Merge branch 'topic/misc' into for-linus
[linux-2.6] / 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/bitops.h>
13 #include <linux/compiler.h>
14 #include <linux/hardirq.h>
15 #include <linux/spinlock.h>
16 #include <linux/string.h>
17 #include <linux/sched.h>  /* because linux/wait.h is broken if CONFIG_SMP=n */
18 #include <linux/wait.h>
19
20 #include <asm/bug.h>
21 #include <asm/errno.h>
22 #include <asm/system.h>
23
24 #include "ieee1394.h"
25 #include "ieee1394_types.h"
26 #include "hosts.h"
27 #include "ieee1394_core.h"
28 #include "ieee1394_transactions.h"
29
30 #define PREP_ASYNC_HEAD_ADDRESS(tc) \
31         packet->tcode = tc; \
32         packet->header[0] = (packet->node_id << 16) | (packet->tlabel << 10) \
33                 | (1 << 8) | (tc << 4); \
34         packet->header[1] = (packet->host->node_id << 16) | (addr >> 32); \
35         packet->header[2] = addr & 0xffffffff
36
37 #ifndef HPSB_DEBUG_TLABELS
38 static
39 #endif
40 DEFINE_SPINLOCK(hpsb_tlabel_lock);
41
42 static DECLARE_WAIT_QUEUE_HEAD(tlabel_wq);
43
44 static void fill_async_readquad(struct hpsb_packet *packet, u64 addr)
45 {
46         PREP_ASYNC_HEAD_ADDRESS(TCODE_READQ);
47         packet->header_size = 12;
48         packet->data_size = 0;
49         packet->expect_response = 1;
50 }
51
52 static void fill_async_readblock(struct hpsb_packet *packet, u64 addr,
53                                  int length)
54 {
55         PREP_ASYNC_HEAD_ADDRESS(TCODE_READB);
56         packet->header[3] = length << 16;
57         packet->header_size = 16;
58         packet->data_size = 0;
59         packet->expect_response = 1;
60 }
61
62 static void fill_async_writequad(struct hpsb_packet *packet, u64 addr,
63                                  quadlet_t data)
64 {
65         PREP_ASYNC_HEAD_ADDRESS(TCODE_WRITEQ);
66         packet->header[3] = data;
67         packet->header_size = 16;
68         packet->data_size = 0;
69         packet->expect_response = 1;
70 }
71
72 static void fill_async_writeblock(struct hpsb_packet *packet, u64 addr,
73                                   int length)
74 {
75         PREP_ASYNC_HEAD_ADDRESS(TCODE_WRITEB);
76         packet->header[3] = length << 16;
77         packet->header_size = 16;
78         packet->expect_response = 1;
79         packet->data_size = length + (length % 4 ? 4 - (length % 4) : 0);
80 }
81
82 static void fill_async_lock(struct hpsb_packet *packet, u64 addr, int extcode,
83                             int length)
84 {
85         PREP_ASYNC_HEAD_ADDRESS(TCODE_LOCK_REQUEST);
86         packet->header[3] = (length << 16) | extcode;
87         packet->header_size = 16;
88         packet->data_size = length;
89         packet->expect_response = 1;
90 }
91
92 static void fill_phy_packet(struct hpsb_packet *packet, quadlet_t data)
93 {
94         packet->header[0] = data;
95         packet->header[1] = ~data;
96         packet->header_size = 8;
97         packet->data_size = 0;
98         packet->expect_response = 0;
99         packet->type = hpsb_raw;        /* No CRC added */
100         packet->speed_code = IEEE1394_SPEED_100;        /* Force speed to be 100Mbps */
101 }
102
103 static void fill_async_stream_packet(struct hpsb_packet *packet, int length,
104                                      int channel, int tag, int sync)
105 {
106         packet->header[0] = (length << 16) | (tag << 14) | (channel << 8)
107             | (TCODE_STREAM_DATA << 4) | sync;
108
109         packet->header_size = 4;
110         packet->data_size = length;
111         packet->type = hpsb_async;
112         packet->tcode = TCODE_ISO_DATA;
113 }
114
115 /* same as hpsb_get_tlabel, except that it returns immediately */
116 static int hpsb_get_tlabel_atomic(struct hpsb_packet *packet)
117 {
118         unsigned long flags, *tp;
119         u8 *next;
120         int tlabel, n = NODEID_TO_NODE(packet->node_id);
121
122         /* Broadcast transactions are complete once the request has been sent.
123          * Use the same transaction label for all broadcast transactions. */
124         if (unlikely(n == ALL_NODES)) {
125                 packet->tlabel = 0;
126                 return 0;
127         }
128         tp = packet->host->tl_pool[n].map;
129         next = &packet->host->next_tl[n];
130
131         spin_lock_irqsave(&hpsb_tlabel_lock, flags);
132         tlabel = find_next_zero_bit(tp, 64, *next);
133         if (tlabel > 63)
134                 tlabel = find_first_zero_bit(tp, 64);
135         if (tlabel > 63) {
136                 spin_unlock_irqrestore(&hpsb_tlabel_lock, flags);
137                 return -EAGAIN;
138         }
139         __set_bit(tlabel, tp);
140         *next = (tlabel + 1) & 63;
141         spin_unlock_irqrestore(&hpsb_tlabel_lock, flags);
142
143         packet->tlabel = tlabel;
144         return 0;
145 }
146
147 /**
148  * hpsb_get_tlabel - allocate a transaction label
149  * @packet: the packet whose tlabel and tl_pool we set
150  *
151  * Every asynchronous transaction on the 1394 bus needs a transaction
152  * label to match the response to the request.  This label has to be
153  * different from any other transaction label in an outstanding request to
154  * the same node to make matching possible without ambiguity.
155  *
156  * There are 64 different tlabels, so an allocated tlabel has to be freed
157  * with hpsb_free_tlabel() after the transaction is complete (unless it's
158  * reused again for the same target node).
159  *
160  * Return value: Zero on success, otherwise non-zero. A non-zero return
161  * generally means there are no available tlabels. If this is called out
162  * of interrupt or atomic context, then it will sleep until can return a
163  * tlabel or a signal is received.
164  */
165 int hpsb_get_tlabel(struct hpsb_packet *packet)
166 {
167         if (irqs_disabled() || in_atomic())
168                 return hpsb_get_tlabel_atomic(packet);
169
170         /* NB: The macro wait_event_interruptible() is called with a condition
171          * argument with side effect.  This is only possible because the side
172          * effect does not occur until the condition became true, and
173          * wait_event_interruptible() won't evaluate the condition again after
174          * that. */
175         return wait_event_interruptible(tlabel_wq,
176                                         !hpsb_get_tlabel_atomic(packet));
177 }
178
179 /**
180  * hpsb_free_tlabel - free an allocated transaction label
181  * @packet: packet whose tlabel and tl_pool needs to be cleared
182  *
183  * Frees the transaction label allocated with hpsb_get_tlabel().  The
184  * tlabel has to be freed after the transaction is complete (i.e. response
185  * was received for a split transaction or packet was sent for a unified
186  * transaction).
187  *
188  * A tlabel must not be freed twice.
189  */
190 void hpsb_free_tlabel(struct hpsb_packet *packet)
191 {
192         unsigned long flags, *tp;
193         int tlabel, n = NODEID_TO_NODE(packet->node_id);
194
195         if (unlikely(n == ALL_NODES))
196                 return;
197         tp = packet->host->tl_pool[n].map;
198         tlabel = packet->tlabel;
199         BUG_ON(tlabel > 63 || tlabel < 0);
200
201         spin_lock_irqsave(&hpsb_tlabel_lock, flags);
202         BUG_ON(!__test_and_clear_bit(tlabel, tp));
203         spin_unlock_irqrestore(&hpsb_tlabel_lock, flags);
204
205         wake_up_interruptible(&tlabel_wq);
206 }
207
208 /**
209  * hpsb_packet_success - Make sense of the ack and reply codes
210  *
211  * Make sense of the ack and reply codes and return more convenient error codes:
212  * 0 = success.  -%EBUSY = node is busy, try again.  -%EAGAIN = error which can
213  * probably resolved by retry.  -%EREMOTEIO = node suffers from an internal
214  * error.  -%EACCES = this transaction is not allowed on requested address.
215  * -%EINVAL = invalid address at node.
216  */
217 int hpsb_packet_success(struct hpsb_packet *packet)
218 {
219         switch (packet->ack_code) {
220         case ACK_PENDING:
221                 switch ((packet->header[1] >> 12) & 0xf) {
222                 case RCODE_COMPLETE:
223                         return 0;
224                 case RCODE_CONFLICT_ERROR:
225                         return -EAGAIN;
226                 case RCODE_DATA_ERROR:
227                         return -EREMOTEIO;
228                 case RCODE_TYPE_ERROR:
229                         return -EACCES;
230                 case RCODE_ADDRESS_ERROR:
231                         return -EINVAL;
232                 default:
233                         HPSB_ERR("received reserved rcode %d from node %d",
234                                  (packet->header[1] >> 12) & 0xf,
235                                  packet->node_id);
236                         return -EAGAIN;
237                 }
238
239         case ACK_BUSY_X:
240         case ACK_BUSY_A:
241         case ACK_BUSY_B:
242                 return -EBUSY;
243
244         case ACK_TYPE_ERROR:
245                 return -EACCES;
246
247         case ACK_COMPLETE:
248                 if (packet->tcode == TCODE_WRITEQ
249                     || packet->tcode == TCODE_WRITEB) {
250                         return 0;
251                 } else {
252                         HPSB_ERR("impossible ack_complete from node %d "
253                                  "(tcode %d)", packet->node_id, packet->tcode);
254                         return -EAGAIN;
255                 }
256
257         case ACK_DATA_ERROR:
258                 if (packet->tcode == TCODE_WRITEB
259                     || packet->tcode == TCODE_LOCK_REQUEST) {
260                         return -EAGAIN;
261                 } else {
262                         HPSB_ERR("impossible ack_data_error from node %d "
263                                  "(tcode %d)", packet->node_id, packet->tcode);
264                         return -EAGAIN;
265                 }
266
267         case ACK_ADDRESS_ERROR:
268                 return -EINVAL;
269
270         case ACK_TARDY:
271         case ACK_CONFLICT_ERROR:
272         case ACKX_NONE:
273         case ACKX_SEND_ERROR:
274         case ACKX_ABORTED:
275         case ACKX_TIMEOUT:
276                 /* error while sending */
277                 return -EAGAIN;
278
279         default:
280                 HPSB_ERR("got invalid ack %d from node %d (tcode %d)",
281                          packet->ack_code, packet->node_id, packet->tcode);
282                 return -EAGAIN;
283         }
284 }
285
286 struct hpsb_packet *hpsb_make_readpacket(struct hpsb_host *host, nodeid_t node,
287                                          u64 addr, size_t length)
288 {
289         struct hpsb_packet *packet;
290
291         if (length == 0)
292                 return NULL;
293
294         packet = hpsb_alloc_packet(length);
295         if (!packet)
296                 return NULL;
297
298         packet->host = host;
299         packet->node_id = node;
300
301         if (hpsb_get_tlabel(packet)) {
302                 hpsb_free_packet(packet);
303                 return NULL;
304         }
305
306         if (length == 4)
307                 fill_async_readquad(packet, addr);
308         else
309                 fill_async_readblock(packet, addr, length);
310
311         return packet;
312 }
313
314 struct hpsb_packet *hpsb_make_writepacket(struct hpsb_host *host, nodeid_t node,
315                                           u64 addr, quadlet_t * buffer,
316                                           size_t length)
317 {
318         struct hpsb_packet *packet;
319
320         if (length == 0)
321                 return NULL;
322
323         packet = hpsb_alloc_packet(length);
324         if (!packet)
325                 return NULL;
326
327         if (length % 4) {       /* zero padding bytes */
328                 packet->data[length >> 2] = 0;
329         }
330         packet->host = host;
331         packet->node_id = node;
332
333         if (hpsb_get_tlabel(packet)) {
334                 hpsb_free_packet(packet);
335                 return NULL;
336         }
337
338         if (length == 4) {
339                 fill_async_writequad(packet, addr, buffer ? *buffer : 0);
340         } else {
341                 fill_async_writeblock(packet, addr, length);
342                 if (buffer)
343                         memcpy(packet->data, buffer, length);
344         }
345
346         return packet;
347 }
348
349 struct hpsb_packet *hpsb_make_streampacket(struct hpsb_host *host, u8 * buffer,
350                                            int length, int channel, int tag,
351                                            int sync)
352 {
353         struct hpsb_packet *packet;
354
355         if (length == 0)
356                 return NULL;
357
358         packet = hpsb_alloc_packet(length);
359         if (!packet)
360                 return NULL;
361
362         if (length % 4) {       /* zero padding bytes */
363                 packet->data[length >> 2] = 0;
364         }
365         packet->host = host;
366
367         /* Because it is too difficult to determine all PHY speeds and link
368          * speeds here, we use S100... */
369         packet->speed_code = IEEE1394_SPEED_100;
370
371         /* ...and prevent hpsb_send_packet() from overriding it. */
372         packet->node_id = LOCAL_BUS | ALL_NODES;
373
374         if (hpsb_get_tlabel(packet)) {
375                 hpsb_free_packet(packet);
376                 return NULL;
377         }
378
379         fill_async_stream_packet(packet, length, channel, tag, sync);
380         if (buffer)
381                 memcpy(packet->data, buffer, length);
382
383         return packet;
384 }
385
386 struct hpsb_packet *hpsb_make_lockpacket(struct hpsb_host *host, nodeid_t node,
387                                          u64 addr, int extcode,
388                                          quadlet_t * data, quadlet_t arg)
389 {
390         struct hpsb_packet *p;
391         u32 length;
392
393         p = hpsb_alloc_packet(8);
394         if (!p)
395                 return NULL;
396
397         p->host = host;
398         p->node_id = node;
399         if (hpsb_get_tlabel(p)) {
400                 hpsb_free_packet(p);
401                 return NULL;
402         }
403
404         switch (extcode) {
405         case EXTCODE_FETCH_ADD:
406         case EXTCODE_LITTLE_ADD:
407                 length = 4;
408                 if (data)
409                         p->data[0] = *data;
410                 break;
411         default:
412                 length = 8;
413                 if (data) {
414                         p->data[0] = arg;
415                         p->data[1] = *data;
416                 }
417                 break;
418         }
419         fill_async_lock(p, addr, extcode, length);
420
421         return p;
422 }
423
424 struct hpsb_packet *hpsb_make_lock64packet(struct hpsb_host *host,
425                                            nodeid_t node, u64 addr, int extcode,
426                                            octlet_t * data, octlet_t arg)
427 {
428         struct hpsb_packet *p;
429         u32 length;
430
431         p = hpsb_alloc_packet(16);
432         if (!p)
433                 return NULL;
434
435         p->host = host;
436         p->node_id = node;
437         if (hpsb_get_tlabel(p)) {
438                 hpsb_free_packet(p);
439                 return NULL;
440         }
441
442         switch (extcode) {
443         case EXTCODE_FETCH_ADD:
444         case EXTCODE_LITTLE_ADD:
445                 length = 8;
446                 if (data) {
447                         p->data[0] = *data >> 32;
448                         p->data[1] = *data & 0xffffffff;
449                 }
450                 break;
451         default:
452                 length = 16;
453                 if (data) {
454                         p->data[0] = arg >> 32;
455                         p->data[1] = arg & 0xffffffff;
456                         p->data[2] = *data >> 32;
457                         p->data[3] = *data & 0xffffffff;
458                 }
459                 break;
460         }
461         fill_async_lock(p, addr, extcode, length);
462
463         return p;
464 }
465
466 struct hpsb_packet *hpsb_make_phypacket(struct hpsb_host *host, quadlet_t data)
467 {
468         struct hpsb_packet *p;
469
470         p = hpsb_alloc_packet(0);
471         if (!p)
472                 return NULL;
473
474         p->host = host;
475         fill_phy_packet(p, data);
476
477         return p;
478 }
479
480 /*
481  * FIXME - these functions should probably read from / write to user space to
482  * avoid in kernel buffers for user space callers
483  */
484
485 /**
486  * hpsb_read - generic read function
487  *
488  * Recognizes the local node ID and act accordingly.  Automatically uses a
489  * quadlet read request if @length == 4 and and a block read request otherwise.
490  * It does not yet support lengths that are not a multiple of 4.
491  *
492  * You must explicitly specifiy the @generation for which the node ID is valid,
493  * to avoid sending packets to the wrong nodes when we race with a bus reset.
494  */
495 int hpsb_read(struct hpsb_host *host, nodeid_t node, unsigned int generation,
496               u64 addr, quadlet_t * buffer, size_t length)
497 {
498         struct hpsb_packet *packet;
499         int retval = 0;
500
501         if (length == 0)
502                 return -EINVAL;
503
504         packet = hpsb_make_readpacket(host, node, addr, length);
505
506         if (!packet) {
507                 return -ENOMEM;
508         }
509
510         packet->generation = generation;
511         retval = hpsb_send_packet_and_wait(packet);
512         if (retval < 0)
513                 goto hpsb_read_fail;
514
515         retval = hpsb_packet_success(packet);
516
517         if (retval == 0) {
518                 if (length == 4) {
519                         *buffer = packet->header[3];
520                 } else {
521                         memcpy(buffer, packet->data, length);
522                 }
523         }
524
525       hpsb_read_fail:
526         hpsb_free_tlabel(packet);
527         hpsb_free_packet(packet);
528
529         return retval;
530 }
531
532 /**
533  * hpsb_write - generic write function
534  *
535  * Recognizes the local node ID and act accordingly.  Automatically uses a
536  * quadlet write request if @length == 4 and and a block write request
537  * otherwise.  It does not yet support lengths that are not a multiple of 4.
538  *
539  * You must explicitly specifiy the @generation for which the node ID is valid,
540  * to avoid sending packets to the wrong nodes when we race with a bus reset.
541  */
542 int hpsb_write(struct hpsb_host *host, nodeid_t node, unsigned int generation,
543                u64 addr, quadlet_t * buffer, size_t length)
544 {
545         struct hpsb_packet *packet;
546         int retval;
547
548         if (length == 0)
549                 return -EINVAL;
550
551         packet = hpsb_make_writepacket(host, node, addr, buffer, length);
552
553         if (!packet)
554                 return -ENOMEM;
555
556         packet->generation = generation;
557         retval = hpsb_send_packet_and_wait(packet);
558         if (retval < 0)
559                 goto hpsb_write_fail;
560
561         retval = hpsb_packet_success(packet);
562
563       hpsb_write_fail:
564         hpsb_free_tlabel(packet);
565         hpsb_free_packet(packet);
566
567         return retval;
568 }
569
570 int hpsb_lock(struct hpsb_host *host, nodeid_t node, unsigned int generation,
571               u64 addr, int extcode, quadlet_t *data, quadlet_t arg)
572 {
573         struct hpsb_packet *packet;
574         int retval = 0;
575
576         packet = hpsb_make_lockpacket(host, node, addr, extcode, data, arg);
577         if (!packet)
578                 return -ENOMEM;
579
580         packet->generation = generation;
581         retval = hpsb_send_packet_and_wait(packet);
582         if (retval < 0)
583                 goto hpsb_lock_fail;
584
585         retval = hpsb_packet_success(packet);
586
587         if (retval == 0)
588                 *data = packet->data[0];
589
590 hpsb_lock_fail:
591         hpsb_free_tlabel(packet);
592         hpsb_free_packet(packet);
593
594         return retval;
595 }