CHIPS: Fix potential starvation in cfi_cmdset_0001
[deliverable/linux.git] / drivers / ieee1394 / ieee1394_transactions.c
1 /*
2 * IEEE 1394 for Linux
3 *
4 * Transaction support.
5 *
6 * Copyright (C) 1999 Andreas E. Bombe
7 *
8 * This code is licensed under the GPL. See the file COPYING in the root
9 * directory of the kernel sources for details.
10 */
11
12 #include <linux/sched.h>
13 #include <linux/bitops.h>
14 #include <linux/smp_lock.h>
15 #include <linux/interrupt.h>
16
17 #include <asm/errno.h>
18
19 #include "ieee1394.h"
20 #include "ieee1394_types.h"
21 #include "hosts.h"
22 #include "ieee1394_core.h"
23 #include "highlevel.h"
24 #include "nodemgr.h"
25 #include "ieee1394_transactions.h"
26
27 #define PREP_ASYNC_HEAD_ADDRESS(tc) \
28 packet->tcode = tc; \
29 packet->header[0] = (packet->node_id << 16) | (packet->tlabel << 10) \
30 | (1 << 8) | (tc << 4); \
31 packet->header[1] = (packet->host->node_id << 16) | (addr >> 32); \
32 packet->header[2] = addr & 0xffffffff
33
34 static void fill_async_readquad(struct hpsb_packet *packet, u64 addr)
35 {
36 PREP_ASYNC_HEAD_ADDRESS(TCODE_READQ);
37 packet->header_size = 12;
38 packet->data_size = 0;
39 packet->expect_response = 1;
40 }
41
42 static void fill_async_readblock(struct hpsb_packet *packet, u64 addr,
43 int length)
44 {
45 PREP_ASYNC_HEAD_ADDRESS(TCODE_READB);
46 packet->header[3] = length << 16;
47 packet->header_size = 16;
48 packet->data_size = 0;
49 packet->expect_response = 1;
50 }
51
52 static void fill_async_writequad(struct hpsb_packet *packet, u64 addr,
53 quadlet_t data)
54 {
55 PREP_ASYNC_HEAD_ADDRESS(TCODE_WRITEQ);
56 packet->header[3] = data;
57 packet->header_size = 16;
58 packet->data_size = 0;
59 packet->expect_response = 1;
60 }
61
62 static void fill_async_writeblock(struct hpsb_packet *packet, u64 addr,
63 int length)
64 {
65 PREP_ASYNC_HEAD_ADDRESS(TCODE_WRITEB);
66 packet->header[3] = length << 16;
67 packet->header_size = 16;
68 packet->expect_response = 1;
69 packet->data_size = length + (length % 4 ? 4 - (length % 4) : 0);
70 }
71
72 static void fill_async_lock(struct hpsb_packet *packet, u64 addr, int extcode,
73 int length)
74 {
75 PREP_ASYNC_HEAD_ADDRESS(TCODE_LOCK_REQUEST);
76 packet->header[3] = (length << 16) | extcode;
77 packet->header_size = 16;
78 packet->data_size = length;
79 packet->expect_response = 1;
80 }
81
82 static void fill_iso_packet(struct hpsb_packet *packet, int length, int channel,
83 int tag, int sync)
84 {
85 packet->header[0] = (length << 16) | (tag << 14) | (channel << 8)
86 | (TCODE_ISO_DATA << 4) | sync;
87
88 packet->header_size = 4;
89 packet->data_size = length;
90 packet->type = hpsb_iso;
91 packet->tcode = TCODE_ISO_DATA;
92 }
93
94 static void fill_phy_packet(struct hpsb_packet *packet, quadlet_t data)
95 {
96 packet->header[0] = data;
97 packet->header[1] = ~data;
98 packet->header_size = 8;
99 packet->data_size = 0;
100 packet->expect_response = 0;
101 packet->type = hpsb_raw; /* No CRC added */
102 packet->speed_code = IEEE1394_SPEED_100; /* Force speed to be 100Mbps */
103 }
104
105 static void fill_async_stream_packet(struct hpsb_packet *packet, int length,
106 int channel, int tag, int sync)
107 {
108 packet->header[0] = (length << 16) | (tag << 14) | (channel << 8)
109 | (TCODE_STREAM_DATA << 4) | sync;
110
111 packet->header_size = 4;
112 packet->data_size = length;
113 packet->type = hpsb_async;
114 packet->tcode = TCODE_ISO_DATA;
115 }
116
117 /**
118 * hpsb_get_tlabel - allocate a transaction label
119 * @packet: the packet who's tlabel/tpool we set
120 *
121 * Every asynchronous transaction on the 1394 bus needs a transaction
122 * label to match the response to the request. This label has to be
123 * different from any other transaction label in an outstanding request to
124 * the same node to make matching possible without ambiguity.
125 *
126 * There are 64 different tlabels, so an allocated tlabel has to be freed
127 * with hpsb_free_tlabel() after the transaction is complete (unless it's
128 * reused again for the same target node).
129 *
130 * Return value: Zero on success, otherwise non-zero. A non-zero return
131 * generally means there are no available tlabels. If this is called out
132 * of interrupt or atomic context, then it will sleep until can return a
133 * tlabel.
134 */
135 int hpsb_get_tlabel(struct hpsb_packet *packet)
136 {
137 unsigned long flags;
138 struct hpsb_tlabel_pool *tp;
139
140 tp = &packet->host->tpool[packet->node_id & NODE_MASK];
141
142 if (irqs_disabled() || in_atomic()) {
143 if (down_trylock(&tp->count))
144 return 1;
145 } else {
146 down(&tp->count);
147 }
148
149 spin_lock_irqsave(&tp->lock, flags);
150
151 packet->tlabel = find_next_zero_bit(tp->pool, 64, tp->next);
152 if (packet->tlabel > 63)
153 packet->tlabel = find_first_zero_bit(tp->pool, 64);
154 tp->next = (packet->tlabel + 1) % 64;
155 /* Should _never_ happen */
156 BUG_ON(test_and_set_bit(packet->tlabel, tp->pool));
157 tp->allocations++;
158 spin_unlock_irqrestore(&tp->lock, flags);
159
160 return 0;
161 }
162
163 /**
164 * hpsb_free_tlabel - free an allocated transaction label
165 * @packet: packet whos tlabel/tpool needs to be cleared
166 *
167 * Frees the transaction label allocated with hpsb_get_tlabel(). The
168 * tlabel has to be freed after the transaction is complete (i.e. response
169 * was received for a split transaction or packet was sent for a unified
170 * transaction).
171 *
172 * A tlabel must not be freed twice.
173 */
174 void hpsb_free_tlabel(struct hpsb_packet *packet)
175 {
176 unsigned long flags;
177 struct hpsb_tlabel_pool *tp;
178
179 tp = &packet->host->tpool[packet->node_id & NODE_MASK];
180
181 BUG_ON(packet->tlabel > 63 || packet->tlabel < 0);
182
183 spin_lock_irqsave(&tp->lock, flags);
184 BUG_ON(!test_and_clear_bit(packet->tlabel, tp->pool));
185 spin_unlock_irqrestore(&tp->lock, flags);
186
187 up(&tp->count);
188 }
189
190 int hpsb_packet_success(struct hpsb_packet *packet)
191 {
192 switch (packet->ack_code) {
193 case ACK_PENDING:
194 switch ((packet->header[1] >> 12) & 0xf) {
195 case RCODE_COMPLETE:
196 return 0;
197 case RCODE_CONFLICT_ERROR:
198 return -EAGAIN;
199 case RCODE_DATA_ERROR:
200 return -EREMOTEIO;
201 case RCODE_TYPE_ERROR:
202 return -EACCES;
203 case RCODE_ADDRESS_ERROR:
204 return -EINVAL;
205 default:
206 HPSB_ERR("received reserved rcode %d from node %d",
207 (packet->header[1] >> 12) & 0xf,
208 packet->node_id);
209 return -EAGAIN;
210 }
211 HPSB_PANIC("reached unreachable code 1 in %s", __FUNCTION__);
212
213 case ACK_BUSY_X:
214 case ACK_BUSY_A:
215 case ACK_BUSY_B:
216 return -EBUSY;
217
218 case ACK_TYPE_ERROR:
219 return -EACCES;
220
221 case ACK_COMPLETE:
222 if (packet->tcode == TCODE_WRITEQ
223 || packet->tcode == TCODE_WRITEB) {
224 return 0;
225 } else {
226 HPSB_ERR("impossible ack_complete from node %d "
227 "(tcode %d)", packet->node_id, packet->tcode);
228 return -EAGAIN;
229 }
230
231 case ACK_DATA_ERROR:
232 if (packet->tcode == TCODE_WRITEB
233 || packet->tcode == TCODE_LOCK_REQUEST) {
234 return -EAGAIN;
235 } else {
236 HPSB_ERR("impossible ack_data_error from node %d "
237 "(tcode %d)", packet->node_id, packet->tcode);
238 return -EAGAIN;
239 }
240
241 case ACK_ADDRESS_ERROR:
242 return -EINVAL;
243
244 case ACK_TARDY:
245 case ACK_CONFLICT_ERROR:
246 case ACKX_NONE:
247 case ACKX_SEND_ERROR:
248 case ACKX_ABORTED:
249 case ACKX_TIMEOUT:
250 /* error while sending */
251 return -EAGAIN;
252
253 default:
254 HPSB_ERR("got invalid ack %d from node %d (tcode %d)",
255 packet->ack_code, packet->node_id, packet->tcode);
256 return -EAGAIN;
257 }
258
259 HPSB_PANIC("reached unreachable code 2 in %s", __FUNCTION__);
260 }
261
262 struct hpsb_packet *hpsb_make_readpacket(struct hpsb_host *host, nodeid_t node,
263 u64 addr, size_t length)
264 {
265 struct hpsb_packet *packet;
266
267 if (length == 0)
268 return NULL;
269
270 packet = hpsb_alloc_packet(length);
271 if (!packet)
272 return NULL;
273
274 packet->host = host;
275 packet->node_id = node;
276
277 if (hpsb_get_tlabel(packet)) {
278 hpsb_free_packet(packet);
279 return NULL;
280 }
281
282 if (length == 4)
283 fill_async_readquad(packet, addr);
284 else
285 fill_async_readblock(packet, addr, length);
286
287 return packet;
288 }
289
290 struct hpsb_packet *hpsb_make_writepacket(struct hpsb_host *host, nodeid_t node,
291 u64 addr, quadlet_t * buffer,
292 size_t length)
293 {
294 struct hpsb_packet *packet;
295
296 if (length == 0)
297 return NULL;
298
299 packet = hpsb_alloc_packet(length);
300 if (!packet)
301 return NULL;
302
303 if (length % 4) { /* zero padding bytes */
304 packet->data[length >> 2] = 0;
305 }
306 packet->host = host;
307 packet->node_id = node;
308
309 if (hpsb_get_tlabel(packet)) {
310 hpsb_free_packet(packet);
311 return NULL;
312 }
313
314 if (length == 4) {
315 fill_async_writequad(packet, addr, buffer ? *buffer : 0);
316 } else {
317 fill_async_writeblock(packet, addr, length);
318 if (buffer)
319 memcpy(packet->data, buffer, length);
320 }
321
322 return packet;
323 }
324
325 struct hpsb_packet *hpsb_make_streampacket(struct hpsb_host *host, u8 * buffer,
326 int length, int channel, int tag,
327 int sync)
328 {
329 struct hpsb_packet *packet;
330
331 if (length == 0)
332 return NULL;
333
334 packet = hpsb_alloc_packet(length);
335 if (!packet)
336 return NULL;
337
338 if (length % 4) { /* zero padding bytes */
339 packet->data[length >> 2] = 0;
340 }
341 packet->host = host;
342
343 if (hpsb_get_tlabel(packet)) {
344 hpsb_free_packet(packet);
345 return NULL;
346 }
347
348 fill_async_stream_packet(packet, length, channel, tag, sync);
349 if (buffer)
350 memcpy(packet->data, buffer, length);
351
352 return packet;
353 }
354
355 struct hpsb_packet *hpsb_make_lockpacket(struct hpsb_host *host, nodeid_t node,
356 u64 addr, int extcode,
357 quadlet_t * data, quadlet_t arg)
358 {
359 struct hpsb_packet *p;
360 u32 length;
361
362 p = hpsb_alloc_packet(8);
363 if (!p)
364 return NULL;
365
366 p->host = host;
367 p->node_id = node;
368 if (hpsb_get_tlabel(p)) {
369 hpsb_free_packet(p);
370 return NULL;
371 }
372
373 switch (extcode) {
374 case EXTCODE_FETCH_ADD:
375 case EXTCODE_LITTLE_ADD:
376 length = 4;
377 if (data)
378 p->data[0] = *data;
379 break;
380 default:
381 length = 8;
382 if (data) {
383 p->data[0] = arg;
384 p->data[1] = *data;
385 }
386 break;
387 }
388 fill_async_lock(p, addr, extcode, length);
389
390 return p;
391 }
392
393 struct hpsb_packet *hpsb_make_lock64packet(struct hpsb_host *host,
394 nodeid_t node, u64 addr, int extcode,
395 octlet_t * data, octlet_t arg)
396 {
397 struct hpsb_packet *p;
398 u32 length;
399
400 p = hpsb_alloc_packet(16);
401 if (!p)
402 return NULL;
403
404 p->host = host;
405 p->node_id = node;
406 if (hpsb_get_tlabel(p)) {
407 hpsb_free_packet(p);
408 return NULL;
409 }
410
411 switch (extcode) {
412 case EXTCODE_FETCH_ADD:
413 case EXTCODE_LITTLE_ADD:
414 length = 8;
415 if (data) {
416 p->data[0] = *data >> 32;
417 p->data[1] = *data & 0xffffffff;
418 }
419 break;
420 default:
421 length = 16;
422 if (data) {
423 p->data[0] = arg >> 32;
424 p->data[1] = arg & 0xffffffff;
425 p->data[2] = *data >> 32;
426 p->data[3] = *data & 0xffffffff;
427 }
428 break;
429 }
430 fill_async_lock(p, addr, extcode, length);
431
432 return p;
433 }
434
435 struct hpsb_packet *hpsb_make_phypacket(struct hpsb_host *host, quadlet_t data)
436 {
437 struct hpsb_packet *p;
438
439 p = hpsb_alloc_packet(0);
440 if (!p)
441 return NULL;
442
443 p->host = host;
444 fill_phy_packet(p, data);
445
446 return p;
447 }
448
449 struct hpsb_packet *hpsb_make_isopacket(struct hpsb_host *host,
450 int length, int channel,
451 int tag, int sync)
452 {
453 struct hpsb_packet *p;
454
455 p = hpsb_alloc_packet(length);
456 if (!p)
457 return NULL;
458
459 p->host = host;
460 fill_iso_packet(p, length, channel, tag, sync);
461
462 p->generation = get_hpsb_generation(host);
463
464 return p;
465 }
466
467 /*
468 * FIXME - these functions should probably read from / write to user space to
469 * avoid in kernel buffers for user space callers
470 */
471
472 int hpsb_read(struct hpsb_host *host, nodeid_t node, unsigned int generation,
473 u64 addr, quadlet_t * buffer, size_t length)
474 {
475 struct hpsb_packet *packet;
476 int retval = 0;
477
478 if (length == 0)
479 return -EINVAL;
480
481 BUG_ON(in_interrupt()); // We can't be called in an interrupt, yet
482
483 packet = hpsb_make_readpacket(host, node, addr, length);
484
485 if (!packet) {
486 return -ENOMEM;
487 }
488
489 packet->generation = generation;
490 retval = hpsb_send_packet_and_wait(packet);
491 if (retval < 0)
492 goto hpsb_read_fail;
493
494 retval = hpsb_packet_success(packet);
495
496 if (retval == 0) {
497 if (length == 4) {
498 *buffer = packet->header[3];
499 } else {
500 memcpy(buffer, packet->data, length);
501 }
502 }
503
504 hpsb_read_fail:
505 hpsb_free_tlabel(packet);
506 hpsb_free_packet(packet);
507
508 return retval;
509 }
510
511 int hpsb_write(struct hpsb_host *host, nodeid_t node, unsigned int generation,
512 u64 addr, quadlet_t * buffer, size_t length)
513 {
514 struct hpsb_packet *packet;
515 int retval;
516
517 if (length == 0)
518 return -EINVAL;
519
520 BUG_ON(in_interrupt()); // We can't be called in an interrupt, yet
521
522 packet = hpsb_make_writepacket(host, node, addr, buffer, length);
523
524 if (!packet)
525 return -ENOMEM;
526
527 packet->generation = generation;
528 retval = hpsb_send_packet_and_wait(packet);
529 if (retval < 0)
530 goto hpsb_write_fail;
531
532 retval = hpsb_packet_success(packet);
533
534 hpsb_write_fail:
535 hpsb_free_tlabel(packet);
536 hpsb_free_packet(packet);
537
538 return retval;
539 }
540
541 #if 0
542
543 int hpsb_lock(struct hpsb_host *host, nodeid_t node, unsigned int generation,
544 u64 addr, int extcode, quadlet_t * data, quadlet_t arg)
545 {
546 struct hpsb_packet *packet;
547 int retval = 0;
548
549 BUG_ON(in_interrupt()); // We can't be called in an interrupt, yet
550
551 packet = hpsb_make_lockpacket(host, node, addr, extcode, data, arg);
552 if (!packet)
553 return -ENOMEM;
554
555 packet->generation = generation;
556 retval = hpsb_send_packet_and_wait(packet);
557 if (retval < 0)
558 goto hpsb_lock_fail;
559
560 retval = hpsb_packet_success(packet);
561
562 if (retval == 0) {
563 *data = packet->data[0];
564 }
565
566 hpsb_lock_fail:
567 hpsb_free_tlabel(packet);
568 hpsb_free_packet(packet);
569
570 return retval;
571 }
572
573 int hpsb_send_gasp(struct hpsb_host *host, int channel, unsigned int generation,
574 quadlet_t * buffer, size_t length, u32 specifier_id,
575 unsigned int version)
576 {
577 struct hpsb_packet *packet;
578 int retval = 0;
579 u16 specifier_id_hi = (specifier_id & 0x00ffff00) >> 8;
580 u8 specifier_id_lo = specifier_id & 0xff;
581
582 HPSB_VERBOSE("Send GASP: channel = %d, length = %Zd", channel, length);
583
584 length += 8;
585
586 packet = hpsb_make_streampacket(host, NULL, length, channel, 3, 0);
587 if (!packet)
588 return -ENOMEM;
589
590 packet->data[0] = cpu_to_be32((host->node_id << 16) | specifier_id_hi);
591 packet->data[1] =
592 cpu_to_be32((specifier_id_lo << 24) | (version & 0x00ffffff));
593
594 memcpy(&(packet->data[2]), buffer, length - 8);
595
596 packet->generation = generation;
597
598 packet->no_waiter = 1;
599
600 retval = hpsb_send_packet(packet);
601 if (retval < 0)
602 hpsb_free_packet(packet);
603
604 return retval;
605 }
606
607 #endif /* 0 */
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