[PATCH] dcdbas: add Dell Systems Management Base Driver with sysfs support
[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/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 <asm/io.h>
37 #include <asm/semaphore.h>
38
39 #include "dcdbas.h"
40
41 #define DRIVER_NAME             "dcdbas"
42 #define DRIVER_VERSION          "5.6.0-1"
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 DECLARE_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                 __FUNCTION__, 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                         __FUNCTION__, 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                 __FUNCTION__, 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         down(&smi_data_lock);
143         ret = smi_data_buf_realloc(buf_size);
144         up(&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, char *buf, loff_t pos,
152                              size_t count)
153 {
154         size_t max_read;
155         ssize_t ret;
156
157         down(&smi_data_lock);
158
159         if (pos >= smi_data_buf_size) {
160                 ret = 0;
161                 goto out;
162         }
163
164         max_read = smi_data_buf_size - pos;
165         ret = min(max_read, count);
166         memcpy(buf, smi_data_buf + pos, ret);
167 out:
168         up(&smi_data_lock);
169         return ret;
170 }
171
172 static ssize_t smi_data_write(struct kobject *kobj, char *buf, loff_t pos,
173                               size_t count)
174 {
175         ssize_t ret;
176
177         down(&smi_data_lock);
178
179         ret = smi_data_buf_realloc(pos + count);
180         if (ret)
181                 goto out;
182
183         memcpy(smi_data_buf + pos, buf, count);
184         ret = count;
185 out:
186         up(&smi_data_lock);
187         return ret;
188 }
189
190 static ssize_t host_control_action_show(struct device *dev,
191                                         struct device_attribute *attr,
192                                         char *buf)
193 {
194         return sprintf(buf, "%u\n", host_control_action);
195 }
196
197 static ssize_t host_control_action_store(struct device *dev,
198                                          struct device_attribute *attr,
199                                          const char *buf, size_t count)
200 {
201         ssize_t ret;
202
203         /* make sure buffer is available for host control command */
204         down(&smi_data_lock);
205         ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
206         up(&smi_data_lock);
207         if (ret)
208                 return ret;
209
210         host_control_action = simple_strtoul(buf, NULL, 10);
211         return count;
212 }
213
214 static ssize_t host_control_smi_type_show(struct device *dev,
215                                           struct device_attribute *attr,
216                                           char *buf)
217 {
218         return sprintf(buf, "%u\n", host_control_smi_type);
219 }
220
221 static ssize_t host_control_smi_type_store(struct device *dev,
222                                            struct device_attribute *attr,
223                                            const char *buf, size_t count)
224 {
225         host_control_smi_type = simple_strtoul(buf, NULL, 10);
226         return count;
227 }
228
229 static ssize_t host_control_on_shutdown_show(struct device *dev,
230                                              struct device_attribute *attr,
231                                              char *buf)
232 {
233         return sprintf(buf, "%u\n", host_control_on_shutdown);
234 }
235
236 static ssize_t host_control_on_shutdown_store(struct device *dev,
237                                               struct device_attribute *attr,
238                                               const char *buf, size_t count)
239 {
240         host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
241         return count;
242 }
243
244 /**
245  * smi_request: generate SMI request
246  *
247  * Called with smi_data_lock.
248  */
249 static int smi_request(struct smi_cmd *smi_cmd)
250 {
251         cpumask_t old_mask;
252         int ret = 0;
253
254         if (smi_cmd->magic != SMI_CMD_MAGIC) {
255                 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
256                          __FUNCTION__);
257                 return -EBADR;
258         }
259
260         /* SMI requires CPU 0 */
261         old_mask = current->cpus_allowed;
262         set_cpus_allowed(current, cpumask_of_cpu(0));
263         if (smp_processor_id() != 0) {
264                 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
265                         __FUNCTION__);
266                 ret = -EBUSY;
267                 goto out;
268         }
269
270         /* generate SMI */
271         asm volatile (
272                 "outb %b0,%w1"
273                 : /* no output args */
274                 : "a" (smi_cmd->command_code),
275                   "d" (smi_cmd->command_address),
276                   "b" (smi_cmd->ebx),
277                   "c" (smi_cmd->ecx)
278                 : "memory"
279         );
280
281 out:
282         set_cpus_allowed(current, 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         down(&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 = 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 = 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         up(&smi_data_lock);
338         return ret;
339 }
340
341 /**
342  * host_control_smi: generate host control SMI
343  *
344  * Caller must set up the host control command in smi_data_buf.
345  */
346 static int host_control_smi(void)
347 {
348         struct apm_cmd *apm_cmd;
349         u8 *data;
350         unsigned long flags;
351         u32 num_ticks;
352         s8 cmd_status;
353         u8 index;
354
355         apm_cmd = (struct apm_cmd *)smi_data_buf;
356         apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
357
358         switch (host_control_smi_type) {
359         case HC_SMITYPE_TYPE1:
360                 spin_lock_irqsave(&rtc_lock, flags);
361                 /* write SMI data buffer physical address */
362                 data = (u8 *)&smi_data_buf_phys_addr;
363                 for (index = PE1300_CMOS_CMD_STRUCT_PTR;
364                      index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
365                      index++, data++) {
366                         outb(index,
367                              (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
368                         outb(*data,
369                              (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
370                 }
371
372                 /* first set status to -1 as called by spec */
373                 cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
374                 outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
375
376                 /* generate SMM call */
377                 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
378                 spin_unlock_irqrestore(&rtc_lock, flags);
379
380                 /* wait a few to see if it executed */
381                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
382                 while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
383                        == ESM_STATUS_CMD_UNSUCCESSFUL) {
384                         num_ticks--;
385                         if (num_ticks == EXPIRED_TIMER)
386                                 return -ETIME;
387                 }
388                 break;
389
390         case HC_SMITYPE_TYPE2:
391         case HC_SMITYPE_TYPE3:
392                 spin_lock_irqsave(&rtc_lock, flags);
393                 /* write SMI data buffer physical address */
394                 data = (u8 *)&smi_data_buf_phys_addr;
395                 for (index = PE1400_CMOS_CMD_STRUCT_PTR;
396                      index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
397                      index++, data++) {
398                         outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
399                         outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
400                 }
401
402                 /* generate SMM call */
403                 if (host_control_smi_type == HC_SMITYPE_TYPE3)
404                         outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
405                 else
406                         outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
407
408                 /* restore RTC index pointer since it was written to above */
409                 CMOS_READ(RTC_REG_C);
410                 spin_unlock_irqrestore(&rtc_lock, flags);
411
412                 /* read control port back to serialize write */
413                 cmd_status = inb(PE1400_APM_CONTROL_PORT);
414
415                 /* wait a few to see if it executed */
416                 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
417                 while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
418                         num_ticks--;
419                         if (num_ticks == EXPIRED_TIMER)
420                                 return -ETIME;
421                 }
422                 break;
423
424         default:
425                 dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
426                         __FUNCTION__, host_control_smi_type);
427                 return -ENOSYS;
428         }
429
430         return 0;
431 }
432
433 /**
434  * dcdbas_host_control: initiate host control
435  *
436  * This function is called by the driver after the system has
437  * finished shutting down if the user application specified a
438  * host control action to perform on shutdown.  It is safe to
439  * use smi_data_buf at this point because the system has finished
440  * shutting down and no userspace apps are running.
441  */
442 static void dcdbas_host_control(void)
443 {
444         struct apm_cmd *apm_cmd;
445         u8 action;
446
447         if (host_control_action == HC_ACTION_NONE)
448                 return;
449
450         action = host_control_action;
451         host_control_action = HC_ACTION_NONE;
452
453         if (!smi_data_buf) {
454                 dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __FUNCTION__);
455                 return;
456         }
457
458         if (smi_data_buf_size < sizeof(struct apm_cmd)) {
459                 dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
460                         __FUNCTION__);
461                 return;
462         }
463
464         apm_cmd = (struct apm_cmd *)smi_data_buf;
465
466         /* power off takes precedence */
467         if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
468                 apm_cmd->command = ESM_APM_POWER_CYCLE;
469                 apm_cmd->reserved = 0;
470                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
471                 host_control_smi();
472         } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
473                 apm_cmd->command = ESM_APM_POWER_CYCLE;
474                 apm_cmd->reserved = 0;
475                 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
476                 host_control_smi();
477         }
478 }
479
480 /**
481  * dcdbas_reboot_notify: handle reboot notification for host control
482  */
483 static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
484                                 void *unused)
485 {
486         static unsigned int notify_cnt = 0;
487
488         switch (code) {
489         case SYS_DOWN:
490         case SYS_HALT:
491         case SYS_POWER_OFF:
492                 if (host_control_on_shutdown) {
493                         /* firmware is going to perform host control action */
494                         if (++notify_cnt == 2) {
495                                 printk(KERN_WARNING
496                                        "Please wait for shutdown "
497                                        "action to complete...\n");
498                                 dcdbas_host_control();
499                         }
500                         /*
501                          * register again and initiate the host control
502                          * action on the second notification to allow
503                          * everyone that registered to be notified
504                          */
505                         register_reboot_notifier(nb);
506                 }
507                 break;
508         }
509
510         return NOTIFY_DONE;
511 }
512
513 static struct notifier_block dcdbas_reboot_nb = {
514         .notifier_call = dcdbas_reboot_notify,
515         .next = NULL,
516         .priority = 0
517 };
518
519 static DCDBAS_BIN_ATTR_RW(smi_data);
520
521 static struct bin_attribute *dcdbas_bin_attrs[] = {
522         &bin_attr_smi_data,
523         NULL
524 };
525
526 static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
527 static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
528 static DCDBAS_DEV_ATTR_WO(smi_request);
529 static DCDBAS_DEV_ATTR_RW(host_control_action);
530 static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
531 static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
532
533 static struct device_attribute *dcdbas_dev_attrs[] = {
534         &dev_attr_smi_data_buf_size,
535         &dev_attr_smi_data_buf_phys_addr,
536         &dev_attr_smi_request,
537         &dev_attr_host_control_action,
538         &dev_attr_host_control_smi_type,
539         &dev_attr_host_control_on_shutdown,
540         NULL
541 };
542
543 /**
544  * dcdbas_init: initialize driver
545  */
546 static int __init dcdbas_init(void)
547 {
548         int i;
549
550         host_control_action = HC_ACTION_NONE;
551         host_control_smi_type = HC_SMITYPE_NONE;
552
553         dcdbas_pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
554         if (IS_ERR(dcdbas_pdev))
555                 return PTR_ERR(dcdbas_pdev);
556
557         /*
558          * BIOS SMI calls require buffer addresses be in 32-bit address space.
559          * This is done by setting the DMA mask below.
560          */
561         dcdbas_pdev->dev.coherent_dma_mask = DMA_32BIT_MASK;
562         dcdbas_pdev->dev.dma_mask = &dcdbas_pdev->dev.coherent_dma_mask;
563
564         register_reboot_notifier(&dcdbas_reboot_nb);
565
566         for (i = 0; dcdbas_bin_attrs[i]; i++)
567                 sysfs_create_bin_file(&dcdbas_pdev->dev.kobj,
568                                       dcdbas_bin_attrs[i]);
569
570         for (i = 0; dcdbas_dev_attrs[i]; i++)
571                 device_create_file(&dcdbas_pdev->dev, dcdbas_dev_attrs[i]);
572
573         dev_info(&dcdbas_pdev->dev, "%s (version %s)\n",
574                  DRIVER_DESCRIPTION, DRIVER_VERSION);
575
576         return 0;
577 }
578
579 /**
580  * dcdbas_exit: perform driver cleanup
581  */
582 static void __exit dcdbas_exit(void)
583 {
584         platform_device_unregister(dcdbas_pdev);
585         unregister_reboot_notifier(&dcdbas_reboot_nb);
586         smi_data_buf_free();
587 }
588
589 module_init(dcdbas_init);
590 module_exit(dcdbas_exit);
591
592 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
593 MODULE_VERSION(DRIVER_VERSION);
594 MODULE_AUTHOR("Dell Inc.");
595 MODULE_LICENSE("GPL");
596