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74c5b31c MW |
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> | |
afd605f6 | 30 | #include <linux/module.h> |
a614e192 | 31 | #include <linux/ucs2_string.h> |
74c5b31c MW |
32 | |
33 | #define GSMI_SHUTDOWN_CLEAN 0 /* Clean Shutdown */ | |
34 | /* TODO(mikew@google.com): Tie in HARDLOCKUP_DETECTOR with NMIWDT */ | |
35 | #define GSMI_SHUTDOWN_NMIWDT 1 /* NMI Watchdog */ | |
36 | #define GSMI_SHUTDOWN_PANIC 2 /* Panic */ | |
37 | #define GSMI_SHUTDOWN_OOPS 3 /* Oops */ | |
38 | #define GSMI_SHUTDOWN_DIE 4 /* Die -- No longer meaningful */ | |
39 | #define GSMI_SHUTDOWN_MCE 5 /* Machine Check */ | |
40 | #define GSMI_SHUTDOWN_SOFTWDT 6 /* Software Watchdog */ | |
41 | #define GSMI_SHUTDOWN_MBE 7 /* Uncorrected ECC */ | |
42 | #define GSMI_SHUTDOWN_TRIPLE 8 /* Triple Fault */ | |
43 | ||
44 | #define DRIVER_VERSION "1.0" | |
45 | #define GSMI_GUID_SIZE 16 | |
46 | #define GSMI_BUF_SIZE 1024 | |
47 | #define GSMI_BUF_ALIGN sizeof(u64) | |
48 | #define GSMI_CALLBACK 0xef | |
49 | ||
50 | /* SMI return codes */ | |
51 | #define GSMI_SUCCESS 0x00 | |
52 | #define GSMI_UNSUPPORTED2 0x03 | |
53 | #define GSMI_LOG_FULL 0x0b | |
54 | #define GSMI_VAR_NOT_FOUND 0x0e | |
55 | #define GSMI_HANDSHAKE_SPIN 0x7d | |
56 | #define GSMI_HANDSHAKE_CF 0x7e | |
57 | #define GSMI_HANDSHAKE_NONE 0x7f | |
58 | #define GSMI_INVALID_PARAMETER 0x82 | |
59 | #define GSMI_UNSUPPORTED 0x83 | |
60 | #define GSMI_BUFFER_TOO_SMALL 0x85 | |
61 | #define GSMI_NOT_READY 0x86 | |
62 | #define GSMI_DEVICE_ERROR 0x87 | |
63 | #define GSMI_NOT_FOUND 0x8e | |
64 | ||
65 | #define QUIRKY_BOARD_HASH 0x78a30a50 | |
66 | ||
67 | /* Internally used commands passed to the firmware */ | |
68 | #define GSMI_CMD_GET_NVRAM_VAR 0x01 | |
69 | #define GSMI_CMD_GET_NEXT_VAR 0x02 | |
70 | #define GSMI_CMD_SET_NVRAM_VAR 0x03 | |
71 | #define GSMI_CMD_SET_EVENT_LOG 0x08 | |
72 | #define GSMI_CMD_CLEAR_EVENT_LOG 0x09 | |
73 | #define GSMI_CMD_CLEAR_CONFIG 0x20 | |
74 | #define GSMI_CMD_HANDSHAKE_TYPE 0xC1 | |
75 | ||
76 | /* Magic entry type for kernel events */ | |
77 | #define GSMI_LOG_ENTRY_TYPE_KERNEL 0xDEAD | |
78 | ||
79 | /* SMI buffers must be in 32bit physical address space */ | |
80 | struct gsmi_buf { | |
81 | u8 *start; /* start of buffer */ | |
82 | size_t length; /* length of buffer */ | |
83 | dma_addr_t handle; /* dma allocation handle */ | |
84 | u32 address; /* physical address of buffer */ | |
85 | }; | |
86 | ||
87 | struct gsmi_device { | |
88 | struct platform_device *pdev; /* platform device */ | |
89 | struct gsmi_buf *name_buf; /* variable name buffer */ | |
90 | struct gsmi_buf *data_buf; /* generic data buffer */ | |
91 | struct gsmi_buf *param_buf; /* parameter buffer */ | |
92 | spinlock_t lock; /* serialize access to SMIs */ | |
93 | u16 smi_cmd; /* SMI command port */ | |
94 | int handshake_type; /* firmware handler interlock type */ | |
95 | struct dma_pool *dma_pool; /* DMA buffer pool */ | |
96 | } gsmi_dev; | |
97 | ||
98 | /* Packed structures for communicating with the firmware */ | |
99 | struct gsmi_nvram_var_param { | |
100 | efi_guid_t guid; | |
101 | u32 name_ptr; | |
102 | u32 attributes; | |
103 | u32 data_len; | |
104 | u32 data_ptr; | |
105 | } __packed; | |
106 | ||
107 | struct gsmi_get_next_var_param { | |
108 | u8 guid[GSMI_GUID_SIZE]; | |
109 | u32 name_ptr; | |
110 | u32 name_len; | |
111 | } __packed; | |
112 | ||
113 | struct gsmi_set_eventlog_param { | |
114 | u32 data_ptr; | |
115 | u32 data_len; | |
116 | u32 type; | |
117 | } __packed; | |
118 | ||
119 | /* Event log formats */ | |
120 | struct gsmi_log_entry_type_1 { | |
121 | u16 type; | |
122 | u32 instance; | |
123 | } __packed; | |
124 | ||
125 | ||
126 | /* | |
127 | * Some platforms don't have explicit SMI handshake | |
128 | * and need to wait for SMI to complete. | |
129 | */ | |
130 | #define GSMI_DEFAULT_SPINCOUNT 0x10000 | |
131 | static unsigned int spincount = GSMI_DEFAULT_SPINCOUNT; | |
132 | module_param(spincount, uint, 0600); | |
133 | MODULE_PARM_DESC(spincount, | |
134 | "The number of loop iterations to use when using the spin handshake."); | |
135 | ||
136 | static struct gsmi_buf *gsmi_buf_alloc(void) | |
137 | { | |
138 | struct gsmi_buf *smibuf; | |
139 | ||
140 | smibuf = kzalloc(sizeof(*smibuf), GFP_KERNEL); | |
141 | if (!smibuf) { | |
142 | printk(KERN_ERR "gsmi: out of memory\n"); | |
143 | return NULL; | |
144 | } | |
145 | ||
146 | /* allocate buffer in 32bit address space */ | |
147 | smibuf->start = dma_pool_alloc(gsmi_dev.dma_pool, GFP_KERNEL, | |
148 | &smibuf->handle); | |
149 | if (!smibuf->start) { | |
150 | printk(KERN_ERR "gsmi: failed to allocate name buffer\n"); | |
151 | kfree(smibuf); | |
152 | return NULL; | |
153 | } | |
154 | ||
155 | /* fill in the buffer handle */ | |
156 | smibuf->length = GSMI_BUF_SIZE; | |
157 | smibuf->address = (u32)virt_to_phys(smibuf->start); | |
158 | ||
159 | return smibuf; | |
160 | } | |
161 | ||
162 | static void gsmi_buf_free(struct gsmi_buf *smibuf) | |
163 | { | |
164 | if (smibuf) { | |
165 | if (smibuf->start) | |
166 | dma_pool_free(gsmi_dev.dma_pool, smibuf->start, | |
167 | smibuf->handle); | |
168 | kfree(smibuf); | |
169 | } | |
170 | } | |
171 | ||
172 | /* | |
173 | * Make a call to gsmi func(sub). GSMI error codes are translated to | |
174 | * in-kernel errnos (0 on success, -ERRNO on error). | |
175 | */ | |
176 | static int gsmi_exec(u8 func, u8 sub) | |
177 | { | |
178 | u16 cmd = (sub << 8) | func; | |
179 | u16 result = 0; | |
180 | int rc = 0; | |
181 | ||
182 | /* | |
183 | * AH : Subfunction number | |
184 | * AL : Function number | |
185 | * EBX : Parameter block address | |
186 | * DX : SMI command port | |
187 | * | |
188 | * Three protocols here. See also the comment in gsmi_init(). | |
189 | */ | |
190 | if (gsmi_dev.handshake_type == GSMI_HANDSHAKE_CF) { | |
191 | /* | |
192 | * If handshake_type == HANDSHAKE_CF then set CF on the | |
193 | * way in and wait for the handler to clear it; this avoids | |
194 | * corrupting register state on those chipsets which have | |
195 | * a delay between writing the SMI trigger register and | |
196 | * entering SMM. | |
197 | */ | |
198 | asm volatile ( | |
199 | "stc\n" | |
200 | "outb %%al, %%dx\n" | |
201 | "1: jc 1b\n" | |
202 | : "=a" (result) | |
203 | : "0" (cmd), | |
204 | "d" (gsmi_dev.smi_cmd), | |
205 | "b" (gsmi_dev.param_buf->address) | |
206 | : "memory", "cc" | |
207 | ); | |
208 | } else if (gsmi_dev.handshake_type == GSMI_HANDSHAKE_SPIN) { | |
209 | /* | |
210 | * If handshake_type == HANDSHAKE_SPIN we spin a | |
211 | * hundred-ish usecs to ensure the SMI has triggered. | |
212 | */ | |
213 | asm volatile ( | |
214 | "outb %%al, %%dx\n" | |
215 | "1: loop 1b\n" | |
216 | : "=a" (result) | |
217 | : "0" (cmd), | |
218 | "d" (gsmi_dev.smi_cmd), | |
219 | "b" (gsmi_dev.param_buf->address), | |
220 | "c" (spincount) | |
221 | : "memory", "cc" | |
222 | ); | |
223 | } else { | |
224 | /* | |
225 | * If handshake_type == HANDSHAKE_NONE we do nothing; | |
226 | * either we don't need to or it's legacy firmware that | |
227 | * doesn't understand the CF protocol. | |
228 | */ | |
229 | asm volatile ( | |
230 | "outb %%al, %%dx\n\t" | |
231 | : "=a" (result) | |
232 | : "0" (cmd), | |
233 | "d" (gsmi_dev.smi_cmd), | |
234 | "b" (gsmi_dev.param_buf->address) | |
235 | : "memory", "cc" | |
236 | ); | |
237 | } | |
238 | ||
239 | /* check return code from SMI handler */ | |
240 | switch (result) { | |
241 | case GSMI_SUCCESS: | |
242 | break; | |
243 | case GSMI_VAR_NOT_FOUND: | |
244 | /* not really an error, but let the caller know */ | |
245 | rc = 1; | |
246 | break; | |
247 | case GSMI_INVALID_PARAMETER: | |
248 | printk(KERN_ERR "gsmi: exec 0x%04x: Invalid parameter\n", cmd); | |
249 | rc = -EINVAL; | |
250 | break; | |
251 | case GSMI_BUFFER_TOO_SMALL: | |
252 | printk(KERN_ERR "gsmi: exec 0x%04x: Buffer too small\n", cmd); | |
253 | rc = -ENOMEM; | |
254 | break; | |
255 | case GSMI_UNSUPPORTED: | |
256 | case GSMI_UNSUPPORTED2: | |
257 | if (sub != GSMI_CMD_HANDSHAKE_TYPE) | |
258 | printk(KERN_ERR "gsmi: exec 0x%04x: Not supported\n", | |
259 | cmd); | |
260 | rc = -ENOSYS; | |
261 | break; | |
262 | case GSMI_NOT_READY: | |
263 | printk(KERN_ERR "gsmi: exec 0x%04x: Not ready\n", cmd); | |
264 | rc = -EBUSY; | |
265 | break; | |
266 | case GSMI_DEVICE_ERROR: | |
267 | printk(KERN_ERR "gsmi: exec 0x%04x: Device error\n", cmd); | |
268 | rc = -EFAULT; | |
269 | break; | |
270 | case GSMI_NOT_FOUND: | |
271 | printk(KERN_ERR "gsmi: exec 0x%04x: Data not found\n", cmd); | |
272 | rc = -ENOENT; | |
273 | break; | |
274 | case GSMI_LOG_FULL: | |
275 | printk(KERN_ERR "gsmi: exec 0x%04x: Log full\n", cmd); | |
276 | rc = -ENOSPC; | |
277 | break; | |
278 | case GSMI_HANDSHAKE_CF: | |
279 | case GSMI_HANDSHAKE_SPIN: | |
280 | case GSMI_HANDSHAKE_NONE: | |
281 | rc = result; | |
282 | break; | |
283 | default: | |
284 | printk(KERN_ERR "gsmi: exec 0x%04x: Unknown error 0x%04x\n", | |
285 | cmd, result); | |
286 | rc = -ENXIO; | |
287 | } | |
288 | ||
289 | return rc; | |
290 | } | |
291 | ||
74c5b31c MW |
292 | static efi_status_t gsmi_get_variable(efi_char16_t *name, |
293 | efi_guid_t *vendor, u32 *attr, | |
294 | unsigned long *data_size, | |
295 | void *data) | |
296 | { | |
297 | struct gsmi_nvram_var_param param = { | |
298 | .name_ptr = gsmi_dev.name_buf->address, | |
299 | .data_ptr = gsmi_dev.data_buf->address, | |
300 | .data_len = (u32)*data_size, | |
301 | }; | |
302 | efi_status_t ret = EFI_SUCCESS; | |
303 | unsigned long flags; | |
a614e192 | 304 | size_t name_len = ucs2_strnlen(name, GSMI_BUF_SIZE / 2); |
74c5b31c MW |
305 | int rc; |
306 | ||
307 | if (name_len >= GSMI_BUF_SIZE / 2) | |
308 | return EFI_BAD_BUFFER_SIZE; | |
309 | ||
310 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
311 | ||
312 | /* Vendor guid */ | |
313 | memcpy(¶m.guid, vendor, sizeof(param.guid)); | |
314 | ||
315 | /* variable name, already in UTF-16 */ | |
316 | memset(gsmi_dev.name_buf->start, 0, gsmi_dev.name_buf->length); | |
317 | memcpy(gsmi_dev.name_buf->start, name, name_len * 2); | |
318 | ||
319 | /* data pointer */ | |
320 | memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length); | |
321 | ||
322 | /* parameter buffer */ | |
323 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
324 | memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param)); | |
325 | ||
326 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_GET_NVRAM_VAR); | |
327 | if (rc < 0) { | |
328 | printk(KERN_ERR "gsmi: Get Variable failed\n"); | |
329 | ret = EFI_LOAD_ERROR; | |
330 | } else if (rc == 1) { | |
331 | /* variable was not found */ | |
332 | ret = EFI_NOT_FOUND; | |
333 | } else { | |
334 | /* Get the arguments back */ | |
335 | memcpy(¶m, gsmi_dev.param_buf->start, sizeof(param)); | |
336 | ||
337 | /* The size reported is the min of all of our buffers */ | |
d2554f50 MJ |
338 | *data_size = min_t(unsigned long, *data_size, |
339 | gsmi_dev.data_buf->length); | |
74c5b31c MW |
340 | *data_size = min_t(unsigned long, *data_size, param.data_len); |
341 | ||
342 | /* Copy data back to return buffer. */ | |
343 | memcpy(data, gsmi_dev.data_buf->start, *data_size); | |
344 | ||
345 | /* All variables are have the following attributes */ | |
346 | *attr = EFI_VARIABLE_NON_VOLATILE | | |
347 | EFI_VARIABLE_BOOTSERVICE_ACCESS | | |
348 | EFI_VARIABLE_RUNTIME_ACCESS; | |
349 | } | |
350 | ||
351 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
352 | ||
353 | return ret; | |
354 | } | |
355 | ||
356 | static efi_status_t gsmi_get_next_variable(unsigned long *name_size, | |
357 | efi_char16_t *name, | |
358 | efi_guid_t *vendor) | |
359 | { | |
360 | struct gsmi_get_next_var_param param = { | |
361 | .name_ptr = gsmi_dev.name_buf->address, | |
362 | .name_len = gsmi_dev.name_buf->length, | |
363 | }; | |
364 | efi_status_t ret = EFI_SUCCESS; | |
365 | int rc; | |
366 | unsigned long flags; | |
367 | ||
368 | /* For the moment, only support buffers that exactly match in size */ | |
369 | if (*name_size != GSMI_BUF_SIZE) | |
370 | return EFI_BAD_BUFFER_SIZE; | |
371 | ||
372 | /* Let's make sure the thing is at least null-terminated */ | |
a614e192 | 373 | if (ucs2_strnlen(name, GSMI_BUF_SIZE / 2) == GSMI_BUF_SIZE / 2) |
74c5b31c MW |
374 | return EFI_INVALID_PARAMETER; |
375 | ||
376 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
377 | ||
378 | /* guid */ | |
379 | memcpy(¶m.guid, vendor, sizeof(param.guid)); | |
380 | ||
381 | /* variable name, already in UTF-16 */ | |
382 | memcpy(gsmi_dev.name_buf->start, name, *name_size); | |
383 | ||
384 | /* parameter buffer */ | |
385 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
386 | memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param)); | |
387 | ||
388 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_GET_NEXT_VAR); | |
389 | if (rc < 0) { | |
390 | printk(KERN_ERR "gsmi: Get Next Variable Name failed\n"); | |
391 | ret = EFI_LOAD_ERROR; | |
392 | } else if (rc == 1) { | |
393 | /* variable not found -- end of list */ | |
394 | ret = EFI_NOT_FOUND; | |
395 | } else { | |
396 | /* copy variable data back to return buffer */ | |
397 | memcpy(¶m, gsmi_dev.param_buf->start, sizeof(param)); | |
398 | ||
399 | /* Copy the name back */ | |
400 | memcpy(name, gsmi_dev.name_buf->start, GSMI_BUF_SIZE); | |
a614e192 | 401 | *name_size = ucs2_strnlen(name, GSMI_BUF_SIZE / 2) * 2; |
74c5b31c MW |
402 | |
403 | /* copy guid to return buffer */ | |
404 | memcpy(vendor, ¶m.guid, sizeof(param.guid)); | |
405 | ret = EFI_SUCCESS; | |
406 | } | |
407 | ||
408 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
409 | ||
410 | return ret; | |
411 | } | |
412 | ||
413 | static efi_status_t gsmi_set_variable(efi_char16_t *name, | |
414 | efi_guid_t *vendor, | |
a88769cd | 415 | u32 attr, |
74c5b31c MW |
416 | unsigned long data_size, |
417 | void *data) | |
418 | { | |
419 | struct gsmi_nvram_var_param param = { | |
420 | .name_ptr = gsmi_dev.name_buf->address, | |
421 | .data_ptr = gsmi_dev.data_buf->address, | |
422 | .data_len = (u32)data_size, | |
423 | .attributes = EFI_VARIABLE_NON_VOLATILE | | |
424 | EFI_VARIABLE_BOOTSERVICE_ACCESS | | |
425 | EFI_VARIABLE_RUNTIME_ACCESS, | |
426 | }; | |
a614e192 | 427 | size_t name_len = ucs2_strnlen(name, GSMI_BUF_SIZE / 2); |
74c5b31c MW |
428 | efi_status_t ret = EFI_SUCCESS; |
429 | int rc; | |
430 | unsigned long flags; | |
431 | ||
432 | if (name_len >= GSMI_BUF_SIZE / 2) | |
433 | return EFI_BAD_BUFFER_SIZE; | |
434 | ||
435 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
436 | ||
437 | /* guid */ | |
438 | memcpy(¶m.guid, vendor, sizeof(param.guid)); | |
439 | ||
440 | /* variable name, already in UTF-16 */ | |
441 | memset(gsmi_dev.name_buf->start, 0, gsmi_dev.name_buf->length); | |
442 | memcpy(gsmi_dev.name_buf->start, name, name_len * 2); | |
443 | ||
444 | /* data pointer */ | |
445 | memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length); | |
446 | memcpy(gsmi_dev.data_buf->start, data, data_size); | |
447 | ||
448 | /* parameter buffer */ | |
449 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
450 | memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param)); | |
451 | ||
452 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_NVRAM_VAR); | |
453 | if (rc < 0) { | |
454 | printk(KERN_ERR "gsmi: Set Variable failed\n"); | |
455 | ret = EFI_INVALID_PARAMETER; | |
456 | } | |
457 | ||
458 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
459 | ||
460 | return ret; | |
461 | } | |
462 | ||
463 | static const struct efivar_operations efivar_ops = { | |
464 | .get_variable = gsmi_get_variable, | |
465 | .set_variable = gsmi_set_variable, | |
466 | .get_next_variable = gsmi_get_next_variable, | |
467 | }; | |
468 | ||
469 | static ssize_t eventlog_write(struct file *filp, struct kobject *kobj, | |
470 | struct bin_attribute *bin_attr, | |
471 | char *buf, loff_t pos, size_t count) | |
472 | { | |
473 | struct gsmi_set_eventlog_param param = { | |
474 | .data_ptr = gsmi_dev.data_buf->address, | |
475 | }; | |
476 | int rc = 0; | |
477 | unsigned long flags; | |
478 | ||
479 | /* Pull the type out */ | |
480 | if (count < sizeof(u32)) | |
481 | return -EINVAL; | |
482 | param.type = *(u32 *)buf; | |
483 | count -= sizeof(u32); | |
484 | buf += sizeof(u32); | |
485 | ||
486 | /* The remaining buffer is the data payload */ | |
487 | if (count > gsmi_dev.data_buf->length) | |
488 | return -EINVAL; | |
489 | param.data_len = count - sizeof(u32); | |
490 | ||
491 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
492 | ||
493 | /* data pointer */ | |
494 | memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length); | |
495 | memcpy(gsmi_dev.data_buf->start, buf, param.data_len); | |
496 | ||
497 | /* parameter buffer */ | |
498 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
499 | memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param)); | |
500 | ||
501 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_EVENT_LOG); | |
502 | if (rc < 0) | |
503 | printk(KERN_ERR "gsmi: Set Event Log failed\n"); | |
504 | ||
505 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
506 | ||
507 | return rc; | |
508 | ||
509 | } | |
510 | ||
511 | static struct bin_attribute eventlog_bin_attr = { | |
512 | .attr = {.name = "append_to_eventlog", .mode = 0200}, | |
513 | .write = eventlog_write, | |
514 | }; | |
515 | ||
516 | static ssize_t gsmi_clear_eventlog_store(struct kobject *kobj, | |
517 | struct kobj_attribute *attr, | |
518 | const char *buf, size_t count) | |
519 | { | |
520 | int rc; | |
521 | unsigned long flags; | |
522 | unsigned long val; | |
523 | struct { | |
524 | u32 percentage; | |
525 | u32 data_type; | |
526 | } param; | |
527 | ||
20d0e570 | 528 | rc = kstrtoul(buf, 0, &val); |
74c5b31c MW |
529 | if (rc) |
530 | return rc; | |
531 | ||
532 | /* | |
533 | * Value entered is a percentage, 0 through 100, anything else | |
534 | * is invalid. | |
535 | */ | |
536 | if (val > 100) | |
537 | return -EINVAL; | |
538 | ||
539 | /* data_type here selects the smbios event log. */ | |
540 | param.percentage = val; | |
541 | param.data_type = 0; | |
542 | ||
543 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
544 | ||
545 | /* parameter buffer */ | |
546 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
547 | memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param)); | |
548 | ||
549 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_CLEAR_EVENT_LOG); | |
550 | ||
551 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
552 | ||
553 | if (rc) | |
554 | return rc; | |
555 | return count; | |
556 | } | |
557 | ||
558 | static struct kobj_attribute gsmi_clear_eventlog_attr = { | |
559 | .attr = {.name = "clear_eventlog", .mode = 0200}, | |
560 | .store = gsmi_clear_eventlog_store, | |
561 | }; | |
562 | ||
563 | static ssize_t gsmi_clear_config_store(struct kobject *kobj, | |
564 | struct kobj_attribute *attr, | |
565 | const char *buf, size_t count) | |
566 | { | |
567 | int rc; | |
568 | unsigned long flags; | |
569 | ||
570 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
571 | ||
572 | /* clear parameter buffer */ | |
573 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
574 | ||
575 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_CLEAR_CONFIG); | |
576 | ||
577 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
578 | ||
579 | if (rc) | |
580 | return rc; | |
581 | return count; | |
582 | } | |
583 | ||
584 | static struct kobj_attribute gsmi_clear_config_attr = { | |
585 | .attr = {.name = "clear_config", .mode = 0200}, | |
586 | .store = gsmi_clear_config_store, | |
587 | }; | |
588 | ||
589 | static const struct attribute *gsmi_attrs[] = { | |
590 | &gsmi_clear_config_attr.attr, | |
591 | &gsmi_clear_eventlog_attr.attr, | |
592 | NULL, | |
593 | }; | |
594 | ||
595 | static int gsmi_shutdown_reason(int reason) | |
596 | { | |
597 | struct gsmi_log_entry_type_1 entry = { | |
598 | .type = GSMI_LOG_ENTRY_TYPE_KERNEL, | |
599 | .instance = reason, | |
600 | }; | |
601 | struct gsmi_set_eventlog_param param = { | |
602 | .data_len = sizeof(entry), | |
603 | .type = 1, | |
604 | }; | |
605 | static int saved_reason; | |
606 | int rc = 0; | |
607 | unsigned long flags; | |
608 | ||
609 | /* avoid duplicate entries in the log */ | |
610 | if (saved_reason & (1 << reason)) | |
611 | return 0; | |
612 | ||
613 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
614 | ||
615 | saved_reason |= (1 << reason); | |
616 | ||
617 | /* data pointer */ | |
618 | memset(gsmi_dev.data_buf->start, 0, gsmi_dev.data_buf->length); | |
619 | memcpy(gsmi_dev.data_buf->start, &entry, sizeof(entry)); | |
620 | ||
621 | /* parameter buffer */ | |
622 | param.data_ptr = gsmi_dev.data_buf->address; | |
623 | memset(gsmi_dev.param_buf->start, 0, gsmi_dev.param_buf->length); | |
624 | memcpy(gsmi_dev.param_buf->start, ¶m, sizeof(param)); | |
625 | ||
626 | rc = gsmi_exec(GSMI_CALLBACK, GSMI_CMD_SET_EVENT_LOG); | |
627 | ||
628 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
629 | ||
630 | if (rc < 0) | |
631 | printk(KERN_ERR "gsmi: Log Shutdown Reason failed\n"); | |
632 | else | |
633 | printk(KERN_EMERG "gsmi: Log Shutdown Reason 0x%02x\n", | |
634 | reason); | |
635 | ||
636 | return rc; | |
637 | } | |
638 | ||
639 | static int gsmi_reboot_callback(struct notifier_block *nb, | |
640 | unsigned long reason, void *arg) | |
641 | { | |
642 | gsmi_shutdown_reason(GSMI_SHUTDOWN_CLEAN); | |
643 | return NOTIFY_DONE; | |
644 | } | |
645 | ||
646 | static struct notifier_block gsmi_reboot_notifier = { | |
647 | .notifier_call = gsmi_reboot_callback | |
648 | }; | |
649 | ||
650 | static int gsmi_die_callback(struct notifier_block *nb, | |
651 | unsigned long reason, void *arg) | |
652 | { | |
653 | if (reason == DIE_OOPS) | |
654 | gsmi_shutdown_reason(GSMI_SHUTDOWN_OOPS); | |
655 | return NOTIFY_DONE; | |
656 | } | |
657 | ||
658 | static struct notifier_block gsmi_die_notifier = { | |
659 | .notifier_call = gsmi_die_callback | |
660 | }; | |
661 | ||
662 | static int gsmi_panic_callback(struct notifier_block *nb, | |
663 | unsigned long reason, void *arg) | |
664 | { | |
665 | gsmi_shutdown_reason(GSMI_SHUTDOWN_PANIC); | |
666 | return NOTIFY_DONE; | |
667 | } | |
668 | ||
669 | static struct notifier_block gsmi_panic_notifier = { | |
670 | .notifier_call = gsmi_panic_callback, | |
671 | }; | |
672 | ||
673 | /* | |
674 | * This hash function was blatantly copied from include/linux/hash.h. | |
675 | * It is used by this driver to obfuscate a board name that requires a | |
676 | * quirk within this driver. | |
677 | * | |
678 | * Please do not remove this copy of the function as any changes to the | |
679 | * global utility hash_64() function would break this driver's ability | |
680 | * to identify a board and provide the appropriate quirk -- mikew@google.com | |
681 | */ | |
682 | static u64 __init local_hash_64(u64 val, unsigned bits) | |
683 | { | |
684 | u64 hash = val; | |
685 | ||
686 | /* Sigh, gcc can't optimise this alone like it does for 32 bits. */ | |
687 | u64 n = hash; | |
688 | n <<= 18; | |
689 | hash -= n; | |
690 | n <<= 33; | |
691 | hash -= n; | |
692 | n <<= 3; | |
693 | hash += n; | |
694 | n <<= 3; | |
695 | hash -= n; | |
696 | n <<= 4; | |
697 | hash += n; | |
698 | n <<= 2; | |
699 | hash += n; | |
700 | ||
701 | /* High bits are more random, so use them. */ | |
702 | return hash >> (64 - bits); | |
703 | } | |
704 | ||
705 | static u32 __init hash_oem_table_id(char s[8]) | |
706 | { | |
707 | u64 input; | |
708 | memcpy(&input, s, 8); | |
709 | return local_hash_64(input, 32); | |
710 | } | |
711 | ||
712 | static struct dmi_system_id gsmi_dmi_table[] __initdata = { | |
713 | { | |
714 | .ident = "Google Board", | |
715 | .matches = { | |
716 | DMI_MATCH(DMI_BOARD_VENDOR, "Google, Inc."), | |
717 | }, | |
718 | }, | |
719 | {} | |
720 | }; | |
721 | MODULE_DEVICE_TABLE(dmi, gsmi_dmi_table); | |
722 | ||
723 | static __init int gsmi_system_valid(void) | |
724 | { | |
725 | u32 hash; | |
726 | ||
727 | if (!dmi_check_system(gsmi_dmi_table)) | |
728 | return -ENODEV; | |
729 | ||
730 | /* | |
731 | * Only newer firmware supports the gsmi interface. All older | |
732 | * firmware that didn't support this interface used to plug the | |
733 | * table name in the first four bytes of the oem_table_id field. | |
734 | * Newer firmware doesn't do that though, so use that as the | |
735 | * discriminant factor. We have to do this in order to | |
736 | * whitewash our board names out of the public driver. | |
737 | */ | |
738 | if (!strncmp(acpi_gbl_FADT.header.oem_table_id, "FACP", 4)) { | |
739 | printk(KERN_INFO "gsmi: Board is too old\n"); | |
740 | return -ENODEV; | |
741 | } | |
742 | ||
743 | /* Disable on board with 1.0 BIOS due to Google bug 2602657 */ | |
744 | hash = hash_oem_table_id(acpi_gbl_FADT.header.oem_table_id); | |
745 | if (hash == QUIRKY_BOARD_HASH) { | |
746 | const char *bios_ver = dmi_get_system_info(DMI_BIOS_VERSION); | |
747 | if (strncmp(bios_ver, "1.0", 3) == 0) { | |
748 | pr_info("gsmi: disabled on this board's BIOS %s\n", | |
749 | bios_ver); | |
750 | return -ENODEV; | |
751 | } | |
752 | } | |
753 | ||
754 | /* check for valid SMI command port in ACPI FADT */ | |
755 | if (acpi_gbl_FADT.smi_command == 0) { | |
756 | pr_info("gsmi: missing smi_command\n"); | |
757 | return -ENODEV; | |
758 | } | |
759 | ||
760 | /* Found */ | |
761 | return 0; | |
762 | } | |
763 | ||
764 | static struct kobject *gsmi_kobj; | |
765 | static struct efivars efivars; | |
766 | ||
536dc1eb RK |
767 | static const struct platform_device_info gsmi_dev_info = { |
768 | .name = "gsmi", | |
769 | .id = -1, | |
770 | /* SMI callbacks require 32bit addresses */ | |
771 | .dma_mask = DMA_BIT_MASK(32), | |
772 | }; | |
773 | ||
74c5b31c MW |
774 | static __init int gsmi_init(void) |
775 | { | |
776 | unsigned long flags; | |
777 | int ret; | |
778 | ||
779 | ret = gsmi_system_valid(); | |
780 | if (ret) | |
781 | return ret; | |
782 | ||
783 | gsmi_dev.smi_cmd = acpi_gbl_FADT.smi_command; | |
784 | ||
785 | /* register device */ | |
536dc1eb | 786 | gsmi_dev.pdev = platform_device_register_full(&gsmi_dev_info); |
74c5b31c MW |
787 | if (IS_ERR(gsmi_dev.pdev)) { |
788 | printk(KERN_ERR "gsmi: unable to register platform device\n"); | |
789 | return PTR_ERR(gsmi_dev.pdev); | |
790 | } | |
791 | ||
792 | /* SMI access needs to be serialized */ | |
793 | spin_lock_init(&gsmi_dev.lock); | |
794 | ||
74c5b31c MW |
795 | ret = -ENOMEM; |
796 | gsmi_dev.dma_pool = dma_pool_create("gsmi", &gsmi_dev.pdev->dev, | |
797 | GSMI_BUF_SIZE, GSMI_BUF_ALIGN, 0); | |
798 | if (!gsmi_dev.dma_pool) | |
799 | goto out_err; | |
800 | ||
801 | /* | |
802 | * pre-allocate buffers because sometimes we are called when | |
803 | * this is not feasible: oops, panic, die, mce, etc | |
804 | */ | |
805 | gsmi_dev.name_buf = gsmi_buf_alloc(); | |
806 | if (!gsmi_dev.name_buf) { | |
807 | printk(KERN_ERR "gsmi: failed to allocate name buffer\n"); | |
808 | goto out_err; | |
809 | } | |
810 | ||
811 | gsmi_dev.data_buf = gsmi_buf_alloc(); | |
812 | if (!gsmi_dev.data_buf) { | |
813 | printk(KERN_ERR "gsmi: failed to allocate data buffer\n"); | |
814 | goto out_err; | |
815 | } | |
816 | ||
817 | gsmi_dev.param_buf = gsmi_buf_alloc(); | |
818 | if (!gsmi_dev.param_buf) { | |
819 | printk(KERN_ERR "gsmi: failed to allocate param buffer\n"); | |
820 | goto out_err; | |
821 | } | |
822 | ||
823 | /* | |
824 | * Determine type of handshake used to serialize the SMI | |
825 | * entry. See also gsmi_exec(). | |
826 | * | |
827 | * There's a "behavior" present on some chipsets where writing the | |
828 | * SMI trigger register in the southbridge doesn't result in an | |
829 | * immediate SMI. Rather, the processor can execute "a few" more | |
830 | * instructions before the SMI takes effect. To ensure synchronous | |
831 | * behavior, implement a handshake between the kernel driver and the | |
832 | * firmware handler to spin until released. This ioctl determines | |
833 | * the type of handshake. | |
834 | * | |
835 | * NONE: The firmware handler does not implement any | |
836 | * handshake. Either it doesn't need to, or it's legacy firmware | |
837 | * that doesn't know it needs to and never will. | |
838 | * | |
839 | * CF: The firmware handler will clear the CF in the saved | |
840 | * state before returning. The driver may set the CF and test for | |
841 | * it to clear before proceeding. | |
842 | * | |
843 | * SPIN: The firmware handler does not implement any handshake | |
844 | * but the driver should spin for a hundred or so microseconds | |
845 | * to ensure the SMI has triggered. | |
846 | * | |
847 | * Finally, the handler will return -ENOSYS if | |
848 | * GSMI_CMD_HANDSHAKE_TYPE is unimplemented, which implies | |
849 | * HANDSHAKE_NONE. | |
850 | */ | |
851 | spin_lock_irqsave(&gsmi_dev.lock, flags); | |
852 | gsmi_dev.handshake_type = GSMI_HANDSHAKE_SPIN; | |
853 | gsmi_dev.handshake_type = | |
854 | gsmi_exec(GSMI_CALLBACK, GSMI_CMD_HANDSHAKE_TYPE); | |
855 | if (gsmi_dev.handshake_type == -ENOSYS) | |
856 | gsmi_dev.handshake_type = GSMI_HANDSHAKE_NONE; | |
857 | spin_unlock_irqrestore(&gsmi_dev.lock, flags); | |
858 | ||
859 | /* Remove and clean up gsmi if the handshake could not complete. */ | |
860 | if (gsmi_dev.handshake_type == -ENXIO) { | |
861 | printk(KERN_INFO "gsmi version " DRIVER_VERSION | |
862 | " failed to load\n"); | |
863 | ret = -ENODEV; | |
864 | goto out_err; | |
865 | } | |
866 | ||
74c5b31c MW |
867 | /* Register in the firmware directory */ |
868 | ret = -ENOMEM; | |
869 | gsmi_kobj = kobject_create_and_add("gsmi", firmware_kobj); | |
870 | if (!gsmi_kobj) { | |
871 | printk(KERN_INFO "gsmi: Failed to create firmware kobj\n"); | |
872 | goto out_err; | |
873 | } | |
874 | ||
875 | /* Setup eventlog access */ | |
876 | ret = sysfs_create_bin_file(gsmi_kobj, &eventlog_bin_attr); | |
877 | if (ret) { | |
878 | printk(KERN_INFO "gsmi: Failed to setup eventlog"); | |
879 | goto out_err; | |
880 | } | |
881 | ||
882 | /* Other attributes */ | |
883 | ret = sysfs_create_files(gsmi_kobj, gsmi_attrs); | |
884 | if (ret) { | |
885 | printk(KERN_INFO "gsmi: Failed to add attrs"); | |
1e4de816 | 886 | goto out_remove_bin_file; |
74c5b31c MW |
887 | } |
888 | ||
e14ab23d | 889 | ret = efivars_register(&efivars, &efivar_ops, gsmi_kobj); |
1e4de816 | 890 | if (ret) { |
74c5b31c | 891 | printk(KERN_INFO "gsmi: Failed to register efivars\n"); |
1e4de816 | 892 | goto out_remove_sysfs_files; |
74c5b31c MW |
893 | } |
894 | ||
895 | register_reboot_notifier(&gsmi_reboot_notifier); | |
896 | register_die_notifier(&gsmi_die_notifier); | |
897 | atomic_notifier_chain_register(&panic_notifier_list, | |
898 | &gsmi_panic_notifier); | |
899 | ||
1e4de816 AL |
900 | printk(KERN_INFO "gsmi version " DRIVER_VERSION " loaded\n"); |
901 | ||
74c5b31c MW |
902 | return 0; |
903 | ||
1e4de816 AL |
904 | out_remove_sysfs_files: |
905 | sysfs_remove_files(gsmi_kobj, gsmi_attrs); | |
906 | out_remove_bin_file: | |
907 | sysfs_remove_bin_file(gsmi_kobj, &eventlog_bin_attr); | |
908 | out_err: | |
74c5b31c MW |
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); | |
e14ab23d | 926 | efivars_unregister(&efivars); |
74c5b31c | 927 | |
1e4de816 AL |
928 | sysfs_remove_files(gsmi_kobj, gsmi_attrs); |
929 | sysfs_remove_bin_file(gsmi_kobj, &eventlog_bin_attr); | |
74c5b31c MW |
930 | kobject_put(gsmi_kobj); |
931 | gsmi_buf_free(gsmi_dev.param_buf); | |
932 | gsmi_buf_free(gsmi_dev.data_buf); | |
933 | gsmi_buf_free(gsmi_dev.name_buf); | |
934 | dma_pool_destroy(gsmi_dev.dma_pool); | |
935 | platform_device_unregister(gsmi_dev.pdev); | |
936 | } | |
937 | ||
938 | module_init(gsmi_init); | |
939 | module_exit(gsmi_exit); | |
940 | ||
941 | MODULE_AUTHOR("Google, Inc."); | |
942 | MODULE_LICENSE("GPL"); |