditions and the following disclaimer in the
13
 *   documentation and/or other materials provided with the distribution.
14
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
1248 jermar 29
/**
30
 * @file    as.c
31
 * @brief   Address space related functions.
32
 *
703 jermar 33
 * This file contains address space manipulation functions.
34
 * Roughly speaking, this is a higher-level client of
35
 * Virtual Address Translation (VAT) subsystem.
1248 jermar 36
 *
37
 * Functionality provided by this file allows one to
38
 * create address space and create, resize and share
39
 * address space areas.
40
 *
41
 * @see page.c
42
 *
703 jermar 43
 */
44
 
45
#include <mm/as.h>
756 jermar 46
#include <arch/mm/as.h>
703 jermar 47
#include <mm/page.h>
48
#include <mm/frame.h>
814 palkovsky 49
#include <mm/slab.h>
703 jermar 50
#include <mm/tlb.h>
51
#include <arch/mm/page.h>
52
#include <genarch/mm/page_pt.h>
1108 jermar 53
#include <genarch/mm/page_ht.h>
727 jermar 54
#include <mm/asid.h>
703 jermar 55
#include <arch/mm/asid.h>
56
#include <synch/spinlock.h>
1380 jermar 57
#include <synch/mutex.h>
788 jermar 58
#include <adt/list.h>
1147 jermar 59
#include <adt/btree.h>
1235 jermar 60
#include <proc/task.h>
1288 jermar 61
#include <proc/thread.h>
1235 jermar 62
#include <arch/asm.h>
703 jermar 63
#include <panic.h>
64
#include <debug.h>
1235 jermar 65
#include <print.h>
703 jermar 66
#include <memstr.h>
1070 jermar 67
#include <macros.h>
703 jermar 68
#include <arch.h>
1235 jermar 69
#include <errno.h>
70
#include <config.h>
1387 jermar 71
#include <align.h>
1235 jermar 72
#include <arch/types.h>
73
#include <typedefs.h>
1288 jermar 74
#include <syscall/copy.h>
75
#include <arch/interrupt.h>
703 jermar 76
 
756 jermar 77
as_operations_t *as_operations = NULL;
703 jermar 78
 
1415 jermar 79
/** This lock protects inactive_as_with_asid_head list. It must be acquired before as_t mutex. */
80
SPINLOCK_INITIALIZE(inactive_as_with_asid_lock);
823 jermar 81
 
82
/**
83
 * This list contains address spaces that are not active on any
84
 * processor and that have valid ASID.
85
 */
86
LIST_INITIALIZE(inactive_as_with_asid_head);
87
 
757 jermar 88
/** Kernel address space. */
89
as_t *AS_KERNEL = NULL;
90
 
1235 jermar 91
static int area_flags_to_page_flags(int aflags);
977 jermar 92
static as_area_t *find_area_and_lock(as_t *as, __address va);
1048 jermar 93
static bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area);
1409 jermar 94
static void sh_info_remove_reference(share_info_t *sh_info);
703 jermar 95
 
756 jermar 96
/** Initialize address space subsystem. */
97
void as_init(void)
98
{
99
    as_arch_init();
789 palkovsky 100
    AS_KERNEL = as_create(FLAG_AS_KERNEL);
1383 decky 101
    if (!AS_KERNEL)
102
        panic("can't create kernel address space\n");
103
 
756 jermar 104
}
105
 
757 jermar 106
/** Create address space.
107
 *
108
 * @param flags Flags that influence way in wich the address space is created.
109
 */
756 jermar 110
as_t *as_create(int flags)
703 jermar 111
{
112
    as_t *as;
113
 
822 palkovsky 114
    as = (as_t *) malloc(sizeof(as_t), 0);
823 jermar 115
    link_initialize(&as->inactive_as_with_asid_link);
1380 jermar 116
    mutex_initialize(&as->lock);
1147 jermar 117
    btree_create(&as->as_area_btree);
822 palkovsky 118
 
119
    if (flags & FLAG_AS_KERNEL)
120
        as->asid = ASID_KERNEL;
121
    else
122
        as->asid = ASID_INVALID;
123
 
1468 jermar 124
    as->refcount = 0;
1415 jermar 125
    as->cpu_refcount = 0;
822 palkovsky 126
    as->page_table = page_table_create(flags);
703 jermar 127
 
128
    return as;
129
}
130
 
1468 jermar 131
/** Destroy adress space.
132
 *
133
 * When there are no tasks referencing this address space (i.e. its refcount is zero),
134
 * the address space can be destroyed.
135
 */
136
void as_destroy(as_t *as)
973 palkovsky 137
{
1468 jermar 138
    ipl_t ipl;
1495 jermar 139
    link_t *cur;
973 palkovsky 140
 
1468 jermar 141
    ASSERT(as->refcount == 0);
142
 
143
    /*
144
     * Since there is no reference to this area,
145
     * it is safe not to lock its mutex.
146
     */
147
 
148
    ipl = interrupts_disable();
149
    spinlock_lock(&inactive_as_with_asid_lock);
150
    if (as->asid != ASID_INVALID && as->asid != ASID_KERNEL) {
151
        list_remove(&as->inactive_as_with_asid_link);
152
        asid_put(as->asid);
153
    }
154
    spinlock_unlock(&inactive_as_with_asid_lock);
155
 
156
    /*
157
     * Destroy address space areas of the address space.
158
     */
1495 jermar 159
    for (cur = as->as_area_btree.leaf_head.next; cur != &as->as_area_btree.leaf_head; cur = cur->next) {
1468 jermar 160
        btree_node_t *node;
1495 jermar 161
        int i;
1468 jermar 162
 
1495 jermar 163
        node = list_get_instance(cur, btree_node_t, leaf_link);
164
        for (i = 0; i < node->keys; i++)
165
            as_area_destroy(as, node->key[i]);
1468 jermar 166
    }
1495 jermar 167
 
1483 jermar 168
    btree_destroy(&as->as_area_btree);
1468 jermar 169
    page_table_destroy(as->page_table);
170
 
171
    interrupts_restore(ipl);
172
 
973 palkovsky 173
    free(as);
174
}
175
 
703 jermar 176
/** Create address space area of common attributes.
177
 *
178
 * The created address space area is added to the target address space.
179
 *
180
 * @param as Target address space.
1239 jermar 181
 * @param flags Flags of the area memory.
1048 jermar 182
 * @param size Size of area.
703 jermar 183
 * @param base Base address of area.
1239 jermar 184
 * @param attrs Attributes of the area.
1409 jermar 185
 * @param backend Address space area backend. NULL if no backend is used.
186
 * @param backend_data NULL or a pointer to an array holding two void *.
703 jermar 187
 *
188
 * @return Address space area on success or NULL on failure.
189
 */
1409 jermar 190
as_area_t *as_area_create(as_t *as, int flags, size_t size, __address base, int attrs,
1424 jermar 191
           mem_backend_t *backend, mem_backend_data_t *backend_data)
703 jermar 192
{
193
    ipl_t ipl;
194
    as_area_t *a;
195
 
196
    if (base % PAGE_SIZE)
1048 jermar 197
        return NULL;
198
 
1233 jermar 199
    if (!size)
200
        return NULL;
201
 
1048 jermar 202
    /* Writeable executable areas are not supported. */
203
    if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
204
        return NULL;
703 jermar 205
 
206
    ipl = interrupts_disable();
1380 jermar 207
    mutex_lock(&as->lock);
703 jermar 208
 
1048 jermar 209
    if (!check_area_conflicts(as, base, size, NULL)) {
1380 jermar 210
        mutex_unlock(&as->lock);
1048 jermar 211
        interrupts_restore(ipl);
212
        return NULL;
213
    }
703 jermar 214
 
822 palkovsky 215
    a = (as_area_t *) malloc(sizeof(as_area_t), 0);
703 jermar 216
 
1380 jermar 217
    mutex_initialize(&a->lock);
822 palkovsky 218
 
1424 jermar 219
    a->as = as;
1026 jermar 220
    a->flags = flags;
1239 jermar 221
    a->attributes = attrs;
1048 jermar 222
    a->pages = SIZE2FRAMES(size);
822 palkovsky 223
    a->base = base;
1409 jermar 224
    a->sh_info = NULL;
225
    a->backend = backend;
1424 jermar 226
    if (backend_data)
227
        a->backend_data = *backend_data;
228
    else
229
        memsetb((__address) &a->backend_data, sizeof(a->backend_data), 0);
230
 
1387 jermar 231
    btree_create(&a->used_space);
822 palkovsky 232
 
1147 jermar 233
    btree_insert(&as->as_area_btree, base, (void *) a, NULL);
822 palkovsky 234
 
1380 jermar 235
    mutex_unlock(&as->lock);
703 jermar 236
    interrupts_restore(ipl);
704 jermar 237
 
703 jermar 238
    return a;
239
}
240
 
1235 jermar 241
/** Find address space area and change it.
242
 *
243
 * @param as Address space.
244
 * @param address Virtual address belonging to the area to be changed. Must be page-aligned.
245
 * @param size New size of the virtual memory block starting at address.
246
 * @param flags Flags influencing the remap operation. Currently unused.
247
 *
1306 jermar 248
 * @return Zero on success or a value from @ref errno.h otherwise.
1235 jermar 249
 */
1306 jermar 250
int as_area_resize(as_t *as, __address address, size_t size, int flags)
1235 jermar 251
{
1306 jermar 252
    as_area_t *area;
1235 jermar 253
    ipl_t ipl;
254
    size_t pages;
255
 
256
    ipl = interrupts_disable();
1380 jermar 257
    mutex_lock(&as->lock);
1235 jermar 258
 
259
    /*
260
     * Locate the area.
261
     */
262
    area = find_area_and_lock(as, address);
263
    if (!area) {
1380 jermar 264
        mutex_unlock(&as->lock);
1235 jermar 265
        interrupts_restore(ipl);
1306 jermar 266
        return ENOENT;
1235 jermar 267
    }
268
 
1424 jermar 269
    if (area->backend == &phys_backend) {
1235 jermar 270
        /*
271
         * Remapping of address space areas associated
272
         * with memory mapped devices is not supported.
273
         */
1380 jermar 274
        mutex_unlock(&area->lock);
275
        mutex_unlock(&as->lock);
1235 jermar 276
        interrupts_restore(ipl);
1306 jermar 277
        return ENOTSUP;
1235 jermar 278
    }
1409 jermar 279
    if (area->sh_info) {
280
        /*
281
         * Remapping of shared address space areas
282
         * is not supported.
283
         */
284
        mutex_unlock(&area->lock);
285
        mutex_unlock(&as->lock);
286
        interrupts_restore(ipl);
287
        return ENOTSUP;
288
    }
1235 jermar 289
 
290
    pages = SIZE2FRAMES((address - area->base) + size);
291
    if (!pages) {
292
        /*
293
         * Zero size address space areas are not allowed.
294
         */
1380 jermar 295
        mutex_unlock(&area->lock);
296
        mutex_unlock(&as->lock);
1235 jermar 297
        interrupts_restore(ipl);
1306 jermar 298
        return EPERM;
1235 jermar 299
    }
300
 
301
    if (pages < area->pages) {
1403 jermar 302
        bool cond;
303
        __address start_free = area->base + pages*PAGE_SIZE;
1235 jermar 304
 
305
        /*
306
         * Shrinking the area.
307
         * No need to check for overlaps.
308
         */
1403 jermar 309
 
310
        /*
1436 jermar 311
         * Start TLB shootdown sequence.
312
         */
313
        tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
314
 
315
        /*
1403 jermar 316
         * Remove frames belonging to used space starting from
317
         * the highest addresses downwards until an overlap with
318
         * the resized address space area is found. Note that this
319
         * is also the right way to remove part of the used_space
320
         * B+tree leaf list.
321
         */    
322
        for (cond = true; cond;) {
323
            btree_node_t *node;
324
 
325
            ASSERT(!list_empty(&area->used_space.leaf_head));
326
            node = list_get_instance(area->used_space.leaf_head.prev, btree_node_t, leaf_link);
327
            if ((cond = (bool) node->keys)) {
328
                __address b = node->key[node->keys - 1];
329
                count_t c = (count_t) node->value[node->keys - 1];
330
                int i = 0;
1235 jermar 331
 
1403 jermar 332
                if (overlaps(b, c*PAGE_SIZE, area->base, pages*PAGE_SIZE)) {
333
 
334
                    if (b + c*PAGE_SIZE <= start_free) {
335
                        /*
336
                         * The whole interval fits completely
337
                         * in the resized address space area.
338
                         */
339
                        break;
340
                    }
341
 
342
                    /*
343
                     * Part of the interval corresponding to b and c
344
                     * overlaps with the resized address space area.
345
                     */
346
 
347
                    cond = false;   /* we are almost done */
348
                    i = (start_free - b) >> PAGE_WIDTH;
349
                    if (!used_space_remove(area, start_free, c - i))
350
                        panic("Could not remove used space.");
351
                } else {
352
                    /*
353
                     * The interval of used space can be completely removed.
354
                     */
355
                    if (!used_space_remove(area, b, c))
356
                        panic("Could not remove used space.\n");
357
                }
358
 
359
                for (; i < c; i++) {
360
                    pte_t *pte;
361
 
362
                    page_table_lock(as, false);
363
                    pte = page_mapping_find(as, b + i*PAGE_SIZE);
364
                    ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424 jermar 365
                    if (area->backend && area->backend->frame_free) {
366
                        area->backend->frame_free(area,
1409 jermar 367
                            b + i*PAGE_SIZE, PTE_GET_FRAME(pte));
368
                    }
1403 jermar 369
                    page_mapping_remove(as, b + i*PAGE_SIZE);
370
                    page_table_unlock(as, false);
371
                }
1235 jermar 372
            }
373
        }
1436 jermar 374
 
1235 jermar 375
        /*
1436 jermar 376
         * Finish TLB shootdown sequence.
1235 jermar 377
         */
378
        tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
379
        tlb_shootdown_finalize();
380
    } else {
381
        /*
382
         * Growing the area.
383
         * Check for overlaps with other address space areas.
384
         */
385
        if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
1380 jermar 386
            mutex_unlock(&area->lock);
387
            mutex_unlock(&as->lock);       
1235 jermar 388
            interrupts_restore(ipl);
1306 jermar 389
            return EADDRNOTAVAIL;
1235 jermar 390
        }
391
    }
392
 
393
    area->pages = pages;
394
 
1380 jermar 395
    mutex_unlock(&area->lock);
396
    mutex_unlock(&as->lock);
1235 jermar 397
    interrupts_restore(ipl);
398
 
1306 jermar 399
    return 0;
1235 jermar 400
}
401
 
1306 jermar 402
/** Destroy address space area.
403
 *
404
 * @param as Address space.
405
 * @param address Address withing the area to be deleted.
406
 *
407
 * @return Zero on success or a value from @ref errno.h on failure.
408
 */
409
int as_area_destroy(as_t *as, __address address)
410
{
411
    as_area_t *area;
412
    __address base;
1495 jermar 413
    link_t *cur;
1306 jermar 414
    ipl_t ipl;
415
 
416
    ipl = interrupts_disable();
1380 jermar 417
    mutex_lock(&as->lock);
1306 jermar 418
 
419
    area = find_area_and_lock(as, address);
420
    if (!area) {
1380 jermar 421
        mutex_unlock(&as->lock);
1306 jermar 422
        interrupts_restore(ipl);
423
        return ENOENT;
424
    }
425
 
1403 jermar 426
    base = area->base;
427
 
1411 jermar 428
    /*
1436 jermar 429
     * Start TLB shootdown sequence.
430
     */
431
    tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages);
432
 
433
    /*
1411 jermar 434
     * Visit only the pages mapped by used_space B+tree.
435
     */
1495 jermar 436
    for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {
1411 jermar 437
        btree_node_t *node;
1495 jermar 438
        int i;
1403 jermar 439
 
1495 jermar 440
        node = list_get_instance(cur, btree_node_t, leaf_link);
441
        for (i = 0; i < node->keys; i++) {
442
            __address b = node->key[i];
443
            count_t j;
1411 jermar 444
            pte_t *pte;
1403 jermar 445
 
1495 jermar 446
            for (j = 0; j < (count_t) node->value[i]; j++) {
1411 jermar 447
                page_table_lock(as, false);
1495 jermar 448
                pte = page_mapping_find(as, b + j*PAGE_SIZE);
1411 jermar 449
                ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424 jermar 450
                if (area->backend && area->backend->frame_free) {
451
                    area->backend->frame_free(area,
1495 jermar 452
                        b + j*PAGE_SIZE, PTE_GET_FRAME(pte));
1403 jermar 453
                }
1495 jermar 454
                page_mapping_remove(as, b + j*PAGE_SIZE);
1411 jermar 455
                page_table_unlock(as, false);
1306 jermar 456
            }
457
        }
458
    }
1403 jermar 459
 
1306 jermar 460
    /*
1436 jermar 461
     * Finish TLB shootdown sequence.
1306 jermar 462
     */
463
    tlb_invalidate_pages(AS->asid, area->base, area->pages);
464
    tlb_shootdown_finalize();
1436 jermar 465
 
466
    btree_destroy(&area->used_space);
1306 jermar 467
 
1309 jermar 468
    area->attributes |= AS_AREA_ATTR_PARTIAL;
1409 jermar 469
 
470
    if (area->sh_info)
471
        sh_info_remove_reference(area->sh_info);
472
 
1380 jermar 473
    mutex_unlock(&area->lock);
1306 jermar 474
 
475
    /*
476
     * Remove the empty area from address space.
477
     */
478
    btree_remove(&AS->as_area_btree, base, NULL);
479
 
1309 jermar 480
    free(area);
481
 
1380 jermar 482
    mutex_unlock(&AS->lock);
1306 jermar 483
    interrupts_restore(ipl);
484
    return 0;
485
}
486
 
1413 jermar 487
/** Share address space area with another or the same address space.
1235 jermar 488
 *
1424 jermar 489
 * Address space area mapping is shared with a new address space area.
490
 * If the source address space area has not been shared so far,
491
 * a new sh_info is created. The new address space area simply gets the
492
 * sh_info of the source area. The process of duplicating the
493
 * mapping is done through the backend share function.
1413 jermar 494
 *
1417 jermar 495
 * @param src_as Pointer to source address space.
1239 jermar 496
 * @param src_base Base address of the source address space area.
1417 jermar 497
 * @param acc_size Expected size of the source area.
1428 palkovsky 498
 * @param dst_as Pointer to destination address space.
1417 jermar 499
 * @param dst_base Target base address.
500
 * @param dst_flags_mask Destination address space area flags mask.
1235 jermar 501
 *
1306 jermar 502
 * @return Zero on success or ENOENT if there is no such task or
1235 jermar 503
 *     if there is no such address space area,
504
 *     EPERM if there was a problem in accepting the area or
505
 *     ENOMEM if there was a problem in allocating destination
1413 jermar 506
 *     address space area. ENOTSUP is returned if an attempt
507
 *     to share non-anonymous address space area is detected.
1235 jermar 508
 */
1413 jermar 509
int as_area_share(as_t *src_as, __address src_base, size_t acc_size,
1428 palkovsky 510
          as_t *dst_as, __address dst_base, int dst_flags_mask)
1235 jermar 511
{
512
    ipl_t ipl;
1239 jermar 513
    int src_flags;
514
    size_t src_size;
515
    as_area_t *src_area, *dst_area;
1413 jermar 516
    share_info_t *sh_info;
1424 jermar 517
    mem_backend_t *src_backend;
518
    mem_backend_data_t src_backend_data;
1434 palkovsky 519
 
1235 jermar 520
    ipl = interrupts_disable();
1380 jermar 521
    mutex_lock(&src_as->lock);
1329 palkovsky 522
    src_area = find_area_and_lock(src_as, src_base);
1239 jermar 523
    if (!src_area) {
1238 jermar 524
        /*
525
         * Could not find the source address space area.
526
         */
1380 jermar 527
        mutex_unlock(&src_as->lock);
1238 jermar 528
        interrupts_restore(ipl);
529
        return ENOENT;
530
    }
1413 jermar 531
 
1424 jermar 532
    if (!src_area->backend || !src_area->backend->share) {
1413 jermar 533
        /*
1424 jermar 534
         * There is now backend or the backend does not
535
         * know how to share the area.
1413 jermar 536
         */
537
        mutex_unlock(&src_area->lock);
538
        mutex_unlock(&src_as->lock);
539
        interrupts_restore(ipl);
540
        return ENOTSUP;
541
    }
542
 
1239 jermar 543
    src_size = src_area->pages * PAGE_SIZE;
544
    src_flags = src_area->flags;
1424 jermar 545
    src_backend = src_area->backend;
546
    src_backend_data = src_area->backend_data;
1544 palkovsky 547
 
548
    /* Share the cacheable flag from the original mapping */
549
    if (src_flags & AS_AREA_CACHEABLE)
550
        dst_flags_mask |= AS_AREA_CACHEABLE;
551
 
1461 palkovsky 552
    if (src_size != acc_size || (src_flags & dst_flags_mask) != dst_flags_mask) {
1413 jermar 553
        mutex_unlock(&src_area->lock);
554
        mutex_unlock(&src_as->lock);
1235 jermar 555
        interrupts_restore(ipl);
556
        return EPERM;
557
    }
1413 jermar 558
 
1235 jermar 559
    /*
1413 jermar 560
     * Now we are committed to sharing the area.
561
     * First prepare the area for sharing.
562
     * Then it will be safe to unlock it.
563
     */
564
    sh_info = src_area->sh_info;
565
    if (!sh_info) {
566
        sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0);
567
        mutex_initialize(&sh_info->lock);
568
        sh_info->refcount = 2;
569
        btree_create(&sh_info->pagemap);
570
        src_area->sh_info = sh_info;
571
    } else {
572
        mutex_lock(&sh_info->lock);
573
        sh_info->refcount++;
574
        mutex_unlock(&sh_info->lock);
575
    }
576
 
1424 jermar 577
    src_area->backend->share(src_area);
1413 jermar 578
 
579
    mutex_unlock(&src_area->lock);
580
    mutex_unlock(&src_as->lock);
581
 
582
    /*
1239 jermar 583
     * Create copy of the source address space area.
584
     * The destination area is created with AS_AREA_ATTR_PARTIAL
585
     * attribute set which prevents race condition with
586
     * preliminary as_page_fault() calls.
1417 jermar 587
     * The flags of the source area are masked against dst_flags_mask
588
     * to support sharing in less privileged mode.
1235 jermar 589
     */
1461 palkovsky 590
    dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base,
1424 jermar 591
                  AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data);
1239 jermar 592
    if (!dst_area) {
1235 jermar 593
        /*
594
         * Destination address space area could not be created.
595
         */
1413 jermar 596
        sh_info_remove_reference(sh_info);
597
 
1235 jermar 598
        interrupts_restore(ipl);
599
        return ENOMEM;
600
    }
601
 
602
    /*
1239 jermar 603
     * Now the destination address space area has been
604
     * fully initialized. Clear the AS_AREA_ATTR_PARTIAL
1413 jermar 605
     * attribute and set the sh_info.
1239 jermar 606
     */
1380 jermar 607
    mutex_lock(&dst_area->lock);
1239 jermar 608
    dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
1413 jermar 609
    dst_area->sh_info = sh_info;
1380 jermar 610
    mutex_unlock(&dst_area->lock);
1235 jermar 611
 
612
    interrupts_restore(ipl);
613
 
614
    return 0;
615
}
616
 
1423 jermar 617
/** Check access mode for address space area.
618
 *
619
 * The address space area must be locked prior to this call.
620
 *
621
 * @param area Address space area.
622
 * @param access Access mode.
623
 *
624
 * @return False if access violates area's permissions, true otherwise.
625
 */
626
bool as_area_check_access(as_area_t *area, pf_access_t access)
627
{
628
    int flagmap[] = {
629
        [PF_ACCESS_READ] = AS_AREA_READ,
630
        [PF_ACCESS_WRITE] = AS_AREA_WRITE,
631
        [PF_ACCESS_EXEC] = AS_AREA_EXEC
632
    };
633
 
634
    if (!(area->flags & flagmap[access]))
635
        return false;
636
 
637
    return true;
638
}
639
 
703 jermar 640
/** Handle page fault within the current address space.
641
 *
1409 jermar 642
 * This is the high-level page fault handler. It decides
643
 * whether the page fault can be resolved by any backend
644
 * and if so, it invokes the backend to resolve the page
645
 * fault.
646
 *
703 jermar 647
 * Interrupts are assumed disabled.
648
 *
649
 * @param page Faulting page.
1411 jermar 650
 * @param access Access mode that caused the fault (i.e. read/write/exec).
1288 jermar 651
 * @param istate Pointer to interrupted state.
703 jermar 652
 *
1409 jermar 653
 * @return AS_PF_FAULT on page fault, AS_PF_OK on success or AS_PF_DEFER if the
654
 *     fault was caused by copy_to_uspace() or copy_from_uspace().
703 jermar 655
 */
1411 jermar 656
int as_page_fault(__address page, pf_access_t access, istate_t *istate)
703 jermar 657
{
1044 jermar 658
    pte_t *pte;
977 jermar 659
    as_area_t *area;
703 jermar 660
 
1380 jermar 661
    if (!THREAD)
1409 jermar 662
        return AS_PF_FAULT;
1380 jermar 663
 
703 jermar 664
    ASSERT(AS);
1044 jermar 665
 
1380 jermar 666
    mutex_lock(&AS->lock);
977 jermar 667
    area = find_area_and_lock(AS, page);   
703 jermar 668
    if (!area) {
669
        /*
670
         * No area contained mapping for 'page'.
671
         * Signal page fault to low-level handler.
672
         */
1380 jermar 673
        mutex_unlock(&AS->lock);
1288 jermar 674
        goto page_fault;
703 jermar 675
    }
676
 
1239 jermar 677
    if (area->attributes & AS_AREA_ATTR_PARTIAL) {
678
        /*
679
         * The address space area is not fully initialized.
680
         * Avoid possible race by returning error.
681
         */
1380 jermar 682
        mutex_unlock(&area->lock);
683
        mutex_unlock(&AS->lock);
1288 jermar 684
        goto page_fault;       
1239 jermar 685
    }
686
 
1424 jermar 687
    if (!area->backend || !area->backend->page_fault) {
1409 jermar 688
        /*
689
         * The address space area is not backed by any backend
690
         * or the backend cannot handle page faults.
691
         */
692
        mutex_unlock(&area->lock);
693
        mutex_unlock(&AS->lock);
694
        goto page_fault;       
695
    }
1179 jermar 696
 
1044 jermar 697
    page_table_lock(AS, false);
698
 
703 jermar 699
    /*
1044 jermar 700
     * To avoid race condition between two page faults
701
     * on the same address, we need to make sure
702
     * the mapping has not been already inserted.
703
     */
704
    if ((pte = page_mapping_find(AS, page))) {
705
        if (PTE_PRESENT(pte)) {
1423 jermar 706
            if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) ||
707
                (access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) ||
708
                (access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) {
709
                page_table_unlock(AS, false);
710
                mutex_unlock(&area->lock);
711
                mutex_unlock(&AS->lock);
712
                return AS_PF_OK;
713
            }
1044 jermar 714
        }
715
    }
1409 jermar 716
 
1044 jermar 717
    /*
1409 jermar 718
     * Resort to the backend page fault handler.
703 jermar 719
     */
1424 jermar 720
    if (area->backend->page_fault(area, page, access) != AS_PF_OK) {
1409 jermar 721
        page_table_unlock(AS, false);
722
        mutex_unlock(&area->lock);
723
        mutex_unlock(&AS->lock);
724
        goto page_fault;
725
    }
703 jermar 726
 
1044 jermar 727
    page_table_unlock(AS, false);
1380 jermar 728
    mutex_unlock(&area->lock);
729
    mutex_unlock(&AS->lock);
1288 jermar 730
    return AS_PF_OK;
731
 
732
page_fault:
733
    if (THREAD->in_copy_from_uspace) {
734
        THREAD->in_copy_from_uspace = false;
735
        istate_set_retaddr(istate, (__address) &memcpy_from_uspace_failover_address);
736
    } else if (THREAD->in_copy_to_uspace) {
737
        THREAD->in_copy_to_uspace = false;
738
        istate_set_retaddr(istate, (__address) &memcpy_to_uspace_failover_address);
739
    } else {
740
        return AS_PF_FAULT;
741
    }
742
 
743
    return AS_PF_DEFER;
703 jermar 744
}
745
 
823 jermar 746
/** Switch address spaces.
703 jermar 747
 *
1380 jermar 748
 * Note that this function cannot sleep as it is essentially a part of
1415 jermar 749
 * scheduling. Sleeping here would lead to deadlock on wakeup.
1380 jermar 750
 *
823 jermar 751
 * @param old Old address space or NULL.
752
 * @param new New address space.
703 jermar 753
 */
823 jermar 754
void as_switch(as_t *old, as_t *new)
703 jermar 755
{
756
    ipl_t ipl;
823 jermar 757
    bool needs_asid = false;
703 jermar 758
 
759
    ipl = interrupts_disable();
1415 jermar 760
    spinlock_lock(&inactive_as_with_asid_lock);
703 jermar 761
 
762
    /*
823 jermar 763
     * First, take care of the old address space.
764
     */
765
    if (old) {
1380 jermar 766
        mutex_lock_active(&old->lock);
1415 jermar 767
        ASSERT(old->cpu_refcount);
768
        if((--old->cpu_refcount == 0) && (old != AS_KERNEL)) {
823 jermar 769
            /*
770
             * The old address space is no longer active on
771
             * any processor. It can be appended to the
772
             * list of inactive address spaces with assigned
773
             * ASID.
774
             */
775
             ASSERT(old->asid != ASID_INVALID);
776
             list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head);
777
        }
1380 jermar 778
        mutex_unlock(&old->lock);
823 jermar 779
    }
780
 
781
    /*
782
     * Second, prepare the new address space.
783
     */
1380 jermar 784
    mutex_lock_active(&new->lock);
1415 jermar 785
    if ((new->cpu_refcount++ == 0) && (new != AS_KERNEL)) {
823 jermar 786
        if (new->asid != ASID_INVALID)
787
            list_remove(&new->inactive_as_with_asid_link);
788
        else
789
            needs_asid = true;  /* defer call to asid_get() until new->lock is released */
790
    }
791
    SET_PTL0_ADDRESS(new->page_table);
1380 jermar 792
    mutex_unlock(&new->lock);
823 jermar 793
 
794
    if (needs_asid) {
795
        /*
796
         * Allocation of new ASID was deferred
797
         * until now in order to avoid deadlock.
798
         */
799
        asid_t asid;
800
 
801
        asid = asid_get();
1380 jermar 802
        mutex_lock_active(&new->lock);
823 jermar 803
        new->asid = asid;
1380 jermar 804
        mutex_unlock(&new->lock);
823 jermar 805
    }
1415 jermar 806
    spinlock_unlock(&inactive_as_with_asid_lock);
823 jermar 807
    interrupts_restore(ipl);
808
 
809
    /*
703 jermar 810
     * Perform architecture-specific steps.
727 jermar 811
     * (e.g. write ASID to hardware register etc.)
703 jermar 812
     */
823 jermar 813
    as_install_arch(new);
703 jermar 814
 
823 jermar 815
    AS = new;
703 jermar 816
}
754 jermar 817
 
1235 jermar 818
/** Convert address space area flags to page flags.
754 jermar 819
 *
1235 jermar 820
 * @param aflags Flags of some address space area.
754 jermar 821
 *
1235 jermar 822
 * @return Flags to be passed to page_mapping_insert().
754 jermar 823
 */
1235 jermar 824
int area_flags_to_page_flags(int aflags)
754 jermar 825
{
826
    int flags;
827
 
1178 jermar 828
    flags = PAGE_USER | PAGE_PRESENT;
754 jermar 829
 
1235 jermar 830
    if (aflags & AS_AREA_READ)
1026 jermar 831
        flags |= PAGE_READ;
832
 
1235 jermar 833
    if (aflags & AS_AREA_WRITE)
1026 jermar 834
        flags |= PAGE_WRITE;
835
 
1235 jermar 836
    if (aflags & AS_AREA_EXEC)
1026 jermar 837
        flags |= PAGE_EXEC;
838
 
1424 jermar 839
    if (aflags & AS_AREA_CACHEABLE)
1178 jermar 840
        flags |= PAGE_CACHEABLE;
841
 
754 jermar 842
    return flags;
843
}
756 jermar 844
 
1235 jermar 845
/** Compute flags for virtual address translation subsytem.
846
 *
847
 * The address space area must be locked.
848
 * Interrupts must be disabled.
849
 *
850
 * @param a Address space area.
851
 *
852
 * @return Flags to be used in page_mapping_insert().
853
 */
1409 jermar 854
int as_area_get_flags(as_area_t *a)
1235 jermar 855
{
856
    return area_flags_to_page_flags(a->flags);
857
}
858
 
756 jermar 859
/** Create page table.
860
 *
861
 * Depending on architecture, create either address space
862
 * private or global page table.
863
 *
864
 * @param flags Flags saying whether the page table is for kernel address space.
865
 *
866
 * @return First entry of the page table.
867
 */
868
pte_t *page_table_create(int flags)
869
{
870
        ASSERT(as_operations);
871
        ASSERT(as_operations->page_table_create);
872
 
873
        return as_operations->page_table_create(flags);
874
}
977 jermar 875
 
1468 jermar 876
/** Destroy page table.
877
 *
878
 * Destroy page table in architecture specific way.
879
 *
880
 * @param page_table Physical address of PTL0.
881
 */
882
void page_table_destroy(pte_t *page_table)
883
{
884
        ASSERT(as_operations);
885
        ASSERT(as_operations->page_table_destroy);
886
 
887
        as_operations->page_table_destroy(page_table);
888
}
889
 
1044 jermar 890
/** Lock page table.
891
 *
892
 * This function should be called before any page_mapping_insert(),
893
 * page_mapping_remove() and page_mapping_find().
894
 *
895
 * Locking order is such that address space areas must be locked
896
 * prior to this call. Address space can be locked prior to this
897
 * call in which case the lock argument is false.
898
 *
899
 * @param as Address space.
1248 jermar 900
 * @param lock If false, do not attempt to lock as->lock.
1044 jermar 901
 */
902
void page_table_lock(as_t *as, bool lock)
903
{
904
    ASSERT(as_operations);
905
    ASSERT(as_operations->page_table_lock);
906
 
907
    as_operations->page_table_lock(as, lock);
908
}
909
 
910
/** Unlock page table.
911
 *
912
 * @param as Address space.
1248 jermar 913
 * @param unlock If false, do not attempt to unlock as->lock.
1044 jermar 914
 */
915
void page_table_unlock(as_t *as, bool unlock)
916
{
917
    ASSERT(as_operations);
918
    ASSERT(as_operations->page_table_unlock);
919
 
920
    as_operations->page_table_unlock(as, unlock);
921
}
922
 
977 jermar 923
 
924
/** Find address space area and lock it.
925
 *
926
 * The address space must be locked and interrupts must be disabled.
927
 *
928
 * @param as Address space.
929
 * @param va Virtual address.
930
 *
931
 * @return Locked address space area containing va on success or NULL on failure.
932
 */
933
as_area_t *find_area_and_lock(as_t *as, __address va)
934
{
935
    as_area_t *a;
1147 jermar 936
    btree_node_t *leaf, *lnode;
937
    int i;
977 jermar 938
 
1147 jermar 939
    a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
940
    if (a) {
941
        /* va is the base address of an address space area */
1380 jermar 942
        mutex_lock(&a->lock);
1147 jermar 943
        return a;
944
    }
945
 
946
    /*
1150 jermar 947
     * Search the leaf node and the righmost record of its left neighbour
1147 jermar 948
     * to find out whether this is a miss or va belongs to an address
949
     * space area found there.
950
     */
951
 
952
    /* First, search the leaf node itself. */
953
    for (i = 0; i < leaf->keys; i++) {
954
        a = (as_area_t *) leaf->value[i];
1380 jermar 955
        mutex_lock(&a->lock);
1147 jermar 956
        if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
957
            return a;
958
        }
1380 jermar 959
        mutex_unlock(&a->lock);
1147 jermar 960
    }
977 jermar 961
 
1147 jermar 962
    /*
1150 jermar 963
     * Second, locate the left neighbour and test its last record.
1148 jermar 964
     * Because of its position in the B+tree, it must have base < va.
1147 jermar 965
     */
1150 jermar 966
    if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 967
        a = (as_area_t *) lnode->value[lnode->keys - 1];
1380 jermar 968
        mutex_lock(&a->lock);
1147 jermar 969
        if (va < a->base + a->pages * PAGE_SIZE) {
1048 jermar 970
            return a;
1147 jermar 971
        }
1380 jermar 972
        mutex_unlock(&a->lock);
977 jermar 973
    }
974
 
975
    return NULL;
976
}
1048 jermar 977
 
978
/** Check area conflicts with other areas.
979
 *
980
 * The address space must be locked and interrupts must be disabled.
981
 *
982
 * @param as Address space.
983
 * @param va Starting virtual address of the area being tested.
984
 * @param size Size of the area being tested.
985
 * @param avoid_area Do not touch this area.
986
 *
987
 * @return True if there is no conflict, false otherwise.
988
 */
989
bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area)
990
{
991
    as_area_t *a;
1147 jermar 992
    btree_node_t *leaf, *node;
993
    int i;
1048 jermar 994
 
1070 jermar 995
    /*
996
     * We don't want any area to have conflicts with NULL page.
997
     */
998
    if (overlaps(va, size, NULL, PAGE_SIZE))
999
        return false;
1000
 
1147 jermar 1001
    /*
1002
     * The leaf node is found in O(log n), where n is proportional to
1003
     * the number of address space areas belonging to as.
1004
     * The check for conflicts is then attempted on the rightmost
1150 jermar 1005
     * record in the left neighbour, the leftmost record in the right
1006
     * neighbour and all records in the leaf node itself.
1147 jermar 1007
     */
1048 jermar 1008
 
1147 jermar 1009
    if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
1010
        if (a != avoid_area)
1011
            return false;
1012
    }
1013
 
1014
    /* First, check the two border cases. */
1150 jermar 1015
    if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 1016
        a = (as_area_t *) node->value[node->keys - 1];
1380 jermar 1017
        mutex_lock(&a->lock);
1147 jermar 1018
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 1019
            mutex_unlock(&a->lock);
1147 jermar 1020
            return false;
1021
        }
1380 jermar 1022
        mutex_unlock(&a->lock);
1147 jermar 1023
    }
1150 jermar 1024
    if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 1025
        a = (as_area_t *) node->value[0];
1380 jermar 1026
        mutex_lock(&a->lock);
1147 jermar 1027
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 1028
            mutex_unlock(&a->lock);
1147 jermar 1029
            return false;
1030
        }
1380 jermar 1031
        mutex_unlock(&a->lock);
1147 jermar 1032
    }
1033
 
1034
    /* Second, check the leaf node. */
1035
    for (i = 0; i < leaf->keys; i++) {
1036
        a = (as_area_t *) leaf->value[i];
1037
 
1048 jermar 1038
        if (a == avoid_area)
1039
            continue;
1147 jermar 1040
 
1380 jermar 1041
        mutex_lock(&a->lock);
1147 jermar 1042
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 1043
            mutex_unlock(&a->lock);
1147 jermar 1044
            return false;
1045
        }
1380 jermar 1046
        mutex_unlock(&a->lock);
1048 jermar 1047
    }
1048
 
1070 jermar 1049
    /*
1050
     * So far, the area does not conflict with other areas.
1051
     * Check if it doesn't conflict with kernel address space.
1052
     */  
1053
    if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
1054
        return !overlaps(va, size,
1055
            KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START);
1056
    }
1057
 
1048 jermar 1058
    return true;
1059
}
1235 jermar 1060
 
1380 jermar 1061
/** Return size of the address space area with given base.  */
1329 palkovsky 1062
size_t as_get_size(__address base)
1063
{
1064
    ipl_t ipl;
1065
    as_area_t *src_area;
1066
    size_t size;
1067
 
1068
    ipl = interrupts_disable();
1069
    src_area = find_area_and_lock(AS, base);
1070
    if (src_area){
1071
        size = src_area->pages * PAGE_SIZE;
1380 jermar 1072
        mutex_unlock(&src_area->lock);
1329 palkovsky 1073
    } else {
1074
        size = 0;
1075
    }
1076
    interrupts_restore(ipl);
1077
    return size;
1078
}
1079
 
1387 jermar 1080
/** Mark portion of address space area as used.
1081
 *
1082
 * The address space area must be already locked.
1083
 *
1084
 * @param a Address space area.
1085
 * @param page First page to be marked.
1086
 * @param count Number of page to be marked.
1087
 *
1088
 * @return 0 on failure and 1 on success.
1089
 */
1090
int used_space_insert(as_area_t *a, __address page, count_t count)
1091
{
1092
    btree_node_t *leaf, *node;
1093
    count_t pages;
1094
    int i;
1095
 
1096
    ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
1097
    ASSERT(count);
1098
 
1099
    pages = (count_t) btree_search(&a->used_space, page, &leaf);
1100
    if (pages) {
1101
        /*
1102
         * We hit the beginning of some used space.
1103
         */
1104
        return 0;
1105
    }
1106
 
1437 jermar 1107
    if (!leaf->keys) {
1108
        btree_insert(&a->used_space, page, (void *) count, leaf);
1109
        return 1;
1110
    }
1111
 
1387 jermar 1112
    node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
1113
    if (node) {
1114
        __address left_pg = node->key[node->keys - 1], right_pg = leaf->key[0];
1115
        count_t left_cnt = (count_t) node->value[node->keys - 1], right_cnt = (count_t) leaf->value[0];
1116
 
1117
        /*
1118
         * Examine the possibility that the interval fits
1119
         * somewhere between the rightmost interval of
1120
         * the left neigbour and the first interval of the leaf.
1121
         */
1122
 
1123
        if (page >= right_pg) {
1124
            /* Do nothing. */
1125
        } else if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1126
            /* The interval intersects with the left interval. */
1127
            return 0;
1128
        } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1129
            /* The interval intersects with the right interval. */
1130
            return 0;          
1131
        } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
1132
            /* The interval can be added by merging the two already present intervals. */
1403 jermar 1133
            node->value[node->keys - 1] += count + right_cnt;
1387 jermar 1134
            btree_remove(&a->used_space, right_pg, leaf);
1135
            return 1;
1136
        } else if (page == left_pg + left_cnt*PAGE_SIZE) {
1137
            /* The interval can be added by simply growing the left interval. */
1403 jermar 1138
            node->value[node->keys - 1] += count;
1387 jermar 1139
            return 1;
1140
        } else if (page + count*PAGE_SIZE == right_pg) {
1141
            /*
1142
             * The interval can be addded by simply moving base of the right
1143
             * interval down and increasing its size accordingly.
1144
             */
1403 jermar 1145
            leaf->value[0] += count;
1387 jermar 1146
            leaf->key[0] = page;
1147
            return 1;
1148
        } else {
1149
            /*
1150
             * The interval is between both neigbouring intervals,
1151
             * but cannot be merged with any of them.
1152
             */
1153
            btree_insert(&a->used_space, page, (void *) count, leaf);
1154
            return 1;
1155
        }
1156
    } else if (page < leaf->key[0]) {
1157
        __address right_pg = leaf->key[0];
1158
        count_t right_cnt = (count_t) leaf->value[0];
1159
 
1160
        /*
1161
         * Investigate the border case in which the left neighbour does not
1162
         * exist but the interval fits from the left.
1163
         */
1164
 
1165
        if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1166
            /* The interval intersects with the right interval. */
1167
            return 0;
1168
        } else if (page + count*PAGE_SIZE == right_pg) {
1169
            /*
1170
             * The interval can be added by moving the base of the right interval down
1171
             * and increasing its size accordingly.
1172
             */
1173
            leaf->key[0] = page;
1403 jermar 1174
            leaf->value[0] += count;
1387 jermar 1175
            return 1;
1176
        } else {
1177
            /*
1178
             * The interval doesn't adjoin with the right interval.
1179
             * It must be added individually.
1180
             */
1181
            btree_insert(&a->used_space, page, (void *) count, leaf);
1182
            return 1;
1183
        }
1184
    }
1185
 
1186
    node = btree_leaf_node_right_neighbour(&a->used_space, leaf);
1187
    if (node) {
1188
        __address left_pg = leaf->key[leaf->keys - 1], right_pg = node->key[0];
1189
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1], right_cnt = (count_t) node->value[0];
1190
 
1191
        /*
1192
         * Examine the possibility that the interval fits
1193
         * somewhere between the leftmost interval of
1194
         * the right neigbour and the last interval of the leaf.
1195
         */
1196
 
1197
        if (page < left_pg) {
1198
            /* Do nothing. */
1199
        } else if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1200
            /* The interval intersects with the left interval. */
1201
            return 0;
1202
        } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1203
            /* The interval intersects with the right interval. */
1204
            return 0;          
1205
        } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
1206
            /* The interval can be added by merging the two already present intervals. */
1403 jermar 1207
            leaf->value[leaf->keys - 1] += count + right_cnt;
1387 jermar 1208
            btree_remove(&a->used_space, right_pg, node);
1209
            return 1;
1210
        } else if (page == left_pg + left_cnt*PAGE_SIZE) {
1211
            /* The interval can be added by simply growing the left interval. */
1403 jermar 1212
            leaf->value[leaf->keys - 1] +=  count;
1387 jermar 1213
            return 1;
1214
        } else if (page + count*PAGE_SIZE == right_pg) {
1215
            /*
1216
             * The interval can be addded by simply moving base of the right
1217
             * interval down and increasing its size accordingly.
1218
             */
1403 jermar 1219
            node->value[0] += count;
1387 jermar 1220
            node->key[0] = page;
1221
            return 1;
1222
        } else {
1223
            /*
1224
             * The interval is between both neigbouring intervals,
1225
             * but cannot be merged with any of them.
1226
             */
1227
            btree_insert(&a->used_space, page, (void *) count, leaf);
1228
            return 1;
1229
        }
1230
    } else if (page >= leaf->key[leaf->keys - 1]) {
1231
        __address left_pg = leaf->key[leaf->keys - 1];
1232
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
1233
 
1234
        /*
1235
         * Investigate the border case in which the right neighbour does not
1236
         * exist but the interval fits from the right.
1237
         */
1238
 
1239
        if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1403 jermar 1240
            /* The interval intersects with the left interval. */
1387 jermar 1241
            return 0;
1242
        } else if (left_pg + left_cnt*PAGE_SIZE == page) {
1243
            /* The interval can be added by growing the left interval. */
1403 jermar 1244
            leaf->value[leaf->keys - 1] += count;
1387 jermar 1245
            return 1;
1246
        } else {
1247
            /*
1248
             * The interval doesn't adjoin with the left interval.
1249
             * It must be added individually.
1250
             */
1251
            btree_insert(&a->used_space, page, (void *) count, leaf);
1252
            return 1;
1253
        }
1254
    }
1255
 
1256
    /*
1257
     * Note that if the algorithm made it thus far, the interval can fit only
1258
     * between two other intervals of the leaf. The two border cases were already
1259
     * resolved.
1260
     */
1261
    for (i = 1; i < leaf->keys; i++) {
1262
        if (page < leaf->key[i]) {
1263
            __address left_pg = leaf->key[i - 1], right_pg = leaf->key[i];
1264
            count_t left_cnt = (count_t) leaf->value[i - 1], right_cnt = (count_t) leaf->value[i];
1265
 
1266
            /*
1267
             * The interval fits between left_pg and right_pg.
1268
             */
1269
 
1270
            if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1271
                /* The interval intersects with the left interval. */
1272
                return 0;
1273
            } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1274
                /* The interval intersects with the right interval. */
1275
                return 0;          
1276
            } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
1277
                /* The interval can be added by merging the two already present intervals. */
1403 jermar 1278
                leaf->value[i - 1] += count + right_cnt;
1387 jermar 1279
                btree_remove(&a->used_space, right_pg, leaf);
1280
                return 1;
1281
            } else if (page == left_pg + left_cnt*PAGE_SIZE) {
1282
                /* The interval can be added by simply growing the left interval. */
1403 jermar 1283
                leaf->value[i - 1] += count;
1387 jermar 1284
                return 1;
1285
            } else if (page + count*PAGE_SIZE == right_pg) {
1286
                /*
1287
                     * The interval can be addded by simply moving base of the right
1288
                 * interval down and increasing its size accordingly.
1289
                 */
1403 jermar 1290
                leaf->value[i] += count;
1387 jermar 1291
                leaf->key[i] = page;
1292
                return 1;
1293
            } else {
1294
                /*
1295
                 * The interval is between both neigbouring intervals,
1296
                 * but cannot be merged with any of them.
1297
                 */
1298
                btree_insert(&a->used_space, page, (void *) count, leaf);
1299
                return 1;
1300
            }
1301
        }
1302
    }
1303
 
1304
    panic("Inconsistency detected while adding %d pages of used space at %P.\n", count, page);
1305
}
1306
 
1307
/** Mark portion of address space area as unused.
1308
 *
1309
 * The address space area must be already locked.
1310
 *
1311
 * @param a Address space area.
1312
 * @param page First page to be marked.
1313
 * @param count Number of page to be marked.
1314
 *
1315
 * @return 0 on failure and 1 on success.
1316
 */
1317
int used_space_remove(as_area_t *a, __address page, count_t count)
1318
{
1319
    btree_node_t *leaf, *node;
1320
    count_t pages;
1321
    int i;
1322
 
1323
    ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
1324
    ASSERT(count);
1325
 
1326
    pages = (count_t) btree_search(&a->used_space, page, &leaf);
1327
    if (pages) {
1328
        /*
1329
         * We are lucky, page is the beginning of some interval.
1330
         */
1331
        if (count > pages) {
1332
            return 0;
1333
        } else if (count == pages) {
1334
            btree_remove(&a->used_space, page, leaf);
1403 jermar 1335
            return 1;
1387 jermar 1336
        } else {
1337
            /*
1338
             * Find the respective interval.
1339
             * Decrease its size and relocate its start address.
1340
             */
1341
            for (i = 0; i < leaf->keys; i++) {
1342
                if (leaf->key[i] == page) {
1343
                    leaf->key[i] += count*PAGE_SIZE;
1403 jermar 1344
                    leaf->value[i] -= count;
1387 jermar 1345
                    return 1;
1346
                }
1347
            }
1348
            goto error;
1349
        }
1350
    }
1351
 
1352
    node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
1353
    if (node && page < leaf->key[0]) {
1354
        __address left_pg = node->key[node->keys - 1];
1355
        count_t left_cnt = (count_t) node->value[node->keys - 1];
1356
 
1357
        if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
1358
            if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
1359
                /*
1360
                 * The interval is contained in the rightmost interval
1361
                 * of the left neighbour and can be removed by
1362
                 * updating the size of the bigger interval.
1363
                 */
1403 jermar 1364
                node->value[node->keys - 1] -= count;
1387 jermar 1365
                return 1;
1366
            } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
1403 jermar 1367
                count_t new_cnt;
1387 jermar 1368
 
1369
                /*
1370
                 * The interval is contained in the rightmost interval
1371
                 * of the left neighbour but its removal requires
1372
                 * both updating the size of the original interval and
1373
                 * also inserting a new interval.
1374
                 */
1403 jermar 1375
                new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1376
                node->value[node->keys - 1] -= count + new_cnt;
1387 jermar 1377
                btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
1378
                return 1;
1379
            }
1380
        }
1381
        return 0;
1382
    } else if (page < leaf->key[0]) {
1383
        return 0;
1384
    }
1385
 
1386
    if (page > leaf->key[leaf->keys - 1]) {
1387
        __address left_pg = leaf->key[leaf->keys - 1];
1388
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
1389
 
1390
        if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
1391
            if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
1392
                /*
1393
                 * The interval is contained in the rightmost interval
1394
                 * of the leaf and can be removed by updating the size
1395
                 * of the bigger interval.
1396
                 */
1403 jermar 1397
                leaf->value[leaf->keys - 1] -= count;
1387 jermar 1398
                return 1;
1399
            } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
1403 jermar 1400
                count_t new_cnt;
1387 jermar 1401
 
1402
                /*
1403
                 * The interval is contained in the rightmost interval
1404
                 * of the leaf but its removal requires both updating
1405
                 * the size of the original interval and
1406
                 * also inserting a new interval.
1407
                 */
1403 jermar 1408
                new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1409
                leaf->value[leaf->keys - 1] -= count + new_cnt;
1387 jermar 1410
                btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
1411
                return 1;
1412
            }
1413
        }
1414
        return 0;
1415
    }  
1416
 
1417
    /*
1418
     * The border cases have been already resolved.
1419
     * Now the interval can be only between intervals of the leaf.
1420
     */
1421
    for (i = 1; i < leaf->keys - 1; i++) {
1422
        if (page < leaf->key[i]) {
1423
            __address left_pg = leaf->key[i - 1];
1424
            count_t left_cnt = (count_t) leaf->value[i - 1];
1425
 
1426
            /*
1427
             * Now the interval is between intervals corresponding to (i - 1) and i.
1428
             */
1429
            if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
1430
                if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
1431
                    /*
1432
                    * The interval is contained in the interval (i - 1)
1433
                     * of the leaf and can be removed by updating the size
1434
                     * of the bigger interval.
1435
                     */
1403 jermar 1436
                    leaf->value[i - 1] -= count;
1387 jermar 1437
                    return 1;
1438
                } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
1403 jermar 1439
                    count_t new_cnt;
1387 jermar 1440
 
1441
                    /*
1442
                     * The interval is contained in the interval (i - 1)
1443
                     * of the leaf but its removal requires both updating
1444
                     * the size of the original interval and
1445
                     * also inserting a new interval.
1446
                     */
1403 jermar 1447
                    new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1448
                    leaf->value[i - 1] -= count + new_cnt;
1387 jermar 1449
                    btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
1450
                    return 1;
1451
                }
1452
            }
1453
            return 0;
1454
        }
1455
    }
1456
 
1457
error:
1458
    panic("Inconsistency detected while removing %d pages of used space from %P.\n", count, page);
1459
}
1460
 
1409 jermar 1461
/** Remove reference to address space area share info.
1462
 *
1463
 * If the reference count drops to 0, the sh_info is deallocated.
1464
 *
1465
 * @param sh_info Pointer to address space area share info.
1466
 */
1467
void sh_info_remove_reference(share_info_t *sh_info)
1468
{
1469
    bool dealloc = false;
1470
 
1471
    mutex_lock(&sh_info->lock);
1472
    ASSERT(sh_info->refcount);
1473
    if (--sh_info->refcount == 0) {
1474
        dealloc = true;
1495 jermar 1475
        link_t *cur;
1409 jermar 1476
 
1477
        /*
1478
         * Now walk carefully the pagemap B+tree and free/remove
1479
         * reference from all frames found there.
1480
         */
1495 jermar 1481
        for (cur = sh_info->pagemap.leaf_head.next; cur != &sh_info->pagemap.leaf_head; cur = cur->next) {
1409 jermar 1482
            btree_node_t *node;
1495 jermar 1483
            int i;
1409 jermar 1484
 
1495 jermar 1485
            node = list_get_instance(cur, btree_node_t, leaf_link);
1486
            for (i = 0; i < node->keys; i++)
1487
                frame_free(ADDR2PFN((__address) node->value[i]));
1409 jermar 1488
        }
1489
 
1490
    }
1491
    mutex_unlock(&sh_info->lock);
1492
 
1493
    if (dealloc) {
1494
        btree_destroy(&sh_info->pagemap);
1495
        free(sh_info);
1496
    }
1497
}
1498
 
1235 jermar 1499
/*
1500
 * Address space related syscalls.
1501
 */
1502
 
1503
/** Wrapper for as_area_create(). */
1504
__native sys_as_area_create(__address address, size_t size, int flags)
1505
{
1424 jermar 1506
    if (as_area_create(AS, flags | AS_AREA_CACHEABLE, size, address, AS_AREA_ATTR_NONE, &anon_backend, NULL))
1235 jermar 1507
        return (__native) address;
1508
    else
1509
        return (__native) -1;
1510
}
1511
 
1512
/** Wrapper for as_area_resize. */
1513
__native sys_as_area_resize(__address address, size_t size, int flags)
1514
{
1306 jermar 1515
    return (__native) as_area_resize(AS, address, size, 0);
1235 jermar 1516
}
1517
 
1306 jermar 1518
/** Wrapper for as_area_destroy. */
1519
__native sys_as_area_destroy(__address address)
1520
{
1521
    return (__native) as_area_destroy(AS, address);
1522
}