aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/firmware/dcdbas.c
blob: 3a4e5c5b4e1fc9d0fb421f9ed3cedd38a5f1fa26 (plain) (blame)
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
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
/*
 *  dcdbas.c: Dell Systems Management Base Driver
 *
 *  The Dell Systems Management Base Driver provides a sysfs interface for
 *  systems management software to perform System Management Interrupts (SMIs)
 *  and Host Control Actions (power cycle or power off after OS shutdown) on
 *  Dell systems.
 *
 *  See Documentation/dcdbas.txt for more information.
 *
 *  Copyright (C) 1995-2005 Dell Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License v2.0 as published by
 *  the Free Software Foundation.
 *
 *  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.
 */

#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mc146818rtc.h>
#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/types.h>
#include <asm/io.h>
#include <asm/semaphore.h>

#include "dcdbas.h"

#define DRIVER_NAME		"dcdbas"
#define DRIVER_VERSION		"5.6.0-2"
#define DRIVER_DESCRIPTION	"Dell Systems Management Base Driver"

static struct platform_device *dcdbas_pdev;

static u8 *smi_data_buf;
static dma_addr_t smi_data_buf_handle;
static unsigned long smi_data_buf_size;
static u32 smi_data_buf_phys_addr;
static DECLARE_MUTEX(smi_data_lock);

static unsigned int host_control_action;
static unsigned int host_control_smi_type;
static unsigned int host_control_on_shutdown;

/**
 * smi_data_buf_free: free SMI data buffer
 */
static void smi_data_buf_free(void)
{
	if (!smi_data_buf)
		return;

	dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
		__FUNCTION__, smi_data_buf_phys_addr, smi_data_buf_size);

	dma_free_coherent(&dcdbas_pdev->dev, smi_data_buf_size, smi_data_buf,
			  smi_data_buf_handle);
	smi_data_buf = NULL;
	smi_data_buf_handle = 0;
	smi_data_buf_phys_addr = 0;
	smi_data_buf_size = 0;
}

/**
 * smi_data_buf_realloc: grow SMI data buffer if needed
 */
static int smi_data_buf_realloc(unsigned long size)
{
	void *buf;
	dma_addr_t handle;

	if (smi_data_buf_size >= size)
		return 0;

	if (size > MAX_SMI_DATA_BUF_SIZE)
		return -EINVAL;

	/* new buffer is needed */
	buf = dma_alloc_coherent(&dcdbas_pdev->dev, size, &handle, GFP_KERNEL);
	if (!buf) {
		dev_dbg(&dcdbas_pdev->dev,
			"%s: failed to allocate memory size %lu\n",
			__FUNCTION__, size);
		return -ENOMEM;
	}
	/* memory zeroed by dma_alloc_coherent */

	if (smi_data_buf)
		memcpy(buf, smi_data_buf, smi_data_buf_size);

	/* free any existing buffer */
	smi_data_buf_free();

	/* set up new buffer for use */
	smi_data_buf = buf;
	smi_data_buf_handle = handle;
	smi_data_buf_phys_addr = (u32) virt_to_phys(buf);
	smi_data_buf_size = size;

	dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
		__FUNCTION__, smi_data_buf_phys_addr, smi_data_buf_size);

	return 0;
}

static ssize_t smi_data_buf_phys_addr_show(struct device *dev,
					   struct device_attribute *attr,
					   char *buf)
{
	return sprintf(buf, "%x\n", smi_data_buf_phys_addr);
}

static ssize_t smi_data_buf_size_show(struct device *dev,
				      struct device_attribute *attr,
				      char *buf)
{
	return sprintf(buf, "%lu\n", smi_data_buf_size);
}

static ssize_t smi_data_buf_size_store(struct device *dev,
				       struct device_attribute *attr,
				       const char *buf, size_t count)
{
	unsigned long buf_size;
	ssize_t ret;

	buf_size = simple_strtoul(buf, NULL, 10);

	/* make sure SMI data buffer is at least buf_size */
	down(&smi_data_lock);
	ret = smi_data_buf_realloc(buf_size);
	up(&smi_data_lock);
	if (ret)
		return ret;

	return count;
}

static ssize_t smi_data_read(struct kobject *kobj, char *buf, loff_t pos,
			     size_t count)
{
	size_t max_read;
	ssize_t ret;

	down(&smi_data_lock);

	if (pos >= smi_data_buf_size) {
		ret = 0;
		goto out;
	}

	max_read = smi_data_buf_size - pos;
	ret = min(max_read, count);
	memcpy(buf, smi_data_buf + pos, ret);
out:
	up(&smi_data_lock);
	return ret;
}

static ssize_t smi_data_write(struct kobject *kobj, char *buf, loff_t pos,
			      size_t count)
{
	ssize_t ret;

	down(&smi_data_lock);

	ret = smi_data_buf_realloc(pos + count);
	if (ret)
		goto out;

	memcpy(smi_data_buf + pos, buf, count);
	ret = count;
out:
	up(&smi_data_lock);
	return ret;
}

static ssize_t host_control_action_show(struct device *dev,
					struct device_attribute *attr,
					char *buf)
{
	return sprintf(buf, "%u\n", host_control_action);
}

static ssize_t host_control_action_store(struct device *dev,
					 struct device_attribute *attr,
					 const char *buf, size_t count)
{
	ssize_t ret;

	/* make sure buffer is available for host control command */
	down(&smi_data_lock);
	ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
	up(&smi_data_lock);
	if (ret)
		return ret;

	host_control_action = simple_strtoul(buf, NULL, 10);
	return count;
}

static ssize_t host_control_smi_type_show(struct device *dev,
					  struct device_attribute *attr,
					  char *buf)
{
	return sprintf(buf, "%u\n", host_control_smi_type);
}

static ssize_t host_control_smi_type_store(struct device *dev,
					   struct device_attribute *attr,
					   const char *buf, size_t count)
{
	host_control_smi_type = simple_strtoul(buf, NULL, 10);
	return count;
}

static ssize_t host_control_on_shutdown_show(struct device *dev,
					     struct device_attribute *attr,
					     char *buf)
{
	return sprintf(buf, "%u\n", host_control_on_shutdown);
}

static ssize_t host_control_on_shutdown_store(struct device *dev,
					      struct device_attribute *attr,
					      const char *buf, size_t count)
{
	host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
	return count;
}

/**
 * smi_request: generate SMI request
 *
 * Called with smi_data_lock.
 */
static int smi_request(struct smi_cmd *smi_cmd)
{
	cpumask_t old_mask;
	int ret = 0;

	if (smi_cmd->magic != SMI_CMD_MAGIC) {
		dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
			 __FUNCTION__);
		return -EBADR;
	}

	/* SMI requires CPU 0 */
	old_mask = current->cpus_allowed;
	set_cpus_allowed(current, cpumask_of_cpu(0));
	if (smp_processor_id() != 0) {
		dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
			__FUNCTION__);
		ret = -EBUSY;
		goto out;
	}

	/* generate SMI */
	asm volatile (
		"outb %b0,%w1"
		: /* no output args */
		: "a" (smi_cmd->command_code),
		  "d" (smi_cmd->command_address),
		  "b" (smi_cmd->ebx),
		  "c" (smi_cmd->ecx)
		: "memory"
	);

out:
	set_cpus_allowed(current, old_mask);
	return ret;
}

/**
 * smi_request_store:
 *
 * The valid values are:
 * 0: zero SMI data buffer
 * 1: generate calling interface SMI
 * 2: generate raw SMI
 *
 * User application writes smi_cmd to smi_data before telling driver
 * to generate SMI.
 */
static ssize_t smi_request_store(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf, size_t count)
{
	struct smi_cmd *smi_cmd;
	unsigned long val = simple_strtoul(buf, NULL, 10);
	ssize_t ret;

	down(&smi_data_lock);

	if (smi_data_buf_size < sizeof(struct smi_cmd)) {
		ret = -ENODEV;
		goto out;
	}
	smi_cmd = (struct smi_cmd *)smi_data_buf;

	switch (val) {
	case 2:
		/* Raw SMI */
		ret = smi_request(smi_cmd);
		if (!ret)
			ret = count;
		break;
	case 1:
		/* Calling Interface SMI */
		smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
		ret = smi_request(smi_cmd);
		if (!ret)
			ret = count;
		break;
	case 0:
		memset(smi_data_buf, 0, smi_data_buf_size);
		ret = count;
		break;
	default:
		ret = -EINVAL;
		break;
	}

out:
	up(&smi_data_lock);
	return ret;
}

/**
 * host_control_smi: generate host control SMI
 *
 * Caller must set up the host control command in smi_data_buf.
 */
static int host_control_smi(void)
{
	struct apm_cmd *apm_cmd;
	u8 *data;
	unsigned long flags;
	u32 num_ticks;
	s8 cmd_status;
	u8 index;

	apm_cmd = (struct apm_cmd *)smi_data_buf;
	apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;

	switch (host_control_smi_type) {
	case HC_SMITYPE_TYPE1:
		spin_lock_irqsave(&rtc_lock, flags);
		/* write SMI data buffer physical address */
		data = (u8 *)&smi_data_buf_phys_addr;
		for (index = PE1300_CMOS_CMD_STRUCT_PTR;
		     index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
		     index++, data++) {
			outb(index,
			     (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
			outb(*data,
			     (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
		}

		/* first set status to -1 as called by spec */
		cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
		outb((u8) cmd_status, PCAT_APM_STATUS_PORT);

		/* generate SMM call */
		outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
		spin_unlock_irqrestore(&rtc_lock, flags);

		/* wait a few to see if it executed */
		num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
		while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
		       == ESM_STATUS_CMD_UNSUCCESSFUL) {
			num_ticks--;
			if (num_ticks == EXPIRED_TIMER)
				return -ETIME;
		}
		break;

	case HC_SMITYPE_TYPE2:
	case HC_SMITYPE_TYPE3:
		spin_lock_irqsave(&rtc_lock, flags);
		/* write SMI data buffer physical address */
		data = (u8 *)&smi_data_buf_phys_addr;
		for (index = PE1400_CMOS_CMD_STRUCT_PTR;
		     index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
		     index++, data++) {
			outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
			outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
		}

		/* generate SMM call */
		if (host_control_smi_type == HC_SMITYPE_TYPE3)
			outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
		else
			outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);

		/* restore RTC index pointer since it was written to above */
		CMOS_READ(RTC_REG_C);
		spin_unlock_irqrestore(&rtc_lock, flags);

		/* read control port back to serialize write */
		cmd_status = inb(PE1400_APM_CONTROL_PORT);

		/* wait a few to see if it executed */
		num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
		while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
			num_ticks--;
			if (num_ticks == EXPIRED_TIMER)
				return -ETIME;
		}
		break;

	default:
		dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
			__FUNCTION__, host_control_smi_type);
		return -ENOSYS;
	}

	return 0;
}

/**
 * dcdbas_host_control: initiate host control
 *
 * This function is called by the driver after the system has
 * finished shutting down if the user application specified a
 * host control action to perform on shutdown.  It is safe to
 * use smi_data_buf at this point because the system has finished
 * shutting down and no userspace apps are running.
 */
static void dcdbas_host_control(void)
{
	struct apm_cmd *apm_cmd;
	u8 action;

	if (host_control_action == HC_ACTION_NONE)
		return;

	action = host_control_action;
	host_control_action = HC_ACTION_NONE;

	if (!smi_data_buf) {
		dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __FUNCTION__);
		return;
	}

	if (smi_data_buf_size < sizeof(struct apm_cmd)) {
		dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
			__FUNCTION__);
		return;
	}

	apm_cmd = (struct apm_cmd *)smi_data_buf;

	/* power off takes precedence */
	if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
		apm_cmd->command = ESM_APM_POWER_CYCLE;
		apm_cmd->reserved = 0;
		*((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
		host_control_smi();
	} else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
		apm_cmd->command = ESM_APM_POWER_CYCLE;
		apm_cmd->reserved = 0;
		*((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
		host_control_smi();
	}
}

/**
 * dcdbas_reboot_notify: handle reboot notification for host control
 */
static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
				void *unused)
{
	static unsigned int notify_cnt = 0;

	switch (code) {
	case SYS_DOWN:
	case SYS_HALT:
	case SYS_POWER_OFF:
		if (host_control_on_shutdown) {
			/* firmware is going to perform host control action */
			if (++notify_cnt == 2) {
				printk(KERN_WARNING
				       "Please wait for shutdown "
				       "action to complete...\n");
				dcdbas_host_control();
			}
			/*
			 * register again and initiate the host control
			 * action on the second notification to allow
			 * everyone that registered to be notified
			 */
			register_reboot_notifier(nb);
		}
		break;
	}

	return NOTIFY_DONE;
}

static struct notifier_block dcdbas_reboot_nb = {
	.notifier_call = dcdbas_reboot_notify,
	.next = NULL,
	.priority = 0
};

static DCDBAS_BIN_ATTR_RW(smi_data);

static struct bin_attribute *dcdbas_bin_attrs[] = {
	&bin_attr_smi_data,
	NULL
};

static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
static DCDBAS_DEV_ATTR_WO(smi_request);
static DCDBAS_DEV_ATTR_RW(host_control_action);
static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);

static struct attribute *dcdbas_dev_attrs[] = {
	&dev_attr_smi_data_buf_size.attr,
	&dev_attr_smi_data_buf_phys_addr.attr,
	&dev_attr_smi_request.attr,
	&dev_attr_host_control_action.attr,
	&dev_attr_host_control_smi_type.attr,
	&dev_attr_host_control_on_shutdown.attr,
	NULL
};

static struct attribute_group dcdbas_attr_group = {
	.attrs = dcdbas_dev_attrs,
};

static int __devinit dcdbas_probe(struct platform_device *dev)
{
	int i, error;

	host_control_action = HC_ACTION_NONE;
	host_control_smi_type = HC_SMITYPE_NONE;

	/*
	 * BIOS SMI calls require buffer addresses be in 32-bit address space.
	 * This is done by setting the DMA mask below.
	 */
	dcdbas_pdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
	dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;

	error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
	if (error)
		return error;

	for (i = 0; dcdbas_bin_attrs[i]; i++) {
		error = sysfs_create_bin_file(&dev->dev.kobj,
					      dcdbas_bin_attrs[i]);
		if (error) {
			while (--i >= 0)
				sysfs_remove_bin_file(&dev->dev.kobj,
						      dcdbas_bin_attrs[i]);
			sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
			return error;
		}
	}

	register_reboot_notifier(&dcdbas_reboot_nb);

	dev_info(&dev->dev, "%s (version %s)\n",
		 DRIVER_DESCRIPTION, DRIVER_VERSION);

	return 0;
}

static int __devexit dcdbas_remove(struct platform_device *dev)
{
	int i;

	unregister_reboot_notifier(&dcdbas_reboot_nb);
	for (i = 0; dcdbas_bin_attrs[i]; i++)
		sysfs_remove_bin_file(&dev->dev.kobj, dcdbas_bin_attrs[i]);
	sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);

	return 0;
}

static struct platform_driver dcdbas_driver = {
	.driver		= {
		.name	= DRIVER_NAME,
		.owner	= THIS_MODULE,
	},
	.probe		= dcdbas_probe,
	.remove		= __devexit_p(dcdbas_remove),
};

/**
 * dcdbas_init: initialize driver
 */
static int __init dcdbas_init(void)
{
	int error;

	error = platform_driver_register(&dcdbas_driver);
	if (error)
		return error;

	dcdbas_pdev = platform_device_alloc(DRIVER_NAME, -1);
	if (!dcdbas_pdev) {
		error = -ENOMEM;
		goto err_unregister_driver;
	}

	error = platform_device_add(dcdbas_pdev);
	if (error)
		goto err_free_device;

	return 0;

 err_free_device:
	platform_device_put(dcdbas_pdev);
 err_unregister_driver:
	platform_driver_unregister(&dcdbas_driver);
	return error;
}

/**
 * dcdbas_exit: perform driver cleanup
 */
static void __exit dcdbas_exit(void)
{
	/*
	 * make sure functions that use dcdbas_pdev are called
	 * before platform_device_unregister
	 */
	unregister_reboot_notifier(&dcdbas_reboot_nb);
	smi_data_buf_free();
	platform_device_unregister(dcdbas_pdev);
	platform_driver_unregister(&dcdbas_driver);

	/*
	 * We have to free the buffer here instead of dcdbas_remove
	 * because only in module exit function we can be sure that
	 * all sysfs attributes belonging to this module have been
	 * released.
	 */
	smi_data_buf_free();
}

module_init(dcdbas_init);
module_exit(dcdbas_exit);

MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
MODULE_VERSION(DRIVER_VERSION);
MODULE_AUTHOR("Dell Inc.");
MODULE_LICENSE("GPL");