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3521 jermar 1
/*
2
 * Copyright (c) 2008 Jakub Jermar
3
 * Copyright (c) 2008 Martin Decky
4
 * All rights reserved.
5
 *
6
 * Redistribution and use in source and binary forms, with or without
7
 * modification, are permitted provided that the following conditions
8
 * are met:
9
 *
10
 * - Redistributions of source code must retain the above copyright
11
 *   notice, this list of conditions and the following disclaimer.
12
 * - Redistributions in binary form must reproduce the above copyright
13
 *   notice, this list of conditions and the following disclaimer in the
14
 *   documentation and/or other materials provided with the distribution.
15
 * - The name of the author may not be used to endorse or promote products
16
 *   derived from this software without specific prior written permission.
17
 *
18
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28
 */
29
 
4001 decky 30
/** @addtogroup libblock
3521 jermar 31
 * @{
4001 decky 32
 */
3521 jermar 33
/**
34
 * @file
35
 * @brief
36
 */
37
 
4001 decky 38
#include "libblock.h"
3521 jermar 39
#include "../../srv/vfs/vfs.h"
3530 jermar 40
#include <ipc/devmap.h>
4420 trochtova 41
#include <ipc/bd.h>
3530 jermar 42
#include <ipc/services.h>
3521 jermar 43
#include <errno.h>
3530 jermar 44
#include <sys/mman.h>
3521 jermar 45
#include <async.h>
46
#include <ipc/ipc.h>
47
#include <as.h>
48
#include <assert.h>
3531 jermar 49
#include <futex.h>
50
#include <libadt/list.h>
3539 jermar 51
#include <libadt/hash_table.h>
3521 jermar 52
 
3531 jermar 53
/** Lock protecting the device connection list */
54
static futex_t dcl_lock = FUTEX_INITIALIZER;
55
/** Device connection list head. */
56
static LIST_INITIALIZE(dcl_head);
3530 jermar 57
 
3539 jermar 58
#define CACHE_BUCKETS_LOG2      10
59
#define CACHE_BUCKETS           (1 << CACHE_BUCKETS_LOG2)
60
 
3531 jermar 61
typedef struct {
3539 jermar 62
    futex_t lock;
63
    size_t block_size;      /**< Block size. */
64
    unsigned block_count;       /**< Total number of blocks. */
65
    hash_table_t block_hash;
66
    link_t free_head;
67
} cache_t;
68
 
69
typedef struct {
3531 jermar 70
    link_t link;
4439 trochtova 71
    dev_handle_t dev_handle;
3531 jermar 72
    int dev_phone;
73
    void *com_area;
74
    size_t com_size;
75
    void *bb_buf;
76
    off_t bb_off;
77
    size_t bb_size;
3539 jermar 78
    cache_t *cache;
3531 jermar 79
} devcon_t;
80
 
81
static devcon_t *devcon_search(dev_handle_t dev_handle)
82
{
83
    link_t *cur;
84
 
85
    futex_down(&dcl_lock);
86
    for (cur = dcl_head.next; cur != &dcl_head; cur = cur->next) {
87
        devcon_t *devcon = list_get_instance(cur, devcon_t, link);
88
        if (devcon->dev_handle == dev_handle) {
89
            futex_up(&dcl_lock);
90
            return devcon;
91
        }
92
    }
93
    futex_up(&dcl_lock);
94
    return NULL;
95
}
96
 
97
static int devcon_add(dev_handle_t dev_handle, int dev_phone, void *com_area,
3537 jermar 98
   size_t com_size)
3531 jermar 99
{
100
    link_t *cur;
101
    devcon_t *devcon;
102
 
103
    devcon = malloc(sizeof(devcon_t));
104
    if (!devcon)
105
        return ENOMEM;
106
 
107
    link_initialize(&devcon->link);
108
    devcon->dev_handle = dev_handle;
109
    devcon->dev_phone = dev_phone;
110
    devcon->com_area = com_area;
111
    devcon->com_size = com_size;
3537 jermar 112
    devcon->bb_buf = NULL;
113
    devcon->bb_off = 0;
114
    devcon->bb_size = 0;
3539 jermar 115
    devcon->cache = NULL;
3531 jermar 116
 
117
    futex_down(&dcl_lock);
118
    for (cur = dcl_head.next; cur != &dcl_head; cur = cur->next) {
119
        devcon_t *d = list_get_instance(cur, devcon_t, link);
120
        if (d->dev_handle == dev_handle) {
121
            futex_up(&dcl_lock);
122
            free(devcon);
123
            return EEXIST;
124
        }
125
    }
126
    list_append(&devcon->link, &dcl_head);
127
    futex_up(&dcl_lock);
128
    return EOK;
129
}
130
 
131
static void devcon_remove(devcon_t *devcon)
132
{
133
    futex_down(&dcl_lock);
134
    list_remove(&devcon->link);
135
    futex_up(&dcl_lock);
136
}
137
 
3537 jermar 138
int block_init(dev_handle_t dev_handle, size_t com_size)
3530 jermar 139
{
140
    int rc;
3531 jermar 141
    int dev_phone;
142
    void *com_area;
143
 
144
    com_area = mmap(NULL, com_size, PROTO_READ | PROTO_WRITE,
3530 jermar 145
        MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
3531 jermar 146
    if (!com_area) {
3530 jermar 147
        return ENOMEM;
148
    }
149
 
4420 trochtova 150
    dev_phone = devmap_device_connect(dev_handle, IPC_FLAG_BLOCKING);
3530 jermar 151
    if (dev_phone < 0) {
3531 jermar 152
        munmap(com_area, com_size);
3530 jermar 153
        return dev_phone;
154
    }
155
 
3531 jermar 156
    rc = ipc_share_out_start(dev_phone, com_area,
3530 jermar 157
        AS_AREA_READ | AS_AREA_WRITE);
158
    if (rc != EOK) {
3531 jermar 159
            munmap(com_area, com_size);
3530 jermar 160
        ipc_hangup(dev_phone);
161
        return rc;
162
    }
3531 jermar 163
 
3537 jermar 164
    rc = devcon_add(dev_handle, dev_phone, com_area, com_size);
3531 jermar 165
    if (rc != EOK) {
166
        munmap(com_area, com_size);
167
        ipc_hangup(dev_phone);
168
        return rc;
169
    }
170
 
3530 jermar 171
    return EOK;
172
}
173
 
174
void block_fini(dev_handle_t dev_handle)
175
{
3531 jermar 176
    devcon_t *devcon = devcon_search(dev_handle);
177
    assert(devcon);
178
 
179
    devcon_remove(devcon);
180
 
3537 jermar 181
    if (devcon->bb_buf)
182
        free(devcon->bb_buf);
3539 jermar 183
 
184
    if (devcon->cache) {
185
        hash_table_destroy(&devcon->cache->block_hash);
186
        free(devcon->cache);
187
    }
188
 
3531 jermar 189
    munmap(devcon->com_area, devcon->com_size);
190
    ipc_hangup(devcon->dev_phone);
191
 
192
    free(devcon);  
3530 jermar 193
}
194
 
3537 jermar 195
int block_bb_read(dev_handle_t dev_handle, off_t off, size_t size)
196
{
197
    void *bb_buf;
3538 jermar 198
    int rc;
3537 jermar 199
 
200
    devcon_t *devcon = devcon_search(dev_handle);
201
    if (!devcon)
202
        return ENOENT;
203
    if (devcon->bb_buf)
204
        return EEXIST;
205
    bb_buf = malloc(size);
206
    if (!bb_buf)
207
        return ENOMEM;
208
 
209
    off_t bufpos = 0;
210
    size_t buflen = 0;
3538 jermar 211
    rc = block_read(dev_handle, &bufpos, &buflen, &off,
212
        bb_buf, size, size);
213
    if (rc != EOK) {
3537 jermar 214
            free(bb_buf);
3538 jermar 215
        return rc;
3537 jermar 216
    }
217
    devcon->bb_buf = bb_buf;
218
    devcon->bb_off = off;
219
    devcon->bb_size = size;
220
 
221
    return EOK;
222
}
223
 
3530 jermar 224
void *block_bb_get(dev_handle_t dev_handle)
225
{
3531 jermar 226
    devcon_t *devcon = devcon_search(dev_handle);
227
    assert(devcon);
228
    return devcon->bb_buf;
3530 jermar 229
}
230
 
3539 jermar 231
static hash_index_t cache_hash(unsigned long *key)
232
{
233
    return *key & (CACHE_BUCKETS - 1);
234
}
235
 
236
static int cache_compare(unsigned long *key, hash_count_t keys, link_t *item)
237
{
238
    block_t *b = hash_table_get_instance(item, block_t, hash_link);
239
    return b->boff == *key;
240
}
241
 
242
static void cache_remove_callback(link_t *item)
243
{
244
}
245
 
246
static hash_table_operations_t cache_ops = {
247
    .hash = cache_hash,
248
    .compare = cache_compare,
249
    .remove_callback = cache_remove_callback
250
};
251
 
252
int block_cache_init(dev_handle_t dev_handle, size_t size, unsigned blocks)
253
{
254
    devcon_t *devcon = devcon_search(dev_handle);
255
    cache_t *cache;
256
    if (!devcon)
257
        return ENOENT;
258
    if (devcon->cache)
259
        return EEXIST;
260
    cache = malloc(sizeof(cache_t));
261
    if (!cache)
262
        return ENOMEM;
263
 
3540 jermar 264
    futex_initialize(&cache->lock, 1);
3539 jermar 265
    list_initialize(&cache->free_head);
266
    cache->block_size = size;
267
    cache->block_count = blocks;
268
 
269
    if (!hash_table_create(&cache->block_hash, CACHE_BUCKETS, 1,
270
        &cache_ops)) {
271
        free(cache);
272
        return ENOMEM;
273
    }
274
 
275
    devcon->cache = cache;
276
    return EOK;
277
}
278
 
3540 jermar 279
static bool cache_can_grow(cache_t *cache)
3521 jermar 280
{
3540 jermar 281
    return true;
282
}
283
 
284
static void block_initialize(block_t *b)
285
{
286
    futex_initialize(&b->lock, 1);
287
    b->refcnt = 1;
288
    b->dirty = false;
289
    rwlock_initialize(&b->contents_lock);
290
    link_initialize(&b->free_link);
291
    link_initialize(&b->hash_link);
292
}
293
 
294
/** Instantiate a block in memory and get a reference to it.
295
 *
296
 * @param dev_handle        Device handle of the block device.
297
 * @param boff          Block offset.
3595 jermar 298
 * @param flags         If BLOCK_FLAGS_NOREAD is specified, block_get()
299
 *              will not read the contents of the block from the
300
 *              device.
3540 jermar 301
 *
302
 * @return          Block structure.
303
 */
3595 jermar 304
block_t *block_get(dev_handle_t dev_handle, bn_t boff, int flags)
3540 jermar 305
{
306
    devcon_t *devcon;
307
    cache_t *cache;
3521 jermar 308
    block_t *b;
3540 jermar 309
    link_t *l;
310
    unsigned long key = boff;
311
 
312
    devcon = devcon_search(dev_handle);
3521 jermar 313
 
3540 jermar 314
    assert(devcon);
315
    assert(devcon->cache);
3521 jermar 316
 
3540 jermar 317
    cache = devcon->cache;
318
    futex_down(&cache->lock);
319
    l = hash_table_find(&cache->block_hash, &key);
320
    if (l) {
321
        /*
322
         * We found the block in the cache.
323
         */
324
        b = hash_table_get_instance(l, block_t, hash_link);
325
        futex_down(&b->lock);
326
        if (b->refcnt++ == 0)
327
            list_remove(&b->free_link);
328
        futex_up(&b->lock);
3544 jermar 329
        futex_up(&cache->lock);
3540 jermar 330
    } else {
331
        /*
332
         * The block was not found in the cache.
333
         */
334
        int rc;
335
        off_t bufpos = 0;
336
        size_t buflen = 0;
337
        off_t pos = boff * cache->block_size;
3544 jermar 338
        bool sync = false;
3521 jermar 339
 
3540 jermar 340
        if (cache_can_grow(cache)) {
341
            /*
342
             * We can grow the cache by allocating new blocks.
343
             * Should the allocation fail, we fail over and try to
344
             * recycle a block from the cache.
345
             */
346
            b = malloc(sizeof(block_t));
347
            if (!b)
348
                goto recycle;
349
            b->data = malloc(cache->block_size);
350
            if (!b->data) {
351
                free(b);
352
                goto recycle;
353
            }
354
        } else {
355
            /*
356
             * Try to recycle a block from the free list.
357
             */
358
            unsigned long temp_key;
359
recycle:
360
            assert(!list_empty(&cache->free_head));
361
            l = cache->free_head.next;
362
            list_remove(l);
363
            b = hash_table_get_instance(l, block_t, hash_link);
3544 jermar 364
            sync = b->dirty;
3540 jermar 365
            temp_key = b->boff;
366
            hash_table_remove(&cache->block_hash, &temp_key, 1);
367
        }
368
 
369
        block_initialize(b);
370
        b->dev_handle = dev_handle;
371
        b->size = cache->block_size;
372
        b->boff = boff;
3544 jermar 373
        hash_table_insert(&cache->block_hash, &key, &b->hash_link);
374
 
375
        /*
376
         * Lock the block before releasing the cache lock. Thus we don't
377
         * kill concurent operations on the cache while doing I/O on the
378
         * block.
379
         */
380
        futex_down(&b->lock);
381
        futex_up(&cache->lock);
382
 
383
        if (sync) {
384
            /*
385
             * The block is dirty and needs to be written back to
386
             * the device before we can read in the new contents.
387
             */
388
            abort();    /* TODO: block_write() */
389
        }
3595 jermar 390
        if (!(flags & BLOCK_FLAGS_NOREAD)) {
391
            /*
392
             * The block contains old or no data. We need to read
393
             * the new contents from the device.
394
             */
395
            rc = block_read(dev_handle, &bufpos, &buflen, &pos,
396
                b->data, cache->block_size, cache->block_size);
397
            assert(rc == EOK);
398
        }
3544 jermar 399
 
400
        futex_up(&b->lock);
3521 jermar 401
    }
402
    return b;
403
}
404
 
3543 jermar 405
/** Release a reference to a block.
406
 *
3544 jermar 407
 * If the last reference is dropped, the block is put on the free list.
3543 jermar 408
 *
409
 * @param block     Block of which a reference is to be released.
410
 */
3521 jermar 411
void block_put(block_t *block)
412
{
3543 jermar 413
    devcon_t *devcon = devcon_search(block->dev_handle);
414
    cache_t *cache;
415
 
416
    assert(devcon);
417
    assert(devcon->cache);
418
 
419
    cache = devcon->cache;
420
    futex_down(&cache->lock);
421
    futex_down(&block->lock);
422
    if (!--block->refcnt) {
423
        /*
424
         * Last reference to the block was dropped, put the block on the
425
         * free list.
426
         */
427
        list_append(&block->free_link, &cache->free_head);
428
    }
429
    futex_up(&block->lock);
3544 jermar 430
    futex_up(&cache->lock);
3543 jermar 431
}
432
 
433
/** Read data from a block device.
434
 *
435
 * @param dev_handle    Device handle of the block device.
436
 * @param bufpos    Pointer to the first unread valid offset within the
437
 *          communication buffer.
438
 * @param buflen    Pointer to the number of unread bytes that are ready in
439
 *          the communication buffer.
440
 * @param pos       Device position to be read.
441
 * @param dst       Destination buffer.
442
 * @param size      Size of the destination buffer.
443
 * @param block_size    Block size to be used for the transfer.
444
 *
445
 * @return      EOK on success or a negative return code on failure.
446
 */
447
int
4439 trochtova 448
block_read(dev_handle_t dev_handle, off_t *bufpos, size_t *buflen, off_t *pos,
449
    void *dst, size_t size, size_t block_size)
3543 jermar 450
{
451
    off_t offset = 0;
452
    size_t left = size;
453
    devcon_t *devcon = devcon_search(dev_handle);
454
    assert(devcon);
3540 jermar 455
 
3543 jermar 456
    while (left > 0) {
457
        size_t rd;
458
 
459
        if (*bufpos + left < *buflen)
460
            rd = left;
461
        else
462
            rd = *buflen - *bufpos;
463
 
464
        if (rd > 0) {
465
            /*
466
             * Copy the contents of the communication buffer to the
467
             * destination buffer.
468
             */
469
            memcpy(dst + offset, devcon->com_area + *bufpos, rd);
470
            offset += rd;
471
            *bufpos += rd;
472
            *pos += rd;
473
            left -= rd;
474
        }
475
 
476
        if (*bufpos == *buflen) {
477
            /* Refill the communication buffer with a new block. */
478
            ipcarg_t retval;
4420 trochtova 479
            int rc = async_req_2_1(devcon->dev_phone, BD_READ_BLOCK,
3543 jermar 480
                *pos / block_size, block_size, &retval);
481
            if ((rc != EOK) || (retval != EOK))
482
                return (rc != EOK ? rc : retval);
483
 
484
            *bufpos = 0;
485
            *buflen = block_size;
486
        }
487
    }
488
 
489
    return EOK;
3521 jermar 490
}
491
 
492
/** @}
493
 */