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
47 static struct platform_device *dcdbas_pdev;
48
49 static u8 *smi_data_buf;
50 static dma_addr_t smi_data_buf_handle;
51 static unsigned long smi_data_buf_size;
52 static u32 smi_data_buf_phys_addr;
53 static DEFINE_MUTEX(smi_data_lock);
54
55 static unsigned int host_control_action;
56 static unsigned int host_control_smi_type;
57 static unsigned int host_control_on_shutdown;
58
59 /**
60 * smi_data_buf_free: free SMI data buffer
61 */
smi_data_buf_free(void)62 static 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 */
smi_data_buf_realloc(unsigned long size)81 static 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
smi_data_buf_phys_addr_show(struct device * dev,struct device_attribute * attr,char * buf)120 static 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
smi_data_buf_size_show(struct device * dev,struct device_attribute * attr,char * buf)127 static 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
smi_data_buf_size_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)134 static 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
smi_data_read(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t pos,size_t count)153 static 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
smi_data_write(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t pos,size_t count)166 static 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;
183 out:
184 mutex_unlock(&smi_data_lock);
185 return ret;
186 }
187
host_control_action_show(struct device * dev,struct device_attribute * attr,char * buf)188 static 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
host_control_action_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)195 static 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
host_control_smi_type_show(struct device * dev,struct device_attribute * attr,char * buf)212 static 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
host_control_smi_type_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)219 static 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
host_control_on_shutdown_show(struct device * dev,struct device_attribute * attr,char * buf)227 static 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
host_control_on_shutdown_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)234 static 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
raise_smi(void * par)242 static 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 */
dcdbas_smi_request(struct smi_cmd * smi_cmd)272 int 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 */
smi_request_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)301 static 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
340 out:
341 mutex_unlock(&smi_data_lock);
342 return ret;
343 }
344 EXPORT_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 */
host_control_smi(void)351 static 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 */
dcdbas_host_control(void)447 static 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 */
dcdbas_reboot_notify(struct notifier_block * nb,unsigned long code,void * unused)488 static 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
507 static struct notifier_block dcdbas_reboot_nb = {
508 .notifier_call = dcdbas_reboot_notify,
509 .next = NULL,
510 .priority = INT_MIN
511 };
512
513 static DCDBAS_BIN_ATTR_RW(smi_data);
514
515 static struct bin_attribute *dcdbas_bin_attrs[] = {
516 &bin_attr_smi_data,
517 NULL
518 };
519
520 static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
521 static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
522 static DCDBAS_DEV_ATTR_WO(smi_request);
523 static DCDBAS_DEV_ATTR_RW(host_control_action);
524 static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
525 static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
526
527 static 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
537 static const struct attribute_group dcdbas_attr_group = {
538 .attrs = dcdbas_dev_attrs,
539 .bin_attrs = dcdbas_bin_attrs,
540 };
541
dcdbas_probe(struct platform_device * dev)542 static 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
dcdbas_remove(struct platform_device * dev)571 static 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
579 static struct platform_driver dcdbas_driver = {
580 .driver = {
581 .name = DRIVER_NAME,
582 },
583 .probe = dcdbas_probe,
584 .remove = dcdbas_remove,
585 };
586
587 static 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
593 static struct platform_device *dcdbas_pdev_reg;
594
595 /**
596 * dcdbas_init: initialize driver
597 */
dcdbas_init(void)598 static 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 */
dcdbas_exit(void)622 static 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
642 module_init(dcdbas_init);
643 module_exit(dcdbas_exit);
644
645 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
646 MODULE_VERSION(DRIVER_VERSION);
647 MODULE_AUTHOR("Dell Inc.");
648 MODULE_LICENSE("GPL");
649 /* Any System or BIOS claiming to be by Dell */
650 MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");
651