8bcb58cd4ac0f93daf7b4bdc3924e2ef4caa2e2a
[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) 1995-2005 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 #include <asm/semaphore.h>
39
40 #include "dcdbas.h"
41
42 #define DRIVER_NAME             "dcdbas"
43 #define DRIVER_VERSION          "5.6.0-2"
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  */
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                 __FUNCTION__, 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  */
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                         __FUNCTION__, 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                 __FUNCTION__, smi_data_buf_phys_addr, smi_data_buf_size);
115
116         return 0;
117 }
118
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
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
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
152 static ssize_t smi_data_read(struct kobject *kobj, char *buf, loff_t pos,
153                              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, char *buf, loff_t pos,
174                               size_t count)
175 {
176         ssize_t ret;
177
178         mutex_lock(&smi_data_lock);
179
180         ret = smi_data_buf_realloc(pos + count);
181         if (ret)
182                 goto out;
183
184         memcpy(smi_data_buf + pos, buf, count);
185         ret = count;
186 out:
187         mutex_unlock(&smi_data_lock);
188         return ret;
189 }
190
191 static ssize_t host_control_action_show(struct device *dev,
192                                         struct device_attribute *attr,
193                                         char *buf)
194 {
195         return sprintf(buf, "%u\n", host_control_action);
196 }
197
198 static ssize_t host_control_action_store(struct device *dev,
199                                          struct device_attribute *attr,
200                                          const char *buf, size_t count)
201 {
202         ssize_t ret;
203
204         /* make sure buffer is available for host control command */
205         mutex_lock(&smi_data_lock);
206         ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
207         mutex_unlock(&smi_data_lock);
208         if (ret)
209                 return ret;
210
211         host_control_action = simple_strtoul(buf, NULL, 10);
212         return count;
213 }
214
215 static ssize_t host_control_smi_type_show(struct device *dev,
216                                           struct device_attribute *attr,
217                                           char *buf)
218 {
219         return sprintf(buf, "%u\n", host_control_smi_type);
220 }
221
222 static ssize_t host_control_smi_type_store(struct device *dev,
223                                            struct device_attribute *attr,
224                                            const char *buf, size_t count)
225 {
226         host_control_smi_type = simple_strtoul(buf, NULL, 10);
227         return count;
228 }
229
230 static ssize_t host_control_on_shutdown_show(struct device *dev,
231                                              struct device_attribute *attr,
232                                              char *buf)
233 {
234         return sprintf(buf, "%u\n", host_control_on_shutdown);
235 }
236
237 static ssize_t host_control_on_shutdown_store(struct device *dev,
238                                               struct device_attribute *attr,
239                                               const char *buf, size_t count)
240 {
241         host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
242         return count;
243 }
244
245 /**
246  * smi_request: generate SMI request
247  *
248  * Called with smi_data_lock.
249  */
250 static int smi_request(struct smi_cmd *smi_cmd)
251 {
252         cpumask_t old_mask;
253         int ret = 0;
254
255         if (smi_cmd->magic != SMI_CMD_MAGIC) {
256                 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
257                          __FUNCTION__);
258                 return -EBADR;
259         }
260
261         /* SMI requires CPU 0 */
262         old_mask = current->cpus_allowed;
263         set_cpus_allowed(current, cpumask_of_cpu(0));
264         if (smp_processor_id() != 0) {
265                 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
266                         __FUNCTION__);
267                 ret = -EBUSY;
268                 goto out;
269         }
270
271         /* generate SMI */
272         asm volatile (
273                 "outb %b0,%w1"
274                 : /* no output args */
275                 : "a" (smi_cmd->command_code),
276                   "d" (smi_cmd->command_address),
277                   "b" (smi_cmd->ebx),
278                   "c" (smi_cmd->ecx)
279                 : "memory"
280         );
281
282 out:
283         set_cpus_allowed(current, old_mask);
284         return ret;
285 }
286
287 /**
288  * smi_request_store:
289  *
290  * The valid values are:
291  * 0: zero SMI data buffer
292  * 1: generate calling interface SMI
293  * 2: generate raw SMI
294  *
295  * User application writes smi_cmd to smi_data before telling driver
296  * to generate SMI.
297  */
298 static ssize_t smi_request_store(struct device *dev,
299                                  struct device_attribute *attr,
300                                  const char *buf, size_t count)
301 {
302         struct smi_cmd *smi_cmd;
303         unsigned long val = simple_strtoul(buf, NULL, 10);
304         ssize_t ret;
305
306         mutex_lock(&smi_data_lock);
307
308         if (smi_data_buf_size < sizeof(struct smi_cmd)) {
309                 ret = -ENODEV;
310                 goto out;
311         }
312         smi_cmd = (struct smi_cmd *)smi_data_buf;
313
314         switch (val) {
315         case 2:
316                 /* Raw SMI */
317                 ret = smi_request(smi_cmd);
318                 if (!ret)
319                         ret = count;
320                 break;
321         case 1:
322                 /* Calling Interface SMI */
323                 smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer);
324                 ret = smi_request(smi_cmd);
325                 if (!ret)
326                         ret = count;
327                 break;
328         case 0:
329                 memset(smi_data_buf, 0, smi_data_buf_size);
330                 ret = count;
331                 break;
332         default:
333                 ret = -EINVAL;
334                 break;
335         }
336
337 out:
338         mutex_unlock(&smi_data_lock);
339         return ret;
340 }
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                         __FUNCTION__, 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", __FUNCTION__);
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                         __FUNCTION__);
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_32BIT_MASK;
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