Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-next-2.6
[linux-2.6.git] / drivers / firmware / dcdbas.c
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/init.h>
27 #include <linux/kernel.h>
28 #include <linux/mc146818rtc.h>
29 #include <linux/module.h>
30 #include <linux/reboot.h>
31 #include <linux/sched.h>
32 #include <linux/smp.h>
33 #include <linux/spinlock.h>
34 #include <linux/string.h>
35 #include <linux/types.h>
36 #include <linux/mutex.h>
37 #include <asm/io.h>
38
39 #include "dcdbas.h"
40
41 #define DRIVER_NAME             "dcdbas"
42 #define DRIVER_VERSION          "5.6.0-3.2"
43 #define DRIVER_DESCRIPTION      "Dell Systems Management Base Driver"
44
45 static struct platform_device *dcdbas_pdev;
46
47 static u8 *smi_data_buf;
48 static dma_addr_t smi_data_buf_handle;
49 static unsigned long smi_data_buf_size;
50 static u32 smi_data_buf_phys_addr;
51 static DEFINE_MUTEX(smi_data_lock);
52
53 static unsigned int host_control_action;
54 static unsigned int host_control_smi_type;
55 static unsigned int host_control_on_shutdown;
56
57 /**
58  * smi_data_buf_free: free SMI data buffer
59  */
60 static void smi_data_buf_free(void)
61 {
62         if (!smi_data_buf)
63                 return;
64
65         dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
66                 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
67
68         dma_free_coherent(&dcdbas_pdev->dev, smi_data_buf_size, smi_data_buf,
69                           smi_data_buf_handle);
70         smi_data_buf = NULL;
71         smi_data_buf_handle = 0;
72         smi_data_buf_phys_addr = 0;
73         smi_data_buf_size = 0;
74 }
75
76 /**
77  * smi_data_buf_realloc: grow SMI data buffer if needed
78  */
79 static int smi_data_buf_realloc(unsigned long size)
80 {
81         void *buf;
82         dma_addr_t handle;
83
84         if (smi_data_buf_size >= size)
85                 return 0;
86
87         if (size > MAX_SMI_DATA_BUF_SIZE)
88                 return -EINVAL;
89
90         /* new buffer is needed */
91         buf = dma_alloc_coherent(&dcdbas_pdev->dev, size, &handle, GFP_KERNEL);
92         if (!buf) {
93                 dev_dbg(&dcdbas_pdev->dev,
94                         "%s: failed to allocate memory size %lu\n",
95                         __func__, size);
96                 return -ENOMEM;
97         }
98         /* memory zeroed by dma_alloc_coherent */
99
100         if (smi_data_buf)
101                 memcpy(buf, smi_data_buf, smi_data_buf_size);
102
103         /* free any existing buffer */
104         smi_data_buf_free();
105
106         /* set up new buffer for use */
107         smi_data_buf = buf;
108         smi_data_buf_handle = handle;
109         smi_data_buf_phys_addr = (u32) virt_to_phys(buf);
110         smi_data_buf_size = size;
111
112         dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
113                 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
114
115         return 0;
116 }
117
118 static ssize_t smi_data_buf_phys_addr_show(struct device *dev,
119                                            struct device_attribute *attr,
120                                            char *buf)
121 {
122         return sprintf(buf, "%x\n", smi_data_buf_phys_addr);
123 }
124
125 static ssize_t smi_data_buf_size_show(struct device *dev,
126                                       struct device_attribute *attr,
127                                       char *buf)
128 {
129         return sprintf(buf, "%lu\n", smi_data_buf_size);
130 }
131
132 static ssize_t smi_data_buf_size_store(struct device *dev,
133                                        struct device_attribute *attr,
134                                        const char *buf, size_t count)
135 {
136         unsigned long buf_size;
137         ssize_t ret;
138
139         buf_size = simple_strtoul(buf, NULL, 10);
140
141         /* make sure SMI data buffer is at least buf_size */
142         mutex_lock(&smi_data_lock);
143         ret = smi_data_buf_realloc(buf_size);
144         mutex_unlock(&smi_data_lock);
145         if (ret)
146                 return ret;
147
148         return count;
149 }
150
151 static ssize_t smi_data_read(struct kobject *kobj,
152                              struct bin_attribute *bin_attr,
153                              char *buf, loff_t pos, size_t count)
154 {
155         ssize_t ret;
156
157         mutex_lock(&smi_data_lock);
158         ret = memory_read_from_buffer(buf, count, &pos, smi_data_buf,
159                                         smi_data_buf_size);
160         mutex_unlock(&smi_data_lock);
161         return ret;
162 }
163
164 static ssize_t smi_data_write(struct kobject *kobj,
165                               struct bin_attribute *bin_attr,
166                               char *buf, loff_t pos, size_t count)
167 {
168         ssize_t ret;
169
170         if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
171                 return -EINVAL;
172
173         mutex_lock(&smi_data_lock);
174
175         ret = smi_data_buf_realloc(pos + count);
176         if (ret)
177                 goto out;
178
179         memcpy(smi_data_buf + pos, buf, count);
180         ret = count;
181 out:
182         mutex_unlock(&smi_data_lock);
183         return ret;
184 }
185
186 static ssize_t host_control_action_show(struct device *dev,
187                                         struct device_attribute *attr,
188                                         char *buf)
189 {
190         return sprintf(buf, "%u\n", host_control_action);
191 }
192
193 static ssize_t host_control_action_store(struct device *dev,
194                                          struct device_attribute *attr,
195                                          const char *buf, size_t count)
196 {
197         ssize_t ret;
198
199         /* make sure buffer is available for host control command */
200         mutex_lock(&smi_data_lock);
201         ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
202         mutex_unlock(&smi_data_lock);
203         if (ret)
204                 return ret;
205
206         host_control_action = simple_strtoul(buf, NULL, 10);
207         return count;
208 }
209
210 static ssize_t host_control_smi_type_show(struct device *dev,
211                                           struct device_attribute *attr,
212                                           char *buf)
213 {
214         return sprintf(buf, "%u\n", host_control_smi_type);
215 }
216
217 static ssize_t host_control_smi_type_store(struct device *dev,
218                                            struct device_attribute *attr,
219                                            const char *buf, size_t count)
220 {
221         host_control_smi_type = simple_strtoul(buf, NULL, 10);
222         return count;
223 }
224
225 static ssize_t host_control_on_shutdown_show(struct device *dev,
226                                              struct device_attribute *attr,
227                                              char *buf)
228 {
229         return sprintf(buf, "%u\n", host_control_on_shutdown);
230 }
231
232 static ssize_t host_control_on_shutdown_store(struct device *dev,
233                                               struct device_attribute *attr,
234                                               const char *buf, size_t count)
235 {
236         host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
237         return count;
238 }
239
240 /**
241  * dcdbas_smi_request: generate SMI request
242  *
243  * Called with smi_data_lock.
244  */
245 int dcdbas_smi_request(struct smi_cmd *smi_cmd)
246 {
247         cpumask_var_t old_mask;
248         int ret = 0;
249
250         if (smi_cmd->magic != SMI_CMD_MAGIC) {
251                 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
252                          __func__);
253                 return -EBADR;
254         }
255
256         /* SMI requires CPU 0 */
257         if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
258                 return -ENOMEM;
259
260         cpumask_copy(old_mask, &current->cpus_allowed);
261         set_cpus_allowed_ptr(current, cpumask_of(0));
262         if (smp_processor_id() != 0) {
263                 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
264                         __func__);
265                 ret = -EBUSY;
266                 goto out;
267         }
268
269         /* generate SMI */
270         asm volatile (
271                 "outb %b0,%w1"
272                 : /* no output args */
273                 : "a" (smi_cmd->command_code),
274                   "d" (smi_cmd->command_address),
275                   "b" (smi_cmd->ebx),
276                   "c" (smi_cmd->ecx)
277                 : "memory"
278         );
279
280 out:
281         set_cpus_allowed_ptr(current, old_mask);
282         free_cpumask_var(old_mask);
283         return ret;
284 }
285
286 /**
287  * smi_request_store:
288  *
289  * The valid values are:
290  * 0: zero SMI data buffer
291  * 1: generate calling interface SMI
292  * 2: generate raw SMI
293  *
294  * User application writes smi_cmd to smi_data before telling driver
295  * to generate SMI.
296  */
297 static ssize_t smi_request_store(struct device *dev,
298                                  struct device_attribute *attr,
299                                  const char *buf, size_t count)
300 {
301         struct smi_cmd *smi_cmd;
302         unsigned long val = simple_strtoul(buf, NULL, 10);
303         ssize_t ret;
304
305         mutex_lock(&smi_data_lock);
306
307         if (smi_data_buf_size < sizeof(struct smi_cmd)) {
308                 ret = -ENODEV;
309                 goto out;
310         }
311         smi_cmd = (struct smi_cmd *)smi_data_buf;
312
313         switch (val) {
314         case 2:
315                 /* Raw SMI */
316                 ret = dcdbas_smi_request(smi_cmd);
317                 if (!ret)
318                         ret = count;
319                 break;
320         case 1:
321                 /* Calling Interface SMI */
322                 smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
323                 ret = dcdbas_smi_request(smi_cmd);
324                 if (!ret)
325                         ret = count;
326                 break;
327         case 0:
328                 memset(smi_data_buf, 0, smi_data_buf_size);
329                 ret = count;
330                 break;
331         default:
332                 ret = -EINVAL;
333                 break;
334         }
335
336 out:
337         mutex_unlock(&smi_data_lock);
338         return ret;
339 }
340 EXPORT_SYMBOL(dcdbas_smi_request);
341
342 /**
343  * host_control_smi: generate host control SMI
344  *
345  * Caller must set up the host control command in smi_data_buf.
346  */
347 static int host_control_smi(void)
348 {
349         struct apm_cmd *apm_cmd;
350         u8 *data;
351         unsigned long flags;
352         u32 num_ticks;
353         s8 cmd_status;
354         u8 index;
355
356         apm_cmd = (struct apm_cmd *)smi_data_buf;
357         apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
358
359         switch (host_control_smi_type) {
360         case HC_SMITYPE_TYPE1:
361                 spin_lock_irqsave(&rtc_lock, flags);
362                 /* write SMI data buffer physical address */
363                 data = (u8 *)&smi_data_buf_phys_addr;
364                 for (index = PE1300_CMOS_CMD_STRUCT_PTR;
365                      index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
366                      index++, data++) {
367                         outb(index,
368                              (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
369                         outb(*data,
370                              (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
371                 }
372
373                 /* first set status to -1 as called by spec */
374                 cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
375                 outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
376
377                 /* generate SMM call */
378                 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
379                 spin_unlock_irqrestore(&rtc_lock, flags);
380
381                 /* wait a few to see if it executed */
382                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
383                 while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
384                        == ESM_STATUS_CMD_UNSUCCESSFUL) {
385                         num_ticks--;
386                         if (num_ticks == EXPIRED_TIMER)
387                                 return -ETIME;
388                 }
389                 break;
390
391         case HC_SMITYPE_TYPE2:
392         case HC_SMITYPE_TYPE3:
393                 spin_lock_irqsave(&rtc_lock, flags);
394                 /* write SMI data buffer physical address */
395                 data = (u8 *)&smi_data_buf_phys_addr;
396                 for (index = PE1400_CMOS_CMD_STRUCT_PTR;
397                      index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
398                      index++, data++) {
399                         outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
400                         outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
401                 }
402
403                 /* generate SMM call */
404                 if (host_control_smi_type == HC_SMITYPE_TYPE3)
405                         outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
406                 else
407                         outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
408
409                 /* restore RTC index pointer since it was written to above */
410                 CMOS_READ(RTC_REG_C);
411                 spin_unlock_irqrestore(&rtc_lock, flags);
412
413                 /* read control port back to serialize write */
414                 cmd_status = inb(PE1400_APM_CONTROL_PORT);
415
416                 /* wait a few to see if it executed */
417                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
418                 while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
419                         num_ticks--;
420                         if (num_ticks == EXPIRED_TIMER)
421                                 return -ETIME;
422                 }
423                 break;
424
425         default:
426                 dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
427                         __func__, host_control_smi_type);
428                 return -ENOSYS;
429         }
430
431         return 0;
432 }
433
434 /**
435  * dcdbas_host_control: initiate host control
436  *
437  * This function is called by the driver after the system has
438  * finished shutting down if the user application specified a
439  * host control action to perform on shutdown.  It is safe to
440  * use smi_data_buf at this point because the system has finished
441  * shutting down and no userspace apps are running.
442  */
443 static void dcdbas_host_control(void)
444 {
445         struct apm_cmd *apm_cmd;
446         u8 action;
447
448         if (host_control_action == HC_ACTION_NONE)
449                 return;
450
451         action = host_control_action;
452         host_control_action = HC_ACTION_NONE;
453
454         if (!smi_data_buf) {
455                 dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __func__);
456                 return;
457         }
458
459         if (smi_data_buf_size < sizeof(struct apm_cmd)) {
460                 dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
461                         __func__);
462                 return;
463         }
464
465         apm_cmd = (struct apm_cmd *)smi_data_buf;
466
467         /* power off takes precedence */
468         if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
469                 apm_cmd->command = ESM_APM_POWER_CYCLE;
470                 apm_cmd->reserved = 0;
471                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
472                 host_control_smi();
473         } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
474                 apm_cmd->command = ESM_APM_POWER_CYCLE;
475                 apm_cmd->reserved = 0;
476                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
477                 host_control_smi();
478         }
479 }
480
481 /**
482  * dcdbas_reboot_notify: handle reboot notification for host control
483  */
484 static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
485                                 void *unused)
486 {
487         switch (code) {
488         case SYS_DOWN:
489         case SYS_HALT:
490         case SYS_POWER_OFF:
491                 if (host_control_on_shutdown) {
492                         /* firmware is going to perform host control action */
493                         printk(KERN_WARNING "Please wait for shutdown "
494                                "action to complete...\n");
495                         dcdbas_host_control();
496                 }
497                 break;
498         }
499
500         return NOTIFY_DONE;
501 }
502
503 static struct notifier_block dcdbas_reboot_nb = {
504         .notifier_call = dcdbas_reboot_notify,
505         .next = NULL,
506         .priority = INT_MIN
507 };
508
509 static DCDBAS_BIN_ATTR_RW(smi_data);
510
511 static struct bin_attribute *dcdbas_bin_attrs[] = {
512         &bin_attr_smi_data,
513         NULL
514 };
515
516 static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
517 static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
518 static DCDBAS_DEV_ATTR_WO(smi_request);
519 static DCDBAS_DEV_ATTR_RW(host_control_action);
520 static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
521 static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
522
523 static struct attribute *dcdbas_dev_attrs[] = {
524         &dev_attr_smi_data_buf_size.attr,
525         &dev_attr_smi_data_buf_phys_addr.attr,
526         &dev_attr_smi_request.attr,
527         &dev_attr_host_control_action.attr,
528         &dev_attr_host_control_smi_type.attr,
529         &dev_attr_host_control_on_shutdown.attr,
530         NULL
531 };
532
533 static struct attribute_group dcdbas_attr_group = {
534         .attrs = dcdbas_dev_attrs,
535 };
536
537 static int __devinit dcdbas_probe(struct platform_device *dev)
538 {
539         int i, error;
540
541         host_control_action = HC_ACTION_NONE;
542         host_control_smi_type = HC_SMITYPE_NONE;
543
544         /*
545          * BIOS SMI calls require buffer addresses be in 32-bit address space.
546          * This is done by setting the DMA mask below.
547          */
548         dcdbas_pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
549         dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
550
551         error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
552         if (error)
553                 return error;
554
555         for (i = 0; dcdbas_bin_attrs[i]; i++) {
556                 error = sysfs_create_bin_file(&dev->dev.kobj,
557                                               dcdbas_bin_attrs[i]);
558                 if (error) {
559                         while (--i >= 0)
560                                 sysfs_remove_bin_file(&dev->dev.kobj,
561                                                       dcdbas_bin_attrs[i]);
562                         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
563                         return error;
564                 }
565         }
566
567         register_reboot_notifier(&dcdbas_reboot_nb);
568
569         dev_info(&dev->dev, "%s (version %s)\n",
570                  DRIVER_DESCRIPTION, DRIVER_VERSION);
571
572         return 0;
573 }
574
575 static int __devexit dcdbas_remove(struct platform_device *dev)
576 {
577         int i;
578
579         unregister_reboot_notifier(&dcdbas_reboot_nb);
580         for (i = 0; dcdbas_bin_attrs[i]; i++)
581                 sysfs_remove_bin_file(&dev->dev.kobj, dcdbas_bin_attrs[i]);
582         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
583
584         return 0;
585 }
586
587 static struct platform_driver dcdbas_driver = {
588         .driver         = {
589                 .name   = DRIVER_NAME,
590                 .owner  = THIS_MODULE,
591         },
592         .probe          = dcdbas_probe,
593         .remove         = __devexit_p(dcdbas_remove),
594 };
595
596 /**
597  * dcdbas_init: initialize driver
598  */
599 static int __init dcdbas_init(void)
600 {
601         int error;
602
603         error = platform_driver_register(&dcdbas_driver);
604         if (error)
605                 return error;
606
607         dcdbas_pdev = platform_device_alloc(DRIVER_NAME, -1);
608         if (!dcdbas_pdev) {
609                 error = -ENOMEM;
610                 goto err_unregister_driver;
611         }
612
613         error = platform_device_add(dcdbas_pdev);
614         if (error)
615                 goto err_free_device;
616
617         return 0;
618
619  err_free_device:
620         platform_device_put(dcdbas_pdev);
621  err_unregister_driver:
622         platform_driver_unregister(&dcdbas_driver);
623         return error;
624 }
625
626 /**
627  * dcdbas_exit: perform driver cleanup
628  */
629 static void __exit dcdbas_exit(void)
630 {
631         /*
632          * make sure functions that use dcdbas_pdev are called
633          * before platform_device_unregister
634          */
635         unregister_reboot_notifier(&dcdbas_reboot_nb);
636         smi_data_buf_free();
637         platform_device_unregister(dcdbas_pdev);
638         platform_driver_unregister(&dcdbas_driver);
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 }
648
649 module_init(dcdbas_init);
650 module_exit(dcdbas_exit);
651
652 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
653 MODULE_VERSION(DRIVER_VERSION);
654 MODULE_AUTHOR("Dell Inc.");
655 MODULE_LICENSE("GPL");
656 /* Any System or BIOS claiming to be by Dell */
657 MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");