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Linux/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/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  */
 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  */
 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 
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 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 
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 
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 
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 
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 
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 
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 
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  */
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, &current->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  */
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  */
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  */
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  */
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         .bin_attrs = dcdbas_bin_attrs,
539 };
540 
541 static int dcdbas_probe(struct platform_device *dev)
542 {
543         int error;
544 
545         host_control_action = HC_ACTION_NONE;
546         host_control_smi_type = HC_SMITYPE_NONE;
547 
548         dcdbas_pdev = dev;
549 
550         /*
551          * BIOS SMI calls require buffer addresses be in 32-bit address space.
552          * This is done by setting the DMA mask below.
553          */
554         error = dma_set_coherent_mask(&dcdbas_pdev->dev, DMA_BIT_MASK(32));
555         if (error)
556                 return error;
557 
558         error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
559         if (error)
560                 return error;
561 
562         register_reboot_notifier(&dcdbas_reboot_nb);
563 
564         dev_info(&dev->dev, "%s (version %s)\n",
565                  DRIVER_DESCRIPTION, DRIVER_VERSION);
566 
567         return 0;
568 }
569 
570 static int dcdbas_remove(struct platform_device *dev)
571 {
572         unregister_reboot_notifier(&dcdbas_reboot_nb);
573         sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
574 
575         return 0;
576 }
577 
578 static struct platform_driver dcdbas_driver = {
579         .driver         = {
580                 .name   = DRIVER_NAME,
581                 .owner  = THIS_MODULE,
582         },
583         .probe          = dcdbas_probe,
584         .remove         = dcdbas_remove,
585 };
586 
587 static const struct platform_device_info dcdbas_dev_info __initconst = {
588         .name           = DRIVER_NAME,
589         .id             = -1,
590         .dma_mask       = DMA_BIT_MASK(32),
591 };
592 
593 static struct platform_device *dcdbas_pdev_reg;
594 
595 /**
596  * dcdbas_init: initialize driver
597  */
598 static int __init dcdbas_init(void)
599 {
600         int error;
601 
602         error = platform_driver_register(&dcdbas_driver);
603         if (error)
604                 return error;
605 
606         dcdbas_pdev_reg = platform_device_register_full(&dcdbas_dev_info);
607         if (IS_ERR(dcdbas_pdev_reg)) {
608                 error = PTR_ERR(dcdbas_pdev_reg);
609                 goto err_unregister_driver;
610         }
611 
612         return 0;
613 
614  err_unregister_driver:
615         platform_driver_unregister(&dcdbas_driver);
616         return error;
617 }
618 
619 /**
620  * dcdbas_exit: perform driver cleanup
621  */
622 static void __exit dcdbas_exit(void)
623 {
624         /*
625          * make sure functions that use dcdbas_pdev are called
626          * before platform_device_unregister
627          */
628         unregister_reboot_notifier(&dcdbas_reboot_nb);
629 
630         /*
631          * We have to free the buffer here instead of dcdbas_remove
632          * because only in module exit function we can be sure that
633          * all sysfs attributes belonging to this module have been
634          * released.
635          */
636         if (dcdbas_pdev)
637                 smi_data_buf_free();
638         platform_device_unregister(dcdbas_pdev_reg);
639         platform_driver_unregister(&dcdbas_driver);
640 }
641 
642 module_init(dcdbas_init);
643 module_exit(dcdbas_exit);
644 
645 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
646 MODULE_VERSION(DRIVER_VERSION);
647 MODULE_AUTHOR("Dell Inc.");
648 MODULE_LICENSE("GPL");
649 /* Any System or BIOS claiming to be by Dell */
650 MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");
651 

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