Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
8cfb0cdf LZ |
2 | /* |
3 | * ACPI AML interfacing support | |
4 | * | |
5 | * Copyright (C) 2015, Intel Corporation | |
6 | * Authors: Lv Zheng <lv.zheng@intel.com> | |
8cfb0cdf LZ |
7 | */ |
8 | ||
9 | /* #define DEBUG */ | |
b6aeab44 | 10 | #define pr_fmt(fmt) "ACPI: AML: " fmt |
8cfb0cdf LZ |
11 | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/wait.h> | |
15 | #include <linux/poll.h> | |
16 | #include <linux/sched.h> | |
17 | #include <linux/kthread.h> | |
18 | #include <linux/proc_fs.h> | |
19 | #include <linux/debugfs.h> | |
20 | #include <linux/circ_buf.h> | |
836d0830 | 21 | #include <linux/acpi.h> |
8cfb0cdf LZ |
22 | #include "internal.h" |
23 | ||
24 | #define ACPI_AML_BUF_ALIGN (sizeof (acpi_size)) | |
25 | #define ACPI_AML_BUF_SIZE PAGE_SIZE | |
26 | ||
27 | #define circ_count(circ) \ | |
28 | (CIRC_CNT((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE)) | |
29 | #define circ_count_to_end(circ) \ | |
30 | (CIRC_CNT_TO_END((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE)) | |
31 | #define circ_space(circ) \ | |
32 | (CIRC_SPACE((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE)) | |
33 | #define circ_space_to_end(circ) \ | |
34 | (CIRC_SPACE_TO_END((circ)->head, (circ)->tail, ACPI_AML_BUF_SIZE)) | |
35 | ||
36 | #define ACPI_AML_OPENED 0x0001 | |
37 | #define ACPI_AML_CLOSED 0x0002 | |
38 | #define ACPI_AML_IN_USER 0x0004 /* user space is writing cmd */ | |
39 | #define ACPI_AML_IN_KERN 0x0008 /* kernel space is reading cmd */ | |
40 | #define ACPI_AML_OUT_USER 0x0010 /* user space is reading log */ | |
41 | #define ACPI_AML_OUT_KERN 0x0020 /* kernel space is writing log */ | |
42 | #define ACPI_AML_USER (ACPI_AML_IN_USER | ACPI_AML_OUT_USER) | |
43 | #define ACPI_AML_KERN (ACPI_AML_IN_KERN | ACPI_AML_OUT_KERN) | |
44 | #define ACPI_AML_BUSY (ACPI_AML_USER | ACPI_AML_KERN) | |
45 | #define ACPI_AML_OPEN (ACPI_AML_OPENED | ACPI_AML_CLOSED) | |
46 | ||
47 | struct acpi_aml_io { | |
48 | wait_queue_head_t wait; | |
49 | unsigned long flags; | |
50 | unsigned long users; | |
51 | struct mutex lock; | |
52 | struct task_struct *thread; | |
53 | char out_buf[ACPI_AML_BUF_SIZE] __aligned(ACPI_AML_BUF_ALIGN); | |
54 | struct circ_buf out_crc; | |
55 | char in_buf[ACPI_AML_BUF_SIZE] __aligned(ACPI_AML_BUF_ALIGN); | |
56 | struct circ_buf in_crc; | |
57 | acpi_osd_exec_callback function; | |
58 | void *context; | |
59 | unsigned long usages; | |
60 | }; | |
61 | ||
62 | static struct acpi_aml_io acpi_aml_io; | |
63 | static bool acpi_aml_initialized; | |
64 | static struct file *acpi_aml_active_reader; | |
65 | static struct dentry *acpi_aml_dentry; | |
66 | ||
67 | static inline bool __acpi_aml_running(void) | |
68 | { | |
69 | return acpi_aml_io.thread ? true : false; | |
70 | } | |
71 | ||
72 | static inline bool __acpi_aml_access_ok(unsigned long flag) | |
73 | { | |
74 | /* | |
75 | * The debugger interface is in opened state (OPENED && !CLOSED), | |
76 | * then it is allowed to access the debugger buffers from either | |
77 | * user space or the kernel space. | |
78 | * In addition, for the kernel space, only the debugger thread | |
79 | * (thread ID matched) is allowed to access. | |
80 | */ | |
81 | if (!(acpi_aml_io.flags & ACPI_AML_OPENED) || | |
82 | (acpi_aml_io.flags & ACPI_AML_CLOSED) || | |
83 | !__acpi_aml_running()) | |
84 | return false; | |
85 | if ((flag & ACPI_AML_KERN) && | |
86 | current != acpi_aml_io.thread) | |
87 | return false; | |
88 | return true; | |
89 | } | |
90 | ||
91 | static inline bool __acpi_aml_readable(struct circ_buf *circ, unsigned long flag) | |
92 | { | |
93 | /* | |
94 | * Another read is not in progress and there is data in buffer | |
95 | * available for read. | |
96 | */ | |
97 | if (!(acpi_aml_io.flags & flag) && circ_count(circ)) | |
98 | return true; | |
99 | return false; | |
100 | } | |
101 | ||
102 | static inline bool __acpi_aml_writable(struct circ_buf *circ, unsigned long flag) | |
103 | { | |
104 | /* | |
105 | * Another write is not in progress and there is buffer space | |
106 | * available for write. | |
107 | */ | |
108 | if (!(acpi_aml_io.flags & flag) && circ_space(circ)) | |
109 | return true; | |
110 | return false; | |
111 | } | |
112 | ||
113 | static inline bool __acpi_aml_busy(void) | |
114 | { | |
115 | if (acpi_aml_io.flags & ACPI_AML_BUSY) | |
116 | return true; | |
117 | return false; | |
118 | } | |
119 | ||
8cfb0cdf LZ |
120 | static inline bool __acpi_aml_used(void) |
121 | { | |
122 | return acpi_aml_io.usages ? true : false; | |
123 | } | |
124 | ||
125 | static inline bool acpi_aml_running(void) | |
126 | { | |
127 | bool ret; | |
128 | ||
129 | mutex_lock(&acpi_aml_io.lock); | |
130 | ret = __acpi_aml_running(); | |
131 | mutex_unlock(&acpi_aml_io.lock); | |
132 | return ret; | |
133 | } | |
134 | ||
135 | static bool acpi_aml_busy(void) | |
136 | { | |
137 | bool ret; | |
138 | ||
139 | mutex_lock(&acpi_aml_io.lock); | |
140 | ret = __acpi_aml_busy(); | |
141 | mutex_unlock(&acpi_aml_io.lock); | |
142 | return ret; | |
143 | } | |
144 | ||
145 | static bool acpi_aml_used(void) | |
146 | { | |
147 | bool ret; | |
148 | ||
149 | /* | |
150 | * The usage count is prepared to avoid race conditions between the | |
151 | * starts and the stops of the debugger thread. | |
152 | */ | |
153 | mutex_lock(&acpi_aml_io.lock); | |
154 | ret = __acpi_aml_used(); | |
155 | mutex_unlock(&acpi_aml_io.lock); | |
156 | return ret; | |
157 | } | |
158 | ||
159 | static bool acpi_aml_kern_readable(void) | |
160 | { | |
161 | bool ret; | |
162 | ||
163 | mutex_lock(&acpi_aml_io.lock); | |
164 | ret = !__acpi_aml_access_ok(ACPI_AML_IN_KERN) || | |
165 | __acpi_aml_readable(&acpi_aml_io.in_crc, ACPI_AML_IN_KERN); | |
166 | mutex_unlock(&acpi_aml_io.lock); | |
167 | return ret; | |
168 | } | |
169 | ||
170 | static bool acpi_aml_kern_writable(void) | |
171 | { | |
172 | bool ret; | |
173 | ||
174 | mutex_lock(&acpi_aml_io.lock); | |
175 | ret = !__acpi_aml_access_ok(ACPI_AML_OUT_KERN) || | |
176 | __acpi_aml_writable(&acpi_aml_io.out_crc, ACPI_AML_OUT_KERN); | |
177 | mutex_unlock(&acpi_aml_io.lock); | |
178 | return ret; | |
179 | } | |
180 | ||
181 | static bool acpi_aml_user_readable(void) | |
182 | { | |
183 | bool ret; | |
184 | ||
185 | mutex_lock(&acpi_aml_io.lock); | |
186 | ret = !__acpi_aml_access_ok(ACPI_AML_OUT_USER) || | |
187 | __acpi_aml_readable(&acpi_aml_io.out_crc, ACPI_AML_OUT_USER); | |
188 | mutex_unlock(&acpi_aml_io.lock); | |
189 | return ret; | |
190 | } | |
191 | ||
192 | static bool acpi_aml_user_writable(void) | |
193 | { | |
194 | bool ret; | |
195 | ||
196 | mutex_lock(&acpi_aml_io.lock); | |
197 | ret = !__acpi_aml_access_ok(ACPI_AML_IN_USER) || | |
198 | __acpi_aml_writable(&acpi_aml_io.in_crc, ACPI_AML_IN_USER); | |
199 | mutex_unlock(&acpi_aml_io.lock); | |
200 | return ret; | |
201 | } | |
202 | ||
203 | static int acpi_aml_lock_write(struct circ_buf *circ, unsigned long flag) | |
204 | { | |
205 | int ret = 0; | |
206 | ||
207 | mutex_lock(&acpi_aml_io.lock); | |
208 | if (!__acpi_aml_access_ok(flag)) { | |
209 | ret = -EFAULT; | |
210 | goto out; | |
211 | } | |
212 | if (!__acpi_aml_writable(circ, flag)) { | |
213 | ret = -EAGAIN; | |
214 | goto out; | |
215 | } | |
216 | acpi_aml_io.flags |= flag; | |
217 | out: | |
218 | mutex_unlock(&acpi_aml_io.lock); | |
219 | return ret; | |
220 | } | |
221 | ||
222 | static int acpi_aml_lock_read(struct circ_buf *circ, unsigned long flag) | |
223 | { | |
224 | int ret = 0; | |
225 | ||
226 | mutex_lock(&acpi_aml_io.lock); | |
227 | if (!__acpi_aml_access_ok(flag)) { | |
228 | ret = -EFAULT; | |
229 | goto out; | |
230 | } | |
231 | if (!__acpi_aml_readable(circ, flag)) { | |
232 | ret = -EAGAIN; | |
233 | goto out; | |
234 | } | |
235 | acpi_aml_io.flags |= flag; | |
236 | out: | |
237 | mutex_unlock(&acpi_aml_io.lock); | |
238 | return ret; | |
239 | } | |
240 | ||
241 | static void acpi_aml_unlock_fifo(unsigned long flag, bool wakeup) | |
242 | { | |
243 | mutex_lock(&acpi_aml_io.lock); | |
244 | acpi_aml_io.flags &= ~flag; | |
245 | if (wakeup) | |
246 | wake_up_interruptible(&acpi_aml_io.wait); | |
247 | mutex_unlock(&acpi_aml_io.lock); | |
248 | } | |
249 | ||
250 | static int acpi_aml_write_kern(const char *buf, int len) | |
251 | { | |
252 | int ret; | |
253 | struct circ_buf *crc = &acpi_aml_io.out_crc; | |
254 | int n; | |
255 | char *p; | |
256 | ||
257 | ret = acpi_aml_lock_write(crc, ACPI_AML_OUT_KERN); | |
287980e4 | 258 | if (ret < 0) |
8cfb0cdf LZ |
259 | return ret; |
260 | /* sync tail before inserting logs */ | |
261 | smp_mb(); | |
262 | p = &crc->buf[crc->head]; | |
263 | n = min(len, circ_space_to_end(crc)); | |
264 | memcpy(p, buf, n); | |
265 | /* sync head after inserting logs */ | |
266 | smp_wmb(); | |
267 | crc->head = (crc->head + n) & (ACPI_AML_BUF_SIZE - 1); | |
268 | acpi_aml_unlock_fifo(ACPI_AML_OUT_KERN, true); | |
269 | return n; | |
270 | } | |
271 | ||
272 | static int acpi_aml_readb_kern(void) | |
273 | { | |
274 | int ret; | |
275 | struct circ_buf *crc = &acpi_aml_io.in_crc; | |
276 | char *p; | |
277 | ||
278 | ret = acpi_aml_lock_read(crc, ACPI_AML_IN_KERN); | |
287980e4 | 279 | if (ret < 0) |
8cfb0cdf LZ |
280 | return ret; |
281 | /* sync head before removing cmds */ | |
282 | smp_rmb(); | |
283 | p = &crc->buf[crc->tail]; | |
284 | ret = (int)*p; | |
285 | /* sync tail before inserting cmds */ | |
286 | smp_mb(); | |
287 | crc->tail = (crc->tail + 1) & (ACPI_AML_BUF_SIZE - 1); | |
288 | acpi_aml_unlock_fifo(ACPI_AML_IN_KERN, true); | |
289 | return ret; | |
290 | } | |
291 | ||
292 | /* | |
293 | * acpi_aml_write_log() - Capture debugger output | |
294 | * @msg: the debugger output | |
295 | * | |
296 | * This function should be used to implement acpi_os_printf() to filter out | |
297 | * the debugger output and store the output into the debugger interface | |
298 | * buffer. Return the size of stored logs or errno. | |
299 | */ | |
836d0830 | 300 | static ssize_t acpi_aml_write_log(const char *msg) |
8cfb0cdf LZ |
301 | { |
302 | int ret = 0; | |
303 | int count = 0, size = 0; | |
304 | ||
305 | if (!acpi_aml_initialized) | |
306 | return -ENODEV; | |
307 | if (msg) | |
308 | count = strlen(msg); | |
309 | while (count > 0) { | |
310 | again: | |
311 | ret = acpi_aml_write_kern(msg + size, count); | |
312 | if (ret == -EAGAIN) { | |
313 | ret = wait_event_interruptible(acpi_aml_io.wait, | |
314 | acpi_aml_kern_writable()); | |
315 | /* | |
316 | * We need to retry when the condition | |
317 | * becomes true. | |
318 | */ | |
319 | if (ret == 0) | |
320 | goto again; | |
321 | break; | |
322 | } | |
287980e4 | 323 | if (ret < 0) |
8cfb0cdf LZ |
324 | break; |
325 | size += ret; | |
326 | count -= ret; | |
327 | } | |
328 | return size > 0 ? size : ret; | |
329 | } | |
8cfb0cdf LZ |
330 | |
331 | /* | |
332 | * acpi_aml_read_cmd() - Capture debugger input | |
333 | * @msg: the debugger input | |
334 | * @size: the size of the debugger input | |
335 | * | |
336 | * This function should be used to implement acpi_os_get_line() to capture | |
337 | * the debugger input commands and store the input commands into the | |
338 | * debugger interface buffer. Return the size of stored commands or errno. | |
339 | */ | |
836d0830 | 340 | static ssize_t acpi_aml_read_cmd(char *msg, size_t count) |
8cfb0cdf LZ |
341 | { |
342 | int ret = 0; | |
343 | int size = 0; | |
344 | ||
345 | /* | |
346 | * This is ensured by the running fact of the debugger thread | |
347 | * unless a bug is introduced. | |
348 | */ | |
349 | BUG_ON(!acpi_aml_initialized); | |
350 | while (count > 0) { | |
351 | again: | |
352 | /* | |
353 | * Check each input byte to find the end of the command. | |
354 | */ | |
355 | ret = acpi_aml_readb_kern(); | |
356 | if (ret == -EAGAIN) { | |
357 | ret = wait_event_interruptible(acpi_aml_io.wait, | |
358 | acpi_aml_kern_readable()); | |
359 | /* | |
360 | * We need to retry when the condition becomes | |
361 | * true. | |
362 | */ | |
363 | if (ret == 0) | |
364 | goto again; | |
365 | } | |
287980e4 | 366 | if (ret < 0) |
8cfb0cdf LZ |
367 | break; |
368 | *(msg + size) = (char)ret; | |
369 | size++; | |
370 | count--; | |
371 | if (ret == '\n') { | |
372 | /* | |
373 | * acpi_os_get_line() requires a zero terminated command | |
374 | * string. | |
375 | */ | |
376 | *(msg + size - 1) = '\0'; | |
377 | break; | |
378 | } | |
379 | } | |
380 | return size > 0 ? size : ret; | |
381 | } | |
8cfb0cdf | 382 | |
603fadf3 | 383 | static int acpi_aml_thread(void *unused) |
8cfb0cdf LZ |
384 | { |
385 | acpi_osd_exec_callback function = NULL; | |
386 | void *context; | |
387 | ||
388 | mutex_lock(&acpi_aml_io.lock); | |
389 | if (acpi_aml_io.function) { | |
390 | acpi_aml_io.usages++; | |
391 | function = acpi_aml_io.function; | |
392 | context = acpi_aml_io.context; | |
393 | } | |
394 | mutex_unlock(&acpi_aml_io.lock); | |
395 | ||
396 | if (function) | |
397 | function(context); | |
398 | ||
399 | mutex_lock(&acpi_aml_io.lock); | |
400 | acpi_aml_io.usages--; | |
401 | if (!__acpi_aml_used()) { | |
402 | acpi_aml_io.thread = NULL; | |
403 | wake_up(&acpi_aml_io.wait); | |
404 | } | |
405 | mutex_unlock(&acpi_aml_io.lock); | |
406 | ||
407 | return 0; | |
408 | } | |
409 | ||
410 | /* | |
411 | * acpi_aml_create_thread() - Create AML debugger thread | |
412 | * @function: the debugger thread callback | |
413 | * @context: the context to be passed to the debugger thread | |
414 | * | |
415 | * This function should be used to implement acpi_os_execute() which is | |
416 | * used by the ACPICA debugger to create the debugger thread. | |
417 | */ | |
836d0830 | 418 | static int acpi_aml_create_thread(acpi_osd_exec_callback function, void *context) |
8cfb0cdf LZ |
419 | { |
420 | struct task_struct *t; | |
421 | ||
422 | mutex_lock(&acpi_aml_io.lock); | |
423 | acpi_aml_io.function = function; | |
424 | acpi_aml_io.context = context; | |
425 | mutex_unlock(&acpi_aml_io.lock); | |
426 | ||
427 | t = kthread_create(acpi_aml_thread, NULL, "aml"); | |
428 | if (IS_ERR(t)) { | |
429 | pr_err("Failed to create AML debugger thread.\n"); | |
430 | return PTR_ERR(t); | |
431 | } | |
432 | ||
433 | mutex_lock(&acpi_aml_io.lock); | |
434 | acpi_aml_io.thread = t; | |
435 | acpi_set_debugger_thread_id((acpi_thread_id)(unsigned long)t); | |
436 | wake_up_process(t); | |
437 | mutex_unlock(&acpi_aml_io.lock); | |
438 | return 0; | |
439 | } | |
8cfb0cdf | 440 | |
836d0830 LZ |
441 | static int acpi_aml_wait_command_ready(bool single_step, |
442 | char *buffer, size_t length) | |
8cfb0cdf LZ |
443 | { |
444 | acpi_status status; | |
445 | ||
836d0830 | 446 | if (single_step) |
8cfb0cdf | 447 | acpi_os_printf("\n%1c ", ACPI_DEBUGGER_EXECUTE_PROMPT); |
836d0830 LZ |
448 | else |
449 | acpi_os_printf("\n%1c ", ACPI_DEBUGGER_COMMAND_PROMPT); | |
8cfb0cdf | 450 | |
836d0830 | 451 | status = acpi_os_get_line(buffer, length, NULL); |
8cfb0cdf LZ |
452 | if (ACPI_FAILURE(status)) |
453 | return -EINVAL; | |
454 | return 0; | |
455 | } | |
8cfb0cdf | 456 | |
836d0830 | 457 | static int acpi_aml_notify_command_complete(void) |
8cfb0cdf LZ |
458 | { |
459 | return 0; | |
460 | } | |
8cfb0cdf LZ |
461 | |
462 | static int acpi_aml_open(struct inode *inode, struct file *file) | |
463 | { | |
464 | int ret = 0; | |
465 | acpi_status status; | |
466 | ||
467 | mutex_lock(&acpi_aml_io.lock); | |
468 | /* | |
469 | * The debugger interface is being closed, no new user is allowed | |
470 | * during this period. | |
471 | */ | |
472 | if (acpi_aml_io.flags & ACPI_AML_CLOSED) { | |
473 | ret = -EBUSY; | |
474 | goto err_lock; | |
475 | } | |
476 | if ((file->f_flags & O_ACCMODE) != O_WRONLY) { | |
477 | /* | |
478 | * Only one reader is allowed to initiate the debugger | |
479 | * thread. | |
480 | */ | |
481 | if (acpi_aml_active_reader) { | |
482 | ret = -EBUSY; | |
483 | goto err_lock; | |
484 | } else { | |
485 | pr_debug("Opening debugger reader.\n"); | |
486 | acpi_aml_active_reader = file; | |
487 | } | |
488 | } else { | |
489 | /* | |
490 | * No writer is allowed unless the debugger thread is | |
491 | * ready. | |
492 | */ | |
493 | if (!(acpi_aml_io.flags & ACPI_AML_OPENED)) { | |
494 | ret = -ENODEV; | |
495 | goto err_lock; | |
496 | } | |
497 | } | |
498 | if (acpi_aml_active_reader == file) { | |
499 | pr_debug("Opening debugger interface.\n"); | |
500 | mutex_unlock(&acpi_aml_io.lock); | |
501 | ||
502 | pr_debug("Initializing debugger thread.\n"); | |
503 | status = acpi_initialize_debugger(); | |
504 | if (ACPI_FAILURE(status)) { | |
505 | pr_err("Failed to initialize debugger.\n"); | |
506 | ret = -EINVAL; | |
59adb398 | 507 | goto err_exit; |
8cfb0cdf | 508 | } |
8cfb0cdf LZ |
509 | pr_debug("Debugger thread initialized.\n"); |
510 | ||
511 | mutex_lock(&acpi_aml_io.lock); | |
73af2d59 | 512 | acpi_aml_io.flags |= ACPI_AML_OPENED; |
8cfb0cdf LZ |
513 | acpi_aml_io.out_crc.head = acpi_aml_io.out_crc.tail = 0; |
514 | acpi_aml_io.in_crc.head = acpi_aml_io.in_crc.tail = 0; | |
515 | pr_debug("Debugger interface opened.\n"); | |
516 | } | |
517 | acpi_aml_io.users++; | |
518 | err_lock: | |
287980e4 | 519 | if (ret < 0) { |
8cfb0cdf LZ |
520 | if (acpi_aml_active_reader == file) |
521 | acpi_aml_active_reader = NULL; | |
522 | } | |
523 | mutex_unlock(&acpi_aml_io.lock); | |
59adb398 | 524 | err_exit: |
8cfb0cdf LZ |
525 | return ret; |
526 | } | |
527 | ||
528 | static int acpi_aml_release(struct inode *inode, struct file *file) | |
529 | { | |
530 | mutex_lock(&acpi_aml_io.lock); | |
531 | acpi_aml_io.users--; | |
532 | if (file == acpi_aml_active_reader) { | |
533 | pr_debug("Closing debugger reader.\n"); | |
534 | acpi_aml_active_reader = NULL; | |
535 | ||
536 | pr_debug("Closing debugger interface.\n"); | |
537 | acpi_aml_io.flags |= ACPI_AML_CLOSED; | |
538 | ||
539 | /* | |
540 | * Wake up all user space/kernel space blocked | |
541 | * readers/writers. | |
542 | */ | |
543 | wake_up_interruptible(&acpi_aml_io.wait); | |
544 | mutex_unlock(&acpi_aml_io.lock); | |
545 | /* | |
546 | * Wait all user space/kernel space readers/writers to | |
547 | * stop so that ACPICA command loop of the debugger thread | |
548 | * should fail all its command line reads after this point. | |
549 | */ | |
550 | wait_event(acpi_aml_io.wait, !acpi_aml_busy()); | |
551 | ||
552 | /* | |
553 | * Then we try to terminate the debugger thread if it is | |
554 | * not terminated. | |
555 | */ | |
556 | pr_debug("Terminating debugger thread.\n"); | |
557 | acpi_terminate_debugger(); | |
558 | wait_event(acpi_aml_io.wait, !acpi_aml_used()); | |
559 | pr_debug("Debugger thread terminated.\n"); | |
560 | ||
561 | mutex_lock(&acpi_aml_io.lock); | |
562 | acpi_aml_io.flags &= ~ACPI_AML_OPENED; | |
563 | } | |
564 | if (acpi_aml_io.users == 0) { | |
565 | pr_debug("Debugger interface closed.\n"); | |
566 | acpi_aml_io.flags &= ~ACPI_AML_CLOSED; | |
567 | } | |
568 | mutex_unlock(&acpi_aml_io.lock); | |
569 | return 0; | |
570 | } | |
571 | ||
572 | static int acpi_aml_read_user(char __user *buf, int len) | |
573 | { | |
574 | int ret; | |
575 | struct circ_buf *crc = &acpi_aml_io.out_crc; | |
576 | int n; | |
577 | char *p; | |
578 | ||
579 | ret = acpi_aml_lock_read(crc, ACPI_AML_OUT_USER); | |
287980e4 | 580 | if (ret < 0) |
8cfb0cdf LZ |
581 | return ret; |
582 | /* sync head before removing logs */ | |
583 | smp_rmb(); | |
584 | p = &crc->buf[crc->tail]; | |
585 | n = min(len, circ_count_to_end(crc)); | |
ec74765d DC |
586 | if (copy_to_user(buf, p, n)) { |
587 | ret = -EFAULT; | |
8cfb0cdf | 588 | goto out; |
ec74765d | 589 | } |
8cfb0cdf LZ |
590 | /* sync tail after removing logs */ |
591 | smp_mb(); | |
592 | crc->tail = (crc->tail + n) & (ACPI_AML_BUF_SIZE - 1); | |
593 | ret = n; | |
594 | out: | |
7e3fd813 | 595 | acpi_aml_unlock_fifo(ACPI_AML_OUT_USER, ret >= 0); |
8cfb0cdf LZ |
596 | return ret; |
597 | } | |
598 | ||
599 | static ssize_t acpi_aml_read(struct file *file, char __user *buf, | |
600 | size_t count, loff_t *ppos) | |
601 | { | |
602 | int ret = 0; | |
603 | int size = 0; | |
604 | ||
8cfb0cdf LZ |
605 | if (!count) |
606 | return 0; | |
96d4f267 | 607 | if (!access_ok(buf, count)) |
8cfb0cdf LZ |
608 | return -EFAULT; |
609 | ||
610 | while (count > 0) { | |
611 | again: | |
612 | ret = acpi_aml_read_user(buf + size, count); | |
613 | if (ret == -EAGAIN) { | |
614 | if (file->f_flags & O_NONBLOCK) | |
615 | break; | |
616 | else { | |
617 | ret = wait_event_interruptible(acpi_aml_io.wait, | |
618 | acpi_aml_user_readable()); | |
619 | /* | |
620 | * We need to retry when the condition | |
621 | * becomes true. | |
622 | */ | |
623 | if (ret == 0) | |
624 | goto again; | |
625 | } | |
626 | } | |
287980e4 | 627 | if (ret < 0) { |
8cfb0cdf LZ |
628 | if (!acpi_aml_running()) |
629 | ret = 0; | |
630 | break; | |
631 | } | |
632 | if (ret) { | |
633 | size += ret; | |
634 | count -= ret; | |
635 | *ppos += ret; | |
636 | break; | |
637 | } | |
638 | } | |
639 | return size > 0 ? size : ret; | |
640 | } | |
641 | ||
642 | static int acpi_aml_write_user(const char __user *buf, int len) | |
643 | { | |
644 | int ret; | |
645 | struct circ_buf *crc = &acpi_aml_io.in_crc; | |
646 | int n; | |
647 | char *p; | |
648 | ||
649 | ret = acpi_aml_lock_write(crc, ACPI_AML_IN_USER); | |
287980e4 | 650 | if (ret < 0) |
8cfb0cdf LZ |
651 | return ret; |
652 | /* sync tail before inserting cmds */ | |
653 | smp_mb(); | |
654 | p = &crc->buf[crc->head]; | |
655 | n = min(len, circ_space_to_end(crc)); | |
ec74765d DC |
656 | if (copy_from_user(p, buf, n)) { |
657 | ret = -EFAULT; | |
8cfb0cdf | 658 | goto out; |
ec74765d | 659 | } |
8cfb0cdf LZ |
660 | /* sync head after inserting cmds */ |
661 | smp_wmb(); | |
662 | crc->head = (crc->head + n) & (ACPI_AML_BUF_SIZE - 1); | |
663 | ret = n; | |
664 | out: | |
7e3fd813 | 665 | acpi_aml_unlock_fifo(ACPI_AML_IN_USER, ret >= 0); |
8cfb0cdf LZ |
666 | return n; |
667 | } | |
668 | ||
669 | static ssize_t acpi_aml_write(struct file *file, const char __user *buf, | |
670 | size_t count, loff_t *ppos) | |
671 | { | |
672 | int ret = 0; | |
673 | int size = 0; | |
674 | ||
8cfb0cdf LZ |
675 | if (!count) |
676 | return 0; | |
96d4f267 | 677 | if (!access_ok(buf, count)) |
8cfb0cdf LZ |
678 | return -EFAULT; |
679 | ||
680 | while (count > 0) { | |
681 | again: | |
682 | ret = acpi_aml_write_user(buf + size, count); | |
683 | if (ret == -EAGAIN) { | |
684 | if (file->f_flags & O_NONBLOCK) | |
685 | break; | |
686 | else { | |
687 | ret = wait_event_interruptible(acpi_aml_io.wait, | |
688 | acpi_aml_user_writable()); | |
689 | /* | |
690 | * We need to retry when the condition | |
691 | * becomes true. | |
692 | */ | |
693 | if (ret == 0) | |
694 | goto again; | |
695 | } | |
696 | } | |
287980e4 | 697 | if (ret < 0) { |
8cfb0cdf LZ |
698 | if (!acpi_aml_running()) |
699 | ret = 0; | |
700 | break; | |
701 | } | |
702 | if (ret) { | |
703 | size += ret; | |
704 | count -= ret; | |
705 | *ppos += ret; | |
706 | } | |
707 | } | |
708 | return size > 0 ? size : ret; | |
709 | } | |
710 | ||
0d9b87f3 | 711 | static __poll_t acpi_aml_poll(struct file *file, poll_table *wait) |
8cfb0cdf | 712 | { |
0d9b87f3 | 713 | __poll_t masks = 0; |
8cfb0cdf LZ |
714 | |
715 | poll_wait(file, &acpi_aml_io.wait, wait); | |
716 | if (acpi_aml_user_readable()) | |
a9a08845 | 717 | masks |= EPOLLIN | EPOLLRDNORM; |
8cfb0cdf | 718 | if (acpi_aml_user_writable()) |
a9a08845 | 719 | masks |= EPOLLOUT | EPOLLWRNORM; |
8cfb0cdf LZ |
720 | |
721 | return masks; | |
722 | } | |
723 | ||
724 | static const struct file_operations acpi_aml_operations = { | |
725 | .read = acpi_aml_read, | |
726 | .write = acpi_aml_write, | |
727 | .poll = acpi_aml_poll, | |
728 | .open = acpi_aml_open, | |
729 | .release = acpi_aml_release, | |
730 | .llseek = generic_file_llseek, | |
731 | }; | |
732 | ||
836d0830 LZ |
733 | static const struct acpi_debugger_ops acpi_aml_debugger = { |
734 | .create_thread = acpi_aml_create_thread, | |
735 | .read_cmd = acpi_aml_read_cmd, | |
736 | .write_log = acpi_aml_write_log, | |
737 | .wait_command_ready = acpi_aml_wait_command_ready, | |
738 | .notify_command_complete = acpi_aml_notify_command_complete, | |
739 | }; | |
740 | ||
8e22c2e4 | 741 | static int __init acpi_aml_init(void) |
8cfb0cdf | 742 | { |
6010ce3f | 743 | int ret; |
836d0830 | 744 | |
0fada277 JI |
745 | if (acpi_disabled) |
746 | return -ENODEV; | |
747 | ||
8cfb0cdf LZ |
748 | /* Initialize AML IO interface */ |
749 | mutex_init(&acpi_aml_io.lock); | |
750 | init_waitqueue_head(&acpi_aml_io.wait); | |
751 | acpi_aml_io.out_crc.buf = acpi_aml_io.out_buf; | |
752 | acpi_aml_io.in_crc.buf = acpi_aml_io.in_buf; | |
6010ce3f | 753 | |
8cfb0cdf LZ |
754 | acpi_aml_dentry = debugfs_create_file("acpidbg", |
755 | S_IFREG | S_IRUGO | S_IWUSR, | |
756 | acpi_debugfs_dir, NULL, | |
757 | &acpi_aml_operations); | |
836d0830 | 758 | |
6010ce3f | 759 | ret = acpi_register_debugger(THIS_MODULE, &acpi_aml_debugger); |
836d0830 LZ |
760 | if (ret) { |
761 | debugfs_remove(acpi_aml_dentry); | |
762 | acpi_aml_dentry = NULL; | |
6010ce3f | 763 | return ret; |
836d0830 | 764 | } |
6010ce3f RW |
765 | |
766 | acpi_aml_initialized = true; | |
767 | return 0; | |
8cfb0cdf LZ |
768 | } |
769 | ||
8e22c2e4 | 770 | static void __exit acpi_aml_exit(void) |
8cfb0cdf | 771 | { |
836d0830 LZ |
772 | if (acpi_aml_initialized) { |
773 | acpi_unregister_debugger(&acpi_aml_debugger); | |
9ec6dbfb GKH |
774 | debugfs_remove(acpi_aml_dentry); |
775 | acpi_aml_dentry = NULL; | |
836d0830 LZ |
776 | acpi_aml_initialized = false; |
777 | } | |
8cfb0cdf LZ |
778 | } |
779 | ||
780 | module_init(acpi_aml_init); | |
781 | module_exit(acpi_aml_exit); | |
836d0830 LZ |
782 | |
783 | MODULE_AUTHOR("Lv Zheng"); | |
784 | MODULE_DESCRIPTION("ACPI debugger userspace IO driver"); | |
785 | MODULE_LICENSE("GPL"); |