Subversion Repositories HelenOS-historic

Rev

Rev 1757 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
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
 
1757 jermar 29
/** @addtogroup genericmm
1702 cejka 30
 * @{
31
 */
32
 
1248 jermar 33
/**
1702 cejka 34
 * @file
1248 jermar 35
 * @brief   Address space related functions.
36
 *
703 jermar 37
 * This file contains address space manipulation functions.
38
 * Roughly speaking, this is a higher-level client of
39
 * Virtual Address Translation (VAT) subsystem.
1248 jermar 40
 *
41
 * Functionality provided by this file allows one to
1757 jermar 42
 * create address spaces and create, resize and share
1248 jermar 43
 * address space areas.
44
 *
45
 * @see page.c
46
 *
703 jermar 47
 */
48
 
49
#include <mm/as.h>
756 jermar 50
#include <arch/mm/as.h>
703 jermar 51
#include <mm/page.h>
52
#include <mm/frame.h>
814 palkovsky 53
#include <mm/slab.h>
703 jermar 54
#include <mm/tlb.h>
55
#include <arch/mm/page.h>
56
#include <genarch/mm/page_pt.h>
1108 jermar 57
#include <genarch/mm/page_ht.h>
727 jermar 58
#include <mm/asid.h>
703 jermar 59
#include <arch/mm/asid.h>
60
#include <synch/spinlock.h>
1380 jermar 61
#include <synch/mutex.h>
788 jermar 62
#include <adt/list.h>
1147 jermar 63
#include <adt/btree.h>
1235 jermar 64
#include <proc/task.h>
1288 jermar 65
#include <proc/thread.h>
1235 jermar 66
#include <arch/asm.h>
703 jermar 67
#include <panic.h>
68
#include <debug.h>
1235 jermar 69
#include <print.h>
703 jermar 70
#include <memstr.h>
1070 jermar 71
#include <macros.h>
703 jermar 72
#include <arch.h>
1235 jermar 73
#include <errno.h>
74
#include <config.h>
1387 jermar 75
#include <align.h>
1235 jermar 76
#include <arch/types.h>
77
#include <typedefs.h>
1288 jermar 78
#include <syscall/copy.h>
79
#include <arch/interrupt.h>
703 jermar 80
 
1757 jermar 81
/**
82
 * Each architecture decides what functions will be used to carry out
83
 * address space operations such as creating or locking page tables.
84
 */
756 jermar 85
as_operations_t *as_operations = NULL;
703 jermar 86
 
1415 jermar 87
/** This lock protects inactive_as_with_asid_head list. It must be acquired before as_t mutex. */
88
SPINLOCK_INITIALIZE(inactive_as_with_asid_lock);
823 jermar 89
 
90
/**
91
 * This list contains address spaces that are not active on any
92
 * processor and that have valid ASID.
93
 */
94
LIST_INITIALIZE(inactive_as_with_asid_head);
95
 
757 jermar 96
/** Kernel address space. */
97
as_t *AS_KERNEL = NULL;
98
 
1235 jermar 99
static int area_flags_to_page_flags(int aflags);
977 jermar 100
static as_area_t *find_area_and_lock(as_t *as, __address va);
1048 jermar 101
static bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area);
1409 jermar 102
static void sh_info_remove_reference(share_info_t *sh_info);
703 jermar 103
 
756 jermar 104
/** Initialize address space subsystem. */
105
void as_init(void)
106
{
107
    as_arch_init();
789 palkovsky 108
    AS_KERNEL = as_create(FLAG_AS_KERNEL);
1383 decky 109
    if (!AS_KERNEL)
110
        panic("can't create kernel address space\n");
111
 
756 jermar 112
}
113
 
757 jermar 114
/** Create address space.
115
 *
116
 * @param flags Flags that influence way in wich the address space is created.
117
 */
756 jermar 118
as_t *as_create(int flags)
703 jermar 119
{
120
    as_t *as;
121
 
822 palkovsky 122
    as = (as_t *) malloc(sizeof(as_t), 0);
823 jermar 123
    link_initialize(&as->inactive_as_with_asid_link);
1380 jermar 124
    mutex_initialize(&as->lock);
1147 jermar 125
    btree_create(&as->as_area_btree);
822 palkovsky 126
 
127
    if (flags & FLAG_AS_KERNEL)
128
        as->asid = ASID_KERNEL;
129
    else
130
        as->asid = ASID_INVALID;
131
 
1468 jermar 132
    as->refcount = 0;
1415 jermar 133
    as->cpu_refcount = 0;
822 palkovsky 134
    as->page_table = page_table_create(flags);
703 jermar 135
 
136
    return as;
137
}
138
 
1468 jermar 139
/** Destroy adress space.
140
 *
141
 * When there are no tasks referencing this address space (i.e. its refcount is zero),
142
 * the address space can be destroyed.
143
 */
144
void as_destroy(as_t *as)
973 palkovsky 145
{
1468 jermar 146
    ipl_t ipl;
1594 jermar 147
    bool cond;
973 palkovsky 148
 
1468 jermar 149
    ASSERT(as->refcount == 0);
150
 
151
    /*
152
     * Since there is no reference to this area,
153
     * it is safe not to lock its mutex.
154
     */
155
    ipl = interrupts_disable();
156
    spinlock_lock(&inactive_as_with_asid_lock);
1587 jermar 157
    if (as->asid != ASID_INVALID && as != AS_KERNEL) {
1594 jermar 158
        if (as != AS && as->cpu_refcount == 0)
1587 jermar 159
            list_remove(&as->inactive_as_with_asid_link);
1468 jermar 160
        asid_put(as->asid);
161
    }
162
    spinlock_unlock(&inactive_as_with_asid_lock);
163
 
164
    /*
165
     * Destroy address space areas of the address space.
1594 jermar 166
     * The B+tee must be walked carefully because it is
167
     * also being destroyed.
1468 jermar 168
     */
1594 jermar 169
    for (cond = true; cond; ) {
1468 jermar 170
        btree_node_t *node;
1594 jermar 171
 
172
        ASSERT(!list_empty(&as->as_area_btree.leaf_head));
173
        node = list_get_instance(as->as_area_btree.leaf_head.next, btree_node_t, leaf_link);
174
 
175
        if ((cond = node->keys)) {
176
            as_area_destroy(as, node->key[0]);
177
        }
1468 jermar 178
    }
1495 jermar 179
 
1483 jermar 180
    btree_destroy(&as->as_area_btree);
1468 jermar 181
    page_table_destroy(as->page_table);
182
 
183
    interrupts_restore(ipl);
184
 
973 palkovsky 185
    free(as);
186
}
187
 
703 jermar 188
/** Create address space area of common attributes.
189
 *
190
 * The created address space area is added to the target address space.
191
 *
192
 * @param as Target address space.
1239 jermar 193
 * @param flags Flags of the area memory.
1048 jermar 194
 * @param size Size of area.
703 jermar 195
 * @param base Base address of area.
1239 jermar 196
 * @param attrs Attributes of the area.
1409 jermar 197
 * @param backend Address space area backend. NULL if no backend is used.
198
 * @param backend_data NULL or a pointer to an array holding two void *.
703 jermar 199
 *
200
 * @return Address space area on success or NULL on failure.
201
 */
1409 jermar 202
as_area_t *as_area_create(as_t *as, int flags, size_t size, __address base, int attrs,
1424 jermar 203
           mem_backend_t *backend, mem_backend_data_t *backend_data)
703 jermar 204
{
205
    ipl_t ipl;
206
    as_area_t *a;
207
 
208
    if (base % PAGE_SIZE)
1048 jermar 209
        return NULL;
210
 
1233 jermar 211
    if (!size)
212
        return NULL;
213
 
1048 jermar 214
    /* Writeable executable areas are not supported. */
215
    if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
216
        return NULL;
703 jermar 217
 
218
    ipl = interrupts_disable();
1380 jermar 219
    mutex_lock(&as->lock);
703 jermar 220
 
1048 jermar 221
    if (!check_area_conflicts(as, base, size, NULL)) {
1380 jermar 222
        mutex_unlock(&as->lock);
1048 jermar 223
        interrupts_restore(ipl);
224
        return NULL;
225
    }
703 jermar 226
 
822 palkovsky 227
    a = (as_area_t *) malloc(sizeof(as_area_t), 0);
703 jermar 228
 
1380 jermar 229
    mutex_initialize(&a->lock);
822 palkovsky 230
 
1424 jermar 231
    a->as = as;
1026 jermar 232
    a->flags = flags;
1239 jermar 233
    a->attributes = attrs;
1048 jermar 234
    a->pages = SIZE2FRAMES(size);
822 palkovsky 235
    a->base = base;
1409 jermar 236
    a->sh_info = NULL;
237
    a->backend = backend;
1424 jermar 238
    if (backend_data)
239
        a->backend_data = *backend_data;
240
    else
241
        memsetb((__address) &a->backend_data, sizeof(a->backend_data), 0);
242
 
1387 jermar 243
    btree_create(&a->used_space);
822 palkovsky 244
 
1147 jermar 245
    btree_insert(&as->as_area_btree, base, (void *) a, NULL);
822 palkovsky 246
 
1380 jermar 247
    mutex_unlock(&as->lock);
703 jermar 248
    interrupts_restore(ipl);
704 jermar 249
 
703 jermar 250
    return a;
251
}
252
 
1235 jermar 253
/** Find address space area and change it.
254
 *
255
 * @param as Address space.
256
 * @param address Virtual address belonging to the area to be changed. Must be page-aligned.
257
 * @param size New size of the virtual memory block starting at address.
258
 * @param flags Flags influencing the remap operation. Currently unused.
259
 *
1306 jermar 260
 * @return Zero on success or a value from @ref errno.h otherwise.
1235 jermar 261
 */
1306 jermar 262
int as_area_resize(as_t *as, __address address, size_t size, int flags)
1235 jermar 263
{
1306 jermar 264
    as_area_t *area;
1235 jermar 265
    ipl_t ipl;
266
    size_t pages;
267
 
268
    ipl = interrupts_disable();
1380 jermar 269
    mutex_lock(&as->lock);
1235 jermar 270
 
271
    /*
272
     * Locate the area.
273
     */
274
    area = find_area_and_lock(as, address);
275
    if (!area) {
1380 jermar 276
        mutex_unlock(&as->lock);
1235 jermar 277
        interrupts_restore(ipl);
1306 jermar 278
        return ENOENT;
1235 jermar 279
    }
280
 
1424 jermar 281
    if (area->backend == &phys_backend) {
1235 jermar 282
        /*
283
         * Remapping of address space areas associated
284
         * with memory mapped devices is not supported.
285
         */
1380 jermar 286
        mutex_unlock(&area->lock);
287
        mutex_unlock(&as->lock);
1235 jermar 288
        interrupts_restore(ipl);
1306 jermar 289
        return ENOTSUP;
1235 jermar 290
    }
1409 jermar 291
    if (area->sh_info) {
292
        /*
293
         * Remapping of shared address space areas
294
         * is not supported.
295
         */
296
        mutex_unlock(&area->lock);
297
        mutex_unlock(&as->lock);
298
        interrupts_restore(ipl);
299
        return ENOTSUP;
300
    }
1235 jermar 301
 
302
    pages = SIZE2FRAMES((address - area->base) + size);
303
    if (!pages) {
304
        /*
305
         * Zero size address space areas are not allowed.
306
         */
1380 jermar 307
        mutex_unlock(&area->lock);
308
        mutex_unlock(&as->lock);
1235 jermar 309
        interrupts_restore(ipl);
1306 jermar 310
        return EPERM;
1235 jermar 311
    }
312
 
313
    if (pages < area->pages) {
1403 jermar 314
        bool cond;
315
        __address start_free = area->base + pages*PAGE_SIZE;
1235 jermar 316
 
317
        /*
318
         * Shrinking the area.
319
         * No need to check for overlaps.
320
         */
1403 jermar 321
 
322
        /*
1436 jermar 323
         * Start TLB shootdown sequence.
324
         */
325
        tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
326
 
327
        /*
1403 jermar 328
         * Remove frames belonging to used space starting from
329
         * the highest addresses downwards until an overlap with
330
         * the resized address space area is found. Note that this
331
         * is also the right way to remove part of the used_space
332
         * B+tree leaf list.
333
         */    
334
        for (cond = true; cond;) {
335
            btree_node_t *node;
336
 
337
            ASSERT(!list_empty(&area->used_space.leaf_head));
338
            node = list_get_instance(area->used_space.leaf_head.prev, btree_node_t, leaf_link);
339
            if ((cond = (bool) node->keys)) {
340
                __address b = node->key[node->keys - 1];
341
                count_t c = (count_t) node->value[node->keys - 1];
342
                int i = 0;
1235 jermar 343
 
1403 jermar 344
                if (overlaps(b, c*PAGE_SIZE, area->base, pages*PAGE_SIZE)) {
345
 
346
                    if (b + c*PAGE_SIZE <= start_free) {
347
                        /*
348
                         * The whole interval fits completely
349
                         * in the resized address space area.
350
                         */
351
                        break;
352
                    }
353
 
354
                    /*
355
                     * Part of the interval corresponding to b and c
356
                     * overlaps with the resized address space area.
357
                     */
358
 
359
                    cond = false;   /* we are almost done */
360
                    i = (start_free - b) >> PAGE_WIDTH;
361
                    if (!used_space_remove(area, start_free, c - i))
362
                        panic("Could not remove used space.");
363
                } else {
364
                    /*
365
                     * The interval of used space can be completely removed.
366
                     */
367
                    if (!used_space_remove(area, b, c))
368
                        panic("Could not remove used space.\n");
369
                }
370
 
371
                for (; i < c; i++) {
372
                    pte_t *pte;
373
 
374
                    page_table_lock(as, false);
375
                    pte = page_mapping_find(as, b + i*PAGE_SIZE);
376
                    ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424 jermar 377
                    if (area->backend && area->backend->frame_free) {
378
                        area->backend->frame_free(area,
1409 jermar 379
                            b + i*PAGE_SIZE, PTE_GET_FRAME(pte));
380
                    }
1403 jermar 381
                    page_mapping_remove(as, b + i*PAGE_SIZE);
382
                    page_table_unlock(as, false);
383
                }
1235 jermar 384
            }
385
        }
1436 jermar 386
 
1235 jermar 387
        /*
1436 jermar 388
         * Finish TLB shootdown sequence.
1235 jermar 389
         */
390
        tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
391
        tlb_shootdown_finalize();
392
    } else {
393
        /*
394
         * Growing the area.
395
         * Check for overlaps with other address space areas.
396
         */
397
        if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
1380 jermar 398
            mutex_unlock(&area->lock);
399
            mutex_unlock(&as->lock);       
1235 jermar 400
            interrupts_restore(ipl);
1306 jermar 401
            return EADDRNOTAVAIL;
1235 jermar 402
        }
403
    }
404
 
405
    area->pages = pages;
406
 
1380 jermar 407
    mutex_unlock(&area->lock);
408
    mutex_unlock(&as->lock);
1235 jermar 409
    interrupts_restore(ipl);
410
 
1306 jermar 411
    return 0;
1235 jermar 412
}
413
 
1306 jermar 414
/** Destroy address space area.
415
 *
416
 * @param as Address space.
417
 * @param address Address withing the area to be deleted.
418
 *
419
 * @return Zero on success or a value from @ref errno.h on failure.
420
 */
421
int as_area_destroy(as_t *as, __address address)
422
{
423
    as_area_t *area;
424
    __address base;
1495 jermar 425
    link_t *cur;
1306 jermar 426
    ipl_t ipl;
427
 
428
    ipl = interrupts_disable();
1380 jermar 429
    mutex_lock(&as->lock);
1306 jermar 430
 
431
    area = find_area_and_lock(as, address);
432
    if (!area) {
1380 jermar 433
        mutex_unlock(&as->lock);
1306 jermar 434
        interrupts_restore(ipl);
435
        return ENOENT;
436
    }
437
 
1403 jermar 438
    base = area->base;
439
 
1411 jermar 440
    /*
1436 jermar 441
     * Start TLB shootdown sequence.
442
     */
443
    tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages);
444
 
445
    /*
1411 jermar 446
     * Visit only the pages mapped by used_space B+tree.
447
     */
1495 jermar 448
    for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) {
1411 jermar 449
        btree_node_t *node;
1495 jermar 450
        int i;
1403 jermar 451
 
1495 jermar 452
        node = list_get_instance(cur, btree_node_t, leaf_link);
453
        for (i = 0; i < node->keys; i++) {
454
            __address b = node->key[i];
455
            count_t j;
1411 jermar 456
            pte_t *pte;
1403 jermar 457
 
1495 jermar 458
            for (j = 0; j < (count_t) node->value[i]; j++) {
1411 jermar 459
                page_table_lock(as, false);
1495 jermar 460
                pte = page_mapping_find(as, b + j*PAGE_SIZE);
1411 jermar 461
                ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
1424 jermar 462
                if (area->backend && area->backend->frame_free) {
463
                    area->backend->frame_free(area,
1495 jermar 464
                        b + j*PAGE_SIZE, PTE_GET_FRAME(pte));
1403 jermar 465
                }
1495 jermar 466
                page_mapping_remove(as, b + j*PAGE_SIZE);
1411 jermar 467
                page_table_unlock(as, false);
1306 jermar 468
            }
469
        }
470
    }
1403 jermar 471
 
1306 jermar 472
    /*
1436 jermar 473
     * Finish TLB shootdown sequence.
1306 jermar 474
     */
475
    tlb_invalidate_pages(AS->asid, area->base, area->pages);
476
    tlb_shootdown_finalize();
1436 jermar 477
 
478
    btree_destroy(&area->used_space);
1306 jermar 479
 
1309 jermar 480
    area->attributes |= AS_AREA_ATTR_PARTIAL;
1409 jermar 481
 
482
    if (area->sh_info)
483
        sh_info_remove_reference(area->sh_info);
484
 
1380 jermar 485
    mutex_unlock(&area->lock);
1306 jermar 486
 
487
    /*
488
     * Remove the empty area from address space.
489
     */
490
    btree_remove(&AS->as_area_btree, base, NULL);
491
 
1309 jermar 492
    free(area);
493
 
1380 jermar 494
    mutex_unlock(&AS->lock);
1306 jermar 495
    interrupts_restore(ipl);
496
    return 0;
497
}
498
 
1413 jermar 499
/** Share address space area with another or the same address space.
1235 jermar 500
 *
1424 jermar 501
 * Address space area mapping is shared with a new address space area.
502
 * If the source address space area has not been shared so far,
503
 * a new sh_info is created. The new address space area simply gets the
504
 * sh_info of the source area. The process of duplicating the
505
 * mapping is done through the backend share function.
1413 jermar 506
 *
1417 jermar 507
 * @param src_as Pointer to source address space.
1239 jermar 508
 * @param src_base Base address of the source address space area.
1417 jermar 509
 * @param acc_size Expected size of the source area.
1428 palkovsky 510
 * @param dst_as Pointer to destination address space.
1417 jermar 511
 * @param dst_base Target base address.
512
 * @param dst_flags_mask Destination address space area flags mask.
1235 jermar 513
 *
1306 jermar 514
 * @return Zero on success or ENOENT if there is no such task or
1235 jermar 515
 *     if there is no such address space area,
516
 *     EPERM if there was a problem in accepting the area or
517
 *     ENOMEM if there was a problem in allocating destination
1413 jermar 518
 *     address space area. ENOTSUP is returned if an attempt
519
 *     to share non-anonymous address space area is detected.
1235 jermar 520
 */
1413 jermar 521
int as_area_share(as_t *src_as, __address src_base, size_t acc_size,
1428 palkovsky 522
          as_t *dst_as, __address dst_base, int dst_flags_mask)
1235 jermar 523
{
524
    ipl_t ipl;
1239 jermar 525
    int src_flags;
526
    size_t src_size;
527
    as_area_t *src_area, *dst_area;
1413 jermar 528
    share_info_t *sh_info;
1424 jermar 529
    mem_backend_t *src_backend;
530
    mem_backend_data_t src_backend_data;
1434 palkovsky 531
 
1235 jermar 532
    ipl = interrupts_disable();
1380 jermar 533
    mutex_lock(&src_as->lock);
1329 palkovsky 534
    src_area = find_area_and_lock(src_as, src_base);
1239 jermar 535
    if (!src_area) {
1238 jermar 536
        /*
537
         * Could not find the source address space area.
538
         */
1380 jermar 539
        mutex_unlock(&src_as->lock);
1238 jermar 540
        interrupts_restore(ipl);
541
        return ENOENT;
542
    }
1413 jermar 543
 
1424 jermar 544
    if (!src_area->backend || !src_area->backend->share) {
1413 jermar 545
        /*
1424 jermar 546
         * There is now backend or the backend does not
547
         * know how to share the area.
1413 jermar 548
         */
549
        mutex_unlock(&src_area->lock);
550
        mutex_unlock(&src_as->lock);
551
        interrupts_restore(ipl);
552
        return ENOTSUP;
553
    }
554
 
1239 jermar 555
    src_size = src_area->pages * PAGE_SIZE;
556
    src_flags = src_area->flags;
1424 jermar 557
    src_backend = src_area->backend;
558
    src_backend_data = src_area->backend_data;
1544 palkovsky 559
 
560
    /* Share the cacheable flag from the original mapping */
561
    if (src_flags & AS_AREA_CACHEABLE)
562
        dst_flags_mask |= AS_AREA_CACHEABLE;
563
 
1461 palkovsky 564
    if (src_size != acc_size || (src_flags & dst_flags_mask) != dst_flags_mask) {
1413 jermar 565
        mutex_unlock(&src_area->lock);
566
        mutex_unlock(&src_as->lock);
1235 jermar 567
        interrupts_restore(ipl);
568
        return EPERM;
569
    }
1413 jermar 570
 
1235 jermar 571
    /*
1413 jermar 572
     * Now we are committed to sharing the area.
573
     * First prepare the area for sharing.
574
     * Then it will be safe to unlock it.
575
     */
576
    sh_info = src_area->sh_info;
577
    if (!sh_info) {
578
        sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0);
579
        mutex_initialize(&sh_info->lock);
580
        sh_info->refcount = 2;
581
        btree_create(&sh_info->pagemap);
582
        src_area->sh_info = sh_info;
583
    } else {
584
        mutex_lock(&sh_info->lock);
585
        sh_info->refcount++;
586
        mutex_unlock(&sh_info->lock);
587
    }
588
 
1424 jermar 589
    src_area->backend->share(src_area);
1413 jermar 590
 
591
    mutex_unlock(&src_area->lock);
592
    mutex_unlock(&src_as->lock);
593
 
594
    /*
1239 jermar 595
     * Create copy of the source address space area.
596
     * The destination area is created with AS_AREA_ATTR_PARTIAL
597
     * attribute set which prevents race condition with
598
     * preliminary as_page_fault() calls.
1417 jermar 599
     * The flags of the source area are masked against dst_flags_mask
600
     * to support sharing in less privileged mode.
1235 jermar 601
     */
1461 palkovsky 602
    dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base,
1424 jermar 603
                  AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data);
1239 jermar 604
    if (!dst_area) {
1235 jermar 605
        /*
606
         * Destination address space area could not be created.
607
         */
1413 jermar 608
        sh_info_remove_reference(sh_info);
609
 
1235 jermar 610
        interrupts_restore(ipl);
611
        return ENOMEM;
612
    }
613
 
614
    /*
1239 jermar 615
     * Now the destination address space area has been
616
     * fully initialized. Clear the AS_AREA_ATTR_PARTIAL
1413 jermar 617
     * attribute and set the sh_info.
1239 jermar 618
     */
1380 jermar 619
    mutex_lock(&dst_area->lock);
1239 jermar 620
    dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
1413 jermar 621
    dst_area->sh_info = sh_info;
1380 jermar 622
    mutex_unlock(&dst_area->lock);
1235 jermar 623
 
624
    interrupts_restore(ipl);
625
 
626
    return 0;
627
}
628
 
1423 jermar 629
/** Check access mode for address space area.
630
 *
631
 * The address space area must be locked prior to this call.
632
 *
633
 * @param area Address space area.
634
 * @param access Access mode.
635
 *
636
 * @return False if access violates area's permissions, true otherwise.
637
 */
638
bool as_area_check_access(as_area_t *area, pf_access_t access)
639
{
640
    int flagmap[] = {
641
        [PF_ACCESS_READ] = AS_AREA_READ,
642
        [PF_ACCESS_WRITE] = AS_AREA_WRITE,
643
        [PF_ACCESS_EXEC] = AS_AREA_EXEC
644
    };
645
 
646
    if (!(area->flags & flagmap[access]))
647
        return false;
648
 
649
    return true;
650
}
651
 
703 jermar 652
/** Handle page fault within the current address space.
653
 *
1409 jermar 654
 * This is the high-level page fault handler. It decides
655
 * whether the page fault can be resolved by any backend
656
 * and if so, it invokes the backend to resolve the page
657
 * fault.
658
 *
703 jermar 659
 * Interrupts are assumed disabled.
660
 *
661
 * @param page Faulting page.
1411 jermar 662
 * @param access Access mode that caused the fault (i.e. read/write/exec).
1288 jermar 663
 * @param istate Pointer to interrupted state.
703 jermar 664
 *
1409 jermar 665
 * @return AS_PF_FAULT on page fault, AS_PF_OK on success or AS_PF_DEFER if the
666
 *     fault was caused by copy_to_uspace() or copy_from_uspace().
703 jermar 667
 */
1411 jermar 668
int as_page_fault(__address page, pf_access_t access, istate_t *istate)
703 jermar 669
{
1044 jermar 670
    pte_t *pte;
977 jermar 671
    as_area_t *area;
703 jermar 672
 
1380 jermar 673
    if (!THREAD)
1409 jermar 674
        return AS_PF_FAULT;
1380 jermar 675
 
703 jermar 676
    ASSERT(AS);
1044 jermar 677
 
1380 jermar 678
    mutex_lock(&AS->lock);
977 jermar 679
    area = find_area_and_lock(AS, page);   
703 jermar 680
    if (!area) {
681
        /*
682
         * No area contained mapping for 'page'.
683
         * Signal page fault to low-level handler.
684
         */
1380 jermar 685
        mutex_unlock(&AS->lock);
1288 jermar 686
        goto page_fault;
703 jermar 687
    }
688
 
1239 jermar 689
    if (area->attributes & AS_AREA_ATTR_PARTIAL) {
690
        /*
691
         * The address space area is not fully initialized.
692
         * Avoid possible race by returning error.
693
         */
1380 jermar 694
        mutex_unlock(&area->lock);
695
        mutex_unlock(&AS->lock);
1288 jermar 696
        goto page_fault;       
1239 jermar 697
    }
698
 
1424 jermar 699
    if (!area->backend || !area->backend->page_fault) {
1409 jermar 700
        /*
701
         * The address space area is not backed by any backend
702
         * or the backend cannot handle page faults.
703
         */
704
        mutex_unlock(&area->lock);
705
        mutex_unlock(&AS->lock);
706
        goto page_fault;       
707
    }
1179 jermar 708
 
1044 jermar 709
    page_table_lock(AS, false);
710
 
703 jermar 711
    /*
1044 jermar 712
     * To avoid race condition between two page faults
713
     * on the same address, we need to make sure
714
     * the mapping has not been already inserted.
715
     */
716
    if ((pte = page_mapping_find(AS, page))) {
717
        if (PTE_PRESENT(pte)) {
1423 jermar 718
            if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) ||
719
                (access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) ||
720
                (access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) {
721
                page_table_unlock(AS, false);
722
                mutex_unlock(&area->lock);
723
                mutex_unlock(&AS->lock);
724
                return AS_PF_OK;
725
            }
1044 jermar 726
        }
727
    }
1409 jermar 728
 
1044 jermar 729
    /*
1409 jermar 730
     * Resort to the backend page fault handler.
703 jermar 731
     */
1424 jermar 732
    if (area->backend->page_fault(area, page, access) != AS_PF_OK) {
1409 jermar 733
        page_table_unlock(AS, false);
734
        mutex_unlock(&area->lock);
735
        mutex_unlock(&AS->lock);
736
        goto page_fault;
737
    }
703 jermar 738
 
1044 jermar 739
    page_table_unlock(AS, false);
1380 jermar 740
    mutex_unlock(&area->lock);
741
    mutex_unlock(&AS->lock);
1288 jermar 742
    return AS_PF_OK;
743
 
744
page_fault:
745
    if (THREAD->in_copy_from_uspace) {
746
        THREAD->in_copy_from_uspace = false;
747
        istate_set_retaddr(istate, (__address) &memcpy_from_uspace_failover_address);
748
    } else if (THREAD->in_copy_to_uspace) {
749
        THREAD->in_copy_to_uspace = false;
750
        istate_set_retaddr(istate, (__address) &memcpy_to_uspace_failover_address);
751
    } else {
752
        return AS_PF_FAULT;
753
    }
754
 
755
    return AS_PF_DEFER;
703 jermar 756
}
757
 
823 jermar 758
/** Switch address spaces.
703 jermar 759
 *
1380 jermar 760
 * Note that this function cannot sleep as it is essentially a part of
1415 jermar 761
 * scheduling. Sleeping here would lead to deadlock on wakeup.
1380 jermar 762
 *
823 jermar 763
 * @param old Old address space or NULL.
764
 * @param new New address space.
703 jermar 765
 */
823 jermar 766
void as_switch(as_t *old, as_t *new)
703 jermar 767
{
768
    ipl_t ipl;
823 jermar 769
    bool needs_asid = false;
703 jermar 770
 
771
    ipl = interrupts_disable();
1415 jermar 772
    spinlock_lock(&inactive_as_with_asid_lock);
703 jermar 773
 
774
    /*
823 jermar 775
     * First, take care of the old address space.
776
     */
777
    if (old) {
1380 jermar 778
        mutex_lock_active(&old->lock);
1415 jermar 779
        ASSERT(old->cpu_refcount);
780
        if((--old->cpu_refcount == 0) && (old != AS_KERNEL)) {
823 jermar 781
            /*
782
             * The old address space is no longer active on
783
             * any processor. It can be appended to the
784
             * list of inactive address spaces with assigned
785
             * ASID.
786
             */
787
             ASSERT(old->asid != ASID_INVALID);
788
             list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head);
789
        }
1380 jermar 790
        mutex_unlock(&old->lock);
823 jermar 791
    }
792
 
793
    /*
794
     * Second, prepare the new address space.
795
     */
1380 jermar 796
    mutex_lock_active(&new->lock);
1415 jermar 797
    if ((new->cpu_refcount++ == 0) && (new != AS_KERNEL)) {
823 jermar 798
        if (new->asid != ASID_INVALID)
799
            list_remove(&new->inactive_as_with_asid_link);
800
        else
801
            needs_asid = true;  /* defer call to asid_get() until new->lock is released */
802
    }
803
    SET_PTL0_ADDRESS(new->page_table);
1380 jermar 804
    mutex_unlock(&new->lock);
823 jermar 805
 
806
    if (needs_asid) {
807
        /*
808
         * Allocation of new ASID was deferred
809
         * until now in order to avoid deadlock.
810
         */
811
        asid_t asid;
812
 
813
        asid = asid_get();
1380 jermar 814
        mutex_lock_active(&new->lock);
823 jermar 815
        new->asid = asid;
1380 jermar 816
        mutex_unlock(&new->lock);
823 jermar 817
    }
1415 jermar 818
    spinlock_unlock(&inactive_as_with_asid_lock);
823 jermar 819
    interrupts_restore(ipl);
820
 
821
    /*
703 jermar 822
     * Perform architecture-specific steps.
727 jermar 823
     * (e.g. write ASID to hardware register etc.)
703 jermar 824
     */
823 jermar 825
    as_install_arch(new);
703 jermar 826
 
823 jermar 827
    AS = new;
703 jermar 828
}
754 jermar 829
 
1235 jermar 830
/** Convert address space area flags to page flags.
754 jermar 831
 *
1235 jermar 832
 * @param aflags Flags of some address space area.
754 jermar 833
 *
1235 jermar 834
 * @return Flags to be passed to page_mapping_insert().
754 jermar 835
 */
1235 jermar 836
int area_flags_to_page_flags(int aflags)
754 jermar 837
{
838
    int flags;
839
 
1178 jermar 840
    flags = PAGE_USER | PAGE_PRESENT;
754 jermar 841
 
1235 jermar 842
    if (aflags & AS_AREA_READ)
1026 jermar 843
        flags |= PAGE_READ;
844
 
1235 jermar 845
    if (aflags & AS_AREA_WRITE)
1026 jermar 846
        flags |= PAGE_WRITE;
847
 
1235 jermar 848
    if (aflags & AS_AREA_EXEC)
1026 jermar 849
        flags |= PAGE_EXEC;
850
 
1424 jermar 851
    if (aflags & AS_AREA_CACHEABLE)
1178 jermar 852
        flags |= PAGE_CACHEABLE;
853
 
754 jermar 854
    return flags;
855
}
756 jermar 856
 
1235 jermar 857
/** Compute flags for virtual address translation subsytem.
858
 *
859
 * The address space area must be locked.
860
 * Interrupts must be disabled.
861
 *
862
 * @param a Address space area.
863
 *
864
 * @return Flags to be used in page_mapping_insert().
865
 */
1409 jermar 866
int as_area_get_flags(as_area_t *a)
1235 jermar 867
{
868
    return area_flags_to_page_flags(a->flags);
869
}
870
 
756 jermar 871
/** Create page table.
872
 *
873
 * Depending on architecture, create either address space
874
 * private or global page table.
875
 *
876
 * @param flags Flags saying whether the page table is for kernel address space.
877
 *
878
 * @return First entry of the page table.
879
 */
880
pte_t *page_table_create(int flags)
881
{
882
        ASSERT(as_operations);
883
        ASSERT(as_operations->page_table_create);
884
 
885
        return as_operations->page_table_create(flags);
886
}
977 jermar 887
 
1468 jermar 888
/** Destroy page table.
889
 *
890
 * Destroy page table in architecture specific way.
891
 *
892
 * @param page_table Physical address of PTL0.
893
 */
894
void page_table_destroy(pte_t *page_table)
895
{
896
        ASSERT(as_operations);
897
        ASSERT(as_operations->page_table_destroy);
898
 
899
        as_operations->page_table_destroy(page_table);
900
}
901
 
1044 jermar 902
/** Lock page table.
903
 *
904
 * This function should be called before any page_mapping_insert(),
905
 * page_mapping_remove() and page_mapping_find().
906
 *
907
 * Locking order is such that address space areas must be locked
908
 * prior to this call. Address space can be locked prior to this
909
 * call in which case the lock argument is false.
910
 *
911
 * @param as Address space.
1248 jermar 912
 * @param lock If false, do not attempt to lock as->lock.
1044 jermar 913
 */
914
void page_table_lock(as_t *as, bool lock)
915
{
916
    ASSERT(as_operations);
917
    ASSERT(as_operations->page_table_lock);
918
 
919
    as_operations->page_table_lock(as, lock);
920
}
921
 
922
/** Unlock page table.
923
 *
924
 * @param as Address space.
1248 jermar 925
 * @param unlock If false, do not attempt to unlock as->lock.
1044 jermar 926
 */
927
void page_table_unlock(as_t *as, bool unlock)
928
{
929
    ASSERT(as_operations);
930
    ASSERT(as_operations->page_table_unlock);
931
 
932
    as_operations->page_table_unlock(as, unlock);
933
}
934
 
977 jermar 935
 
936
/** Find address space area and lock it.
937
 *
938
 * The address space must be locked and interrupts must be disabled.
939
 *
940
 * @param as Address space.
941
 * @param va Virtual address.
942
 *
943
 * @return Locked address space area containing va on success or NULL on failure.
944
 */
945
as_area_t *find_area_and_lock(as_t *as, __address va)
946
{
947
    as_area_t *a;
1147 jermar 948
    btree_node_t *leaf, *lnode;
949
    int i;
977 jermar 950
 
1147 jermar 951
    a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
952
    if (a) {
953
        /* va is the base address of an address space area */
1380 jermar 954
        mutex_lock(&a->lock);
1147 jermar 955
        return a;
956
    }
957
 
958
    /*
1150 jermar 959
     * Search the leaf node and the righmost record of its left neighbour
1147 jermar 960
     * to find out whether this is a miss or va belongs to an address
961
     * space area found there.
962
     */
963
 
964
    /* First, search the leaf node itself. */
965
    for (i = 0; i < leaf->keys; i++) {
966
        a = (as_area_t *) leaf->value[i];
1380 jermar 967
        mutex_lock(&a->lock);
1147 jermar 968
        if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
969
            return a;
970
        }
1380 jermar 971
        mutex_unlock(&a->lock);
1147 jermar 972
    }
977 jermar 973
 
1147 jermar 974
    /*
1150 jermar 975
     * Second, locate the left neighbour and test its last record.
1148 jermar 976
     * Because of its position in the B+tree, it must have base < va.
1147 jermar 977
     */
1150 jermar 978
    if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 979
        a = (as_area_t *) lnode->value[lnode->keys - 1];
1380 jermar 980
        mutex_lock(&a->lock);
1147 jermar 981
        if (va < a->base + a->pages * PAGE_SIZE) {
1048 jermar 982
            return a;
1147 jermar 983
        }
1380 jermar 984
        mutex_unlock(&a->lock);
977 jermar 985
    }
986
 
987
    return NULL;
988
}
1048 jermar 989
 
990
/** Check area conflicts with other areas.
991
 *
992
 * The address space must be locked and interrupts must be disabled.
993
 *
994
 * @param as Address space.
995
 * @param va Starting virtual address of the area being tested.
996
 * @param size Size of the area being tested.
997
 * @param avoid_area Do not touch this area.
998
 *
999
 * @return True if there is no conflict, false otherwise.
1000
 */
1001
bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area)
1002
{
1003
    as_area_t *a;
1147 jermar 1004
    btree_node_t *leaf, *node;
1005
    int i;
1048 jermar 1006
 
1070 jermar 1007
    /*
1008
     * We don't want any area to have conflicts with NULL page.
1009
     */
1010
    if (overlaps(va, size, NULL, PAGE_SIZE))
1011
        return false;
1012
 
1147 jermar 1013
    /*
1014
     * The leaf node is found in O(log n), where n is proportional to
1015
     * the number of address space areas belonging to as.
1016
     * The check for conflicts is then attempted on the rightmost
1150 jermar 1017
     * record in the left neighbour, the leftmost record in the right
1018
     * neighbour and all records in the leaf node itself.
1147 jermar 1019
     */
1048 jermar 1020
 
1147 jermar 1021
    if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
1022
        if (a != avoid_area)
1023
            return false;
1024
    }
1025
 
1026
    /* First, check the two border cases. */
1150 jermar 1027
    if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 1028
        a = (as_area_t *) node->value[node->keys - 1];
1380 jermar 1029
        mutex_lock(&a->lock);
1147 jermar 1030
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 1031
            mutex_unlock(&a->lock);
1147 jermar 1032
            return false;
1033
        }
1380 jermar 1034
        mutex_unlock(&a->lock);
1147 jermar 1035
    }
1150 jermar 1036
    if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) {
1147 jermar 1037
        a = (as_area_t *) node->value[0];
1380 jermar 1038
        mutex_lock(&a->lock);
1147 jermar 1039
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 1040
            mutex_unlock(&a->lock);
1147 jermar 1041
            return false;
1042
        }
1380 jermar 1043
        mutex_unlock(&a->lock);
1147 jermar 1044
    }
1045
 
1046
    /* Second, check the leaf node. */
1047
    for (i = 0; i < leaf->keys; i++) {
1048
        a = (as_area_t *) leaf->value[i];
1049
 
1048 jermar 1050
        if (a == avoid_area)
1051
            continue;
1147 jermar 1052
 
1380 jermar 1053
        mutex_lock(&a->lock);
1147 jermar 1054
        if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
1380 jermar 1055
            mutex_unlock(&a->lock);
1147 jermar 1056
            return false;
1057
        }
1380 jermar 1058
        mutex_unlock(&a->lock);
1048 jermar 1059
    }
1060
 
1070 jermar 1061
    /*
1062
     * So far, the area does not conflict with other areas.
1063
     * Check if it doesn't conflict with kernel address space.
1064
     */  
1065
    if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
1066
        return !overlaps(va, size,
1067
            KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START);
1068
    }
1069
 
1048 jermar 1070
    return true;
1071
}
1235 jermar 1072
 
1380 jermar 1073
/** Return size of the address space area with given base.  */
1329 palkovsky 1074
size_t as_get_size(__address base)
1075
{
1076
    ipl_t ipl;
1077
    as_area_t *src_area;
1078
    size_t size;
1079
 
1080
    ipl = interrupts_disable();
1081
    src_area = find_area_and_lock(AS, base);
1082
    if (src_area){
1083
        size = src_area->pages * PAGE_SIZE;
1380 jermar 1084
        mutex_unlock(&src_area->lock);
1329 palkovsky 1085
    } else {
1086
        size = 0;
1087
    }
1088
    interrupts_restore(ipl);
1089
    return size;
1090
}
1091
 
1387 jermar 1092
/** Mark portion of address space area as used.
1093
 *
1094
 * The address space area must be already locked.
1095
 *
1096
 * @param a Address space area.
1097
 * @param page First page to be marked.
1098
 * @param count Number of page to be marked.
1099
 *
1100
 * @return 0 on failure and 1 on success.
1101
 */
1102
int used_space_insert(as_area_t *a, __address page, count_t count)
1103
{
1104
    btree_node_t *leaf, *node;
1105
    count_t pages;
1106
    int i;
1107
 
1108
    ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
1109
    ASSERT(count);
1110
 
1111
    pages = (count_t) btree_search(&a->used_space, page, &leaf);
1112
    if (pages) {
1113
        /*
1114
         * We hit the beginning of some used space.
1115
         */
1116
        return 0;
1117
    }
1118
 
1437 jermar 1119
    if (!leaf->keys) {
1120
        btree_insert(&a->used_space, page, (void *) count, leaf);
1121
        return 1;
1122
    }
1123
 
1387 jermar 1124
    node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
1125
    if (node) {
1126
        __address left_pg = node->key[node->keys - 1], right_pg = leaf->key[0];
1127
        count_t left_cnt = (count_t) node->value[node->keys - 1], right_cnt = (count_t) leaf->value[0];
1128
 
1129
        /*
1130
         * Examine the possibility that the interval fits
1131
         * somewhere between the rightmost interval of
1132
         * the left neigbour and the first interval of the leaf.
1133
         */
1134
 
1135
        if (page >= right_pg) {
1136
            /* Do nothing. */
1137
        } else if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1138
            /* The interval intersects with the left interval. */
1139
            return 0;
1140
        } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1141
            /* The interval intersects with the right interval. */
1142
            return 0;          
1143
        } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
1144
            /* The interval can be added by merging the two already present intervals. */
1403 jermar 1145
            node->value[node->keys - 1] += count + right_cnt;
1387 jermar 1146
            btree_remove(&a->used_space, right_pg, leaf);
1147
            return 1;
1148
        } else if (page == left_pg + left_cnt*PAGE_SIZE) {
1149
            /* The interval can be added by simply growing the left interval. */
1403 jermar 1150
            node->value[node->keys - 1] += count;
1387 jermar 1151
            return 1;
1152
        } else if (page + count*PAGE_SIZE == right_pg) {
1153
            /*
1154
             * The interval can be addded by simply moving base of the right
1155
             * interval down and increasing its size accordingly.
1156
             */
1403 jermar 1157
            leaf->value[0] += count;
1387 jermar 1158
            leaf->key[0] = page;
1159
            return 1;
1160
        } else {
1161
            /*
1162
             * The interval is between both neigbouring intervals,
1163
             * but cannot be merged with any of them.
1164
             */
1165
            btree_insert(&a->used_space, page, (void *) count, leaf);
1166
            return 1;
1167
        }
1168
    } else if (page < leaf->key[0]) {
1169
        __address right_pg = leaf->key[0];
1170
        count_t right_cnt = (count_t) leaf->value[0];
1171
 
1172
        /*
1173
         * Investigate the border case in which the left neighbour does not
1174
         * exist but the interval fits from the left.
1175
         */
1176
 
1177
        if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1178
            /* The interval intersects with the right interval. */
1179
            return 0;
1180
        } else if (page + count*PAGE_SIZE == right_pg) {
1181
            /*
1182
             * The interval can be added by moving the base of the right interval down
1183
             * and increasing its size accordingly.
1184
             */
1185
            leaf->key[0] = page;
1403 jermar 1186
            leaf->value[0] += count;
1387 jermar 1187
            return 1;
1188
        } else {
1189
            /*
1190
             * The interval doesn't adjoin with the right interval.
1191
             * It must be added individually.
1192
             */
1193
            btree_insert(&a->used_space, page, (void *) count, leaf);
1194
            return 1;
1195
        }
1196
    }
1197
 
1198
    node = btree_leaf_node_right_neighbour(&a->used_space, leaf);
1199
    if (node) {
1200
        __address left_pg = leaf->key[leaf->keys - 1], right_pg = node->key[0];
1201
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1], right_cnt = (count_t) node->value[0];
1202
 
1203
        /*
1204
         * Examine the possibility that the interval fits
1205
         * somewhere between the leftmost interval of
1206
         * the right neigbour and the last interval of the leaf.
1207
         */
1208
 
1209
        if (page < left_pg) {
1210
            /* Do nothing. */
1211
        } else if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1212
            /* The interval intersects with the left interval. */
1213
            return 0;
1214
        } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1215
            /* The interval intersects with the right interval. */
1216
            return 0;          
1217
        } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
1218
            /* The interval can be added by merging the two already present intervals. */
1403 jermar 1219
            leaf->value[leaf->keys - 1] += count + right_cnt;
1387 jermar 1220
            btree_remove(&a->used_space, right_pg, node);
1221
            return 1;
1222
        } else if (page == left_pg + left_cnt*PAGE_SIZE) {
1223
            /* The interval can be added by simply growing the left interval. */
1403 jermar 1224
            leaf->value[leaf->keys - 1] +=  count;
1387 jermar 1225
            return 1;
1226
        } else if (page + count*PAGE_SIZE == right_pg) {
1227
            /*
1228
             * The interval can be addded by simply moving base of the right
1229
             * interval down and increasing its size accordingly.
1230
             */
1403 jermar 1231
            node->value[0] += count;
1387 jermar 1232
            node->key[0] = page;
1233
            return 1;
1234
        } else {
1235
            /*
1236
             * The interval is between both neigbouring intervals,
1237
             * but cannot be merged with any of them.
1238
             */
1239
            btree_insert(&a->used_space, page, (void *) count, leaf);
1240
            return 1;
1241
        }
1242
    } else if (page >= leaf->key[leaf->keys - 1]) {
1243
        __address left_pg = leaf->key[leaf->keys - 1];
1244
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
1245
 
1246
        /*
1247
         * Investigate the border case in which the right neighbour does not
1248
         * exist but the interval fits from the right.
1249
         */
1250
 
1251
        if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1403 jermar 1252
            /* The interval intersects with the left interval. */
1387 jermar 1253
            return 0;
1254
        } else if (left_pg + left_cnt*PAGE_SIZE == page) {
1255
            /* The interval can be added by growing the left interval. */
1403 jermar 1256
            leaf->value[leaf->keys - 1] += count;
1387 jermar 1257
            return 1;
1258
        } else {
1259
            /*
1260
             * The interval doesn't adjoin with the left interval.
1261
             * It must be added individually.
1262
             */
1263
            btree_insert(&a->used_space, page, (void *) count, leaf);
1264
            return 1;
1265
        }
1266
    }
1267
 
1268
    /*
1269
     * Note that if the algorithm made it thus far, the interval can fit only
1270
     * between two other intervals of the leaf. The two border cases were already
1271
     * resolved.
1272
     */
1273
    for (i = 1; i < leaf->keys; i++) {
1274
        if (page < leaf->key[i]) {
1275
            __address left_pg = leaf->key[i - 1], right_pg = leaf->key[i];
1276
            count_t left_cnt = (count_t) leaf->value[i - 1], right_cnt = (count_t) leaf->value[i];
1277
 
1278
            /*
1279
             * The interval fits between left_pg and right_pg.
1280
             */
1281
 
1282
            if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) {
1283
                /* The interval intersects with the left interval. */
1284
                return 0;
1285
            } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) {
1286
                /* The interval intersects with the right interval. */
1287
                return 0;          
1288
            } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) {
1289
                /* The interval can be added by merging the two already present intervals. */
1403 jermar 1290
                leaf->value[i - 1] += count + right_cnt;
1387 jermar 1291
                btree_remove(&a->used_space, right_pg, leaf);
1292
                return 1;
1293
            } else if (page == left_pg + left_cnt*PAGE_SIZE) {
1294
                /* The interval can be added by simply growing the left interval. */
1403 jermar 1295
                leaf->value[i - 1] += count;
1387 jermar 1296
                return 1;
1297
            } else if (page + count*PAGE_SIZE == right_pg) {
1298
                /*
1299
                     * The interval can be addded by simply moving base of the right
1300
                 * interval down and increasing its size accordingly.
1301
                 */
1403 jermar 1302
                leaf->value[i] += count;
1387 jermar 1303
                leaf->key[i] = page;
1304
                return 1;
1305
            } else {
1306
                /*
1307
                 * The interval is between both neigbouring intervals,
1308
                 * but cannot be merged with any of them.
1309
                 */
1310
                btree_insert(&a->used_space, page, (void *) count, leaf);
1311
                return 1;
1312
            }
1313
        }
1314
    }
1315
 
1735 decky 1316
    panic("Inconsistency detected while adding %d pages of used space at %p.\n", count, page);
1387 jermar 1317
}
1318
 
1319
/** Mark portion of address space area as unused.
1320
 *
1321
 * The address space area must be already locked.
1322
 *
1323
 * @param a Address space area.
1324
 * @param page First page to be marked.
1325
 * @param count Number of page to be marked.
1326
 *
1327
 * @return 0 on failure and 1 on success.
1328
 */
1329
int used_space_remove(as_area_t *a, __address page, count_t count)
1330
{
1331
    btree_node_t *leaf, *node;
1332
    count_t pages;
1333
    int i;
1334
 
1335
    ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE));
1336
    ASSERT(count);
1337
 
1338
    pages = (count_t) btree_search(&a->used_space, page, &leaf);
1339
    if (pages) {
1340
        /*
1341
         * We are lucky, page is the beginning of some interval.
1342
         */
1343
        if (count > pages) {
1344
            return 0;
1345
        } else if (count == pages) {
1346
            btree_remove(&a->used_space, page, leaf);
1403 jermar 1347
            return 1;
1387 jermar 1348
        } else {
1349
            /*
1350
             * Find the respective interval.
1351
             * Decrease its size and relocate its start address.
1352
             */
1353
            for (i = 0; i < leaf->keys; i++) {
1354
                if (leaf->key[i] == page) {
1355
                    leaf->key[i] += count*PAGE_SIZE;
1403 jermar 1356
                    leaf->value[i] -= count;
1387 jermar 1357
                    return 1;
1358
                }
1359
            }
1360
            goto error;
1361
        }
1362
    }
1363
 
1364
    node = btree_leaf_node_left_neighbour(&a->used_space, leaf);
1365
    if (node && page < leaf->key[0]) {
1366
        __address left_pg = node->key[node->keys - 1];
1367
        count_t left_cnt = (count_t) node->value[node->keys - 1];
1368
 
1369
        if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
1370
            if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
1371
                /*
1372
                 * The interval is contained in the rightmost interval
1373
                 * of the left neighbour and can be removed by
1374
                 * updating the size of the bigger interval.
1375
                 */
1403 jermar 1376
                node->value[node->keys - 1] -= count;
1387 jermar 1377
                return 1;
1378
            } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
1403 jermar 1379
                count_t new_cnt;
1387 jermar 1380
 
1381
                /*
1382
                 * The interval is contained in the rightmost interval
1383
                 * of the left neighbour but its removal requires
1384
                 * both updating the size of the original interval and
1385
                 * also inserting a new interval.
1386
                 */
1403 jermar 1387
                new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1388
                node->value[node->keys - 1] -= count + new_cnt;
1387 jermar 1389
                btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
1390
                return 1;
1391
            }
1392
        }
1393
        return 0;
1394
    } else if (page < leaf->key[0]) {
1395
        return 0;
1396
    }
1397
 
1398
    if (page > leaf->key[leaf->keys - 1]) {
1399
        __address left_pg = leaf->key[leaf->keys - 1];
1400
        count_t left_cnt = (count_t) leaf->value[leaf->keys - 1];
1401
 
1402
        if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
1403
            if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
1404
                /*
1405
                 * The interval is contained in the rightmost interval
1406
                 * of the leaf and can be removed by updating the size
1407
                 * of the bigger interval.
1408
                 */
1403 jermar 1409
                leaf->value[leaf->keys - 1] -= count;
1387 jermar 1410
                return 1;
1411
            } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
1403 jermar 1412
                count_t new_cnt;
1387 jermar 1413
 
1414
                /*
1415
                 * The interval is contained in the rightmost interval
1416
                 * of the leaf but its removal requires both updating
1417
                 * the size of the original interval and
1418
                 * also inserting a new interval.
1419
                 */
1403 jermar 1420
                new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1421
                leaf->value[leaf->keys - 1] -= count + new_cnt;
1387 jermar 1422
                btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
1423
                return 1;
1424
            }
1425
        }
1426
        return 0;
1427
    }  
1428
 
1429
    /*
1430
     * The border cases have been already resolved.
1431
     * Now the interval can be only between intervals of the leaf.
1432
     */
1433
    for (i = 1; i < leaf->keys - 1; i++) {
1434
        if (page < leaf->key[i]) {
1435
            __address left_pg = leaf->key[i - 1];
1436
            count_t left_cnt = (count_t) leaf->value[i - 1];
1437
 
1438
            /*
1439
             * Now the interval is between intervals corresponding to (i - 1) and i.
1440
             */
1441
            if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) {
1442
                if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) {
1443
                    /*
1444
                    * The interval is contained in the interval (i - 1)
1445
                     * of the leaf and can be removed by updating the size
1446
                     * of the bigger interval.
1447
                     */
1403 jermar 1448
                    leaf->value[i - 1] -= count;
1387 jermar 1449
                    return 1;
1450
                } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) {
1403 jermar 1451
                    count_t new_cnt;
1387 jermar 1452
 
1453
                    /*
1454
                     * The interval is contained in the interval (i - 1)
1455
                     * of the leaf but its removal requires both updating
1456
                     * the size of the original interval and
1457
                     * also inserting a new interval.
1458
                     */
1403 jermar 1459
                    new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH;
1460
                    leaf->value[i - 1] -= count + new_cnt;
1387 jermar 1461
                    btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf);
1462
                    return 1;
1463
                }
1464
            }
1465
            return 0;
1466
        }
1467
    }
1468
 
1469
error:
1735 decky 1470
    panic("Inconsistency detected while removing %d pages of used space from %p.\n", count, page);
1387 jermar 1471
}
1472
 
1409 jermar 1473
/** Remove reference to address space area share info.
1474
 *
1475
 * If the reference count drops to 0, the sh_info is deallocated.
1476
 *
1477
 * @param sh_info Pointer to address space area share info.
1478
 */
1479
void sh_info_remove_reference(share_info_t *sh_info)
1480
{
1481
    bool dealloc = false;
1482
 
1483
    mutex_lock(&sh_info->lock);
1484
    ASSERT(sh_info->refcount);
1485
    if (--sh_info->refcount == 0) {
1486
        dealloc = true;
1495 jermar 1487
        link_t *cur;
1409 jermar 1488
 
1489
        /*
1490
         * Now walk carefully the pagemap B+tree and free/remove
1491
         * reference from all frames found there.
1492
         */
1495 jermar 1493
        for (cur = sh_info->pagemap.leaf_head.next; cur != &sh_info->pagemap.leaf_head; cur = cur->next) {
1409 jermar 1494
            btree_node_t *node;
1495 jermar 1495
            int i;
1409 jermar 1496
 
1495 jermar 1497
            node = list_get_instance(cur, btree_node_t, leaf_link);
1498
            for (i = 0; i < node->keys; i++)
1760 palkovsky 1499
                frame_free((__address) node->value[i]);
1409 jermar 1500
        }
1501
 
1502
    }
1503
    mutex_unlock(&sh_info->lock);
1504
 
1505
    if (dealloc) {
1506
        btree_destroy(&sh_info->pagemap);
1507
        free(sh_info);
1508
    }
1509
}
1510
 
1235 jermar 1511
/*
1512
 * Address space related syscalls.
1513
 */
1514
 
1515
/** Wrapper for as_area_create(). */
1516
__native sys_as_area_create(__address address, size_t size, int flags)
1517
{
1424 jermar 1518
    if (as_area_create(AS, flags | AS_AREA_CACHEABLE, size, address, AS_AREA_ATTR_NONE, &anon_backend, NULL))
1235 jermar 1519
        return (__native) address;
1520
    else
1521
        return (__native) -1;
1522
}
1523
 
1524
/** Wrapper for as_area_resize. */
1525
__native sys_as_area_resize(__address address, size_t size, int flags)
1526
{
1306 jermar 1527
    return (__native) as_area_resize(AS, address, size, 0);
1235 jermar 1528
}
1529
 
1306 jermar 1530
/** Wrapper for as_area_destroy. */
1531
__native sys_as_area_destroy(__address address)
1532
{
1533
    return (__native) as_area_destroy(AS, address);
1534
}
1702 cejka 1535
 
1757 jermar 1536
/** @}
1702 cejka 1537
 */