1/*
2 * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software Foundation,
16 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18
19#include <linux/module.h>
20#include <linux/errno.h>
21#include <linux/device.h>
22#include <linux/mutex.h>
23#include <linux/crc-itu-t.h>
24#include "fw-transaction.h"
25#include "fw-topology.h"
26#include "fw-device.h"
27
28int fw_compute_block_crc(u32 *block)
29{
30	__be32 be32_block[256];
31	int i, length;
32
33	length = (*block >> 16) & 0xff;
34	for (i = 0; i < length; i++)
35		be32_block[i] = cpu_to_be32(block[i + 1]);
36	*block |= crc_itu_t(0, (u8 *) be32_block, length * 4);
37
38	return length;
39}
40
41static DEFINE_MUTEX(card_mutex);
42static LIST_HEAD(card_list);
43
44static LIST_HEAD(descriptor_list);
45static int descriptor_count;
46
47#define BIB_CRC(v)		((v) <<  0)
48#define BIB_CRC_LENGTH(v)	((v) << 16)
49#define BIB_INFO_LENGTH(v)	((v) << 24)
50
51#define BIB_LINK_SPEED(v)	((v) <<  0)
52#define BIB_GENERATION(v)	((v) <<  4)
53#define BIB_MAX_ROM(v)		((v) <<  8)
54#define BIB_MAX_RECEIVE(v)	((v) << 12)
55#define BIB_CYC_CLK_ACC(v)	((v) << 16)
56#define BIB_PMC			((1) << 27)
57#define BIB_BMC			((1) << 28)
58#define BIB_ISC			((1) << 29)
59#define BIB_CMC			((1) << 30)
60#define BIB_IMC			((1) << 31)
61
62static u32 *
63generate_config_rom(struct fw_card *card, size_t *config_rom_length)
64{
65	struct fw_descriptor *desc;
66	static u32 config_rom[256];
67	int i, j, length;
68
69	/*
70	 * Initialize contents of config rom buffer.  On the OHCI
71	 * controller, block reads to the config rom accesses the host
72	 * memory, but quadlet read access the hardware bus info block
73	 * registers.  That's just crack, but it means we should make
74	 * sure the contents of bus info block in host memory mathces
75	 * the version stored in the OHCI registers.
76	 */
77
78	memset(config_rom, 0, sizeof(config_rom));
79	config_rom[0] = BIB_CRC_LENGTH(4) | BIB_INFO_LENGTH(4) | BIB_CRC(0);
80	config_rom[1] = 0x31333934;
81
82	config_rom[2] =
83		BIB_LINK_SPEED(card->link_speed) |
84		BIB_GENERATION(card->config_rom_generation++ % 14 + 2) |
85		BIB_MAX_ROM(2) |
86		BIB_MAX_RECEIVE(card->max_receive) |
87		BIB_BMC | BIB_ISC | BIB_CMC | BIB_IMC;
88	config_rom[3] = card->guid >> 32;
89	config_rom[4] = card->guid;
90
91	/* Generate root directory. */
92	i = 5;
93	config_rom[i++] = 0;
94	config_rom[i++] = 0x0c0083c0; /* node capabilities */
95	j = i + descriptor_count;
96
97	/* Generate root directory entries for descriptors. */
98	list_for_each_entry (desc, &descriptor_list, link) {
99		if (desc->immediate > 0)
100			config_rom[i++] = desc->immediate;
101		config_rom[i] = desc->key | (j - i);
102		i++;
103		j += desc->length;
104	}
105
106	/* Update root directory length. */
107	config_rom[5] = (i - 5 - 1) << 16;
108
109	/* End of root directory, now copy in descriptors. */
110	list_for_each_entry (desc, &descriptor_list, link) {
111		memcpy(&config_rom[i], desc->data, desc->length * 4);
112		i += desc->length;
113	}
114
115	/* Calculate CRCs for all blocks in the config rom.  This
116	 * assumes that CRC length and info length are identical for
117	 * the bus info block, which is always the case for this
118	 * implementation. */
119	for (i = 0; i < j; i += length + 1)
120		length = fw_compute_block_crc(config_rom + i);
121
122	*config_rom_length = j;
123
124	return config_rom;
125}
126
127static void
128update_config_roms(void)
129{
130	struct fw_card *card;
131	u32 *config_rom;
132	size_t length;
133
134	list_for_each_entry (card, &card_list, link) {
135		config_rom = generate_config_rom(card, &length);
136		card->driver->set_config_rom(card, config_rom, length);
137	}
138}
139
140int
141fw_core_add_descriptor(struct fw_descriptor *desc)
142{
143	size_t i;
144
145	/*
146	 * Check descriptor is valid; the length of all blocks in the
147	 * descriptor has to add up to exactly the length of the
148	 * block.
149	 */
150	i = 0;
151	while (i < desc->length)
152		i += (desc->data[i] >> 16) + 1;
153
154	if (i != desc->length)
155		return -EINVAL;
156
157	mutex_lock(&card_mutex);
158
159	list_add_tail(&desc->link, &descriptor_list);
160	descriptor_count++;
161	if (desc->immediate > 0)
162		descriptor_count++;
163	update_config_roms();
164
165	mutex_unlock(&card_mutex);
166
167	return 0;
168}
169EXPORT_SYMBOL(fw_core_add_descriptor);
170
171void
172fw_core_remove_descriptor(struct fw_descriptor *desc)
173{
174	mutex_lock(&card_mutex);
175
176	list_del(&desc->link);
177	descriptor_count--;
178	if (desc->immediate > 0)
179		descriptor_count--;
180	update_config_roms();
181
182	mutex_unlock(&card_mutex);
183}
184EXPORT_SYMBOL(fw_core_remove_descriptor);
185
186static const char gap_count_table[] = {
187	63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40
188};
189
190struct bm_data {
191	struct fw_transaction t;
192	struct {
193		__be32 arg;
194		__be32 data;
195	} lock;
196	u32 old;
197	int rcode;
198	struct completion done;
199};
200
201static void
202complete_bm_lock(struct fw_card *card, int rcode,
203		 void *payload, size_t length, void *data)
204{
205	struct bm_data *bmd = data;
206
207	if (rcode == RCODE_COMPLETE)
208		bmd->old = be32_to_cpu(*(__be32 *) payload);
209	bmd->rcode = rcode;
210	complete(&bmd->done);
211}
212
213static void
214fw_card_bm_work(struct work_struct *work)
215{
216	struct fw_card *card = container_of(work, struct fw_card, work.work);
217	struct fw_device *root;
218	struct bm_data bmd;
219	unsigned long flags;
220	int root_id, new_root_id, irm_id, gap_count, generation, grace;
221	int do_reset = 0;
222
223	spin_lock_irqsave(&card->lock, flags);
224
225	generation = card->generation;
226	root = card->root_node->data;
227	root_id = card->root_node->node_id;
228	grace = time_after(jiffies, card->reset_jiffies + DIV_ROUND_UP(HZ, 10));
229
230	if (card->bm_generation + 1 == generation ||
231	    (card->bm_generation != generation && grace)) {
232		/*
233		 * This first step is to figure out who is IRM and
234		 * then try to become bus manager.  If the IRM is not
235		 * well defined (e.g. does not have an active link
236		 * layer or does not responds to our lock request, we
237		 * will have to do a little vigilante bus management.
238		 * In that case, we do a goto into the gap count logic
239		 * so that when we do the reset, we still optimize the
240		 * gap count.  That could well save a reset in the
241		 * next generation.
242		 */
243
244		irm_id = card->irm_node->node_id;
245		if (!card->irm_node->link_on) {
246			new_root_id = card->local_node->node_id;
247			fw_notify("IRM has link off, making local node (%02x) root.\n",
248				  new_root_id);
249			goto pick_me;
250		}
251
252		bmd.lock.arg = cpu_to_be32(0x3f);
253		bmd.lock.data = cpu_to_be32(card->local_node->node_id);
254
255		spin_unlock_irqrestore(&card->lock, flags);
256
257		init_completion(&bmd.done);
258		fw_send_request(card, &bmd.t, TCODE_LOCK_COMPARE_SWAP,
259				irm_id, generation,
260				SCODE_100, CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID,
261				&bmd.lock, sizeof(bmd.lock),
262				complete_bm_lock, &bmd);
263		wait_for_completion(&bmd.done);
264
265		if (bmd.rcode == RCODE_GENERATION) {
266			/*
267			 * Another bus reset happened. Just return,
268			 * the BM work has been rescheduled.
269			 */
270			return;
271		}
272
273		if (bmd.rcode == RCODE_COMPLETE && bmd.old != 0x3f)
274			/* Somebody else is BM, let them do the work. */
275			return;
276
277		spin_lock_irqsave(&card->lock, flags);
278		if (bmd.rcode != RCODE_COMPLETE) {
279			/*
280			 * The lock request failed, maybe the IRM
281			 * isn't really IRM capable after all. Let's
282			 * do a bus reset and pick the local node as
283			 * root, and thus, IRM.
284			 */
285			new_root_id = card->local_node->node_id;
286			fw_notify("BM lock failed, making local node (%02x) root.\n",
287				  new_root_id);
288			goto pick_me;
289		}
290	} else if (card->bm_generation != generation) {
291		/*
292		 * OK, we weren't BM in the last generation, and it's
293		 * less than 100ms since last bus reset. Reschedule
294		 * this task 100ms from now.
295		 */
296		spin_unlock_irqrestore(&card->lock, flags);
297		schedule_delayed_work(&card->work, DIV_ROUND_UP(HZ, 10));
298		return;
299	}
300
301	/*
302	 * We're bus manager for this generation, so next step is to
303	 * make sure we have an active cycle master and do gap count
304	 * optimization.
305	 */
306	card->bm_generation = generation;
307
308	if (root == NULL) {
309		/*
310		 * Either link_on is false, or we failed to read the
311		 * config rom.  In either case, pick another root.
312		 */
313		new_root_id = card->local_node->node_id;
314	} else if (atomic_read(&root->state) != FW_DEVICE_RUNNING) {
315		/*
316		 * If we haven't probed this device yet, bail out now
317		 * and let's try again once that's done.
318		 */
319		spin_unlock_irqrestore(&card->lock, flags);
320		return;
321	} else if (root->config_rom[2] & BIB_CMC) {
322		new_root_id = root_id;
323	} else {
324		/*
325		 * Current root has an active link layer and we
326		 * successfully read the config rom, but it's not
327		 * cycle master capable.
328		 */
329		new_root_id = card->local_node->node_id;
330	}
331
332 pick_me:
333	/* Now figure out what gap count to set. */
334	if (card->topology_type == FW_TOPOLOGY_A &&
335	    card->root_node->max_hops < ARRAY_SIZE(gap_count_table))
336		gap_count = gap_count_table[card->root_node->max_hops];
337	else
338		gap_count = 63;
339
340	/*
341	 * Finally, figure out if we should do a reset or not.  If we've
342	 * done less that 5 resets with the same physical topology and we
343	 * have either a new root or a new gap count setting, let's do it.
344	 */
345
346	if (card->bm_retries++ < 5 &&
347	    (card->gap_count != gap_count || new_root_id != root_id))
348		do_reset = 1;
349
350	spin_unlock_irqrestore(&card->lock, flags);
351
352	if (do_reset) {
353		fw_notify("phy config: card %d, new root=%x, gap_count=%d\n",
354			  card->index, new_root_id, gap_count);
355		fw_send_phy_config(card, new_root_id, generation, gap_count);
356		fw_core_initiate_bus_reset(card, 1);
357	}
358}
359
360static void
361flush_timer_callback(unsigned long data)
362{
363	struct fw_card *card = (struct fw_card *)data;
364
365	fw_flush_transactions(card);
366}
367
368void
369fw_card_initialize(struct fw_card *card, const struct fw_card_driver *driver,
370		   struct device *device)
371{
372	static atomic_t index = ATOMIC_INIT(-1);
373
374	kref_init(&card->kref);
375	card->index = atomic_inc_return(&index);
376	card->driver = driver;
377	card->device = device;
378	card->current_tlabel = 0;
379	card->tlabel_mask = 0;
380	card->color = 0;
381
382	INIT_LIST_HEAD(&card->transaction_list);
383	spin_lock_init(&card->lock);
384	setup_timer(&card->flush_timer,
385		    flush_timer_callback, (unsigned long)card);
386
387	card->local_node = NULL;
388
389	INIT_DELAYED_WORK(&card->work, fw_card_bm_work);
390}
391EXPORT_SYMBOL(fw_card_initialize);
392
393int
394fw_card_add(struct fw_card *card,
395	    u32 max_receive, u32 link_speed, u64 guid)
396{
397	u32 *config_rom;
398	size_t length;
399
400	card->max_receive = max_receive;
401	card->link_speed = link_speed;
402	card->guid = guid;
403
404	/*
405	 * The subsystem grabs a reference when the card is added and
406	 * drops it when the driver calls fw_core_remove_card.
407	 */
408	fw_card_get(card);
409
410	mutex_lock(&card_mutex);
411	config_rom = generate_config_rom(card, &length);
412	list_add_tail(&card->link, &card_list);
413	mutex_unlock(&card_mutex);
414
415	return card->driver->enable(card, config_rom, length);
416}
417EXPORT_SYMBOL(fw_card_add);
418
419
420/*
421 * The next few functions implements a dummy driver that use once a
422 * card driver shuts down an fw_card.  This allows the driver to
423 * cleanly unload, as all IO to the card will be handled by the dummy
424 * driver instead of calling into the (possibly) unloaded module.  The
425 * dummy driver just fails all IO.
426 */
427
428static int
429dummy_enable(struct fw_card *card, u32 *config_rom, size_t length)
430{
431	BUG();
432	return -1;
433}
434
435static int
436dummy_update_phy_reg(struct fw_card *card, int address,
437		     int clear_bits, int set_bits)
438{
439	return -ENODEV;
440}
441
442static int
443dummy_set_config_rom(struct fw_card *card,
444		     u32 *config_rom, size_t length)
445{
446	/*
447	 * We take the card out of card_list before setting the dummy
448	 * driver, so this should never get called.
449	 */
450	BUG();
451	return -1;
452}
453
454static void
455dummy_send_request(struct fw_card *card, struct fw_packet *packet)
456{
457	packet->callback(packet, card, -ENODEV);
458}
459
460static void
461dummy_send_response(struct fw_card *card, struct fw_packet *packet)
462{
463	packet->callback(packet, card, -ENODEV);
464}
465
466static int
467dummy_cancel_packet(struct fw_card *card, struct fw_packet *packet)
468{
469	return -ENOENT;
470}
471
472static int
473dummy_enable_phys_dma(struct fw_card *card,
474		      int node_id, int generation)
475{
476	return -ENODEV;
477}
478
479static struct fw_card_driver dummy_driver = {
480	.name            = "dummy",
481	.enable          = dummy_enable,
482	.update_phy_reg  = dummy_update_phy_reg,
483	.set_config_rom  = dummy_set_config_rom,
484	.send_request    = dummy_send_request,
485	.cancel_packet   = dummy_cancel_packet,
486	.send_response   = dummy_send_response,
487	.enable_phys_dma = dummy_enable_phys_dma,
488};
489
490void
491fw_core_remove_card(struct fw_card *card)
492{
493	card->driver->update_phy_reg(card, 4,
494				     PHY_LINK_ACTIVE | PHY_CONTENDER, 0);
495	fw_core_initiate_bus_reset(card, 1);
496
497	mutex_lock(&card_mutex);
498	list_del(&card->link);
499	mutex_unlock(&card_mutex);
500
501	/* Set up the dummy driver. */
502	card->driver = &dummy_driver;
503
504	fw_flush_transactions(card);
505
506	fw_destroy_nodes(card);
507
508	fw_card_put(card);
509}
510EXPORT_SYMBOL(fw_core_remove_card);
511
512struct fw_card *
513fw_card_get(struct fw_card *card)
514{
515	kref_get(&card->kref);
516
517	return card;
518}
519EXPORT_SYMBOL(fw_card_get);
520
521static void
522release_card(struct kref *kref)
523{
524	struct fw_card *card = container_of(kref, struct fw_card, kref);
525
526	kfree(card);
527}
528
529/*
530 * An assumption for fw_card_put() is that the card driver allocates
531 * the fw_card struct with kalloc and that it has been shut down
532 * before the last ref is dropped.
533 */
534void
535fw_card_put(struct fw_card *card)
536{
537	kref_put(&card->kref, release_card);
538}
539EXPORT_SYMBOL(fw_card_put);
540
541int
542fw_core_initiate_bus_reset(struct fw_card *card, int short_reset)
543{
544	int reg = short_reset ? 5 : 1;
545	int bit = short_reset ? PHY_BUS_SHORT_RESET : PHY_BUS_RESET;
546
547	return card->driver->update_phy_reg(card, reg, 0, bit);
548}
549EXPORT_SYMBOL(fw_core_initiate_bus_reset);
550