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1/*
2 * dcdbas.c: Dell Systems Management Base Driver
3 *
4 * The Dell Systems Management Base Driver provides a sysfs interface for
5 * systems management software to perform System Management Interrupts (SMIs)
6 * and Host Control Actions (power cycle or power off after OS shutdown) on
7 * Dell systems.
8 *
9 * See Documentation/dcdbas.txt for more information.
10 *
11 * Copyright (C) 1995-2006 Dell Inc.
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License v2.0 as published by
15 * the Free Software Foundation.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 */
22
23#include <linux/platform_device.h>
24#include <linux/dma-mapping.h>
25#include <linux/errno.h>
26#include <linux/cpu.h>
27#include <linux/gfp.h>
28#include <linux/init.h>
29#include <linux/kernel.h>
30#include <linux/mc146818rtc.h>
31#include <linux/module.h>
32#include <linux/reboot.h>
33#include <linux/sched.h>
34#include <linux/smp.h>
35#include <linux/spinlock.h>
36#include <linux/string.h>
37#include <linux/types.h>
38#include <linux/mutex.h>
39#include <asm/io.h>
40
41#include "dcdbas.h"
42
43#define DRIVER_NAME "dcdbas"
44#define DRIVER_VERSION "5.6.0-3.2"
45#define DRIVER_DESCRIPTION "Dell Systems Management Base Driver"
46
47static struct platform_device *dcdbas_pdev;
48
49static u8 *smi_data_buf;
50static dma_addr_t smi_data_buf_handle;
51static unsigned long smi_data_buf_size;
52static u32 smi_data_buf_phys_addr;
53static DEFINE_MUTEX(smi_data_lock);
54
55static unsigned int host_control_action;
56static unsigned int host_control_smi_type;
57static unsigned int host_control_on_shutdown;
58
59/**
60 * smi_data_buf_free: free SMI data buffer
61 */
62static void smi_data_buf_free(void)
63{
64 if (!smi_data_buf)
65 return;
66
67 dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
68 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
69
70 dma_free_coherent(&dcdbas_pdev->dev, smi_data_buf_size, smi_data_buf,
71 smi_data_buf_handle);
72 smi_data_buf = NULL;
73 smi_data_buf_handle = 0;
74 smi_data_buf_phys_addr = 0;
75 smi_data_buf_size = 0;
76}
77
78/**
79 * smi_data_buf_realloc: grow SMI data buffer if needed
80 */
81static int smi_data_buf_realloc(unsigned long size)
82{
83 void *buf;
84 dma_addr_t handle;
85
86 if (smi_data_buf_size >= size)
87 return 0;
88
89 if (size > MAX_SMI_DATA_BUF_SIZE)
90 return -EINVAL;
91
92 /* new buffer is needed */
93 buf = dma_alloc_coherent(&dcdbas_pdev->dev, size, &handle, GFP_KERNEL);
94 if (!buf) {
95 dev_dbg(&dcdbas_pdev->dev,
96 "%s: failed to allocate memory size %lu\n",
97 __func__, size);
98 return -ENOMEM;
99 }
100 /* memory zeroed by dma_alloc_coherent */
101
102 if (smi_data_buf)
103 memcpy(buf, smi_data_buf, smi_data_buf_size);
104
105 /* free any existing buffer */
106 smi_data_buf_free();
107
108 /* set up new buffer for use */
109 smi_data_buf = buf;
110 smi_data_buf_handle = handle;
111 smi_data_buf_phys_addr = (u32) virt_to_phys(buf);
112 smi_data_buf_size = size;
113
114 dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
115 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
116
117 return 0;
118}
119
120static ssize_t smi_data_buf_phys_addr_show(struct device *dev,
121 struct device_attribute *attr,
122 char *buf)
123{
124 return sprintf(buf, "%x\n", smi_data_buf_phys_addr);
125}
126
127static ssize_t smi_data_buf_size_show(struct device *dev,
128 struct device_attribute *attr,
129 char *buf)
130{
131 return sprintf(buf, "%lu\n", smi_data_buf_size);
132}
133
134static ssize_t smi_data_buf_size_store(struct device *dev,
135 struct device_attribute *attr,
136 const char *buf, size_t count)
137{
138 unsigned long buf_size;
139 ssize_t ret;
140
141 buf_size = simple_strtoul(buf, NULL, 10);
142
143 /* make sure SMI data buffer is at least buf_size */
144 mutex_lock(&smi_data_lock);
145 ret = smi_data_buf_realloc(buf_size);
146 mutex_unlock(&smi_data_lock);
147 if (ret)
148 return ret;
149
150 return count;
151}
152
153static ssize_t smi_data_read(struct file *filp, struct kobject *kobj,
154 struct bin_attribute *bin_attr,
155 char *buf, loff_t pos, size_t count)
156{
157 ssize_t ret;
158
159 mutex_lock(&smi_data_lock);
160 ret = memory_read_from_buffer(buf, count, &pos, smi_data_buf,
161 smi_data_buf_size);
162 mutex_unlock(&smi_data_lock);
163 return ret;
164}
165
166static ssize_t smi_data_write(struct file *filp, struct kobject *kobj,
167 struct bin_attribute *bin_attr,
168 char *buf, loff_t pos, size_t count)
169{
170 ssize_t ret;
171
172 if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
173 return -EINVAL;
174
175 mutex_lock(&smi_data_lock);
176
177 ret = smi_data_buf_realloc(pos + count);
178 if (ret)
179 goto out;
180
181 memcpy(smi_data_buf + pos, buf, count);
182 ret = count;
183out:
184 mutex_unlock(&smi_data_lock);
185 return ret;
186}
187
188static ssize_t host_control_action_show(struct device *dev,
189 struct device_attribute *attr,
190 char *buf)
191{
192 return sprintf(buf, "%u\n", host_control_action);
193}
194
195static ssize_t host_control_action_store(struct device *dev,
196 struct device_attribute *attr,
197 const char *buf, size_t count)
198{
199 ssize_t ret;
200
201 /* make sure buffer is available for host control command */
202 mutex_lock(&smi_data_lock);
203 ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
204 mutex_unlock(&smi_data_lock);
205 if (ret)
206 return ret;
207
208 host_control_action = simple_strtoul(buf, NULL, 10);
209 return count;
210}
211
212static ssize_t host_control_smi_type_show(struct device *dev,
213 struct device_attribute *attr,
214 char *buf)
215{
216 return sprintf(buf, "%u\n", host_control_smi_type);
217}
218
219static ssize_t host_control_smi_type_store(struct device *dev,
220 struct device_attribute *attr,
221 const char *buf, size_t count)
222{
223 host_control_smi_type = simple_strtoul(buf, NULL, 10);
224 return count;
225}
226
227static ssize_t host_control_on_shutdown_show(struct device *dev,
228 struct device_attribute *attr,
229 char *buf)
230{
231 return sprintf(buf, "%u\n", host_control_on_shutdown);
232}
233
234static ssize_t host_control_on_shutdown_store(struct device *dev,
235 struct device_attribute *attr,
236 const char *buf, size_t count)
237{
238 host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
239 return count;
240}
241
242static int raise_smi(void *par)
243{
244 struct smi_cmd *smi_cmd = par;
245
246 if (smp_processor_id() != 0) {
247 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
248 __func__);
249 return -EBUSY;
250 }
251
252 /* generate SMI */
253 /* inb to force posted write through and make SMI happen now */
254 asm volatile (
255 "outb %b0,%w1\n"
256 "inb %w1"
257 : /* no output args */
258 : "a" (smi_cmd->command_code),
259 "d" (smi_cmd->command_address),
260 "b" (smi_cmd->ebx),
261 "c" (smi_cmd->ecx)
262 : "memory"
263 );
264
265 return 0;
266}
267/**
268 * dcdbas_smi_request: generate SMI request
269 *
270 * Called with smi_data_lock.
271 */
272int dcdbas_smi_request(struct smi_cmd *smi_cmd)
273{
274 int ret;
275
276 if (smi_cmd->magic != SMI_CMD_MAGIC) {
277 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
278 __func__);
279 return -EBADR;
280 }
281
282 /* SMI requires CPU 0 */
283 get_online_cpus();
284 ret = smp_call_on_cpu(0, raise_smi, smi_cmd, true);
285 put_online_cpus();
286
287 return ret;
288}
289
290/**
291 * smi_request_store:
292 *
293 * The valid values are:
294 * 0: zero SMI data buffer
295 * 1: generate calling interface SMI
296 * 2: generate raw SMI
297 *
298 * User application writes smi_cmd to smi_data before telling driver
299 * to generate SMI.
300 */
301static ssize_t smi_request_store(struct device *dev,
302 struct device_attribute *attr,
303 const char *buf, size_t count)
304{
305 struct smi_cmd *smi_cmd;
306 unsigned long val = simple_strtoul(buf, NULL, 10);
307 ssize_t ret;
308
309 mutex_lock(&smi_data_lock);
310
311 if (smi_data_buf_size < sizeof(struct smi_cmd)) {
312 ret = -ENODEV;
313 goto out;
314 }
315 smi_cmd = (struct smi_cmd *)smi_data_buf;
316
317 switch (val) {
318 case 2:
319 /* Raw SMI */
320 ret = dcdbas_smi_request(smi_cmd);
321 if (!ret)
322 ret = count;
323 break;
324 case 1:
325 /* Calling Interface SMI */
326 smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
327 ret = dcdbas_smi_request(smi_cmd);
328 if (!ret)
329 ret = count;
330 break;
331 case 0:
332 memset(smi_data_buf, 0, smi_data_buf_size);
333 ret = count;
334 break;
335 default:
336 ret = -EINVAL;
337 break;
338 }
339
340out:
341 mutex_unlock(&smi_data_lock);
342 return ret;
343}
344EXPORT_SYMBOL(dcdbas_smi_request);
345
346/**
347 * host_control_smi: generate host control SMI
348 *
349 * Caller must set up the host control command in smi_data_buf.
350 */
351static int host_control_smi(void)
352{
353 struct apm_cmd *apm_cmd;
354 u8 *data;
355 unsigned long flags;
356 u32 num_ticks;
357 s8 cmd_status;
358 u8 index;
359
360 apm_cmd = (struct apm_cmd *)smi_data_buf;
361 apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
362
363 switch (host_control_smi_type) {
364 case HC_SMITYPE_TYPE1:
365 spin_lock_irqsave(&rtc_lock, flags);
366 /* write SMI data buffer physical address */
367 data = (u8 *)&smi_data_buf_phys_addr;
368 for (index = PE1300_CMOS_CMD_STRUCT_PTR;
369 index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
370 index++, data++) {
371 outb(index,
372 (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
373 outb(*data,
374 (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
375 }
376
377 /* first set status to -1 as called by spec */
378 cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
379 outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
380
381 /* generate SMM call */
382 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
383 spin_unlock_irqrestore(&rtc_lock, flags);
384
385 /* wait a few to see if it executed */
386 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
387 while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
388 == ESM_STATUS_CMD_UNSUCCESSFUL) {
389 num_ticks--;
390 if (num_ticks == EXPIRED_TIMER)
391 return -ETIME;
392 }
393 break;
394
395 case HC_SMITYPE_TYPE2:
396 case HC_SMITYPE_TYPE3:
397 spin_lock_irqsave(&rtc_lock, flags);
398 /* write SMI data buffer physical address */
399 data = (u8 *)&smi_data_buf_phys_addr;
400 for (index = PE1400_CMOS_CMD_STRUCT_PTR;
401 index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
402 index++, data++) {
403 outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
404 outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
405 }
406
407 /* generate SMM call */
408 if (host_control_smi_type == HC_SMITYPE_TYPE3)
409 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
410 else
411 outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
412
413 /* restore RTC index pointer since it was written to above */
414 CMOS_READ(RTC_REG_C);
415 spin_unlock_irqrestore(&rtc_lock, flags);
416
417 /* read control port back to serialize write */
418 cmd_status = inb(PE1400_APM_CONTROL_PORT);
419
420 /* wait a few to see if it executed */
421 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
422 while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
423 num_ticks--;
424 if (num_ticks == EXPIRED_TIMER)
425 return -ETIME;
426 }
427 break;
428
429 default:
430 dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
431 __func__, host_control_smi_type);
432 return -ENOSYS;
433 }
434
435 return 0;
436}
437
438/**
439 * dcdbas_host_control: initiate host control
440 *
441 * This function is called by the driver after the system has
442 * finished shutting down if the user application specified a
443 * host control action to perform on shutdown. It is safe to
444 * use smi_data_buf at this point because the system has finished
445 * shutting down and no userspace apps are running.
446 */
447static void dcdbas_host_control(void)
448{
449 struct apm_cmd *apm_cmd;
450 u8 action;
451
452 if (host_control_action == HC_ACTION_NONE)
453 return;
454
455 action = host_control_action;
456 host_control_action = HC_ACTION_NONE;
457
458 if (!smi_data_buf) {
459 dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __func__);
460 return;
461 }
462
463 if (smi_data_buf_size < sizeof(struct apm_cmd)) {
464 dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
465 __func__);
466 return;
467 }
468
469 apm_cmd = (struct apm_cmd *)smi_data_buf;
470
471 /* power off takes precedence */
472 if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
473 apm_cmd->command = ESM_APM_POWER_CYCLE;
474 apm_cmd->reserved = 0;
475 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
476 host_control_smi();
477 } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
478 apm_cmd->command = ESM_APM_POWER_CYCLE;
479 apm_cmd->reserved = 0;
480 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
481 host_control_smi();
482 }
483}
484
485/**
486 * dcdbas_reboot_notify: handle reboot notification for host control
487 */
488static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
489 void *unused)
490{
491 switch (code) {
492 case SYS_DOWN:
493 case SYS_HALT:
494 case SYS_POWER_OFF:
495 if (host_control_on_shutdown) {
496 /* firmware is going to perform host control action */
497 printk(KERN_WARNING "Please wait for shutdown "
498 "action to complete...\n");
499 dcdbas_host_control();
500 }
501 break;
502 }
503
504 return NOTIFY_DONE;
505}
506
507static struct notifier_block dcdbas_reboot_nb = {
508 .notifier_call = dcdbas_reboot_notify,
509 .next = NULL,
510 .priority = INT_MIN
511};
512
513static DCDBAS_BIN_ATTR_RW(smi_data);
514
515static struct bin_attribute *dcdbas_bin_attrs[] = {
516 &bin_attr_smi_data,
517 NULL
518};
519
520static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
521static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
522static DCDBAS_DEV_ATTR_WO(smi_request);
523static DCDBAS_DEV_ATTR_RW(host_control_action);
524static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
525static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
526
527static struct attribute *dcdbas_dev_attrs[] = {
528 &dev_attr_smi_data_buf_size.attr,
529 &dev_attr_smi_data_buf_phys_addr.attr,
530 &dev_attr_smi_request.attr,
531 &dev_attr_host_control_action.attr,
532 &dev_attr_host_control_smi_type.attr,
533 &dev_attr_host_control_on_shutdown.attr,
534 NULL
535};
536
537static const struct attribute_group dcdbas_attr_group = {
538 .attrs = dcdbas_dev_attrs,
539 .bin_attrs = dcdbas_bin_attrs,
540};
541
542static int dcdbas_probe(struct platform_device *dev)
543{
544 int error;
545
546 host_control_action = HC_ACTION_NONE;
547 host_control_smi_type = HC_SMITYPE_NONE;
548
549 dcdbas_pdev = dev;
550
551 /*
552 * BIOS SMI calls require buffer addresses be in 32-bit address space.
553 * This is done by setting the DMA mask below.
554 */
555 error = dma_set_coherent_mask(&dcdbas_pdev->dev, DMA_BIT_MASK(32));
556 if (error)
557 return error;
558
559 error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
560 if (error)
561 return error;
562
563 register_reboot_notifier(&dcdbas_reboot_nb);
564
565 dev_info(&dev->dev, "%s (version %s)\n",
566 DRIVER_DESCRIPTION, DRIVER_VERSION);
567
568 return 0;
569}
570
571static int dcdbas_remove(struct platform_device *dev)
572{
573 unregister_reboot_notifier(&dcdbas_reboot_nb);
574 sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
575
576 return 0;
577}
578
579static struct platform_driver dcdbas_driver = {
580 .driver = {
581 .name = DRIVER_NAME,
582 },
583 .probe = dcdbas_probe,
584 .remove = dcdbas_remove,
585};
586
587static const struct platform_device_info dcdbas_dev_info __initconst = {
588 .name = DRIVER_NAME,
589 .id = -1,
590 .dma_mask = DMA_BIT_MASK(32),
591};
592
593static struct platform_device *dcdbas_pdev_reg;
594
595/**
596 * dcdbas_init: initialize driver
597 */
598static int __init dcdbas_init(void)
599{
600 int error;
601
602 error = platform_driver_register(&dcdbas_driver);
603 if (error)
604 return error;
605
606 dcdbas_pdev_reg = platform_device_register_full(&dcdbas_dev_info);
607 if (IS_ERR(dcdbas_pdev_reg)) {
608 error = PTR_ERR(dcdbas_pdev_reg);
609 goto err_unregister_driver;
610 }
611
612 return 0;
613
614 err_unregister_driver:
615 platform_driver_unregister(&dcdbas_driver);
616 return error;
617}
618
619/**
620 * dcdbas_exit: perform driver cleanup
621 */
622static void __exit dcdbas_exit(void)
623{
624 /*
625 * make sure functions that use dcdbas_pdev are called
626 * before platform_device_unregister
627 */
628 unregister_reboot_notifier(&dcdbas_reboot_nb);
629
630 /*
631 * We have to free the buffer here instead of dcdbas_remove
632 * because only in module exit function we can be sure that
633 * all sysfs attributes belonging to this module have been
634 * released.
635 */
636 if (dcdbas_pdev)
637 smi_data_buf_free();
638 platform_device_unregister(dcdbas_pdev_reg);
639 platform_driver_unregister(&dcdbas_driver);
640}
641
642subsys_initcall_sync(dcdbas_init);
643module_exit(dcdbas_exit);
644
645MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
646MODULE_VERSION(DRIVER_VERSION);
647MODULE_AUTHOR("Dell Inc.");
648MODULE_LICENSE("GPL");
649/* Any System or BIOS claiming to be by Dell */
650MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");