Free Electrons

Embedded Linux Experts

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
/*
 * Serial Attached SCSI (SAS) Transport Layer initialization
 *
 * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
 * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
 *
 * This file is licensed under GPLv2.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 *
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/spinlock.h>
#include <scsi/sas_ata.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_sas.h>

#include "sas_internal.h"

#include "../scsi_sas_internal.h"

static struct kmem_cache *sas_task_cache;

struct sas_task *sas_alloc_task(gfp_t flags)
{
	struct sas_task *task = kmem_cache_zalloc(sas_task_cache, flags);

	if (task) {
		INIT_LIST_HEAD(&task->list);
		spin_lock_init(&task->task_state_lock);
		task->task_state_flags = SAS_TASK_STATE_PENDING;
		init_timer(&task->timer);
		init_completion(&task->completion);
	}

	return task;
}
EXPORT_SYMBOL_GPL(sas_alloc_task);

void sas_free_task(struct sas_task *task)
{
	if (task) {
		BUG_ON(!list_empty(&task->list));
		kmem_cache_free(sas_task_cache, task);
	}
}
EXPORT_SYMBOL_GPL(sas_free_task);

/*------------ SAS addr hash -----------*/
void sas_hash_addr(u8 *hashed, const u8 *sas_addr)
{
        const u32 poly = 0x00DB2777;
        u32     r = 0;
        int     i;

        for (i = 0; i < 8; i++) {
                int b;
                for (b = 7; b >= 0; b--) {
                        r <<= 1;
                        if ((1 << b) & sas_addr[i]) {
                                if (!(r & 0x01000000))
                                        r ^= poly;
                        } else if (r & 0x01000000)
                                r ^= poly;
                }
        }

        hashed[0] = (r >> 16) & 0xFF;
        hashed[1] = (r >> 8) & 0xFF ;
        hashed[2] = r & 0xFF;
}


/* ---------- HA events ---------- */

void sas_hae_reset(struct work_struct *work)
{
	struct sas_ha_event *ev =
		container_of(work, struct sas_ha_event, work);
	struct sas_ha_struct *ha = ev->ha;

	clear_bit(HAE_RESET, &ha->pending);
}

int sas_register_ha(struct sas_ha_struct *sas_ha)
{
	int error = 0;

	mutex_init(&sas_ha->disco_mutex);
	spin_lock_init(&sas_ha->phy_port_lock);
	sas_hash_addr(sas_ha->hashed_sas_addr, sas_ha->sas_addr);

	if (sas_ha->lldd_queue_size == 0)
		sas_ha->lldd_queue_size = 1;
	else if (sas_ha->lldd_queue_size == -1)
		sas_ha->lldd_queue_size = 128; /* Sanity */

	set_bit(SAS_HA_REGISTERED, &sas_ha->state);
	spin_lock_init(&sas_ha->state_lock);
	mutex_init(&sas_ha->drain_mutex);
	INIT_LIST_HEAD(&sas_ha->defer_q);

	error = sas_register_phys(sas_ha);
	if (error) {
		printk(KERN_NOTICE "couldn't register sas phys:%d\n", error);
		return error;
	}

	error = sas_register_ports(sas_ha);
	if (error) {
		printk(KERN_NOTICE "couldn't register sas ports:%d\n", error);
		goto Undo_phys;
	}

	error = sas_init_events(sas_ha);
	if (error) {
		printk(KERN_NOTICE "couldn't start event thread:%d\n", error);
		goto Undo_ports;
	}

	if (sas_ha->lldd_max_execute_num > 1) {
		error = sas_init_queue(sas_ha);
		if (error) {
			printk(KERN_NOTICE "couldn't start queue thread:%d, "
			       "running in direct mode\n", error);
			sas_ha->lldd_max_execute_num = 1;
		}
	}

	INIT_LIST_HEAD(&sas_ha->eh_done_q);
	INIT_LIST_HEAD(&sas_ha->eh_ata_q);

	return 0;

Undo_ports:
	sas_unregister_ports(sas_ha);
Undo_phys:

	return error;
}

int sas_unregister_ha(struct sas_ha_struct *sas_ha)
{
	/* Set the state to unregistered to avoid further unchained
	 * events to be queued, and flush any in-progress drainers
	 */
	mutex_lock(&sas_ha->drain_mutex);
	spin_lock_irq(&sas_ha->state_lock);
	clear_bit(SAS_HA_REGISTERED, &sas_ha->state);
	spin_unlock_irq(&sas_ha->state_lock);
	__sas_drain_work(sas_ha);
	mutex_unlock(&sas_ha->drain_mutex);

	sas_unregister_ports(sas_ha);

	/* flush unregistration work */
	mutex_lock(&sas_ha->drain_mutex);
	__sas_drain_work(sas_ha);
	mutex_unlock(&sas_ha->drain_mutex);

	if (sas_ha->lldd_max_execute_num > 1) {
		sas_shutdown_queue(sas_ha);
		sas_ha->lldd_max_execute_num = 1;
	}

	return 0;
}

static int sas_get_linkerrors(struct sas_phy *phy)
{
	if (scsi_is_sas_phy_local(phy)) {
		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
		struct sas_internal *i =
			to_sas_internal(sas_ha->core.shost->transportt);

		return i->dft->lldd_control_phy(asd_phy, PHY_FUNC_GET_EVENTS, NULL);
	}

	return sas_smp_get_phy_events(phy);
}

int sas_try_ata_reset(struct asd_sas_phy *asd_phy)
{
	struct domain_device *dev = NULL;

	/* try to route user requested link resets through libata */
	if (asd_phy->port)
		dev = asd_phy->port->port_dev;

	/* validate that dev has been probed */
	if (dev)
		dev = sas_find_dev_by_rphy(dev->rphy);

	if (dev && dev_is_sata(dev)) {
		sas_ata_schedule_reset(dev);
		sas_ata_wait_eh(dev);
		return 0;
	}

	return -ENODEV;
}

/**
 * transport_sas_phy_reset - reset a phy and permit libata to manage the link
 *
 * phy reset request via sysfs in host workqueue context so we know we
 * can block on eh and safely traverse the domain_device topology
 */
static int transport_sas_phy_reset(struct sas_phy *phy, int hard_reset)
{
	enum phy_func reset_type;

	if (hard_reset)
		reset_type = PHY_FUNC_HARD_RESET;
	else
		reset_type = PHY_FUNC_LINK_RESET;

	if (scsi_is_sas_phy_local(phy)) {
		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
		struct sas_internal *i =
			to_sas_internal(sas_ha->core.shost->transportt);

		if (!hard_reset && sas_try_ata_reset(asd_phy) == 0)
			return 0;
		return i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
	} else {
		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
		struct domain_device *ata_dev = sas_ex_to_ata(ddev, phy->number);

		if (ata_dev && !hard_reset) {
			sas_ata_schedule_reset(ata_dev);
			sas_ata_wait_eh(ata_dev);
			return 0;
		} else
			return sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
	}
}

static int sas_phy_enable(struct sas_phy *phy, int enable)
{
	int ret;
	enum phy_func cmd;

	if (enable)
		cmd = PHY_FUNC_LINK_RESET;
	else
		cmd = PHY_FUNC_DISABLE;

	if (scsi_is_sas_phy_local(phy)) {
		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
		struct sas_internal *i =
			to_sas_internal(sas_ha->core.shost->transportt);

		if (enable)
			ret = transport_sas_phy_reset(phy, 0);
		else
			ret = i->dft->lldd_control_phy(asd_phy, cmd, NULL);
	} else {
		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);

		if (enable)
			ret = transport_sas_phy_reset(phy, 0);
		else
			ret = sas_smp_phy_control(ddev, phy->number, cmd, NULL);
	}
	return ret;
}

int sas_phy_reset(struct sas_phy *phy, int hard_reset)
{
	int ret;
	enum phy_func reset_type;

	if (!phy->enabled)
		return -ENODEV;

	if (hard_reset)
		reset_type = PHY_FUNC_HARD_RESET;
	else
		reset_type = PHY_FUNC_LINK_RESET;

	if (scsi_is_sas_phy_local(phy)) {
		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
		struct sas_internal *i =
			to_sas_internal(sas_ha->core.shost->transportt);

		ret = i->dft->lldd_control_phy(asd_phy, reset_type, NULL);
	} else {
		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
		ret = sas_smp_phy_control(ddev, phy->number, reset_type, NULL);
	}
	return ret;
}

int sas_set_phy_speed(struct sas_phy *phy,
		      struct sas_phy_linkrates *rates)
{
	int ret;

	if ((rates->minimum_linkrate &&
	     rates->minimum_linkrate > phy->maximum_linkrate) ||
	    (rates->maximum_linkrate &&
	     rates->maximum_linkrate < phy->minimum_linkrate))
		return -EINVAL;

	if (rates->minimum_linkrate &&
	    rates->minimum_linkrate < phy->minimum_linkrate_hw)
		rates->minimum_linkrate = phy->minimum_linkrate_hw;

	if (rates->maximum_linkrate &&
	    rates->maximum_linkrate > phy->maximum_linkrate_hw)
		rates->maximum_linkrate = phy->maximum_linkrate_hw;

	if (scsi_is_sas_phy_local(phy)) {
		struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
		struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
		struct asd_sas_phy *asd_phy = sas_ha->sas_phy[phy->number];
		struct sas_internal *i =
			to_sas_internal(sas_ha->core.shost->transportt);

		ret = i->dft->lldd_control_phy(asd_phy, PHY_FUNC_SET_LINK_RATE,
					       rates);
	} else {
		struct sas_rphy *rphy = dev_to_rphy(phy->dev.parent);
		struct domain_device *ddev = sas_find_dev_by_rphy(rphy);
		ret = sas_smp_phy_control(ddev, phy->number,
					  PHY_FUNC_LINK_RESET, rates);

	}

	return ret;
}

static void sas_phy_release(struct sas_phy *phy)
{
	kfree(phy->hostdata);
	phy->hostdata = NULL;
}

static void phy_reset_work(struct work_struct *work)
{
	struct sas_phy_data *d = container_of(work, typeof(*d), reset_work);

	d->reset_result = transport_sas_phy_reset(d->phy, d->hard_reset);
}

static void phy_enable_work(struct work_struct *work)
{
	struct sas_phy_data *d = container_of(work, typeof(*d), enable_work);

	d->enable_result = sas_phy_enable(d->phy, d->enable);
}

static int sas_phy_setup(struct sas_phy *phy)
{
	struct sas_phy_data *d = kzalloc(sizeof(*d), GFP_KERNEL);

	if (!d)
		return -ENOMEM;

	mutex_init(&d->event_lock);
	INIT_WORK(&d->reset_work, phy_reset_work);
	INIT_WORK(&d->enable_work, phy_enable_work);
	d->phy = phy;
	phy->hostdata = d;

	return 0;
}

static int queue_phy_reset(struct sas_phy *phy, int hard_reset)
{
	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
	struct sas_phy_data *d = phy->hostdata;
	int rc;

	if (!d)
		return -ENOMEM;

	/* libsas workqueue coordinates ata-eh reset with discovery */
	mutex_lock(&d->event_lock);
	d->reset_result = 0;
	d->hard_reset = hard_reset;

	spin_lock_irq(&ha->state_lock);
	sas_queue_work(ha, &d->reset_work);
	spin_unlock_irq(&ha->state_lock);

	rc = sas_drain_work(ha);
	if (rc == 0)
		rc = d->reset_result;
	mutex_unlock(&d->event_lock);

	return rc;
}

static int queue_phy_enable(struct sas_phy *phy, int enable)
{
	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
	struct sas_phy_data *d = phy->hostdata;
	int rc;

	if (!d)
		return -ENOMEM;

	/* libsas workqueue coordinates ata-eh reset with discovery */
	mutex_lock(&d->event_lock);
	d->enable_result = 0;
	d->enable = enable;

	spin_lock_irq(&ha->state_lock);
	sas_queue_work(ha, &d->enable_work);
	spin_unlock_irq(&ha->state_lock);

	rc = sas_drain_work(ha);
	if (rc == 0)
		rc = d->enable_result;
	mutex_unlock(&d->event_lock);

	return rc;
}

static struct sas_function_template sft = {
	.phy_enable = queue_phy_enable,
	.phy_reset = queue_phy_reset,
	.phy_setup = sas_phy_setup,
	.phy_release = sas_phy_release,
	.set_phy_speed = sas_set_phy_speed,
	.get_linkerrors = sas_get_linkerrors,
	.smp_handler = sas_smp_handler,
};

struct scsi_transport_template *
sas_domain_attach_transport(struct sas_domain_function_template *dft)
{
	struct scsi_transport_template *stt = sas_attach_transport(&sft);
	struct sas_internal *i;

	if (!stt)
		return stt;

	i = to_sas_internal(stt);
	i->dft = dft;
	stt->create_work_queue = 1;
	stt->eh_timed_out = sas_scsi_timed_out;
	stt->eh_strategy_handler = sas_scsi_recover_host;

	return stt;
}
EXPORT_SYMBOL_GPL(sas_domain_attach_transport);


void sas_domain_release_transport(struct scsi_transport_template *stt)
{
	sas_release_transport(stt);
}
EXPORT_SYMBOL_GPL(sas_domain_release_transport);

/* ---------- SAS Class register/unregister ---------- */

static int __init sas_class_init(void)
{
	sas_task_cache = KMEM_CACHE(sas_task, SLAB_HWCACHE_ALIGN);
	if (!sas_task_cache)
		return -ENOMEM;

	return 0;
}

static void __exit sas_class_exit(void)
{
	kmem_cache_destroy(sas_task_cache);
}

MODULE_AUTHOR("Luben Tuikov <luben_tuikov@adaptec.com>");
MODULE_DESCRIPTION("SAS Transport Layer");
MODULE_LICENSE("GPL v2");

module_init(sas_class_init);
module_exit(sas_class_exit);

EXPORT_SYMBOL_GPL(sas_register_ha);
EXPORT_SYMBOL_GPL(sas_unregister_ha);