edd: add default mode CONFIG_EDD_OFF=n, override with edd={on,off}
[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         size_t max_read;
156         ssize_t ret;
157
158         mutex_lock(&smi_data_lock);
159
160         if (pos >= smi_data_buf_size) {
161                 ret = 0;
162                 goto out;
163         }
164
165         max_read = smi_data_buf_size - pos;
166         ret = min(max_read, count);
167         memcpy(buf, smi_data_buf + pos, ret);
168 out:
169         mutex_unlock(&smi_data_lock);
170         return ret;
171 }
172
173 static ssize_t smi_data_write(struct kobject *kobj,
174                               struct bin_attribute *bin_attr,
175                               char *buf, loff_t pos, size_t count)
176 {
177         ssize_t ret;
178
179         if ((pos + count) > MAX_SMI_DATA_BUF_SIZE)
180                 return -EINVAL;
181
182         mutex_lock(&smi_data_lock);
183
184         ret = smi_data_buf_realloc(pos + count);
185         if (ret)
186                 goto out;
187
188         memcpy(smi_data_buf + pos, buf, count);
189         ret = count;
190 out:
191         mutex_unlock(&smi_data_lock);
192         return ret;
193 }
194
195 static ssize_t host_control_action_show(struct device *dev,
196                                         struct device_attribute *attr,
197                                         char *buf)
198 {
199         return sprintf(buf, "%u\n", host_control_action);
200 }
201
202 static ssize_t host_control_action_store(struct device *dev,
203                                          struct device_attribute *attr,
204                                          const char *buf, size_t count)
205 {
206         ssize_t ret;
207
208         /* make sure buffer is available for host control command */
209         mutex_lock(&smi_data_lock);
210         ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
211         mutex_unlock(&smi_data_lock);
212         if (ret)
213                 return ret;
214
215         host_control_action = simple_strtoul(buf, NULL, 10);
216         return count;
217 }
218
219 static ssize_t host_control_smi_type_show(struct device *dev,
220                                           struct device_attribute *attr,
221                                           char *buf)
222 {
223         return sprintf(buf, "%u\n", host_control_smi_type);
224 }
225
226 static ssize_t host_control_smi_type_store(struct device *dev,
227                                            struct device_attribute *attr,
228                                            const char *buf, size_t count)
229 {
230         host_control_smi_type = simple_strtoul(buf, NULL, 10);
231         return count;
232 }
233
234 static ssize_t host_control_on_shutdown_show(struct device *dev,
235                                              struct device_attribute *attr,
236                                              char *buf)
237 {
238         return sprintf(buf, "%u\n", host_control_on_shutdown);
239 }
240
241 static ssize_t host_control_on_shutdown_store(struct device *dev,
242                                               struct device_attribute *attr,
243                                               const char *buf, size_t count)
244 {
245         host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
246         return count;
247 }
248
249 /**
250  * smi_request: generate SMI request
251  *
252  * Called with smi_data_lock.
253  */
254 static int smi_request(struct smi_cmd *smi_cmd)
255 {
256         cpumask_t old_mask;
257         int ret = 0;
258
259         if (smi_cmd->magic != SMI_CMD_MAGIC) {
260                 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
261                          __func__);
262                 return -EBADR;
263         }
264
265         /* SMI requires CPU 0 */
266         old_mask = current->cpus_allowed;
267         set_cpus_allowed_ptr(current, &cpumask_of_cpu(0));
268         if (smp_processor_id() != 0) {
269                 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
270                         __func__);
271                 ret = -EBUSY;
272                 goto out;
273         }
274
275         /* generate SMI */
276         asm volatile (
277                 "outb %b0,%w1"
278                 : /* no output args */
279                 : "a" (smi_cmd->command_code),
280                   "d" (smi_cmd->command_address),
281                   "b" (smi_cmd->ebx),
282                   "c" (smi_cmd->ecx)
283                 : "memory"
284         );
285
286 out:
287         set_cpus_allowed_ptr(current, &old_mask);
288         return ret;
289 }
290
291 /**
292  * smi_request_store:
293  *
294  * The valid values are:
295  * 0: zero SMI data buffer
296  * 1: generate calling interface SMI
297  * 2: generate raw SMI
298  *
299  * User application writes smi_cmd to smi_data before telling driver
300  * to generate SMI.
301  */
302 static ssize_t smi_request_store(struct device *dev,
303                                  struct device_attribute *attr,
304                                  const char *buf, size_t count)
305 {
306         struct smi_cmd *smi_cmd;
307         unsigned long val = simple_strtoul(buf, NULL, 10);
308         ssize_t ret;
309
310         mutex_lock(&smi_data_lock);
311
312         if (smi_data_buf_size < sizeof(struct smi_cmd)) {
313                 ret = -ENODEV;
314                 goto out;
315         }
316         smi_cmd = (struct smi_cmd *)smi_data_buf;
317
318         switch (val) {
319         case 2:
320                 /* Raw SMI */
321                 ret = smi_request(smi_cmd);
322                 if (!ret)
323                         ret = count;
324                 break;
325         case 1:
326                 /* Calling Interface SMI */
327                 smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
328                 ret = smi_request(smi_cmd);
329                 if (!ret)
330                         ret = count;
331                 break;
332         case 0:
333                 memset(smi_data_buf, 0, smi_data_buf_size);
334                 ret = count;
335                 break;
336         default:
337                 ret = -EINVAL;
338                 break;
339         }
340
341 out:
342         mutex_unlock(&smi_data_lock);
343         return ret;
344 }
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  */
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  */
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  */
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 struct attribute_group dcdbas_attr_group = {
538         .attrs = dcdbas_dev_attrs,
539 };
540
541 static int __devinit dcdbas_probe(struct platform_device *dev)
542 {
543         int i, error;
544
545         host_control_action = HC_ACTION_NONE;
546         host_control_smi_type = HC_SMITYPE_NONE;
547
548         /*
549          * BIOS SMI calls require buffer addresses be in 32-bit address space.
550          * This is done by setting the DMA mask below.
551          */
552         dcdbas_pdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
553         dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
554
555         error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
556         if (error)
557                 return error;
558
559         for (i = 0; dcdbas_bin_attrs[i]; i++) {
560                 error = sysfs_create_bin_file(&dev->dev.kobj,
561                                               dcdbas_bin_attrs[i]);
562                 if (error) {
563                         while (--i >= 0)
564                                 sysfs_remove_bin_file(&dev->dev.kobj,
565                                                       dcdbas_bin_attrs[i]);
566                         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
567                         return error;
568                 }
569         }
570
571         register_reboot_notifier(&dcdbas_reboot_nb);
572
573         dev_info(&dev->dev, "%s (version %s)\n",
574                  DRIVER_DESCRIPTION, DRIVER_VERSION);
575
576         return 0;
577 }
578
579 static int __devexit dcdbas_remove(struct platform_device *dev)
580 {
581         int i;
582
583         unregister_reboot_notifier(&dcdbas_reboot_nb);
584         for (i = 0; dcdbas_bin_attrs[i]; i++)
585                 sysfs_remove_bin_file(&dev->dev.kobj, dcdbas_bin_attrs[i]);
586         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
587
588         return 0;
589 }
590
591 static struct platform_driver dcdbas_driver = {
592         .driver         = {
593                 .name   = DRIVER_NAME,
594                 .owner  = THIS_MODULE,
595         },
596         .probe          = dcdbas_probe,
597         .remove         = __devexit_p(dcdbas_remove),
598 };
599
600 /**
601  * dcdbas_init: initialize driver
602  */
603 static int __init dcdbas_init(void)
604 {
605         int error;
606
607         error = platform_driver_register(&dcdbas_driver);
608         if (error)
609                 return error;
610
611         dcdbas_pdev = platform_device_alloc(DRIVER_NAME, -1);
612         if (!dcdbas_pdev) {
613                 error = -ENOMEM;
614                 goto err_unregister_driver;
615         }
616
617         error = platform_device_add(dcdbas_pdev);
618         if (error)
619                 goto err_free_device;
620
621         return 0;
622
623  err_free_device:
624         platform_device_put(dcdbas_pdev);
625  err_unregister_driver:
626         platform_driver_unregister(&dcdbas_driver);
627         return error;
628 }
629
630 /**
631  * dcdbas_exit: perform driver cleanup
632  */
633 static void __exit dcdbas_exit(void)
634 {
635         /*
636          * make sure functions that use dcdbas_pdev are called
637          * before platform_device_unregister
638          */
639         unregister_reboot_notifier(&dcdbas_reboot_nb);
640         smi_data_buf_free();
641         platform_device_unregister(dcdbas_pdev);
642         platform_driver_unregister(&dcdbas_driver);
643
644         /*
645          * We have to free the buffer here instead of dcdbas_remove
646          * because only in module exit function we can be sure that
647          * all sysfs attributes belonging to this module have been
648          * released.
649          */
650         smi_data_buf_free();
651 }
652
653 module_init(dcdbas_init);
654 module_exit(dcdbas_exit);
655
656 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
657 MODULE_VERSION(DRIVER_VERSION);
658 MODULE_AUTHOR("Dell Inc.");
659 MODULE_LICENSE("GPL");
660 /* Any System or BIOS claiming to be by Dell */
661 MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");