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/gfp.h>
27 #include <linux/init.h>
28 #include <linux/kernel.h>
29 #include <linux/mc146818rtc.h>
30 #include <linux/module.h>
31 #include <linux/reboot.h>
32 #include <linux/sched.h>
33 #include <linux/smp.h>
34 #include <linux/spinlock.h>
35 #include <linux/string.h>
36 #include <linux/types.h>
37 #include <linux/mutex.h>
38 #include <asm/io.h>
39
40 #include "dcdbas.h"
41
42 #define DRIVER_NAME "dcdbas"
43 #define DRIVER_VERSION "5.6.0-3.2"
44 #define DRIVER_DESCRIPTION "Dell Systems Management Base Driver"
45
46 static struct platform_device *dcdbas_pdev;
47
48 static u8 *smi_data_buf;
49 static dma_addr_t smi_data_buf_handle;
50 static unsigned long smi_data_buf_size;
51 static u32 smi_data_buf_phys_addr;
52 static DEFINE_MUTEX(smi_data_lock);
53
54 static unsigned int host_control_action;
55 static unsigned int host_control_smi_type;
56 static unsigned int host_control_on_shutdown;
57
58 /**
59 * smi_data_buf_free: free SMI data buffer
60 */
smi_data_buf_free(void)61 static void smi_data_buf_free(void)
62 {
63 if (!smi_data_buf)
64 return;
65
66 dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
67 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
68
69 dma_free_coherent(&dcdbas_pdev->dev, smi_data_buf_size, smi_data_buf,
70 smi_data_buf_handle);
71 smi_data_buf = NULL;
72 smi_data_buf_handle = 0;
73 smi_data_buf_phys_addr = 0;
74 smi_data_buf_size = 0;
75 }
76
77 /**
78 * smi_data_buf_realloc: grow SMI data buffer if needed
79 */
smi_data_buf_realloc(unsigned long size)80 static int smi_data_buf_realloc(unsigned long size)
81 {
82 void *buf;
83 dma_addr_t handle;
84
85 if (smi_data_buf_size >= size)
86 return 0;
87
88 if (size > MAX_SMI_DATA_BUF_SIZE)
89 return -EINVAL;
90
91 /* new buffer is needed */
92 buf = dma_alloc_coherent(&dcdbas_pdev->dev, size, &handle, GFP_KERNEL);
93 if (!buf) {
94 dev_dbg(&dcdbas_pdev->dev,
95 "%s: failed to allocate memory size %lu\n",
96 __func__, size);
97 return -ENOMEM;
98 }
99 /* memory zeroed by dma_alloc_coherent */
100
101 if (smi_data_buf)
102 memcpy(buf, smi_data_buf, smi_data_buf_size);
103
104 /* free any existing buffer */
105 smi_data_buf_free();
106
107 /* set up new buffer for use */
108 smi_data_buf = buf;
109 smi_data_buf_handle = handle;
110 smi_data_buf_phys_addr = (u32) virt_to_phys(buf);
111 smi_data_buf_size = size;
112
113 dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
114 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
115
116 return 0;
117 }
118
smi_data_buf_phys_addr_show(struct device * dev,struct device_attribute * attr,char * buf)119 static ssize_t smi_data_buf_phys_addr_show(struct device *dev,
120 struct device_attribute *attr,
121 char *buf)
122 {
123 return sprintf(buf, "%x\n", smi_data_buf_phys_addr);
124 }
125
smi_data_buf_size_show(struct device * dev,struct device_attribute * attr,char * buf)126 static ssize_t smi_data_buf_size_show(struct device *dev,
127 struct device_attribute *attr,
128 char *buf)
129 {
130 return sprintf(buf, "%lu\n", smi_data_buf_size);
131 }
132
smi_data_buf_size_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)133 static ssize_t smi_data_buf_size_store(struct device *dev,
134 struct device_attribute *attr,
135 const char *buf, size_t count)
136 {
137 unsigned long buf_size;
138 ssize_t ret;
139
140 buf_size = simple_strtoul(buf, NULL, 10);
141
142 /* make sure SMI data buffer is at least buf_size */
143 mutex_lock(&smi_data_lock);
144 ret = smi_data_buf_realloc(buf_size);
145 mutex_unlock(&smi_data_lock);
146 if (ret)
147 return ret;
148
149 return count;
150 }
151
smi_data_read(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t pos,size_t count)152 static ssize_t smi_data_read(struct file *filp, struct kobject *kobj,
153 struct bin_attribute *bin_attr,
154 char *buf, loff_t pos, size_t count)
155 {
156 ssize_t ret;
157
158 mutex_lock(&smi_data_lock);
159 ret = memory_read_from_buffer(buf, count, &pos, smi_data_buf,
160 smi_data_buf_size);
161 mutex_unlock(&smi_data_lock);
162 return ret;
163 }
164
smi_data_write(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t pos,size_t count)165 static ssize_t smi_data_write(struct file *filp, struct kobject *kobj,
166 struct bin_attribute *bin_attr,
167 char *buf, loff_t pos, size_t count)
168 {
169 ssize_t ret;
170
171 if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
172 return -EINVAL;
173
174 mutex_lock(&smi_data_lock);
175
176 ret = smi_data_buf_realloc(pos + count);
177 if (ret)
178 goto out;
179
180 memcpy(smi_data_buf + pos, buf, count);
181 ret = count;
182 out:
183 mutex_unlock(&smi_data_lock);
184 return ret;
185 }
186
host_control_action_show(struct device * dev,struct device_attribute * attr,char * buf)187 static ssize_t host_control_action_show(struct device *dev,
188 struct device_attribute *attr,
189 char *buf)
190 {
191 return sprintf(buf, "%u\n", host_control_action);
192 }
193
host_control_action_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)194 static ssize_t host_control_action_store(struct device *dev,
195 struct device_attribute *attr,
196 const char *buf, size_t count)
197 {
198 ssize_t ret;
199
200 /* make sure buffer is available for host control command */
201 mutex_lock(&smi_data_lock);
202 ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
203 mutex_unlock(&smi_data_lock);
204 if (ret)
205 return ret;
206
207 host_control_action = simple_strtoul(buf, NULL, 10);
208 return count;
209 }
210
host_control_smi_type_show(struct device * dev,struct device_attribute * attr,char * buf)211 static ssize_t host_control_smi_type_show(struct device *dev,
212 struct device_attribute *attr,
213 char *buf)
214 {
215 return sprintf(buf, "%u\n", host_control_smi_type);
216 }
217
host_control_smi_type_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)218 static ssize_t host_control_smi_type_store(struct device *dev,
219 struct device_attribute *attr,
220 const char *buf, size_t count)
221 {
222 host_control_smi_type = simple_strtoul(buf, NULL, 10);
223 return count;
224 }
225
host_control_on_shutdown_show(struct device * dev,struct device_attribute * attr,char * buf)226 static ssize_t host_control_on_shutdown_show(struct device *dev,
227 struct device_attribute *attr,
228 char *buf)
229 {
230 return sprintf(buf, "%u\n", host_control_on_shutdown);
231 }
232
host_control_on_shutdown_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)233 static ssize_t host_control_on_shutdown_store(struct device *dev,
234 struct device_attribute *attr,
235 const char *buf, size_t count)
236 {
237 host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
238 return count;
239 }
240
241 /**
242 * dcdbas_smi_request: generate SMI request
243 *
244 * Called with smi_data_lock.
245 */
dcdbas_smi_request(struct smi_cmd * smi_cmd)246 int dcdbas_smi_request(struct smi_cmd *smi_cmd)
247 {
248 cpumask_var_t old_mask;
249 int ret = 0;
250
251 if (smi_cmd->magic != SMI_CMD_MAGIC) {
252 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
253 __func__);
254 return -EBADR;
255 }
256
257 /* SMI requires CPU 0 */
258 if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
259 return -ENOMEM;
260
261 cpumask_copy(old_mask, ¤t->cpus_allowed);
262 set_cpus_allowed_ptr(current, cpumask_of(0));
263 if (smp_processor_id() != 0) {
264 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
265 __func__);
266 ret = -EBUSY;
267 goto out;
268 }
269
270 /* generate SMI */
271 /* inb to force posted write through and make SMI happen now */
272 asm volatile (
273 "outb %b0,%w1\n"
274 "inb %w1"
275 : /* no output args */
276 : "a" (smi_cmd->command_code),
277 "d" (smi_cmd->command_address),
278 "b" (smi_cmd->ebx),
279 "c" (smi_cmd->ecx)
280 : "memory"
281 );
282
283 out:
284 set_cpus_allowed_ptr(current, old_mask);
285 free_cpumask_var(old_mask);
286 return ret;
287 }
288
289 /**
290 * smi_request_store:
291 *
292 * The valid values are:
293 * 0: zero SMI data buffer
294 * 1: generate calling interface SMI
295 * 2: generate raw SMI
296 *
297 * User application writes smi_cmd to smi_data before telling driver
298 * to generate SMI.
299 */
smi_request_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)300 static ssize_t smi_request_store(struct device *dev,
301 struct device_attribute *attr,
302 const char *buf, size_t count)
303 {
304 struct smi_cmd *smi_cmd;
305 unsigned long val = simple_strtoul(buf, NULL, 10);
306 ssize_t ret;
307
308 mutex_lock(&smi_data_lock);
309
310 if (smi_data_buf_size < sizeof(struct smi_cmd)) {
311 ret = -ENODEV;
312 goto out;
313 }
314 smi_cmd = (struct smi_cmd *)smi_data_buf;
315
316 switch (val) {
317 case 2:
318 /* Raw SMI */
319 ret = dcdbas_smi_request(smi_cmd);
320 if (!ret)
321 ret = count;
322 break;
323 case 1:
324 /* Calling Interface SMI */
325 smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
326 ret = dcdbas_smi_request(smi_cmd);
327 if (!ret)
328 ret = count;
329 break;
330 case 0:
331 memset(smi_data_buf, 0, smi_data_buf_size);
332 ret = count;
333 break;
334 default:
335 ret = -EINVAL;
336 break;
337 }
338
339 out:
340 mutex_unlock(&smi_data_lock);
341 return ret;
342 }
343 EXPORT_SYMBOL(dcdbas_smi_request);
344
345 /**
346 * host_control_smi: generate host control SMI
347 *
348 * Caller must set up the host control command in smi_data_buf.
349 */
host_control_smi(void)350 static int host_control_smi(void)
351 {
352 struct apm_cmd *apm_cmd;
353 u8 *data;
354 unsigned long flags;
355 u32 num_ticks;
356 s8 cmd_status;
357 u8 index;
358
359 apm_cmd = (struct apm_cmd *)smi_data_buf;
360 apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
361
362 switch (host_control_smi_type) {
363 case HC_SMITYPE_TYPE1:
364 spin_lock_irqsave(&rtc_lock, flags);
365 /* write SMI data buffer physical address */
366 data = (u8 *)&smi_data_buf_phys_addr;
367 for (index = PE1300_CMOS_CMD_STRUCT_PTR;
368 index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
369 index++, data++) {
370 outb(index,
371 (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
372 outb(*data,
373 (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
374 }
375
376 /* first set status to -1 as called by spec */
377 cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
378 outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
379
380 /* generate SMM call */
381 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
382 spin_unlock_irqrestore(&rtc_lock, flags);
383
384 /* wait a few to see if it executed */
385 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
386 while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
387 == ESM_STATUS_CMD_UNSUCCESSFUL) {
388 num_ticks--;
389 if (num_ticks == EXPIRED_TIMER)
390 return -ETIME;
391 }
392 break;
393
394 case HC_SMITYPE_TYPE2:
395 case HC_SMITYPE_TYPE3:
396 spin_lock_irqsave(&rtc_lock, flags);
397 /* write SMI data buffer physical address */
398 data = (u8 *)&smi_data_buf_phys_addr;
399 for (index = PE1400_CMOS_CMD_STRUCT_PTR;
400 index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
401 index++, data++) {
402 outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
403 outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
404 }
405
406 /* generate SMM call */
407 if (host_control_smi_type == HC_SMITYPE_TYPE3)
408 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
409 else
410 outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
411
412 /* restore RTC index pointer since it was written to above */
413 CMOS_READ(RTC_REG_C);
414 spin_unlock_irqrestore(&rtc_lock, flags);
415
416 /* read control port back to serialize write */
417 cmd_status = inb(PE1400_APM_CONTROL_PORT);
418
419 /* wait a few to see if it executed */
420 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
421 while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
422 num_ticks--;
423 if (num_ticks == EXPIRED_TIMER)
424 return -ETIME;
425 }
426 break;
427
428 default:
429 dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
430 __func__, host_control_smi_type);
431 return -ENOSYS;
432 }
433
434 return 0;
435 }
436
437 /**
438 * dcdbas_host_control: initiate host control
439 *
440 * This function is called by the driver after the system has
441 * finished shutting down if the user application specified a
442 * host control action to perform on shutdown. It is safe to
443 * use smi_data_buf at this point because the system has finished
444 * shutting down and no userspace apps are running.
445 */
dcdbas_host_control(void)446 static void dcdbas_host_control(void)
447 {
448 struct apm_cmd *apm_cmd;
449 u8 action;
450
451 if (host_control_action == HC_ACTION_NONE)
452 return;
453
454 action = host_control_action;
455 host_control_action = HC_ACTION_NONE;
456
457 if (!smi_data_buf) {
458 dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __func__);
459 return;
460 }
461
462 if (smi_data_buf_size < sizeof(struct apm_cmd)) {
463 dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
464 __func__);
465 return;
466 }
467
468 apm_cmd = (struct apm_cmd *)smi_data_buf;
469
470 /* power off takes precedence */
471 if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
472 apm_cmd->command = ESM_APM_POWER_CYCLE;
473 apm_cmd->reserved = 0;
474 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
475 host_control_smi();
476 } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
477 apm_cmd->command = ESM_APM_POWER_CYCLE;
478 apm_cmd->reserved = 0;
479 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
480 host_control_smi();
481 }
482 }
483
484 /**
485 * dcdbas_reboot_notify: handle reboot notification for host control
486 */
dcdbas_reboot_notify(struct notifier_block * nb,unsigned long code,void * unused)487 static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
488 void *unused)
489 {
490 switch (code) {
491 case SYS_DOWN:
492 case SYS_HALT:
493 case SYS_POWER_OFF:
494 if (host_control_on_shutdown) {
495 /* firmware is going to perform host control action */
496 printk(KERN_WARNING "Please wait for shutdown "
497 "action to complete...\n");
498 dcdbas_host_control();
499 }
500 break;
501 }
502
503 return NOTIFY_DONE;
504 }
505
506 static struct notifier_block dcdbas_reboot_nb = {
507 .notifier_call = dcdbas_reboot_notify,
508 .next = NULL,
509 .priority = INT_MIN
510 };
511
512 static DCDBAS_BIN_ATTR_RW(smi_data);
513
514 static struct bin_attribute *dcdbas_bin_attrs[] = {
515 &bin_attr_smi_data,
516 NULL
517 };
518
519 static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
520 static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
521 static DCDBAS_DEV_ATTR_WO(smi_request);
522 static DCDBAS_DEV_ATTR_RW(host_control_action);
523 static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
524 static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
525
526 static struct attribute *dcdbas_dev_attrs[] = {
527 &dev_attr_smi_data_buf_size.attr,
528 &dev_attr_smi_data_buf_phys_addr.attr,
529 &dev_attr_smi_request.attr,
530 &dev_attr_host_control_action.attr,
531 &dev_attr_host_control_smi_type.attr,
532 &dev_attr_host_control_on_shutdown.attr,
533 NULL
534 };
535
536 static struct attribute_group dcdbas_attr_group = {
537 .attrs = dcdbas_dev_attrs,
538 };
539
dcdbas_probe(struct platform_device * dev)540 static int dcdbas_probe(struct platform_device *dev)
541 {
542 int i, error;
543
544 host_control_action = HC_ACTION_NONE;
545 host_control_smi_type = HC_SMITYPE_NONE;
546
547 /*
548 * BIOS SMI calls require buffer addresses be in 32-bit address space.
549 * This is done by setting the DMA mask below.
550 */
551 dcdbas_pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
552 dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
553
554 error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
555 if (error)
556 return error;
557
558 for (i = 0; dcdbas_bin_attrs[i]; i++) {
559 error = sysfs_create_bin_file(&dev->dev.kobj,
560 dcdbas_bin_attrs[i]);
561 if (error) {
562 while (--i >= 0)
563 sysfs_remove_bin_file(&dev->dev.kobj,
564 dcdbas_bin_attrs[i]);
565 sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
566 return error;
567 }
568 }
569
570 register_reboot_notifier(&dcdbas_reboot_nb);
571
572 dev_info(&dev->dev, "%s (version %s)\n",
573 DRIVER_DESCRIPTION, DRIVER_VERSION);
574
575 return 0;
576 }
577
dcdbas_remove(struct platform_device * dev)578 static int dcdbas_remove(struct platform_device *dev)
579 {
580 int i;
581
582 unregister_reboot_notifier(&dcdbas_reboot_nb);
583 for (i = 0; dcdbas_bin_attrs[i]; i++)
584 sysfs_remove_bin_file(&dev->dev.kobj, dcdbas_bin_attrs[i]);
585 sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
586
587 return 0;
588 }
589
590 static struct platform_driver dcdbas_driver = {
591 .driver = {
592 .name = DRIVER_NAME,
593 .owner = THIS_MODULE,
594 },
595 .probe = dcdbas_probe,
596 .remove = dcdbas_remove,
597 };
598
599 /**
600 * dcdbas_init: initialize driver
601 */
dcdbas_init(void)602 static int __init dcdbas_init(void)
603 {
604 int error;
605
606 error = platform_driver_register(&dcdbas_driver);
607 if (error)
608 return error;
609
610 dcdbas_pdev = platform_device_alloc(DRIVER_NAME, -1);
611 if (!dcdbas_pdev) {
612 error = -ENOMEM;
613 goto err_unregister_driver;
614 }
615
616 error = platform_device_add(dcdbas_pdev);
617 if (error)
618 goto err_free_device;
619
620 return 0;
621
622 err_free_device:
623 platform_device_put(dcdbas_pdev);
624 err_unregister_driver:
625 platform_driver_unregister(&dcdbas_driver);
626 return error;
627 }
628
629 /**
630 * dcdbas_exit: perform driver cleanup
631 */
dcdbas_exit(void)632 static void __exit dcdbas_exit(void)
633 {
634 /*
635 * make sure functions that use dcdbas_pdev are called
636 * before platform_device_unregister
637 */
638 unregister_reboot_notifier(&dcdbas_reboot_nb);
639
640 /*
641 * We have to free the buffer here instead of dcdbas_remove
642 * because only in module exit function we can be sure that
643 * all sysfs attributes belonging to this module have been
644 * released.
645 */
646 smi_data_buf_free();
647 platform_device_unregister(dcdbas_pdev);
648 platform_driver_unregister(&dcdbas_driver);
649 }
650
651 module_init(dcdbas_init);
652 module_exit(dcdbas_exit);
653
654 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
655 MODULE_VERSION(DRIVER_VERSION);
656 MODULE_AUTHOR("Dell Inc.");
657 MODULE_LICENSE("GPL");
658 /* Any System or BIOS claiming to be by Dell */
659 MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");
660