2 * Copyright 2010 Google Inc. All Rights Reserved.
3 * Author: dlaurie@google.com (Duncan Laurie)
5 * Re-worked to expose sysfs APIs by mikew@google.com (Mike Waychison)
7 * EFI SMI interface for Google platforms
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/types.h>
13 #include <linux/device.h>
14 #include <linux/platform_device.h>
15 #include <linux/errno.h>
16 #include <linux/string.h>
17 #include <linux/spinlock.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/dmapool.h>
21 #include <linux/slab.h>
22 #include <linux/ioctl.h>
23 #include <linux/acpi.h>
25 #include <linux/uaccess.h>
26 #include <linux/dmi.h>
27 #include <linux/kdebug.h>
28 #include <linux/reboot.h>
29 #include <linux/efi.h>
30 #include <linux/module.h>
31 #include <linux/ucs2_string.h>
32 #include <linux/suspend.h>
34 #define GSMI_SHUTDOWN_CLEAN 0 /* Clean Shutdown */
35 /* TODO(mikew@google.com): Tie in HARDLOCKUP_DETECTOR with NMIWDT */
36 #define GSMI_SHUTDOWN_NMIWDT 1 /* NMI Watchdog */
37 #define GSMI_SHUTDOWN_PANIC 2 /* Panic */
38 #define GSMI_SHUTDOWN_OOPS 3 /* Oops */
39 #define GSMI_SHUTDOWN_DIE 4 /* Die -- No longer meaningful */
40 #define GSMI_SHUTDOWN_MCE 5 /* Machine Check */
41 #define GSMI_SHUTDOWN_SOFTWDT 6 /* Software Watchdog */
42 #define GSMI_SHUTDOWN_MBE 7 /* Uncorrected ECC */
43 #define GSMI_SHUTDOWN_TRIPLE 8 /* Triple Fault */
45 #define DRIVER_VERSION "1.0"
46 #define GSMI_GUID_SIZE 16
47 #define GSMI_BUF_SIZE 1024
48 #define GSMI_BUF_ALIGN sizeof(u64)
49 #define GSMI_CALLBACK 0xef
51 /* SMI return codes */
52 #define GSMI_SUCCESS 0x00
53 #define GSMI_UNSUPPORTED2 0x03
54 #define GSMI_LOG_FULL 0x0b
55 #define GSMI_VAR_NOT_FOUND 0x0e
56 #define GSMI_HANDSHAKE_SPIN 0x7d
57 #define GSMI_HANDSHAKE_CF 0x7e
58 #define GSMI_HANDSHAKE_NONE 0x7f
59 #define GSMI_INVALID_PARAMETER 0x82
60 #define GSMI_UNSUPPORTED 0x83
61 #define GSMI_BUFFER_TOO_SMALL 0x85
62 #define GSMI_NOT_READY 0x86
63 #define GSMI_DEVICE_ERROR 0x87
64 #define GSMI_NOT_FOUND 0x8e
66 #define QUIRKY_BOARD_HASH 0x78a30a50
68 /* Internally used commands passed to the firmware */
69 #define GSMI_CMD_GET_NVRAM_VAR 0x01
70 #define GSMI_CMD_GET_NEXT_VAR 0x02
71 #define GSMI_CMD_SET_NVRAM_VAR 0x03
72 #define GSMI_CMD_SET_EVENT_LOG 0x08
73 #define GSMI_CMD_CLEAR_EVENT_LOG 0x09
74 #define GSMI_CMD_LOG_S0IX_SUSPEND 0x0a
75 #define GSMI_CMD_LOG_S0IX_RESUME 0x0b
76 #define GSMI_CMD_CLEAR_CONFIG 0x20
77 #define GSMI_CMD_HANDSHAKE_TYPE 0xC1
79 /* Magic entry type for kernel events */
80 #define GSMI_LOG_ENTRY_TYPE_KERNEL 0xDEAD
82 /* SMI buffers must be in 32bit physical address space */
84 u8 *start; /* start of buffer */
85 size_t length; /* length of buffer */
86 dma_addr_t handle; /* dma allocation handle */
87 u32 address; /* physical address of buffer */
90 static struct gsmi_device {
91 struct platform_device *pdev; /* platform device */
92 struct gsmi_buf *name_buf; /* variable name buffer */
93 struct gsmi_buf *data_buf; /* generic data buffer */
94 struct gsmi_buf *param_buf; /* parameter buffer */
95 spinlock_t lock; /* serialize access to SMIs */
96 u16 smi_cmd; /* SMI command port */
97 int handshake_type; /* firmware handler interlock type */
98 struct dma_pool *dma_pool; /* DMA buffer pool */
101 /* Packed structures for communicating with the firmware */
102 struct gsmi_nvram_var_param {
110 struct gsmi_get_next_var_param {
111 u8 guid[GSMI_GUID_SIZE];
116 struct gsmi_set_eventlog_param {
122 /* Event log formats */
123 struct gsmi_log_entry_type_1 {
129 * Some platforms don't have explicit SMI handshake
130 * and need to wait for SMI to complete.
132 #define GSMI_DEFAULT_SPINCOUNT 0x10000
133 static unsigned int spincount = GSMI_DEFAULT_SPINCOUNT;
134 module_param(spincount, uint, 0600);
135 MODULE_PARM_DESC(spincount,
136 "The number of loop iterations to use when using the spin handshake.");
139 * Platforms might not support S0ix logging in their GSMI handlers. In order to
140 * avoid any side-effects of generating an SMI for S0ix logging, use the S0ix
141 * related GSMI commands only for those platforms that explicitly enable this
144 static bool s0ix_logging_enable;
145 module_param(s0ix_logging_enable, bool, 0600);
147 static struct gsmi_buf *gsmi_buf_alloc(void)
149 struct gsmi_buf *smibuf;
151 smibuf = kzalloc(sizeof(*smibuf), GFP_KERNEL);
153 printk(KERN_ERR "gsmi: out of memory\n");
157 /* allocate buffer in 32bit address space */
158 smibuf->start = dma_pool_alloc(gsmi_dev.dma_pool, GFP_KERNEL,
160 if (!smibuf->start) {
161 printk(KERN_ERR "gsmi: failed to allocate name buffer\n");
166 /* fill in the buffer handle */
167 smibuf->length = GSMI_BUF_SIZE;
168 smibuf->address = (u32)virt_to_phys(smibuf->start);
173 static void gsmi_buf_free(struct gsmi_buf *smibuf)
177 dma_pool_free(gsmi_dev.dma_pool, smibuf->start,
184 * Make a call to gsmi func(sub). GSMI error codes are translated to
185 * in-kernel errnos (0 on success, -ERRNO on error).
187 static int gsmi_exec(u8 func, u8 sub)
189 u16 cmd = (sub << 8) | func;
194 * AH : Subfunction number
195 * AL : Function number
196 * EBX : Parameter block address
197 * DX : SMI command port
199 * Three protocols here. See also the comment in gsmi_init().
201 if (gsmi_dev.handshake_type == GSMI_HANDSHAKE_CF) {
203 * If handshake_type == HANDSHAKE_CF then set CF on the
204 * way in and wait for the handler to clear it; this avoids
205 * corrupting register state on those chipsets which have
206 * a delay between writing the SMI trigger register and
215 "d" (gsmi_dev.smi_cmd),
216 "b" (gsmi_dev.param_buf->address)
219 } else if (gsmi_dev.handshake_type == GSMI_HANDSHAKE_SPIN) {
221 * If handshake_type == HANDSHAKE_SPIN we spin a
222 * hundred-ish usecs to ensure the SMI has triggered.
229 "d" (gsmi_dev.smi_cmd),
230 "b" (gsmi_dev.param_buf->address),
236 * If handshake_type == HANDSHAKE_NONE we do nothing;
237 * either we don't need to or it's legacy firmware that
238 * doesn't understand the CF protocol.
241 "outb %%al, %%dx\n\t"
244 "d" (gsmi_dev.smi_cmd),
245 "b" (gsmi_dev.param_buf->address)
250 /* check return code from SMI handler */
254 case GSMI_VAR_NOT_FOUND:
255 /* not really an error, but let the caller know */
258 case GSMI_INVALID_PARAMETER:
259 printk(KERN_ERR "gsmi: exec 0x%04x: Invalid parameter\n", cmd);
262 case GSMI_BUFFER_TOO_SMALL:
263 printk(KERN_ERR "gsmi: exec 0x%04x: Buffer too small\n", cmd);
266 case GSMI_UNSUPPORTED:
267 case GSMI_UNSUPPORTED2:
268 if (sub != GSMI_CMD_HANDSHAKE_TYPE)
269 printk(KERN_ERR "gsmi: exec 0x%04x: Not supported\n",
274 printk(KERN_ERR "gsmi: exec 0x%04x: Not ready\n", cmd);
277 case GSMI_DEVICE_ERROR:
278 printk(KERN_ERR "gsmi: exec 0x%04x: Device error\n", cmd);
282 printk(KERN_ERR "gsmi: exec 0x%04x: Data not found\n", cmd);
286 printk(KERN_ERR "gsmi: exec 0x%04x: Log full\n", cmd);
289 case GSMI_HANDSHAKE_CF:
290 case GSMI_HANDSHAKE_SPIN:
291 case GSMI_HANDSHAKE_NONE:
295 printk(KERN_ERR "gsmi: exec 0x%04x: Unknown error 0x%04x\n",
303 #ifdef CONFIG_EFI_VARS
305 static struct efivars efivars;
307 static efi_status_t gsmi_get_variable(efi_char16_t *name,
308 efi_guid_t *vendor, u32 *attr,
309 unsigned long *data_size,
312 struct gsmi_nvram_var_param param = {
313 .name_ptr = gsmi_dev.name_buf->address,
314 .data_ptr = gsmi_dev.data_buf->address,
315 .data_len = (u32)*data_size,
317 efi_status_t ret = EFI_SUCCESS;
319 size_t name_len = ucs2_strnlen(name, GSMI_BUF_SIZE / 2);
322 if (name_len >= GSMI_BUF_SIZE / 2)
323 return EFI_BAD_BUFFER_SIZE;
325 spin_lock_irqsave(&gsmi_dev.lock, flags);
328 memcpy(¶m.guid, vendor, sizeof(param.guid));
330 /* variable name, already in UTF-16 */
331 memset(gsmi_dev.name_buf->start, 0, gsmi_dev.name_buf->length);
332 memcpy(gsmi_dev.name_buf->start, name, name_len * 2);
335 memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length);
337 /* parameter buffer */
338 memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
339 memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
341 rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_GET_NVRAM_VAR);
343 printk(KERN_ERR "gsmi: Get Variable failed\n");
344 ret = EFI_LOAD_ERROR;
345 } else if (rc == 1) {
346 /* variable was not found */
349 /* Get the arguments back */
350 memcpy(¶m, gsmi_dev.param_buf->start, sizeof(param));
352 /* The size reported is the min of all of our buffers */
353 *data_size = min_t(unsigned long, *data_size,
354 gsmi_dev.data_buf->length);
355 *data_size = min_t(unsigned long, *data_size, param.data_len);
357 /* Copy data back to return buffer. */
358 memcpy(data, gsmi_dev.data_buf->start, *data_size);
360 /* All variables are have the following attributes */
361 *attr = EFI_VARIABLE_NON_VOLATILE |
362 EFI_VARIABLE_BOOTSERVICE_ACCESS |
363 EFI_VARIABLE_RUNTIME_ACCESS;
366 spin_unlock_irqrestore(&gsmi_dev.lock, flags);
371 static efi_status_t gsmi_get_next_variable(unsigned long *name_size,
375 struct gsmi_get_next_var_param param = {
376 .name_ptr = gsmi_dev.name_buf->address,
377 .name_len = gsmi_dev.name_buf->length,
379 efi_status_t ret = EFI_SUCCESS;
383 /* For the moment, only support buffers that exactly match in size */
384 if (*name_size != GSMI_BUF_SIZE)
385 return EFI_BAD_BUFFER_SIZE;
387 /* Let's make sure the thing is at least null-terminated */
388 if (ucs2_strnlen(name, GSMI_BUF_SIZE / 2) == GSMI_BUF_SIZE / 2)
389 return EFI_INVALID_PARAMETER;
391 spin_lock_irqsave(&gsmi_dev.lock, flags);
394 memcpy(¶m.guid, vendor, sizeof(param.guid));
396 /* variable name, already in UTF-16 */
397 memcpy(gsmi_dev.name_buf->start, name, *name_size);
399 /* parameter buffer */
400 memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
401 memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
403 rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_GET_NEXT_VAR);
405 printk(KERN_ERR "gsmi: Get Next Variable Name failed\n");
406 ret = EFI_LOAD_ERROR;
407 } else if (rc == 1) {
408 /* variable not found -- end of list */
411 /* copy variable data back to return buffer */
412 memcpy(¶m, gsmi_dev.param_buf->start, sizeof(param));
414 /* Copy the name back */
415 memcpy(name, gsmi_dev.name_buf->start, GSMI_BUF_SIZE);
416 *name_size = ucs2_strnlen(name, GSMI_BUF_SIZE / 2) * 2;
418 /* copy guid to return buffer */
419 memcpy(vendor, ¶m.guid, sizeof(param.guid));
423 spin_unlock_irqrestore(&gsmi_dev.lock, flags);
428 static efi_status_t gsmi_set_variable(efi_char16_t *name,
431 unsigned long data_size,
434 struct gsmi_nvram_var_param param = {
435 .name_ptr = gsmi_dev.name_buf->address,
436 .data_ptr = gsmi_dev.data_buf->address,
437 .data_len = (u32)data_size,
438 .attributes = EFI_VARIABLE_NON_VOLATILE |
439 EFI_VARIABLE_BOOTSERVICE_ACCESS |
440 EFI_VARIABLE_RUNTIME_ACCESS,
442 size_t name_len = ucs2_strnlen(name, GSMI_BUF_SIZE / 2);
443 efi_status_t ret = EFI_SUCCESS;
447 if (name_len >= GSMI_BUF_SIZE / 2)
448 return EFI_BAD_BUFFER_SIZE;
450 spin_lock_irqsave(&gsmi_dev.lock, flags);
453 memcpy(¶m.guid, vendor, sizeof(param.guid));
455 /* variable name, already in UTF-16 */
456 memset(gsmi_dev.name_buf->start, 0, gsmi_dev.name_buf->length);
457 memcpy(gsmi_dev.name_buf->start, name, name_len * 2);
460 memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length);
461 memcpy(gsmi_dev.data_buf->start, data, data_size);
463 /* parameter buffer */
464 memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
465 memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
467 rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_NVRAM_VAR);
469 printk(KERN_ERR "gsmi: Set Variable failed\n");
470 ret = EFI_INVALID_PARAMETER;
473 spin_unlock_irqrestore(&gsmi_dev.lock, flags);
478 static const struct efivar_operations efivar_ops = {
479 .get_variable = gsmi_get_variable,
480 .set_variable = gsmi_set_variable,
481 .get_next_variable = gsmi_get_next_variable,
484 #endif /* CONFIG_EFI_VARS */
486 static ssize_t eventlog_write(struct file *filp, struct kobject *kobj,
487 struct bin_attribute *bin_attr,
488 char *buf, loff_t pos, size_t count)
490 struct gsmi_set_eventlog_param param = {
491 .data_ptr = gsmi_dev.data_buf->address,
496 /* Pull the type out */
497 if (count < sizeof(u32))
499 param.type = *(u32 *)buf;
502 /* The remaining buffer is the data payload */
503 if ((count - sizeof(u32)) > gsmi_dev.data_buf->length)
505 param.data_len = count - sizeof(u32);
507 spin_lock_irqsave(&gsmi_dev.lock, flags);
510 memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length);
511 memcpy(gsmi_dev.data_buf->start, buf, param.data_len);
513 /* parameter buffer */
514 memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
515 memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
517 rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_EVENT_LOG);
519 printk(KERN_ERR "gsmi: Set Event Log failed\n");
521 spin_unlock_irqrestore(&gsmi_dev.lock, flags);
523 return (rc == 0) ? count : rc;
527 static struct bin_attribute eventlog_bin_attr = {
528 .attr = {.name = "append_to_eventlog", .mode = 0200},
529 .write = eventlog_write,
532 static ssize_t gsmi_clear_eventlog_store(struct kobject *kobj,
533 struct kobj_attribute *attr,
534 const char *buf, size_t count)
544 rc = kstrtoul(buf, 0, &val);
549 * Value entered is a percentage, 0 through 100, anything else
555 /* data_type here selects the smbios event log. */
556 param.percentage = val;
559 spin_lock_irqsave(&gsmi_dev.lock, flags);
561 /* parameter buffer */
562 memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
563 memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
565 rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_CLEAR_EVENT_LOG);
567 spin_unlock_irqrestore(&gsmi_dev.lock, flags);
574 static struct kobj_attribute gsmi_clear_eventlog_attr = {
575 .attr = {.name = "clear_eventlog", .mode = 0200},
576 .store = gsmi_clear_eventlog_store,
579 static ssize_t gsmi_clear_config_store(struct kobject *kobj,
580 struct kobj_attribute *attr,
581 const char *buf, size_t count)
586 spin_lock_irqsave(&gsmi_dev.lock, flags);
588 /* clear parameter buffer */
589 memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
591 rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_CLEAR_CONFIG);
593 spin_unlock_irqrestore(&gsmi_dev.lock, flags);
600 static struct kobj_attribute gsmi_clear_config_attr = {
601 .attr = {.name = "clear_config", .mode = 0200},
602 .store = gsmi_clear_config_store,
605 static const struct attribute *gsmi_attrs[] = {
606 &gsmi_clear_config_attr.attr,
607 &gsmi_clear_eventlog_attr.attr,
611 static int gsmi_shutdown_reason(int reason)
613 struct gsmi_log_entry_type_1 entry = {
614 .type = GSMI_LOG_ENTRY_TYPE_KERNEL,
617 struct gsmi_set_eventlog_param param = {
618 .data_len = sizeof(entry),
621 static int saved_reason;
625 /* avoid duplicate entries in the log */
626 if (saved_reason & (1 << reason))
629 spin_lock_irqsave(&gsmi_dev.lock, flags);
631 saved_reason |= (1 << reason);
634 memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length);
635 memcpy(gsmi_dev.data_buf->start, &entry, sizeof(entry));
637 /* parameter buffer */
638 param.data_ptr = gsmi_dev.data_buf->address;
639 memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
640 memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param));
642 rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_EVENT_LOG);
644 spin_unlock_irqrestore(&gsmi_dev.lock, flags);
647 printk(KERN_ERR "gsmi: Log Shutdown Reason failed\n");
649 printk(KERN_EMERG "gsmi: Log Shutdown Reason 0x%02x\n",
655 static int gsmi_reboot_callback(struct notifier_block *nb,
656 unsigned long reason, void *arg)
658 gsmi_shutdown_reason(GSMI_SHUTDOWN_CLEAN);
662 static struct notifier_block gsmi_reboot_notifier = {
663 .notifier_call = gsmi_reboot_callback
666 static int gsmi_die_callback(struct notifier_block *nb,
667 unsigned long reason, void *arg)
669 if (reason == DIE_OOPS)
670 gsmi_shutdown_reason(GSMI_SHUTDOWN_OOPS);
674 static struct notifier_block gsmi_die_notifier = {
675 .notifier_call = gsmi_die_callback
678 static int gsmi_panic_callback(struct notifier_block *nb,
679 unsigned long reason, void *arg)
681 gsmi_shutdown_reason(GSMI_SHUTDOWN_PANIC);
685 static struct notifier_block gsmi_panic_notifier = {
686 .notifier_call = gsmi_panic_callback,
690 * This hash function was blatantly copied from include/linux/hash.h.
691 * It is used by this driver to obfuscate a board name that requires a
692 * quirk within this driver.
694 * Please do not remove this copy of the function as any changes to the
695 * global utility hash_64() function would break this driver's ability
696 * to identify a board and provide the appropriate quirk -- mikew@google.com
698 static u64 __init local_hash_64(u64 val, unsigned bits)
702 /* Sigh, gcc can't optimise this alone like it does for 32 bits. */
717 /* High bits are more random, so use them. */
718 return hash >> (64 - bits);
721 static u32 __init hash_oem_table_id(char s[8])
724 memcpy(&input, s, 8);
725 return local_hash_64(input, 32);
728 static const struct dmi_system_id gsmi_dmi_table[] __initconst = {
730 .ident = "Google Board",
732 DMI_MATCH(DMI_BOARD_VENDOR, "Google, Inc."),
736 .ident = "Coreboot Firmware",
738 DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
743 MODULE_DEVICE_TABLE(dmi, gsmi_dmi_table);
745 static __init int gsmi_system_valid(void)
749 if (!dmi_check_system(gsmi_dmi_table))
753 * Only newer firmware supports the gsmi interface. All older
754 * firmware that didn't support this interface used to plug the
755 * table name in the first four bytes of the oem_table_id field.
756 * Newer firmware doesn't do that though, so use that as the
757 * discriminant factor. We have to do this in order to
758 * whitewash our board names out of the public driver.
760 if (!strncmp(acpi_gbl_FADT.header.oem_table_id, "FACP", 4)) {
761 printk(KERN_INFO "gsmi: Board is too old\n");
765 /* Disable on board with 1.0 BIOS due to Google bug 2602657 */
766 hash = hash_oem_table_id(acpi_gbl_FADT.header.oem_table_id);
767 if (hash == QUIRKY_BOARD_HASH) {
768 const char *bios_ver = dmi_get_system_info(DMI_BIOS_VERSION);
769 if (strncmp(bios_ver, "1.0", 3) == 0) {
770 pr_info("gsmi: disabled on this board's BIOS %s\n",
776 /* check for valid SMI command port in ACPI FADT */
777 if (acpi_gbl_FADT.smi_command == 0) {
778 pr_info("gsmi: missing smi_command\n");
786 static struct kobject *gsmi_kobj;
788 static const struct platform_device_info gsmi_dev_info = {
791 /* SMI callbacks require 32bit addresses */
792 .dma_mask = DMA_BIT_MASK(32),
796 static void gsmi_log_s0ix_info(u8 cmd)
801 * If platform has not enabled S0ix logging, then no action is
804 if (!s0ix_logging_enable)
807 spin_lock_irqsave(&gsmi_dev.lock, flags);
809 memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length);
811 gsmi_exec(GSMI_CALLBACK, cmd);
813 spin_unlock_irqrestore(&gsmi_dev.lock, flags);
816 static int gsmi_log_s0ix_suspend(struct device *dev)
819 * If system is not suspending via firmware using the standard ACPI Sx
820 * types, then make a GSMI call to log the suspend info.
822 if (!pm_suspend_via_firmware())
823 gsmi_log_s0ix_info(GSMI_CMD_LOG_S0IX_SUSPEND);
826 * Always return success, since we do not want suspend
827 * to fail just because of logging failure.
832 static int gsmi_log_s0ix_resume(struct device *dev)
835 * If system did not resume via firmware, then make a GSMI call to log
836 * the resume info and wake source.
838 if (!pm_resume_via_firmware())
839 gsmi_log_s0ix_info(GSMI_CMD_LOG_S0IX_RESUME);
842 * Always return success, since we do not want resume
843 * to fail just because of logging failure.
848 static const struct dev_pm_ops gsmi_pm_ops = {
849 .suspend_noirq = gsmi_log_s0ix_suspend,
850 .resume_noirq = gsmi_log_s0ix_resume,
853 static int gsmi_platform_driver_probe(struct platform_device *dev)
858 static struct platform_driver gsmi_driver_info = {
863 .probe = gsmi_platform_driver_probe,
867 static __init int gsmi_init(void)
872 ret = gsmi_system_valid();
876 gsmi_dev.smi_cmd = acpi_gbl_FADT.smi_command;
879 ret = platform_driver_register(&gsmi_driver_info);
881 printk(KERN_ERR "gsmi: unable to register platform driver\n");
886 /* register device */
887 gsmi_dev.pdev = platform_device_register_full(&gsmi_dev_info);
888 if (IS_ERR(gsmi_dev.pdev)) {
889 printk(KERN_ERR "gsmi: unable to register platform device\n");
890 return PTR_ERR(gsmi_dev.pdev);
893 /* SMI access needs to be serialized */
894 spin_lock_init(&gsmi_dev.lock);
897 gsmi_dev.dma_pool = dma_pool_create("gsmi", &gsmi_dev.pdev->dev,
898 GSMI_BUF_SIZE, GSMI_BUF_ALIGN, 0);
899 if (!gsmi_dev.dma_pool)
903 * pre-allocate buffers because sometimes we are called when
904 * this is not feasible: oops, panic, die, mce, etc
906 gsmi_dev.name_buf = gsmi_buf_alloc();
907 if (!gsmi_dev.name_buf) {
908 printk(KERN_ERR "gsmi: failed to allocate name buffer\n");
912 gsmi_dev.data_buf = gsmi_buf_alloc();
913 if (!gsmi_dev.data_buf) {
914 printk(KERN_ERR "gsmi: failed to allocate data buffer\n");
918 gsmi_dev.param_buf = gsmi_buf_alloc();
919 if (!gsmi_dev.param_buf) {
920 printk(KERN_ERR "gsmi: failed to allocate param buffer\n");
925 * Determine type of handshake used to serialize the SMI
926 * entry. See also gsmi_exec().
928 * There's a "behavior" present on some chipsets where writing the
929 * SMI trigger register in the southbridge doesn't result in an
930 * immediate SMI. Rather, the processor can execute "a few" more
931 * instructions before the SMI takes effect. To ensure synchronous
932 * behavior, implement a handshake between the kernel driver and the
933 * firmware handler to spin until released. This ioctl determines
934 * the type of handshake.
936 * NONE: The firmware handler does not implement any
937 * handshake. Either it doesn't need to, or it's legacy firmware
938 * that doesn't know it needs to and never will.
940 * CF: The firmware handler will clear the CF in the saved
941 * state before returning. The driver may set the CF and test for
942 * it to clear before proceeding.
944 * SPIN: The firmware handler does not implement any handshake
945 * but the driver should spin for a hundred or so microseconds
946 * to ensure the SMI has triggered.
948 * Finally, the handler will return -ENOSYS if
949 * GSMI_CMD_HANDSHAKE_TYPE is unimplemented, which implies
952 spin_lock_irqsave(&gsmi_dev.lock, flags);
953 gsmi_dev.handshake_type = GSMI_HANDSHAKE_SPIN;
954 gsmi_dev.handshake_type =
955 gsmi_exec(GSMI_CALLBACK, GSMI_CMD_HANDSHAKE_TYPE);
956 if (gsmi_dev.handshake_type == -ENOSYS)
957 gsmi_dev.handshake_type = GSMI_HANDSHAKE_NONE;
958 spin_unlock_irqrestore(&gsmi_dev.lock, flags);
960 /* Remove and clean up gsmi if the handshake could not complete. */
961 if (gsmi_dev.handshake_type == -ENXIO) {
962 printk(KERN_INFO "gsmi version " DRIVER_VERSION
963 " failed to load\n");
968 /* Register in the firmware directory */
970 gsmi_kobj = kobject_create_and_add("gsmi", firmware_kobj);
972 printk(KERN_INFO "gsmi: Failed to create firmware kobj\n");
976 /* Setup eventlog access */
977 ret = sysfs_create_bin_file(gsmi_kobj, &eventlog_bin_attr);
979 printk(KERN_INFO "gsmi: Failed to setup eventlog");
983 /* Other attributes */
984 ret = sysfs_create_files(gsmi_kobj, gsmi_attrs);
986 printk(KERN_INFO "gsmi: Failed to add attrs");
987 goto out_remove_bin_file;
990 #ifdef CONFIG_EFI_VARS
991 ret = efivars_register(&efivars, &efivar_ops, gsmi_kobj);
993 printk(KERN_INFO "gsmi: Failed to register efivars\n");
994 sysfs_remove_files(gsmi_kobj, gsmi_attrs);
995 goto out_remove_bin_file;
999 register_reboot_notifier(&gsmi_reboot_notifier);
1000 register_die_notifier(&gsmi_die_notifier);
1001 atomic_notifier_chain_register(&panic_notifier_list,
1002 &gsmi_panic_notifier);
1004 printk(KERN_INFO "gsmi version " DRIVER_VERSION " loaded\n");
1008 out_remove_bin_file:
1009 sysfs_remove_bin_file(gsmi_kobj, &eventlog_bin_attr);
1011 kobject_put(gsmi_kobj);
1012 gsmi_buf_free(gsmi_dev.param_buf);
1013 gsmi_buf_free(gsmi_dev.data_buf);
1014 gsmi_buf_free(gsmi_dev.name_buf);
1015 dma_pool_destroy(gsmi_dev.dma_pool);
1016 platform_device_unregister(gsmi_dev.pdev);
1017 pr_info("gsmi: failed to load: %d\n", ret);
1021 static void __exit gsmi_exit(void)
1023 unregister_reboot_notifier(&gsmi_reboot_notifier);
1024 unregister_die_notifier(&gsmi_die_notifier);
1025 atomic_notifier_chain_unregister(&panic_notifier_list,
1026 &gsmi_panic_notifier);
1027 #ifdef CONFIG_EFI_VARS
1028 efivars_unregister(&efivars);
1031 sysfs_remove_files(gsmi_kobj, gsmi_attrs);
1032 sysfs_remove_bin_file(gsmi_kobj, &eventlog_bin_attr);
1033 kobject_put(gsmi_kobj);
1034 gsmi_buf_free(gsmi_dev.param_buf);
1035 gsmi_buf_free(gsmi_dev.data_buf);
1036 gsmi_buf_free(gsmi_dev.name_buf);
1037 dma_pool_destroy(gsmi_dev.dma_pool);
1038 platform_device_unregister(gsmi_dev.pdev);
1041 module_init(gsmi_init);
1042 module_exit(gsmi_exit);
1044 MODULE_AUTHOR("Google, Inc.");
1045 MODULE_LICENSE("GPL");