1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * dcdbas.c: Dell Systems Management Base Driver
4 *
5 * The Dell Systems Management Base Driver provides a sysfs interface for
6 * systems management software to perform System Management Interrupts (SMIs)
7 * and Host Control Actions (power cycle or power off after OS shutdown) on
8 * Dell systems.
9 *
10 * See Documentation/driver-api/dcdbas.rst for more information.
11 *
12 * Copyright (C) 1995-2006 Dell Inc.
13 */
14
15 #include <linux/platform_device.h>
16 #include <linux/acpi.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/errno.h>
19 #include <linux/cpu.h>
20 #include <linux/gfp.h>
21 #include <linux/init.h>
22 #include <linux/io.h>
23 #include <linux/kernel.h>
24 #include <linux/mc146818rtc.h>
25 #include <linux/module.h>
26 #include <linux/reboot.h>
27 #include <linux/sched.h>
28 #include <linux/smp.h>
29 #include <linux/spinlock.h>
30 #include <linux/string.h>
31 #include <linux/types.h>
32 #include <linux/mutex.h>
33
34 #include "dcdbas.h"
35
36 #define DRIVER_NAME "dcdbas"
37 #define DRIVER_VERSION "5.6.0-3.3"
38 #define DRIVER_DESCRIPTION "Dell Systems Management Base Driver"
39
40 static struct platform_device *dcdbas_pdev;
41
42 static u8 *smi_data_buf;
43 static dma_addr_t smi_data_buf_handle;
44 static unsigned long smi_data_buf_size;
45 static unsigned long max_smi_data_buf_size = MAX_SMI_DATA_BUF_SIZE;
46 static u32 smi_data_buf_phys_addr;
47 static DEFINE_MUTEX(smi_data_lock);
48 static u8 *eps_buffer;
49
50 static unsigned int host_control_action;
51 static unsigned int host_control_smi_type;
52 static unsigned int host_control_on_shutdown;
53
54 static bool wsmt_enabled;
55
56 /**
57 * smi_data_buf_free: free SMI data buffer
58 */
smi_data_buf_free(void)59 static void smi_data_buf_free(void)
60 {
61 if (!smi_data_buf || wsmt_enabled)
62 return;
63
64 dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
65 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
66
67 dma_free_coherent(&dcdbas_pdev->dev, smi_data_buf_size, smi_data_buf,
68 smi_data_buf_handle);
69 smi_data_buf = NULL;
70 smi_data_buf_handle = 0;
71 smi_data_buf_phys_addr = 0;
72 smi_data_buf_size = 0;
73 }
74
75 /**
76 * smi_data_buf_realloc: grow SMI data buffer if needed
77 */
smi_data_buf_realloc(unsigned long size)78 static int smi_data_buf_realloc(unsigned long size)
79 {
80 void *buf;
81 dma_addr_t handle;
82
83 if (smi_data_buf_size >= size)
84 return 0;
85
86 if (size > max_smi_data_buf_size)
87 return -EINVAL;
88
89 /* new buffer is needed */
90 buf = dma_alloc_coherent(&dcdbas_pdev->dev, size, &handle, GFP_KERNEL);
91 if (!buf) {
92 dev_dbg(&dcdbas_pdev->dev,
93 "%s: failed to allocate memory size %lu\n",
94 __func__, size);
95 return -ENOMEM;
96 }
97 /* memory zeroed by dma_alloc_coherent */
98
99 if (smi_data_buf)
100 memcpy(buf, smi_data_buf, smi_data_buf_size);
101
102 /* free any existing buffer */
103 smi_data_buf_free();
104
105 /* set up new buffer for use */
106 smi_data_buf = buf;
107 smi_data_buf_handle = handle;
108 smi_data_buf_phys_addr = (u32) virt_to_phys(buf);
109 smi_data_buf_size = size;
110
111 dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n",
112 __func__, smi_data_buf_phys_addr, smi_data_buf_size);
113
114 return 0;
115 }
116
smi_data_buf_phys_addr_show(struct device * dev,struct device_attribute * attr,char * buf)117 static ssize_t smi_data_buf_phys_addr_show(struct device *dev,
118 struct device_attribute *attr,
119 char *buf)
120 {
121 return sprintf(buf, "%x\n", smi_data_buf_phys_addr);
122 }
123
smi_data_buf_size_show(struct device * dev,struct device_attribute * attr,char * buf)124 static ssize_t smi_data_buf_size_show(struct device *dev,
125 struct device_attribute *attr,
126 char *buf)
127 {
128 return sprintf(buf, "%lu\n", smi_data_buf_size);
129 }
130
smi_data_buf_size_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)131 static ssize_t smi_data_buf_size_store(struct device *dev,
132 struct device_attribute *attr,
133 const char *buf, size_t count)
134 {
135 unsigned long buf_size;
136 ssize_t ret;
137
138 buf_size = simple_strtoul(buf, NULL, 10);
139
140 /* make sure SMI data buffer is at least buf_size */
141 mutex_lock(&smi_data_lock);
142 ret = smi_data_buf_realloc(buf_size);
143 mutex_unlock(&smi_data_lock);
144 if (ret)
145 return ret;
146
147 return count;
148 }
149
smi_data_read(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t pos,size_t count)150 static ssize_t smi_data_read(struct file *filp, struct kobject *kobj,
151 struct bin_attribute *bin_attr,
152 char *buf, loff_t pos, size_t count)
153 {
154 ssize_t ret;
155
156 mutex_lock(&smi_data_lock);
157 ret = memory_read_from_buffer(buf, count, &pos, smi_data_buf,
158 smi_data_buf_size);
159 mutex_unlock(&smi_data_lock);
160 return ret;
161 }
162
smi_data_write(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t pos,size_t count)163 static ssize_t smi_data_write(struct file *filp, struct kobject *kobj,
164 struct bin_attribute *bin_attr,
165 char *buf, loff_t pos, size_t count)
166 {
167 ssize_t ret;
168
169 if ((pos + count) > max_smi_data_buf_size)
170 return -EINVAL;
171
172 mutex_lock(&smi_data_lock);
173
174 ret = smi_data_buf_realloc(pos + count);
175 if (ret)
176 goto out;
177
178 memcpy(smi_data_buf + pos, buf, count);
179 ret = count;
180 out:
181 mutex_unlock(&smi_data_lock);
182 return ret;
183 }
184
host_control_action_show(struct device * dev,struct device_attribute * attr,char * buf)185 static ssize_t host_control_action_show(struct device *dev,
186 struct device_attribute *attr,
187 char *buf)
188 {
189 return sprintf(buf, "%u\n", host_control_action);
190 }
191
host_control_action_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)192 static ssize_t host_control_action_store(struct device *dev,
193 struct device_attribute *attr,
194 const char *buf, size_t count)
195 {
196 ssize_t ret;
197
198 /* make sure buffer is available for host control command */
199 mutex_lock(&smi_data_lock);
200 ret = smi_data_buf_realloc(sizeof(struct apm_cmd));
201 mutex_unlock(&smi_data_lock);
202 if (ret)
203 return ret;
204
205 host_control_action = simple_strtoul(buf, NULL, 10);
206 return count;
207 }
208
host_control_smi_type_show(struct device * dev,struct device_attribute * attr,char * buf)209 static ssize_t host_control_smi_type_show(struct device *dev,
210 struct device_attribute *attr,
211 char *buf)
212 {
213 return sprintf(buf, "%u\n", host_control_smi_type);
214 }
215
host_control_smi_type_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)216 static ssize_t host_control_smi_type_store(struct device *dev,
217 struct device_attribute *attr,
218 const char *buf, size_t count)
219 {
220 host_control_smi_type = simple_strtoul(buf, NULL, 10);
221 return count;
222 }
223
host_control_on_shutdown_show(struct device * dev,struct device_attribute * attr,char * buf)224 static ssize_t host_control_on_shutdown_show(struct device *dev,
225 struct device_attribute *attr,
226 char *buf)
227 {
228 return sprintf(buf, "%u\n", host_control_on_shutdown);
229 }
230
host_control_on_shutdown_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)231 static ssize_t host_control_on_shutdown_store(struct device *dev,
232 struct device_attribute *attr,
233 const char *buf, size_t count)
234 {
235 host_control_on_shutdown = simple_strtoul(buf, NULL, 10);
236 return count;
237 }
238
raise_smi(void * par)239 static int raise_smi(void *par)
240 {
241 struct smi_cmd *smi_cmd = par;
242
243 if (smp_processor_id() != 0) {
244 dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
245 __func__);
246 return -EBUSY;
247 }
248
249 /* generate SMI */
250 /* inb to force posted write through and make SMI happen now */
251 asm volatile (
252 "outb %b0,%w1\n"
253 "inb %w1"
254 : /* no output args */
255 : "a" (smi_cmd->command_code),
256 "d" (smi_cmd->command_address),
257 "b" (smi_cmd->ebx),
258 "c" (smi_cmd->ecx)
259 : "memory"
260 );
261
262 return 0;
263 }
264 /**
265 * dcdbas_smi_request: generate SMI request
266 *
267 * Called with smi_data_lock.
268 */
dcdbas_smi_request(struct smi_cmd * smi_cmd)269 int dcdbas_smi_request(struct smi_cmd *smi_cmd)
270 {
271 int ret;
272
273 if (smi_cmd->magic != SMI_CMD_MAGIC) {
274 dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
275 __func__);
276 return -EBADR;
277 }
278
279 /* SMI requires CPU 0 */
280 get_online_cpus();
281 ret = smp_call_on_cpu(0, raise_smi, smi_cmd, true);
282 put_online_cpus();
283
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 */
smi_request_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)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 = dcdbas_smi_request(smi_cmd);
318 if (!ret)
319 ret = count;
320 break;
321 case 1:
322 /*
323 * Calling Interface SMI
324 *
325 * Provide physical address of command buffer field within
326 * the struct smi_cmd to BIOS.
327 *
328 * Because the address that smi_cmd (smi_data_buf) points to
329 * will be from memremap() of a non-memory address if WSMT
330 * is present, we can't use virt_to_phys() on smi_cmd, so
331 * we have to use the physical address that was saved when
332 * the virtual address for smi_cmd was received.
333 */
334 smi_cmd->ebx = smi_data_buf_phys_addr +
335 offsetof(struct smi_cmd, command_buffer);
336 ret = dcdbas_smi_request(smi_cmd);
337 if (!ret)
338 ret = count;
339 break;
340 case 0:
341 memset(smi_data_buf, 0, smi_data_buf_size);
342 ret = count;
343 break;
344 default:
345 ret = -EINVAL;
346 break;
347 }
348
349 out:
350 mutex_unlock(&smi_data_lock);
351 return ret;
352 }
353 EXPORT_SYMBOL(dcdbas_smi_request);
354
355 /**
356 * host_control_smi: generate host control SMI
357 *
358 * Caller must set up the host control command in smi_data_buf.
359 */
host_control_smi(void)360 static int host_control_smi(void)
361 {
362 struct apm_cmd *apm_cmd;
363 u8 *data;
364 unsigned long flags;
365 u32 num_ticks;
366 s8 cmd_status;
367 u8 index;
368
369 apm_cmd = (struct apm_cmd *)smi_data_buf;
370 apm_cmd->status = ESM_STATUS_CMD_UNSUCCESSFUL;
371
372 switch (host_control_smi_type) {
373 case HC_SMITYPE_TYPE1:
374 spin_lock_irqsave(&rtc_lock, flags);
375 /* write SMI data buffer physical address */
376 data = (u8 *)&smi_data_buf_phys_addr;
377 for (index = PE1300_CMOS_CMD_STRUCT_PTR;
378 index < (PE1300_CMOS_CMD_STRUCT_PTR + 4);
379 index++, data++) {
380 outb(index,
381 (CMOS_BASE_PORT + CMOS_PAGE2_INDEX_PORT_PIIX4));
382 outb(*data,
383 (CMOS_BASE_PORT + CMOS_PAGE2_DATA_PORT_PIIX4));
384 }
385
386 /* first set status to -1 as called by spec */
387 cmd_status = ESM_STATUS_CMD_UNSUCCESSFUL;
388 outb((u8) cmd_status, PCAT_APM_STATUS_PORT);
389
390 /* generate SMM call */
391 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
392 spin_unlock_irqrestore(&rtc_lock, flags);
393
394 /* wait a few to see if it executed */
395 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
396 while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
397 == ESM_STATUS_CMD_UNSUCCESSFUL) {
398 num_ticks--;
399 if (num_ticks == EXPIRED_TIMER)
400 return -ETIME;
401 }
402 break;
403
404 case HC_SMITYPE_TYPE2:
405 case HC_SMITYPE_TYPE3:
406 spin_lock_irqsave(&rtc_lock, flags);
407 /* write SMI data buffer physical address */
408 data = (u8 *)&smi_data_buf_phys_addr;
409 for (index = PE1400_CMOS_CMD_STRUCT_PTR;
410 index < (PE1400_CMOS_CMD_STRUCT_PTR + 4);
411 index++, data++) {
412 outb(index, (CMOS_BASE_PORT + CMOS_PAGE1_INDEX_PORT));
413 outb(*data, (CMOS_BASE_PORT + CMOS_PAGE1_DATA_PORT));
414 }
415
416 /* generate SMM call */
417 if (host_control_smi_type == HC_SMITYPE_TYPE3)
418 outb(ESM_APM_CMD, PCAT_APM_CONTROL_PORT);
419 else
420 outb(ESM_APM_CMD, PE1400_APM_CONTROL_PORT);
421
422 /* restore RTC index pointer since it was written to above */
423 CMOS_READ(RTC_REG_C);
424 spin_unlock_irqrestore(&rtc_lock, flags);
425
426 /* read control port back to serialize write */
427 cmd_status = inb(PE1400_APM_CONTROL_PORT);
428
429 /* wait a few to see if it executed */
430 num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
431 while (apm_cmd->status == ESM_STATUS_CMD_UNSUCCESSFUL) {
432 num_ticks--;
433 if (num_ticks == EXPIRED_TIMER)
434 return -ETIME;
435 }
436 break;
437
438 default:
439 dev_dbg(&dcdbas_pdev->dev, "%s: invalid SMI type %u\n",
440 __func__, host_control_smi_type);
441 return -ENOSYS;
442 }
443
444 return 0;
445 }
446
447 /**
448 * dcdbas_host_control: initiate host control
449 *
450 * This function is called by the driver after the system has
451 * finished shutting down if the user application specified a
452 * host control action to perform on shutdown. It is safe to
453 * use smi_data_buf at this point because the system has finished
454 * shutting down and no userspace apps are running.
455 */
dcdbas_host_control(void)456 static void dcdbas_host_control(void)
457 {
458 struct apm_cmd *apm_cmd;
459 u8 action;
460
461 if (host_control_action == HC_ACTION_NONE)
462 return;
463
464 action = host_control_action;
465 host_control_action = HC_ACTION_NONE;
466
467 if (!smi_data_buf) {
468 dev_dbg(&dcdbas_pdev->dev, "%s: no SMI buffer\n", __func__);
469 return;
470 }
471
472 if (smi_data_buf_size < sizeof(struct apm_cmd)) {
473 dev_dbg(&dcdbas_pdev->dev, "%s: SMI buffer too small\n",
474 __func__);
475 return;
476 }
477
478 apm_cmd = (struct apm_cmd *)smi_data_buf;
479
480 /* power off takes precedence */
481 if (action & HC_ACTION_HOST_CONTROL_POWEROFF) {
482 apm_cmd->command = ESM_APM_POWER_CYCLE;
483 apm_cmd->reserved = 0;
484 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 0;
485 host_control_smi();
486 } else if (action & HC_ACTION_HOST_CONTROL_POWERCYCLE) {
487 apm_cmd->command = ESM_APM_POWER_CYCLE;
488 apm_cmd->reserved = 0;
489 *((s16 *)&apm_cmd->parameters.shortreq.parm[0]) = (s16) 20;
490 host_control_smi();
491 }
492 }
493
494 /* WSMT */
495
checksum(u8 * buffer,u8 length)496 static u8 checksum(u8 *buffer, u8 length)
497 {
498 u8 sum = 0;
499 u8 *end = buffer + length;
500
501 while (buffer < end)
502 sum += *buffer++;
503 return sum;
504 }
505
check_eps_table(u8 * addr)506 static inline struct smm_eps_table *check_eps_table(u8 *addr)
507 {
508 struct smm_eps_table *eps = (struct smm_eps_table *)addr;
509
510 if (strncmp(eps->smm_comm_buff_anchor, SMM_EPS_SIG, 4) != 0)
511 return NULL;
512
513 if (checksum(addr, eps->length) != 0)
514 return NULL;
515
516 return eps;
517 }
518
dcdbas_check_wsmt(void)519 static int dcdbas_check_wsmt(void)
520 {
521 struct acpi_table_wsmt *wsmt = NULL;
522 struct smm_eps_table *eps = NULL;
523 u64 remap_size;
524 u8 *addr;
525
526 acpi_get_table(ACPI_SIG_WSMT, 0, (struct acpi_table_header **)&wsmt);
527 if (!wsmt)
528 return 0;
529
530 /* Check if WSMT ACPI table shows that protection is enabled */
531 if (!(wsmt->protection_flags & ACPI_WSMT_FIXED_COMM_BUFFERS) ||
532 !(wsmt->protection_flags & ACPI_WSMT_COMM_BUFFER_NESTED_PTR_PROTECTION))
533 return 0;
534
535 /* Scan for EPS (entry point structure) */
536 for (addr = (u8 *)__va(0xf0000);
537 addr < (u8 *)__va(0x100000 - sizeof(struct smm_eps_table));
538 addr += 16) {
539 eps = check_eps_table(addr);
540 if (eps)
541 break;
542 }
543
544 if (!eps) {
545 dev_dbg(&dcdbas_pdev->dev, "found WSMT, but no EPS found\n");
546 return -ENODEV;
547 }
548
549 /*
550 * Get physical address of buffer and map to virtual address.
551 * Table gives size in 4K pages, regardless of actual system page size.
552 */
553 if (upper_32_bits(eps->smm_comm_buff_addr + 8)) {
554 dev_warn(&dcdbas_pdev->dev, "found WSMT, but EPS buffer address is above 4GB\n");
555 return -EINVAL;
556 }
557 /*
558 * Limit remap size to MAX_SMI_DATA_BUF_SIZE + 8 (since the first 8
559 * bytes are used for a semaphore, not the data buffer itself).
560 */
561 remap_size = eps->num_of_4k_pages * PAGE_SIZE;
562 if (remap_size > MAX_SMI_DATA_BUF_SIZE + 8)
563 remap_size = MAX_SMI_DATA_BUF_SIZE + 8;
564 eps_buffer = memremap(eps->smm_comm_buff_addr, remap_size, MEMREMAP_WB);
565 if (!eps_buffer) {
566 dev_warn(&dcdbas_pdev->dev, "found WSMT, but failed to map EPS buffer\n");
567 return -ENOMEM;
568 }
569
570 /* First 8 bytes is for a semaphore, not part of the smi_data_buf */
571 smi_data_buf_phys_addr = eps->smm_comm_buff_addr + 8;
572 smi_data_buf = eps_buffer + 8;
573 smi_data_buf_size = remap_size - 8;
574 max_smi_data_buf_size = smi_data_buf_size;
575 wsmt_enabled = true;
576 dev_info(&dcdbas_pdev->dev,
577 "WSMT found, using firmware-provided SMI buffer.\n");
578 return 1;
579 }
580
581 /**
582 * dcdbas_reboot_notify: handle reboot notification for host control
583 */
dcdbas_reboot_notify(struct notifier_block * nb,unsigned long code,void * unused)584 static int dcdbas_reboot_notify(struct notifier_block *nb, unsigned long code,
585 void *unused)
586 {
587 switch (code) {
588 case SYS_DOWN:
589 case SYS_HALT:
590 case SYS_POWER_OFF:
591 if (host_control_on_shutdown) {
592 /* firmware is going to perform host control action */
593 printk(KERN_WARNING "Please wait for shutdown "
594 "action to complete...\n");
595 dcdbas_host_control();
596 }
597 break;
598 }
599
600 return NOTIFY_DONE;
601 }
602
603 static struct notifier_block dcdbas_reboot_nb = {
604 .notifier_call = dcdbas_reboot_notify,
605 .next = NULL,
606 .priority = INT_MIN
607 };
608
609 static DCDBAS_BIN_ATTR_RW(smi_data);
610
611 static struct bin_attribute *dcdbas_bin_attrs[] = {
612 &bin_attr_smi_data,
613 NULL
614 };
615
616 static DCDBAS_DEV_ATTR_RW(smi_data_buf_size);
617 static DCDBAS_DEV_ATTR_RO(smi_data_buf_phys_addr);
618 static DCDBAS_DEV_ATTR_WO(smi_request);
619 static DCDBAS_DEV_ATTR_RW(host_control_action);
620 static DCDBAS_DEV_ATTR_RW(host_control_smi_type);
621 static DCDBAS_DEV_ATTR_RW(host_control_on_shutdown);
622
623 static struct attribute *dcdbas_dev_attrs[] = {
624 &dev_attr_smi_data_buf_size.attr,
625 &dev_attr_smi_data_buf_phys_addr.attr,
626 &dev_attr_smi_request.attr,
627 &dev_attr_host_control_action.attr,
628 &dev_attr_host_control_smi_type.attr,
629 &dev_attr_host_control_on_shutdown.attr,
630 NULL
631 };
632
633 static const struct attribute_group dcdbas_attr_group = {
634 .attrs = dcdbas_dev_attrs,
635 .bin_attrs = dcdbas_bin_attrs,
636 };
637
dcdbas_probe(struct platform_device * dev)638 static int dcdbas_probe(struct platform_device *dev)
639 {
640 int error;
641
642 host_control_action = HC_ACTION_NONE;
643 host_control_smi_type = HC_SMITYPE_NONE;
644
645 dcdbas_pdev = dev;
646
647 /* Check if ACPI WSMT table specifies protected SMI buffer address */
648 error = dcdbas_check_wsmt();
649 if (error < 0)
650 return error;
651
652 /*
653 * BIOS SMI calls require buffer addresses be in 32-bit address space.
654 * This is done by setting the DMA mask below.
655 */
656 error = dma_set_coherent_mask(&dcdbas_pdev->dev, DMA_BIT_MASK(32));
657 if (error)
658 return error;
659
660 error = sysfs_create_group(&dev->dev.kobj, &dcdbas_attr_group);
661 if (error)
662 return error;
663
664 register_reboot_notifier(&dcdbas_reboot_nb);
665
666 dev_info(&dev->dev, "%s (version %s)\n",
667 DRIVER_DESCRIPTION, DRIVER_VERSION);
668
669 return 0;
670 }
671
dcdbas_remove(struct platform_device * dev)672 static int dcdbas_remove(struct platform_device *dev)
673 {
674 unregister_reboot_notifier(&dcdbas_reboot_nb);
675 sysfs_remove_group(&dev->dev.kobj, &dcdbas_attr_group);
676
677 return 0;
678 }
679
680 static struct platform_driver dcdbas_driver = {
681 .driver = {
682 .name = DRIVER_NAME,
683 },
684 .probe = dcdbas_probe,
685 .remove = dcdbas_remove,
686 };
687
688 static const struct platform_device_info dcdbas_dev_info __initconst = {
689 .name = DRIVER_NAME,
690 .id = -1,
691 .dma_mask = DMA_BIT_MASK(32),
692 };
693
694 static struct platform_device *dcdbas_pdev_reg;
695
696 /**
697 * dcdbas_init: initialize driver
698 */
dcdbas_init(void)699 static int __init dcdbas_init(void)
700 {
701 int error;
702
703 error = platform_driver_register(&dcdbas_driver);
704 if (error)
705 return error;
706
707 dcdbas_pdev_reg = platform_device_register_full(&dcdbas_dev_info);
708 if (IS_ERR(dcdbas_pdev_reg)) {
709 error = PTR_ERR(dcdbas_pdev_reg);
710 goto err_unregister_driver;
711 }
712
713 return 0;
714
715 err_unregister_driver:
716 platform_driver_unregister(&dcdbas_driver);
717 return error;
718 }
719
720 /**
721 * dcdbas_exit: perform driver cleanup
722 */
dcdbas_exit(void)723 static void __exit dcdbas_exit(void)
724 {
725 /*
726 * make sure functions that use dcdbas_pdev are called
727 * before platform_device_unregister
728 */
729 unregister_reboot_notifier(&dcdbas_reboot_nb);
730
731 /*
732 * We have to free the buffer here instead of dcdbas_remove
733 * because only in module exit function we can be sure that
734 * all sysfs attributes belonging to this module have been
735 * released.
736 */
737 if (dcdbas_pdev)
738 smi_data_buf_free();
739 if (eps_buffer)
740 memunmap(eps_buffer);
741 platform_device_unregister(dcdbas_pdev_reg);
742 platform_driver_unregister(&dcdbas_driver);
743 }
744
745 subsys_initcall_sync(dcdbas_init);
746 module_exit(dcdbas_exit);
747
748 MODULE_DESCRIPTION(DRIVER_DESCRIPTION " (version " DRIVER_VERSION ")");
749 MODULE_VERSION(DRIVER_VERSION);
750 MODULE_AUTHOR("Dell Inc.");
751 MODULE_LICENSE("GPL");
752 /* Any System or BIOS claiming to be by Dell */
753 MODULE_ALIAS("dmi:*:[bs]vnD[Ee][Ll][Ll]*:*");
754
