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1 | /* |
2 | * Copyright 2010 Google Inc. All Rights Reserved. | |
3 | * Author: dlaurie@google.com (Duncan Laurie) | |
4 | * | |
5 | * Re-worked to expose sysfs APIs by mikew@google.com (Mike Waychison) | |
6 | * | |
7 | * EFI SMI interface for Google platforms | |
8 | */ | |
9 | ||
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> | |
20 | #include <linux/fs.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/ioctl.h> | |
23 | #include <linux/acpi.h> | |
24 | #include <linux/io.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 | ||
31 | #define GSMI_SHUTDOWN_CLEAN 0 /* Clean Shutdown */ | |
32 | /* TODO(mikew@google.com): Tie in HARDLOCKUP_DETECTOR with NMIWDT */ | |
33 | #define GSMI_SHUTDOWN_NMIWDT 1 /* NMI Watchdog */ | |
34 | #define GSMI_SHUTDOWN_PANIC 2 /* Panic */ | |
35 | #define GSMI_SHUTDOWN_OOPS 3 /* Oops */ | |
36 | #define GSMI_SHUTDOWN_DIE 4 /* Die -- No longer meaningful */ | |
37 | #define GSMI_SHUTDOWN_MCE 5 /* Machine Check */ | |
38 | #define GSMI_SHUTDOWN_SOFTWDT 6 /* Software Watchdog */ | |
39 | #define GSMI_SHUTDOWN_MBE 7 /* Uncorrected ECC */ | |
40 | #define GSMI_SHUTDOWN_TRIPLE 8 /* Triple Fault */ | |
41 | ||
42 | #define DRIVER_VERSION "1.0" | |
43 | #define GSMI_GUID_SIZE 16 | |
44 | #define GSMI_BUF_SIZE 1024 | |
45 | #define GSMI_BUF_ALIGN sizeof(u64) | |
46 | #define GSMI_CALLBACK 0xef | |
47 | ||
48 | /* SMI return codes */ | |
49 | #define GSMI_SUCCESS 0x00 | |
50 | #define GSMI_UNSUPPORTED2 0x03 | |
51 | #define GSMI_LOG_FULL 0x0b | |
52 | #define GSMI_VAR_NOT_FOUND 0x0e | |
53 | #define GSMI_HANDSHAKE_SPIN 0x7d | |
54 | #define GSMI_HANDSHAKE_CF 0x7e | |
55 | #define GSMI_HANDSHAKE_NONE 0x7f | |
56 | #define GSMI_INVALID_PARAMETER 0x82 | |
57 | #define GSMI_UNSUPPORTED 0x83 | |
58 | #define GSMI_BUFFER_TOO_SMALL 0x85 | |
59 | #define GSMI_NOT_READY 0x86 | |
60 | #define GSMI_DEVICE_ERROR 0x87 | |
61 | #define GSMI_NOT_FOUND 0x8e | |
62 | ||
63 | #define QUIRKY_BOARD_HASH 0x78a30a50 | |
64 | ||
65 | /* Internally used commands passed to the firmware */ | |
66 | #define GSMI_CMD_GET_NVRAM_VAR 0x01 | |
67 | #define GSMI_CMD_GET_NEXT_VAR 0x02 | |
68 | #define GSMI_CMD_SET_NVRAM_VAR 0x03 | |
69 | #define GSMI_CMD_SET_EVENT_LOG 0x08 | |
70 | #define GSMI_CMD_CLEAR_EVENT_LOG 0x09 | |
71 | #define GSMI_CMD_CLEAR_CONFIG 0x20 | |
72 | #define GSMI_CMD_HANDSHAKE_TYPE 0xC1 | |
73 | ||
74 | /* Magic entry type for kernel events */ | |
75 | #define GSMI_LOG_ENTRY_TYPE_KERNEL 0xDEAD | |
76 | ||
77 | /* SMI buffers must be in 32bit physical address space */ | |
78 | struct gsmi_buf { | |
79 | u8 *start; /* start of buffer */ | |
80 | size_t length; /* length of buffer */ | |
81 | dma_addr_t handle; /* dma allocation handle */ | |
82 | u32 address; /* physical address of buffer */ | |
83 | }; | |
84 | ||
85 | struct gsmi_device { | |
86 | struct platform_device *pdev; /* platform device */ | |
87 | struct gsmi_buf *name_buf; /* variable name buffer */ | |
88 | struct gsmi_buf *data_buf; /* generic data buffer */ | |
89 | struct gsmi_buf *param_buf; /* parameter buffer */ | |
90 | spinlock_t lock; /* serialize access to SMIs */ | |
91 | u16 smi_cmd; /* SMI command port */ | |
92 | int handshake_type; /* firmware handler interlock type */ | |
93 | struct dma_pool *dma_pool; /* DMA buffer pool */ | |
94 | } gsmi_dev; | |
95 | ||
96 | /* Packed structures for communicating with the firmware */ | |
97 | struct gsmi_nvram_var_param { | |
98 | efi_guid_t guid; | |
99 | u32 name_ptr; | |
100 | u32 attributes; | |
101 | u32 data_len; | |
102 | u32 data_ptr; | |
103 | } __packed; | |
104 | ||
105 | struct gsmi_get_next_var_param { | |
106 | u8 guid[GSMI_GUID_SIZE]; | |
107 | u32 name_ptr; | |
108 | u32 name_len; | |
109 | } __packed; | |
110 | ||
111 | struct gsmi_set_eventlog_param { | |
112 | u32 data_ptr; | |
113 | u32 data_len; | |
114 | u32 type; | |
115 | } __packed; | |
116 | ||
117 | /* Event log formats */ | |
118 | struct gsmi_log_entry_type_1 { | |
119 | u16 type; | |
120 | u32 instance; | |
121 | } __packed; | |
122 | ||
123 | ||
124 | /* | |
125 | * Some platforms don't have explicit SMI handshake | |
126 | * and need to wait for SMI to complete. | |
127 | */ | |
128 | #define GSMI_DEFAULT_SPINCOUNT 0x10000 | |
129 | static unsigned int spincount = GSMI_DEFAULT_SPINCOUNT; | |
130 | module_param(spincount, uint, 0600); | |
131 | MODULE_PARM_DESC(spincount, | |
132 | "The number of loop iterations to use when using the spin handshake."); | |
133 | ||
134 | static struct gsmi_buf *gsmi_buf_alloc(void) | |
135 | { | |
136 | struct gsmi_buf *smibuf; | |
137 | ||
138 | smibuf = kzalloc(sizeof(*smibuf), GFP_KERNEL); | |
139 | if (!smibuf) { | |
140 | printk(KERN_ERR "gsmi: out of memory\n"); | |
141 | return NULL; | |
142 | } | |
143 | ||
144 | /* allocate buffer in 32bit address space */ | |
145 | smibuf->start = dma_pool_alloc(gsmi_dev.dma_pool, GFP_KERNEL, | |
146 | &smibuf->handle); | |
147 | if (!smibuf->start) { | |
148 | printk(KERN_ERR "gsmi: failed to allocate name buffer\n"); | |
149 | kfree(smibuf); | |
150 | return NULL; | |
151 | } | |
152 | ||
153 | /* fill in the buffer handle */ | |
154 | smibuf->length = GSMI_BUF_SIZE; | |
155 | smibuf->address = (u32)virt_to_phys(smibuf->start); | |
156 | ||
157 | return smibuf; | |
158 | } | |
159 | ||
160 | static void gsmi_buf_free(struct gsmi_buf *smibuf) | |
161 | { | |
162 | if (smibuf) { | |
163 | if (smibuf->start) | |
164 | dma_pool_free(gsmi_dev.dma_pool, smibuf->start, | |
165 | smibuf->handle); | |
166 | kfree(smibuf); | |
167 | } | |
168 | } | |
169 | ||
170 | /* | |
171 | * Make a call to gsmi func(sub). GSMI error codes are translated to | |
172 | * in-kernel errnos (0 on success, -ERRNO on error). | |
173 | */ | |
174 | static int gsmi_exec(u8 func, u8 sub) | |
175 | { | |
176 | u16 cmd = (sub << 8) | func; | |
177 | u16 result = 0; | |
178 | int rc = 0; | |
179 | ||
180 | /* | |
181 | * AH : Subfunction number | |
182 | * AL : Function number | |
183 | * EBX : Parameter block address | |
184 | * DX : SMI command port | |
185 | * | |
186 | * Three protocols here. See also the comment in gsmi_init(). | |
187 | */ | |
188 | if (gsmi_dev.handshake_type == GSMI_HANDSHAKE_CF) { | |
189 | /* | |
190 | * If handshake_type == HANDSHAKE_CF then set CF on the | |
191 | * way in and wait for the handler to clear it; this avoids | |
192 | * corrupting register state on those chipsets which have | |
193 | * a delay between writing the SMI trigger register and | |
194 | * entering SMM. | |
195 | */ | |
196 | asm volatile ( | |
197 | "stc\n" | |
198 | "outb %%al, %%dx\n" | |
199 | "1: jc 1b\n" | |
200 | : "=a" (result) | |
201 | : "0" (cmd), | |
202 | "d" (gsmi_dev.smi_cmd), | |
203 | "b" (gsmi_dev.param_buf->address) | |
204 | : "memory", "cc" | |
205 | ); | |
206 | } else if (gsmi_dev.handshake_type == GSMI_HANDSHAKE_SPIN) { | |
207 | /* | |
208 | * If handshake_type == HANDSHAKE_SPIN we spin a | |
209 | * hundred-ish usecs to ensure the SMI has triggered. | |
210 | */ | |
211 | asm volatile ( | |
212 | "outb %%al, %%dx\n" | |
213 | "1: loop 1b\n" | |
214 | : "=a" (result) | |
215 | : "0" (cmd), | |
216 | "d" (gsmi_dev.smi_cmd), | |
217 | "b" (gsmi_dev.param_buf->address), | |
218 | "c" (spincount) | |
219 | : "memory", "cc" | |
220 | ); | |
221 | } else { | |
222 | /* | |
223 | * If handshake_type == HANDSHAKE_NONE we do nothing; | |
224 | * either we don't need to or it's legacy firmware that | |
225 | * doesn't understand the CF protocol. | |
226 | */ | |
227 | asm volatile ( | |
228 | "outb %%al, %%dx\n\t" | |
229 | : "=a" (result) | |
230 | : "0" (cmd), | |
231 | "d" (gsmi_dev.smi_cmd), | |
232 | "b" (gsmi_dev.param_buf->address) | |
233 | : "memory", "cc" | |
234 | ); | |
235 | } | |
236 | ||
237 | /* check return code from SMI handler */ | |
238 | switch (result) { | |
239 | case GSMI_SUCCESS: | |
240 | break; | |
241 | case GSMI_VAR_NOT_FOUND: | |
242 | /* not really an error, but let the caller know */ | |
243 | rc = 1; | |
244 | break; | |
245 | case GSMI_INVALID_PARAMETER: | |
246 | printk(KERN_ERR "gsmi: exec 0x%04x: Invalid parameter\n", cmd); | |
247 | rc = -EINVAL; | |
248 | break; | |
249 | case GSMI_BUFFER_TOO_SMALL: | |
250 | printk(KERN_ERR "gsmi: exec 0x%04x: Buffer too small\n", cmd); | |
251 | rc = -ENOMEM; | |
252 | break; | |
253 | case GSMI_UNSUPPORTED: | |
254 | case GSMI_UNSUPPORTED2: | |
255 | if (sub != GSMI_CMD_HANDSHAKE_TYPE) | |
256 | printk(KERN_ERR "gsmi: exec 0x%04x: Not supported\n", | |
257 | cmd); | |
258 | rc = -ENOSYS; | |
259 | break; | |
260 | case GSMI_NOT_READY: | |
261 | printk(KERN_ERR "gsmi: exec 0x%04x: Not ready\n", cmd); | |
262 | rc = -EBUSY; | |
263 | break; | |
264 | case GSMI_DEVICE_ERROR: | |
265 | printk(KERN_ERR "gsmi: exec 0x%04x: Device error\n", cmd); | |
266 | rc = -EFAULT; | |
267 | break; | |
268 | case GSMI_NOT_FOUND: | |
269 | printk(KERN_ERR "gsmi: exec 0x%04x: Data not found\n", cmd); | |
270 | rc = -ENOENT; | |
271 | break; | |
272 | case GSMI_LOG_FULL: | |
273 | printk(KERN_ERR "gsmi: exec 0x%04x: Log full\n", cmd); | |
274 | rc = -ENOSPC; | |
275 | break; | |
276 | case GSMI_HANDSHAKE_CF: | |
277 | case GSMI_HANDSHAKE_SPIN: | |
278 | case GSMI_HANDSHAKE_NONE: | |
279 | rc = result; | |
280 | break; | |
281 | default: | |
282 | printk(KERN_ERR "gsmi: exec 0x%04x: Unknown error 0x%04x\n", | |
283 | cmd, result); | |
284 | rc = -ENXIO; | |
285 | } | |
286 | ||
287 | return rc; | |
288 | } | |
289 | ||
290 | /* Return the number of unicode characters in data */ | |
291 | static size_t | |
292 | utf16_strlen(efi_char16_t *data, unsigned long maxlength) | |
293 | { | |
294 | unsigned long length = 0; | |
295 | ||
296 | while (*data++ != 0 && length < maxlength) | |
297 | length++; | |
298 | return length; | |
299 | } | |
300 | ||
301 | static efi_status_t gsmi_get_variable(efi_char16_t *name, | |
302 | efi_guid_t *vendor, u32 *attr, | |
303 | unsigned long *data_size, | |
304 | void *data) | |
305 | { | |
306 | struct gsmi_nvram_var_param param = { | |
307 | .name_ptr = gsmi_dev.name_buf->address, | |
308 | .data_ptr = gsmi_dev.data_buf->address, | |
309 | .data_len = (u32)*data_size, | |
310 | }; | |
311 | efi_status_t ret = EFI_SUCCESS; | |
312 | unsigned long flags; | |
313 | size_t name_len = utf16_strlen(name, GSMI_BUF_SIZE / 2); | |
314 | int rc; | |
315 | ||
316 | if (name_len >= GSMI_BUF_SIZE / 2) | |
317 | return EFI_BAD_BUFFER_SIZE; | |
318 | ||
319 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
320 | ||
321 | /* Vendor guid */ | |
322 | memcpy(¶m.guid, vendor, sizeof(param.guid)); | |
323 | ||
324 | /* variable name, already in UTF-16 */ | |
325 | memset(gsmi_dev.name_buf->start, 0, gsmi_dev.name_buf->length); | |
326 | memcpy(gsmi_dev.name_buf->start, name, name_len * 2); | |
327 | ||
328 | /* data pointer */ | |
329 | memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length); | |
330 | ||
331 | /* parameter buffer */ | |
332 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
333 | memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param)); | |
334 | ||
335 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_GET_NVRAM_VAR); | |
336 | if (rc < 0) { | |
337 | printk(KERN_ERR "gsmi: Get Variable failed\n"); | |
338 | ret = EFI_LOAD_ERROR; | |
339 | } else if (rc == 1) { | |
340 | /* variable was not found */ | |
341 | ret = EFI_NOT_FOUND; | |
342 | } else { | |
343 | /* Get the arguments back */ | |
344 | memcpy(¶m, gsmi_dev.param_buf->start, sizeof(param)); | |
345 | ||
346 | /* The size reported is the min of all of our buffers */ | |
347 | *data_size = min(*data_size, gsmi_dev.data_buf->length); | |
348 | *data_size = min_t(unsigned long, *data_size, param.data_len); | |
349 | ||
350 | /* Copy data back to return buffer. */ | |
351 | memcpy(data, gsmi_dev.data_buf->start, *data_size); | |
352 | ||
353 | /* All variables are have the following attributes */ | |
354 | *attr = EFI_VARIABLE_NON_VOLATILE | | |
355 | EFI_VARIABLE_BOOTSERVICE_ACCESS | | |
356 | EFI_VARIABLE_RUNTIME_ACCESS; | |
357 | } | |
358 | ||
359 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
360 | ||
361 | return ret; | |
362 | } | |
363 | ||
364 | static efi_status_t gsmi_get_next_variable(unsigned long *name_size, | |
365 | efi_char16_t *name, | |
366 | efi_guid_t *vendor) | |
367 | { | |
368 | struct gsmi_get_next_var_param param = { | |
369 | .name_ptr = gsmi_dev.name_buf->address, | |
370 | .name_len = gsmi_dev.name_buf->length, | |
371 | }; | |
372 | efi_status_t ret = EFI_SUCCESS; | |
373 | int rc; | |
374 | unsigned long flags; | |
375 | ||
376 | /* For the moment, only support buffers that exactly match in size */ | |
377 | if (*name_size != GSMI_BUF_SIZE) | |
378 | return EFI_BAD_BUFFER_SIZE; | |
379 | ||
380 | /* Let's make sure the thing is at least null-terminated */ | |
381 | if (utf16_strlen(name, GSMI_BUF_SIZE / 2) == GSMI_BUF_SIZE / 2) | |
382 | return EFI_INVALID_PARAMETER; | |
383 | ||
384 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
385 | ||
386 | /* guid */ | |
387 | memcpy(¶m.guid, vendor, sizeof(param.guid)); | |
388 | ||
389 | /* variable name, already in UTF-16 */ | |
390 | memcpy(gsmi_dev.name_buf->start, name, *name_size); | |
391 | ||
392 | /* parameter buffer */ | |
393 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
394 | memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param)); | |
395 | ||
396 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_GET_NEXT_VAR); | |
397 | if (rc < 0) { | |
398 | printk(KERN_ERR "gsmi: Get Next Variable Name failed\n"); | |
399 | ret = EFI_LOAD_ERROR; | |
400 | } else if (rc == 1) { | |
401 | /* variable not found -- end of list */ | |
402 | ret = EFI_NOT_FOUND; | |
403 | } else { | |
404 | /* copy variable data back to return buffer */ | |
405 | memcpy(¶m, gsmi_dev.param_buf->start, sizeof(param)); | |
406 | ||
407 | /* Copy the name back */ | |
408 | memcpy(name, gsmi_dev.name_buf->start, GSMI_BUF_SIZE); | |
409 | *name_size = utf16_strlen(name, GSMI_BUF_SIZE / 2) * 2; | |
410 | ||
411 | /* copy guid to return buffer */ | |
412 | memcpy(vendor, ¶m.guid, sizeof(param.guid)); | |
413 | ret = EFI_SUCCESS; | |
414 | } | |
415 | ||
416 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
417 | ||
418 | return ret; | |
419 | } | |
420 | ||
421 | static efi_status_t gsmi_set_variable(efi_char16_t *name, | |
422 | efi_guid_t *vendor, | |
423 | unsigned long attr, | |
424 | unsigned long data_size, | |
425 | void *data) | |
426 | { | |
427 | struct gsmi_nvram_var_param param = { | |
428 | .name_ptr = gsmi_dev.name_buf->address, | |
429 | .data_ptr = gsmi_dev.data_buf->address, | |
430 | .data_len = (u32)data_size, | |
431 | .attributes = EFI_VARIABLE_NON_VOLATILE | | |
432 | EFI_VARIABLE_BOOTSERVICE_ACCESS | | |
433 | EFI_VARIABLE_RUNTIME_ACCESS, | |
434 | }; | |
435 | size_t name_len = utf16_strlen(name, GSMI_BUF_SIZE / 2); | |
436 | efi_status_t ret = EFI_SUCCESS; | |
437 | int rc; | |
438 | unsigned long flags; | |
439 | ||
440 | if (name_len >= GSMI_BUF_SIZE / 2) | |
441 | return EFI_BAD_BUFFER_SIZE; | |
442 | ||
443 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
444 | ||
445 | /* guid */ | |
446 | memcpy(¶m.guid, vendor, sizeof(param.guid)); | |
447 | ||
448 | /* variable name, already in UTF-16 */ | |
449 | memset(gsmi_dev.name_buf->start, 0, gsmi_dev.name_buf->length); | |
450 | memcpy(gsmi_dev.name_buf->start, name, name_len * 2); | |
451 | ||
452 | /* data pointer */ | |
453 | memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length); | |
454 | memcpy(gsmi_dev.data_buf->start, data, data_size); | |
455 | ||
456 | /* parameter buffer */ | |
457 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
458 | memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param)); | |
459 | ||
460 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_NVRAM_VAR); | |
461 | if (rc < 0) { | |
462 | printk(KERN_ERR "gsmi: Set Variable failed\n"); | |
463 | ret = EFI_INVALID_PARAMETER; | |
464 | } | |
465 | ||
466 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
467 | ||
468 | return ret; | |
469 | } | |
470 | ||
471 | static const struct efivar_operations efivar_ops = { | |
472 | .get_variable = gsmi_get_variable, | |
473 | .set_variable = gsmi_set_variable, | |
474 | .get_next_variable = gsmi_get_next_variable, | |
475 | }; | |
476 | ||
477 | static ssize_t eventlog_write(struct file *filp, struct kobject *kobj, | |
478 | struct bin_attribute *bin_attr, | |
479 | char *buf, loff_t pos, size_t count) | |
480 | { | |
481 | struct gsmi_set_eventlog_param param = { | |
482 | .data_ptr = gsmi_dev.data_buf->address, | |
483 | }; | |
484 | int rc = 0; | |
485 | unsigned long flags; | |
486 | ||
487 | /* Pull the type out */ | |
488 | if (count < sizeof(u32)) | |
489 | return -EINVAL; | |
490 | param.type = *(u32 *)buf; | |
491 | count -= sizeof(u32); | |
492 | buf += sizeof(u32); | |
493 | ||
494 | /* The remaining buffer is the data payload */ | |
495 | if (count > gsmi_dev.data_buf->length) | |
496 | return -EINVAL; | |
497 | param.data_len = count - sizeof(u32); | |
498 | ||
499 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
500 | ||
501 | /* data pointer */ | |
502 | memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length); | |
503 | memcpy(gsmi_dev.data_buf->start, buf, param.data_len); | |
504 | ||
505 | /* parameter buffer */ | |
506 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
507 | memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param)); | |
508 | ||
509 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_EVENT_LOG); | |
510 | if (rc < 0) | |
511 | printk(KERN_ERR "gsmi: Set Event Log failed\n"); | |
512 | ||
513 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
514 | ||
515 | return rc; | |
516 | ||
517 | } | |
518 | ||
519 | static struct bin_attribute eventlog_bin_attr = { | |
520 | .attr = {.name = "append_to_eventlog", .mode = 0200}, | |
521 | .write = eventlog_write, | |
522 | }; | |
523 | ||
524 | static ssize_t gsmi_clear_eventlog_store(struct kobject *kobj, | |
525 | struct kobj_attribute *attr, | |
526 | const char *buf, size_t count) | |
527 | { | |
528 | int rc; | |
529 | unsigned long flags; | |
530 | unsigned long val; | |
531 | struct { | |
532 | u32 percentage; | |
533 | u32 data_type; | |
534 | } param; | |
535 | ||
536 | rc = strict_strtoul(buf, 0, &val); | |
537 | if (rc) | |
538 | return rc; | |
539 | ||
540 | /* | |
541 | * Value entered is a percentage, 0 through 100, anything else | |
542 | * is invalid. | |
543 | */ | |
544 | if (val > 100) | |
545 | return -EINVAL; | |
546 | ||
547 | /* data_type here selects the smbios event log. */ | |
548 | param.percentage = val; | |
549 | param.data_type = 0; | |
550 | ||
551 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
552 | ||
553 | /* parameter buffer */ | |
554 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
555 | memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param)); | |
556 | ||
557 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_CLEAR_EVENT_LOG); | |
558 | ||
559 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
560 | ||
561 | if (rc) | |
562 | return rc; | |
563 | return count; | |
564 | } | |
565 | ||
566 | static struct kobj_attribute gsmi_clear_eventlog_attr = { | |
567 | .attr = {.name = "clear_eventlog", .mode = 0200}, | |
568 | .store = gsmi_clear_eventlog_store, | |
569 | }; | |
570 | ||
571 | static ssize_t gsmi_clear_config_store(struct kobject *kobj, | |
572 | struct kobj_attribute *attr, | |
573 | const char *buf, size_t count) | |
574 | { | |
575 | int rc; | |
576 | unsigned long flags; | |
577 | ||
578 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
579 | ||
580 | /* clear parameter buffer */ | |
581 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
582 | ||
583 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_CLEAR_CONFIG); | |
584 | ||
585 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
586 | ||
587 | if (rc) | |
588 | return rc; | |
589 | return count; | |
590 | } | |
591 | ||
592 | static struct kobj_attribute gsmi_clear_config_attr = { | |
593 | .attr = {.name = "clear_config", .mode = 0200}, | |
594 | .store = gsmi_clear_config_store, | |
595 | }; | |
596 | ||
597 | static const struct attribute *gsmi_attrs[] = { | |
598 | &gsmi_clear_config_attr.attr, | |
599 | &gsmi_clear_eventlog_attr.attr, | |
600 | NULL, | |
601 | }; | |
602 | ||
603 | static int gsmi_shutdown_reason(int reason) | |
604 | { | |
605 | struct gsmi_log_entry_type_1 entry = { | |
606 | .type = GSMI_LOG_ENTRY_TYPE_KERNEL, | |
607 | .instance = reason, | |
608 | }; | |
609 | struct gsmi_set_eventlog_param param = { | |
610 | .data_len = sizeof(entry), | |
611 | .type = 1, | |
612 | }; | |
613 | static int saved_reason; | |
614 | int rc = 0; | |
615 | unsigned long flags; | |
616 | ||
617 | /* avoid duplicate entries in the log */ | |
618 | if (saved_reason & (1 << reason)) | |
619 | return 0; | |
620 | ||
621 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
622 | ||
623 | saved_reason |= (1 << reason); | |
624 | ||
625 | /* data pointer */ | |
626 | memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length); | |
627 | memcpy(gsmi_dev.data_buf->start, &entry, sizeof(entry)); | |
628 | ||
629 | /* parameter buffer */ | |
630 | param.data_ptr = gsmi_dev.data_buf->address; | |
631 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
632 | memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param)); | |
633 | ||
634 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_EVENT_LOG); | |
635 | ||
636 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
637 | ||
638 | if (rc < 0) | |
639 | printk(KERN_ERR "gsmi: Log Shutdown Reason failed\n"); | |
640 | else | |
641 | printk(KERN_EMERG "gsmi: Log Shutdown Reason 0x%02x\n", | |
642 | reason); | |
643 | ||
644 | return rc; | |
645 | } | |
646 | ||
647 | static int gsmi_reboot_callback(struct notifier_block *nb, | |
648 | unsigned long reason, void *arg) | |
649 | { | |
650 | gsmi_shutdown_reason(GSMI_SHUTDOWN_CLEAN); | |
651 | return NOTIFY_DONE; | |
652 | } | |
653 | ||
654 | static struct notifier_block gsmi_reboot_notifier = { | |
655 | .notifier_call = gsmi_reboot_callback | |
656 | }; | |
657 | ||
658 | static int gsmi_die_callback(struct notifier_block *nb, | |
659 | unsigned long reason, void *arg) | |
660 | { | |
661 | if (reason == DIE_OOPS) | |
662 | gsmi_shutdown_reason(GSMI_SHUTDOWN_OOPS); | |
663 | return NOTIFY_DONE; | |
664 | } | |
665 | ||
666 | static struct notifier_block gsmi_die_notifier = { | |
667 | .notifier_call = gsmi_die_callback | |
668 | }; | |
669 | ||
670 | static int gsmi_panic_callback(struct notifier_block *nb, | |
671 | unsigned long reason, void *arg) | |
672 | { | |
673 | gsmi_shutdown_reason(GSMI_SHUTDOWN_PANIC); | |
674 | return NOTIFY_DONE; | |
675 | } | |
676 | ||
677 | static struct notifier_block gsmi_panic_notifier = { | |
678 | .notifier_call = gsmi_panic_callback, | |
679 | }; | |
680 | ||
681 | /* | |
682 | * This hash function was blatantly copied from include/linux/hash.h. | |
683 | * It is used by this driver to obfuscate a board name that requires a | |
684 | * quirk within this driver. | |
685 | * | |
686 | * Please do not remove this copy of the function as any changes to the | |
687 | * global utility hash_64() function would break this driver's ability | |
688 | * to identify a board and provide the appropriate quirk -- mikew@google.com | |
689 | */ | |
690 | static u64 __init local_hash_64(u64 val, unsigned bits) | |
691 | { | |
692 | u64 hash = val; | |
693 | ||
694 | /* Sigh, gcc can't optimise this alone like it does for 32 bits. */ | |
695 | u64 n = hash; | |
696 | n <<= 18; | |
697 | hash -= n; | |
698 | n <<= 33; | |
699 | hash -= n; | |
700 | n <<= 3; | |
701 | hash += n; | |
702 | n <<= 3; | |
703 | hash -= n; | |
704 | n <<= 4; | |
705 | hash += n; | |
706 | n <<= 2; | |
707 | hash += n; | |
708 | ||
709 | /* High bits are more random, so use them. */ | |
710 | return hash >> (64 - bits); | |
711 | } | |
712 | ||
713 | static u32 __init hash_oem_table_id(char s[8]) | |
714 | { | |
715 | u64 input; | |
716 | memcpy(&input, s, 8); | |
717 | return local_hash_64(input, 32); | |
718 | } | |
719 | ||
720 | static struct dmi_system_id gsmi_dmi_table[] __initdata = { | |
721 | { | |
722 | .ident = "Google Board", | |
723 | .matches = { | |
724 | DMI_MATCH(DMI_BOARD_VENDOR, "Google, Inc."), | |
725 | }, | |
726 | }, | |
727 | {} | |
728 | }; | |
729 | MODULE_DEVICE_TABLE(dmi, gsmi_dmi_table); | |
730 | ||
731 | static __init int gsmi_system_valid(void) | |
732 | { | |
733 | u32 hash; | |
734 | ||
735 | if (!dmi_check_system(gsmi_dmi_table)) | |
736 | return -ENODEV; | |
737 | ||
738 | /* | |
739 | * Only newer firmware supports the gsmi interface. All older | |
740 | * firmware that didn't support this interface used to plug the | |
741 | * table name in the first four bytes of the oem_table_id field. | |
742 | * Newer firmware doesn't do that though, so use that as the | |
743 | * discriminant factor. We have to do this in order to | |
744 | * whitewash our board names out of the public driver. | |
745 | */ | |
746 | if (!strncmp(acpi_gbl_FADT.header.oem_table_id, "FACP", 4)) { | |
747 | printk(KERN_INFO "gsmi: Board is too old\n"); | |
748 | return -ENODEV; | |
749 | } | |
750 | ||
751 | /* Disable on board with 1.0 BIOS due to Google bug 2602657 */ | |
752 | hash = hash_oem_table_id(acpi_gbl_FADT.header.oem_table_id); | |
753 | if (hash == QUIRKY_BOARD_HASH) { | |
754 | const char *bios_ver = dmi_get_system_info(DMI_BIOS_VERSION); | |
755 | if (strncmp(bios_ver, "1.0", 3) == 0) { | |
756 | pr_info("gsmi: disabled on this board's BIOS %s\n", | |
757 | bios_ver); | |
758 | return -ENODEV; | |
759 | } | |
760 | } | |
761 | ||
762 | /* check for valid SMI command port in ACPI FADT */ | |
763 | if (acpi_gbl_FADT.smi_command == 0) { | |
764 | pr_info("gsmi: missing smi_command\n"); | |
765 | return -ENODEV; | |
766 | } | |
767 | ||
768 | /* Found */ | |
769 | return 0; | |
770 | } | |
771 | ||
772 | static struct kobject *gsmi_kobj; | |
773 | static struct efivars efivars; | |
774 | ||
775 | static __init int gsmi_init(void) | |
776 | { | |
777 | unsigned long flags; | |
778 | int ret; | |
779 | ||
780 | ret = gsmi_system_valid(); | |
781 | if (ret) | |
782 | return ret; | |
783 | ||
784 | gsmi_dev.smi_cmd = acpi_gbl_FADT.smi_command; | |
785 | ||
786 | /* register device */ | |
787 | gsmi_dev.pdev = platform_device_register_simple("gsmi", -1, NULL, 0); | |
788 | if (IS_ERR(gsmi_dev.pdev)) { | |
789 | printk(KERN_ERR "gsmi: unable to register platform device\n"); | |
790 | return PTR_ERR(gsmi_dev.pdev); | |
791 | } | |
792 | ||
793 | /* SMI access needs to be serialized */ | |
794 | spin_lock_init(&gsmi_dev.lock); | |
795 | ||
796 | /* SMI callbacks require 32bit addresses */ | |
797 | gsmi_dev.pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32); | |
798 | gsmi_dev.pdev->dev.dma_mask = | |
799 | &gsmi_dev.pdev->dev.coherent_dma_mask; | |
800 | ret = -ENOMEM; | |
801 | gsmi_dev.dma_pool = dma_pool_create("gsmi", &gsmi_dev.pdev->dev, | |
802 | GSMI_BUF_SIZE, GSMI_BUF_ALIGN, 0); | |
803 | if (!gsmi_dev.dma_pool) | |
804 | goto out_err; | |
805 | ||
806 | /* | |
807 | * pre-allocate buffers because sometimes we are called when | |
808 | * this is not feasible: oops, panic, die, mce, etc | |
809 | */ | |
810 | gsmi_dev.name_buf = gsmi_buf_alloc(); | |
811 | if (!gsmi_dev.name_buf) { | |
812 | printk(KERN_ERR "gsmi: failed to allocate name buffer\n"); | |
813 | goto out_err; | |
814 | } | |
815 | ||
816 | gsmi_dev.data_buf = gsmi_buf_alloc(); | |
817 | if (!gsmi_dev.data_buf) { | |
818 | printk(KERN_ERR "gsmi: failed to allocate data buffer\n"); | |
819 | goto out_err; | |
820 | } | |
821 | ||
822 | gsmi_dev.param_buf = gsmi_buf_alloc(); | |
823 | if (!gsmi_dev.param_buf) { | |
824 | printk(KERN_ERR "gsmi: failed to allocate param buffer\n"); | |
825 | goto out_err; | |
826 | } | |
827 | ||
828 | /* | |
829 | * Determine type of handshake used to serialize the SMI | |
830 | * entry. See also gsmi_exec(). | |
831 | * | |
832 | * There's a "behavior" present on some chipsets where writing the | |
833 | * SMI trigger register in the southbridge doesn't result in an | |
834 | * immediate SMI. Rather, the processor can execute "a few" more | |
835 | * instructions before the SMI takes effect. To ensure synchronous | |
836 | * behavior, implement a handshake between the kernel driver and the | |
837 | * firmware handler to spin until released. This ioctl determines | |
838 | * the type of handshake. | |
839 | * | |
840 | * NONE: The firmware handler does not implement any | |
841 | * handshake. Either it doesn't need to, or it's legacy firmware | |
842 | * that doesn't know it needs to and never will. | |
843 | * | |
844 | * CF: The firmware handler will clear the CF in the saved | |
845 | * state before returning. The driver may set the CF and test for | |
846 | * it to clear before proceeding. | |
847 | * | |
848 | * SPIN: The firmware handler does not implement any handshake | |
849 | * but the driver should spin for a hundred or so microseconds | |
850 | * to ensure the SMI has triggered. | |
851 | * | |
852 | * Finally, the handler will return -ENOSYS if | |
853 | * GSMI_CMD_HANDSHAKE_TYPE is unimplemented, which implies | |
854 | * HANDSHAKE_NONE. | |
855 | */ | |
856 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
857 | gsmi_dev.handshake_type = GSMI_HANDSHAKE_SPIN; | |
858 | gsmi_dev.handshake_type = | |
859 | gsmi_exec(GSMI_CALLBACK, GSMI_CMD_HANDSHAKE_TYPE); | |
860 | if (gsmi_dev.handshake_type == -ENOSYS) | |
861 | gsmi_dev.handshake_type = GSMI_HANDSHAKE_NONE; | |
862 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
863 | ||
864 | /* Remove and clean up gsmi if the handshake could not complete. */ | |
865 | if (gsmi_dev.handshake_type == -ENXIO) { | |
866 | printk(KERN_INFO "gsmi version " DRIVER_VERSION | |
867 | " failed to load\n"); | |
868 | ret = -ENODEV; | |
869 | goto out_err; | |
870 | } | |
871 | ||
872 | printk(KERN_INFO "gsmi version " DRIVER_VERSION " loaded\n"); | |
873 | ||
874 | /* Register in the firmware directory */ | |
875 | ret = -ENOMEM; | |
876 | gsmi_kobj = kobject_create_and_add("gsmi", firmware_kobj); | |
877 | if (!gsmi_kobj) { | |
878 | printk(KERN_INFO "gsmi: Failed to create firmware kobj\n"); | |
879 | goto out_err; | |
880 | } | |
881 | ||
882 | /* Setup eventlog access */ | |
883 | ret = sysfs_create_bin_file(gsmi_kobj, &eventlog_bin_attr); | |
884 | if (ret) { | |
885 | printk(KERN_INFO "gsmi: Failed to setup eventlog"); | |
886 | goto out_err; | |
887 | } | |
888 | ||
889 | /* Other attributes */ | |
890 | ret = sysfs_create_files(gsmi_kobj, gsmi_attrs); | |
891 | if (ret) { | |
892 | printk(KERN_INFO "gsmi: Failed to add attrs"); | |
893 | goto out_err; | |
894 | } | |
895 | ||
896 | if (register_efivars(&efivars, &efivar_ops, gsmi_kobj)) { | |
897 | printk(KERN_INFO "gsmi: Failed to register efivars\n"); | |
898 | goto out_err; | |
899 | } | |
900 | ||
901 | register_reboot_notifier(&gsmi_reboot_notifier); | |
902 | register_die_notifier(&gsmi_die_notifier); | |
903 | atomic_notifier_chain_register(&panic_notifier_list, | |
904 | &gsmi_panic_notifier); | |
905 | ||
906 | return 0; | |
907 | ||
908 | out_err: | |
909 | kobject_put(gsmi_kobj); | |
910 | gsmi_buf_free(gsmi_dev.param_buf); | |
911 | gsmi_buf_free(gsmi_dev.data_buf); | |
912 | gsmi_buf_free(gsmi_dev.name_buf); | |
913 | if (gsmi_dev.dma_pool) | |
914 | dma_pool_destroy(gsmi_dev.dma_pool); | |
915 | platform_device_unregister(gsmi_dev.pdev); | |
916 | pr_info("gsmi: failed to load: %d\n", ret); | |
917 | return ret; | |
918 | } | |
919 | ||
920 | static void __exit gsmi_exit(void) | |
921 | { | |
922 | unregister_reboot_notifier(&gsmi_reboot_notifier); | |
923 | unregister_die_notifier(&gsmi_die_notifier); | |
924 | atomic_notifier_chain_unregister(&panic_notifier_list, | |
925 | &gsmi_panic_notifier); | |
926 | unregister_efivars(&efivars); | |
927 | ||
928 | kobject_put(gsmi_kobj); | |
929 | gsmi_buf_free(gsmi_dev.param_buf); | |
930 | gsmi_buf_free(gsmi_dev.data_buf); | |
931 | gsmi_buf_free(gsmi_dev.name_buf); | |
932 | dma_pool_destroy(gsmi_dev.dma_pool); | |
933 | platform_device_unregister(gsmi_dev.pdev); | |
934 | } | |
935 | ||
936 | module_init(gsmi_init); | |
937 | module_exit(gsmi_exit); | |
938 | ||
939 | MODULE_AUTHOR("Google, Inc."); | |
940 | MODULE_LICENSE("GPL"); |