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ba82664c AS |
1 | /* |
2 | * Intel(R) Trace Hub Memory Storage Unit | |
3 | * | |
4 | * Copyright (C) 2014-2015 Intel Corporation. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms and conditions of the GNU General Public License, | |
8 | * version 2, as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope it will be useful, but WITHOUT | |
11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
13 | * more details. | |
14 | */ | |
15 | ||
16 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
17 | ||
18 | #include <linux/types.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/device.h> | |
21 | #include <linux/uaccess.h> | |
22 | #include <linux/sizes.h> | |
23 | #include <linux/printk.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/mm.h> | |
26 | #include <linux/fs.h> | |
27 | #include <linux/io.h> | |
28 | #include <linux/dma-mapping.h> | |
29 | ||
30 | #include <asm/cacheflush.h> | |
31 | ||
32 | #include "intel_th.h" | |
33 | #include "msu.h" | |
34 | ||
35 | #define msc_dev(x) (&(x)->thdev->dev) | |
36 | ||
37 | /** | |
38 | * struct msc_block - multiblock mode block descriptor | |
39 | * @bdesc: pointer to hardware descriptor (beginning of the block) | |
40 | * @addr: physical address of the block | |
41 | */ | |
42 | struct msc_block { | |
43 | struct msc_block_desc *bdesc; | |
44 | dma_addr_t addr; | |
45 | }; | |
46 | ||
47 | /** | |
48 | * struct msc_window - multiblock mode window descriptor | |
49 | * @entry: window list linkage (msc::win_list) | |
50 | * @pgoff: page offset into the buffer that this window starts at | |
51 | * @nr_blocks: number of blocks (pages) in this window | |
52 | * @block: array of block descriptors | |
53 | */ | |
54 | struct msc_window { | |
55 | struct list_head entry; | |
56 | unsigned long pgoff; | |
57 | unsigned int nr_blocks; | |
58 | struct msc *msc; | |
59 | struct msc_block block[0]; | |
60 | }; | |
61 | ||
62 | /** | |
63 | * struct msc_iter - iterator for msc buffer | |
64 | * @entry: msc::iter_list linkage | |
65 | * @msc: pointer to the MSC device | |
66 | * @start_win: oldest window | |
67 | * @win: current window | |
68 | * @offset: current logical offset into the buffer | |
69 | * @start_block: oldest block in the window | |
70 | * @block: block number in the window | |
71 | * @block_off: offset into current block | |
72 | * @wrap_count: block wrapping handling | |
73 | * @eof: end of buffer reached | |
74 | */ | |
75 | struct msc_iter { | |
76 | struct list_head entry; | |
77 | struct msc *msc; | |
78 | struct msc_window *start_win; | |
79 | struct msc_window *win; | |
80 | unsigned long offset; | |
81 | int start_block; | |
82 | int block; | |
83 | unsigned int block_off; | |
84 | unsigned int wrap_count; | |
85 | unsigned int eof; | |
86 | }; | |
87 | ||
88 | /** | |
89 | * struct msc - MSC device representation | |
90 | * @reg_base: register window base address | |
91 | * @thdev: intel_th_device pointer | |
92 | * @win_list: list of windows in multiblock mode | |
93 | * @nr_pages: total number of pages allocated for this buffer | |
94 | * @single_sz: amount of data in single mode | |
95 | * @single_wrap: single mode wrap occurred | |
96 | * @base: buffer's base pointer | |
97 | * @base_addr: buffer's base address | |
98 | * @user_count: number of users of the buffer | |
99 | * @mmap_count: number of mappings | |
100 | * @buf_mutex: mutex to serialize access to buffer-related bits | |
101 | ||
102 | * @enabled: MSC is enabled | |
103 | * @wrap: wrapping is enabled | |
104 | * @mode: MSC operating mode | |
105 | * @burst_len: write burst length | |
106 | * @index: number of this MSC in the MSU | |
107 | */ | |
108 | struct msc { | |
109 | void __iomem *reg_base; | |
110 | struct intel_th_device *thdev; | |
111 | ||
112 | struct list_head win_list; | |
113 | unsigned long nr_pages; | |
114 | unsigned long single_sz; | |
115 | unsigned int single_wrap : 1; | |
116 | void *base; | |
117 | dma_addr_t base_addr; | |
118 | ||
119 | /* <0: no buffer, 0: no users, >0: active users */ | |
120 | atomic_t user_count; | |
121 | ||
122 | atomic_t mmap_count; | |
123 | struct mutex buf_mutex; | |
124 | ||
ba82664c AS |
125 | struct list_head iter_list; |
126 | ||
127 | /* config */ | |
128 | unsigned int enabled : 1, | |
129 | wrap : 1; | |
130 | unsigned int mode; | |
131 | unsigned int burst_len; | |
132 | unsigned int index; | |
133 | }; | |
134 | ||
135 | static inline bool msc_block_is_empty(struct msc_block_desc *bdesc) | |
136 | { | |
137 | /* header hasn't been written */ | |
138 | if (!bdesc->valid_dw) | |
139 | return true; | |
140 | ||
141 | /* valid_dw includes the header */ | |
142 | if (!msc_data_sz(bdesc)) | |
143 | return true; | |
144 | ||
145 | return false; | |
146 | } | |
147 | ||
148 | /** | |
149 | * msc_oldest_window() - locate the window with oldest data | |
150 | * @msc: MSC device | |
151 | * | |
152 | * This should only be used in multiblock mode. Caller should hold the | |
153 | * msc::user_count reference. | |
154 | * | |
155 | * Return: the oldest window with valid data | |
156 | */ | |
157 | static struct msc_window *msc_oldest_window(struct msc *msc) | |
158 | { | |
159 | struct msc_window *win; | |
160 | u32 reg = ioread32(msc->reg_base + REG_MSU_MSC0NWSA); | |
161 | unsigned long win_addr = (unsigned long)reg << PAGE_SHIFT; | |
162 | unsigned int found = 0; | |
163 | ||
164 | if (list_empty(&msc->win_list)) | |
165 | return NULL; | |
166 | ||
167 | /* | |
168 | * we might need a radix tree for this, depending on how | |
169 | * many windows a typical user would allocate; ideally it's | |
170 | * something like 2, in which case we're good | |
171 | */ | |
172 | list_for_each_entry(win, &msc->win_list, entry) { | |
173 | if (win->block[0].addr == win_addr) | |
174 | found++; | |
175 | ||
176 | /* skip the empty ones */ | |
177 | if (msc_block_is_empty(win->block[0].bdesc)) | |
178 | continue; | |
179 | ||
180 | if (found) | |
181 | return win; | |
182 | } | |
183 | ||
184 | return list_entry(msc->win_list.next, struct msc_window, entry); | |
185 | } | |
186 | ||
187 | /** | |
188 | * msc_win_oldest_block() - locate the oldest block in a given window | |
189 | * @win: window to look at | |
190 | * | |
191 | * Return: index of the block with the oldest data | |
192 | */ | |
193 | static unsigned int msc_win_oldest_block(struct msc_window *win) | |
194 | { | |
195 | unsigned int blk; | |
196 | struct msc_block_desc *bdesc = win->block[0].bdesc; | |
197 | ||
198 | /* without wrapping, first block is the oldest */ | |
199 | if (!msc_block_wrapped(bdesc)) | |
200 | return 0; | |
201 | ||
202 | /* | |
203 | * with wrapping, last written block contains both the newest and the | |
204 | * oldest data for this window. | |
205 | */ | |
206 | for (blk = 0; blk < win->nr_blocks; blk++) { | |
207 | bdesc = win->block[blk].bdesc; | |
208 | ||
209 | if (msc_block_last_written(bdesc)) | |
210 | return blk; | |
211 | } | |
212 | ||
213 | return 0; | |
214 | } | |
215 | ||
216 | /** | |
217 | * msc_is_last_win() - check if a window is the last one for a given MSC | |
218 | * @win: window | |
219 | * Return: true if @win is the last window in MSC's multiblock buffer | |
220 | */ | |
221 | static inline bool msc_is_last_win(struct msc_window *win) | |
222 | { | |
223 | return win->entry.next == &win->msc->win_list; | |
224 | } | |
225 | ||
226 | /** | |
227 | * msc_next_window() - return next window in the multiblock buffer | |
228 | * @win: current window | |
229 | * | |
230 | * Return: window following the current one | |
231 | */ | |
232 | static struct msc_window *msc_next_window(struct msc_window *win) | |
233 | { | |
234 | if (msc_is_last_win(win)) | |
235 | return list_entry(win->msc->win_list.next, struct msc_window, | |
236 | entry); | |
237 | ||
238 | return list_entry(win->entry.next, struct msc_window, entry); | |
239 | } | |
240 | ||
241 | static struct msc_block_desc *msc_iter_bdesc(struct msc_iter *iter) | |
242 | { | |
243 | return iter->win->block[iter->block].bdesc; | |
244 | } | |
245 | ||
246 | static void msc_iter_init(struct msc_iter *iter) | |
247 | { | |
248 | memset(iter, 0, sizeof(*iter)); | |
249 | iter->start_block = -1; | |
250 | iter->block = -1; | |
251 | } | |
252 | ||
253 | static struct msc_iter *msc_iter_install(struct msc *msc) | |
254 | { | |
255 | struct msc_iter *iter; | |
256 | ||
257 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
258 | if (!iter) | |
a45ff6ed AS |
259 | return ERR_PTR(-ENOMEM); |
260 | ||
261 | mutex_lock(&msc->buf_mutex); | |
262 | ||
263 | /* | |
264 | * Reading and tracing are mutually exclusive; if msc is | |
265 | * enabled, open() will fail; otherwise existing readers | |
266 | * will prevent enabling the msc and the rest of fops don't | |
267 | * need to worry about it. | |
268 | */ | |
269 | if (msc->enabled) { | |
270 | kfree(iter); | |
271 | iter = ERR_PTR(-EBUSY); | |
272 | goto unlock; | |
273 | } | |
ba82664c AS |
274 | |
275 | msc_iter_init(iter); | |
276 | iter->msc = msc; | |
277 | ||
ba82664c | 278 | list_add_tail(&iter->entry, &msc->iter_list); |
a45ff6ed AS |
279 | unlock: |
280 | mutex_unlock(&msc->buf_mutex); | |
ba82664c AS |
281 | |
282 | return iter; | |
283 | } | |
284 | ||
285 | static void msc_iter_remove(struct msc_iter *iter, struct msc *msc) | |
286 | { | |
a45ff6ed | 287 | mutex_lock(&msc->buf_mutex); |
ba82664c | 288 | list_del(&iter->entry); |
a45ff6ed | 289 | mutex_unlock(&msc->buf_mutex); |
ba82664c AS |
290 | |
291 | kfree(iter); | |
292 | } | |
293 | ||
294 | static void msc_iter_block_start(struct msc_iter *iter) | |
295 | { | |
296 | if (iter->start_block != -1) | |
297 | return; | |
298 | ||
299 | iter->start_block = msc_win_oldest_block(iter->win); | |
300 | iter->block = iter->start_block; | |
301 | iter->wrap_count = 0; | |
302 | ||
303 | /* | |
304 | * start with the block with oldest data; if data has wrapped | |
305 | * in this window, it should be in this block | |
306 | */ | |
307 | if (msc_block_wrapped(msc_iter_bdesc(iter))) | |
308 | iter->wrap_count = 2; | |
309 | ||
310 | } | |
311 | ||
312 | static int msc_iter_win_start(struct msc_iter *iter, struct msc *msc) | |
313 | { | |
314 | /* already started, nothing to do */ | |
315 | if (iter->start_win) | |
316 | return 0; | |
317 | ||
318 | iter->start_win = msc_oldest_window(msc); | |
319 | if (!iter->start_win) | |
320 | return -EINVAL; | |
321 | ||
322 | iter->win = iter->start_win; | |
323 | iter->start_block = -1; | |
324 | ||
325 | msc_iter_block_start(iter); | |
326 | ||
327 | return 0; | |
328 | } | |
329 | ||
330 | static int msc_iter_win_advance(struct msc_iter *iter) | |
331 | { | |
332 | iter->win = msc_next_window(iter->win); | |
333 | iter->start_block = -1; | |
334 | ||
335 | if (iter->win == iter->start_win) { | |
336 | iter->eof++; | |
337 | return 1; | |
338 | } | |
339 | ||
340 | msc_iter_block_start(iter); | |
341 | ||
342 | return 0; | |
343 | } | |
344 | ||
345 | static int msc_iter_block_advance(struct msc_iter *iter) | |
346 | { | |
347 | iter->block_off = 0; | |
348 | ||
349 | /* wrapping */ | |
350 | if (iter->wrap_count && iter->block == iter->start_block) { | |
351 | iter->wrap_count--; | |
352 | if (!iter->wrap_count) | |
353 | /* copied newest data from the wrapped block */ | |
354 | return msc_iter_win_advance(iter); | |
355 | } | |
356 | ||
357 | /* no wrapping, check for last written block */ | |
358 | if (!iter->wrap_count && msc_block_last_written(msc_iter_bdesc(iter))) | |
359 | /* copied newest data for the window */ | |
360 | return msc_iter_win_advance(iter); | |
361 | ||
362 | /* block advance */ | |
363 | if (++iter->block == iter->win->nr_blocks) | |
364 | iter->block = 0; | |
365 | ||
366 | /* no wrapping, sanity check in case there is no last written block */ | |
367 | if (!iter->wrap_count && iter->block == iter->start_block) | |
368 | return msc_iter_win_advance(iter); | |
369 | ||
370 | return 0; | |
371 | } | |
372 | ||
373 | /** | |
374 | * msc_buffer_iterate() - go through multiblock buffer's data | |
375 | * @iter: iterator structure | |
376 | * @size: amount of data to scan | |
377 | * @data: callback's private data | |
378 | * @fn: iterator callback | |
379 | * | |
380 | * This will start at the window which will be written to next (containing | |
381 | * the oldest data) and work its way to the current window, calling @fn | |
382 | * for each chunk of data as it goes. | |
383 | * | |
384 | * Caller should have msc::user_count reference to make sure the buffer | |
385 | * doesn't disappear from under us. | |
386 | * | |
387 | * Return: amount of data actually scanned. | |
388 | */ | |
389 | static ssize_t | |
390 | msc_buffer_iterate(struct msc_iter *iter, size_t size, void *data, | |
391 | unsigned long (*fn)(void *, void *, size_t)) | |
392 | { | |
393 | struct msc *msc = iter->msc; | |
394 | size_t len = size; | |
395 | unsigned int advance; | |
396 | ||
397 | if (iter->eof) | |
398 | return 0; | |
399 | ||
400 | /* start with the oldest window */ | |
401 | if (msc_iter_win_start(iter, msc)) | |
402 | return 0; | |
403 | ||
404 | do { | |
405 | unsigned long data_bytes = msc_data_sz(msc_iter_bdesc(iter)); | |
406 | void *src = (void *)msc_iter_bdesc(iter) + MSC_BDESC; | |
407 | size_t tocopy = data_bytes, copied = 0; | |
408 | size_t remaining = 0; | |
409 | ||
410 | advance = 1; | |
411 | ||
412 | /* | |
413 | * If block wrapping happened, we need to visit the last block | |
414 | * twice, because it contains both the oldest and the newest | |
415 | * data in this window. | |
416 | * | |
417 | * First time (wrap_count==2), in the very beginning, to collect | |
418 | * the oldest data, which is in the range | |
419 | * (data_bytes..DATA_IN_PAGE). | |
420 | * | |
421 | * Second time (wrap_count==1), it's just like any other block, | |
422 | * containing data in the range of [MSC_BDESC..data_bytes]. | |
423 | */ | |
e4eca2a1 | 424 | if (iter->block == iter->start_block && iter->wrap_count == 2) { |
ba82664c AS |
425 | tocopy = DATA_IN_PAGE - data_bytes; |
426 | src += data_bytes; | |
427 | } | |
428 | ||
429 | if (!tocopy) | |
430 | goto next_block; | |
431 | ||
432 | tocopy -= iter->block_off; | |
433 | src += iter->block_off; | |
434 | ||
435 | if (len < tocopy) { | |
436 | tocopy = len; | |
437 | advance = 0; | |
438 | } | |
439 | ||
440 | remaining = fn(data, src, tocopy); | |
441 | ||
442 | if (remaining) | |
443 | advance = 0; | |
444 | ||
445 | copied = tocopy - remaining; | |
446 | len -= copied; | |
447 | iter->block_off += copied; | |
448 | iter->offset += copied; | |
449 | ||
450 | if (!advance) | |
451 | break; | |
452 | ||
453 | next_block: | |
454 | if (msc_iter_block_advance(iter)) | |
455 | break; | |
456 | ||
457 | } while (len); | |
458 | ||
459 | return size - len; | |
460 | } | |
461 | ||
462 | /** | |
463 | * msc_buffer_clear_hw_header() - clear hw header for multiblock | |
464 | * @msc: MSC device | |
465 | */ | |
466 | static void msc_buffer_clear_hw_header(struct msc *msc) | |
467 | { | |
468 | struct msc_window *win; | |
469 | ||
ba82664c AS |
470 | list_for_each_entry(win, &msc->win_list, entry) { |
471 | unsigned int blk; | |
472 | size_t hw_sz = sizeof(struct msc_block_desc) - | |
473 | offsetof(struct msc_block_desc, hw_tag); | |
474 | ||
475 | for (blk = 0; blk < win->nr_blocks; blk++) { | |
476 | struct msc_block_desc *bdesc = win->block[blk].bdesc; | |
477 | ||
478 | memset(&bdesc->hw_tag, 0, hw_sz); | |
479 | } | |
480 | } | |
ba82664c AS |
481 | } |
482 | ||
483 | /** | |
484 | * msc_configure() - set up MSC hardware | |
485 | * @msc: the MSC device to configure | |
486 | * | |
487 | * Program storage mode, wrapping, burst length and trace buffer address | |
a45ff6ed AS |
488 | * into a given MSC. Then, enable tracing and set msc::enabled. |
489 | * The latter is serialized on msc::buf_mutex, so make sure to hold it. | |
ba82664c AS |
490 | */ |
491 | static int msc_configure(struct msc *msc) | |
492 | { | |
493 | u32 reg; | |
494 | ||
a45ff6ed AS |
495 | lockdep_assert_held(&msc->buf_mutex); |
496 | ||
ba82664c AS |
497 | if (msc->mode > MSC_MODE_MULTI) |
498 | return -ENOTSUPP; | |
499 | ||
500 | if (msc->mode == MSC_MODE_MULTI) | |
501 | msc_buffer_clear_hw_header(msc); | |
502 | ||
503 | reg = msc->base_addr >> PAGE_SHIFT; | |
504 | iowrite32(reg, msc->reg_base + REG_MSU_MSC0BAR); | |
505 | ||
506 | if (msc->mode == MSC_MODE_SINGLE) { | |
507 | reg = msc->nr_pages; | |
508 | iowrite32(reg, msc->reg_base + REG_MSU_MSC0SIZE); | |
509 | } | |
510 | ||
511 | reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL); | |
512 | reg &= ~(MSC_MODE | MSC_WRAPEN | MSC_EN | MSC_RD_HDR_OVRD); | |
513 | ||
a45ff6ed | 514 | reg |= MSC_EN; |
ba82664c AS |
515 | reg |= msc->mode << __ffs(MSC_MODE); |
516 | reg |= msc->burst_len << __ffs(MSC_LEN); | |
a45ff6ed | 517 | |
ba82664c AS |
518 | if (msc->wrap) |
519 | reg |= MSC_WRAPEN; | |
ba82664c AS |
520 | |
521 | iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL); | |
522 | ||
a45ff6ed AS |
523 | msc->thdev->output.multiblock = msc->mode == MSC_MODE_MULTI; |
524 | intel_th_trace_enable(msc->thdev); | |
525 | msc->enabled = 1; | |
526 | ||
ba82664c AS |
527 | |
528 | return 0; | |
529 | } | |
530 | ||
531 | /** | |
532 | * msc_disable() - disable MSC hardware | |
533 | * @msc: MSC device to disable | |
534 | * | |
535 | * If @msc is enabled, disable tracing on the switch and then disable MSC | |
a45ff6ed | 536 | * storage. Caller must hold msc::buf_mutex. |
ba82664c AS |
537 | */ |
538 | static void msc_disable(struct msc *msc) | |
539 | { | |
540 | unsigned long count; | |
541 | u32 reg; | |
542 | ||
a45ff6ed | 543 | lockdep_assert_held(&msc->buf_mutex); |
ba82664c AS |
544 | |
545 | intel_th_trace_disable(msc->thdev); | |
546 | ||
547 | for (reg = 0, count = MSC_PLE_WAITLOOP_DEPTH; | |
548 | count && !(reg & MSCSTS_PLE); count--) { | |
549 | reg = ioread32(msc->reg_base + REG_MSU_MSC0STS); | |
550 | cpu_relax(); | |
551 | } | |
552 | ||
553 | if (!count) | |
554 | dev_dbg(msc_dev(msc), "timeout waiting for MSC0 PLE\n"); | |
555 | ||
556 | if (msc->mode == MSC_MODE_SINGLE) { | |
557 | msc->single_wrap = !!(reg & MSCSTS_WRAPSTAT); | |
558 | ||
559 | reg = ioread32(msc->reg_base + REG_MSU_MSC0MWP); | |
560 | msc->single_sz = reg & ((msc->nr_pages << PAGE_SHIFT) - 1); | |
561 | dev_dbg(msc_dev(msc), "MSCnMWP: %08x/%08lx, wrap: %d\n", | |
562 | reg, msc->single_sz, msc->single_wrap); | |
563 | } | |
564 | ||
565 | reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL); | |
566 | reg &= ~MSC_EN; | |
567 | iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL); | |
568 | msc->enabled = 0; | |
569 | ||
570 | iowrite32(0, msc->reg_base + REG_MSU_MSC0BAR); | |
571 | iowrite32(0, msc->reg_base + REG_MSU_MSC0SIZE); | |
572 | ||
573 | dev_dbg(msc_dev(msc), "MSCnNWSA: %08x\n", | |
574 | ioread32(msc->reg_base + REG_MSU_MSC0NWSA)); | |
575 | ||
576 | reg = ioread32(msc->reg_base + REG_MSU_MSC0STS); | |
577 | dev_dbg(msc_dev(msc), "MSCnSTS: %08x\n", reg); | |
578 | } | |
579 | ||
580 | static int intel_th_msc_activate(struct intel_th_device *thdev) | |
581 | { | |
582 | struct msc *msc = dev_get_drvdata(&thdev->dev); | |
a45ff6ed | 583 | int ret = -EBUSY; |
ba82664c AS |
584 | |
585 | if (!atomic_inc_unless_negative(&msc->user_count)) | |
586 | return -ENODEV; | |
587 | ||
a45ff6ed | 588 | mutex_lock(&msc->buf_mutex); |
ba82664c | 589 | |
a45ff6ed AS |
590 | /* if there are readers, refuse */ |
591 | if (list_empty(&msc->iter_list)) | |
592 | ret = msc_configure(msc); | |
ba82664c | 593 | |
a45ff6ed AS |
594 | mutex_unlock(&msc->buf_mutex); |
595 | ||
596 | if (ret) | |
597 | atomic_dec(&msc->user_count); | |
ba82664c | 598 | |
a45ff6ed | 599 | return ret; |
ba82664c AS |
600 | } |
601 | ||
602 | static void intel_th_msc_deactivate(struct intel_th_device *thdev) | |
603 | { | |
604 | struct msc *msc = dev_get_drvdata(&thdev->dev); | |
605 | ||
a45ff6ed AS |
606 | mutex_lock(&msc->buf_mutex); |
607 | if (msc->enabled) { | |
608 | msc_disable(msc); | |
609 | atomic_dec(&msc->user_count); | |
610 | } | |
611 | mutex_unlock(&msc->buf_mutex); | |
ba82664c AS |
612 | } |
613 | ||
614 | /** | |
615 | * msc_buffer_contig_alloc() - allocate a contiguous buffer for SINGLE mode | |
616 | * @msc: MSC device | |
617 | * @size: allocation size in bytes | |
618 | * | |
619 | * This modifies msc::base, which requires msc::buf_mutex to serialize, so the | |
620 | * caller is expected to hold it. | |
621 | * | |
622 | * Return: 0 on success, -errno otherwise. | |
623 | */ | |
624 | static int msc_buffer_contig_alloc(struct msc *msc, unsigned long size) | |
625 | { | |
626 | unsigned int order = get_order(size); | |
627 | struct page *page; | |
628 | ||
629 | if (!size) | |
630 | return 0; | |
631 | ||
632 | page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order); | |
633 | if (!page) | |
634 | return -ENOMEM; | |
635 | ||
636 | split_page(page, order); | |
637 | msc->nr_pages = size >> PAGE_SHIFT; | |
638 | msc->base = page_address(page); | |
639 | msc->base_addr = page_to_phys(page); | |
640 | ||
641 | return 0; | |
642 | } | |
643 | ||
644 | /** | |
645 | * msc_buffer_contig_free() - free a contiguous buffer | |
646 | * @msc: MSC configured in SINGLE mode | |
647 | */ | |
648 | static void msc_buffer_contig_free(struct msc *msc) | |
649 | { | |
650 | unsigned long off; | |
651 | ||
652 | for (off = 0; off < msc->nr_pages << PAGE_SHIFT; off += PAGE_SIZE) { | |
653 | struct page *page = virt_to_page(msc->base + off); | |
654 | ||
655 | page->mapping = NULL; | |
656 | __free_page(page); | |
657 | } | |
658 | ||
659 | msc->nr_pages = 0; | |
660 | } | |
661 | ||
662 | /** | |
663 | * msc_buffer_contig_get_page() - find a page at a given offset | |
664 | * @msc: MSC configured in SINGLE mode | |
665 | * @pgoff: page offset | |
666 | * | |
667 | * Return: page, if @pgoff is within the range, NULL otherwise. | |
668 | */ | |
669 | static struct page *msc_buffer_contig_get_page(struct msc *msc, | |
670 | unsigned long pgoff) | |
671 | { | |
672 | if (pgoff >= msc->nr_pages) | |
673 | return NULL; | |
674 | ||
675 | return virt_to_page(msc->base + (pgoff << PAGE_SHIFT)); | |
676 | } | |
677 | ||
678 | /** | |
679 | * msc_buffer_win_alloc() - alloc a window for a multiblock mode | |
680 | * @msc: MSC device | |
681 | * @nr_blocks: number of pages in this window | |
682 | * | |
683 | * This modifies msc::win_list and msc::base, which requires msc::buf_mutex | |
684 | * to serialize, so the caller is expected to hold it. | |
685 | * | |
686 | * Return: 0 on success, -errno otherwise. | |
687 | */ | |
688 | static int msc_buffer_win_alloc(struct msc *msc, unsigned int nr_blocks) | |
689 | { | |
690 | struct msc_window *win; | |
691 | unsigned long size = PAGE_SIZE; | |
692 | int i, ret = -ENOMEM; | |
693 | ||
694 | if (!nr_blocks) | |
695 | return 0; | |
696 | ||
697 | win = kzalloc(offsetof(struct msc_window, block[nr_blocks]), | |
698 | GFP_KERNEL); | |
699 | if (!win) | |
700 | return -ENOMEM; | |
701 | ||
702 | if (!list_empty(&msc->win_list)) { | |
703 | struct msc_window *prev = list_entry(msc->win_list.prev, | |
704 | struct msc_window, entry); | |
705 | ||
706 | win->pgoff = prev->pgoff + prev->nr_blocks; | |
707 | } | |
708 | ||
709 | for (i = 0; i < nr_blocks; i++) { | |
710 | win->block[i].bdesc = dma_alloc_coherent(msc_dev(msc), size, | |
711 | &win->block[i].addr, | |
712 | GFP_KERNEL); | |
713 | ||
714 | #ifdef CONFIG_X86 | |
715 | /* Set the page as uncached */ | |
716 | set_memory_uc((unsigned long)win->block[i].bdesc, 1); | |
717 | #endif | |
718 | ||
719 | if (!win->block[i].bdesc) | |
720 | goto err_nomem; | |
721 | } | |
722 | ||
723 | win->msc = msc; | |
724 | win->nr_blocks = nr_blocks; | |
725 | ||
726 | if (list_empty(&msc->win_list)) { | |
727 | msc->base = win->block[0].bdesc; | |
728 | msc->base_addr = win->block[0].addr; | |
729 | } | |
730 | ||
731 | list_add_tail(&win->entry, &msc->win_list); | |
732 | msc->nr_pages += nr_blocks; | |
733 | ||
734 | return 0; | |
735 | ||
736 | err_nomem: | |
737 | for (i--; i >= 0; i--) { | |
738 | #ifdef CONFIG_X86 | |
739 | /* Reset the page to write-back before releasing */ | |
740 | set_memory_wb((unsigned long)win->block[i].bdesc, 1); | |
741 | #endif | |
742 | dma_free_coherent(msc_dev(msc), size, win->block[i].bdesc, | |
743 | win->block[i].addr); | |
744 | } | |
745 | kfree(win); | |
746 | ||
747 | return ret; | |
748 | } | |
749 | ||
750 | /** | |
751 | * msc_buffer_win_free() - free a window from MSC's window list | |
752 | * @msc: MSC device | |
753 | * @win: window to free | |
754 | * | |
755 | * This modifies msc::win_list and msc::base, which requires msc::buf_mutex | |
756 | * to serialize, so the caller is expected to hold it. | |
757 | */ | |
758 | static void msc_buffer_win_free(struct msc *msc, struct msc_window *win) | |
759 | { | |
760 | int i; | |
761 | ||
762 | msc->nr_pages -= win->nr_blocks; | |
763 | ||
764 | list_del(&win->entry); | |
765 | if (list_empty(&msc->win_list)) { | |
766 | msc->base = NULL; | |
767 | msc->base_addr = 0; | |
768 | } | |
769 | ||
770 | for (i = 0; i < win->nr_blocks; i++) { | |
771 | struct page *page = virt_to_page(win->block[i].bdesc); | |
772 | ||
773 | page->mapping = NULL; | |
774 | #ifdef CONFIG_X86 | |
775 | /* Reset the page to write-back before releasing */ | |
776 | set_memory_wb((unsigned long)win->block[i].bdesc, 1); | |
777 | #endif | |
778 | dma_free_coherent(msc_dev(win->msc), PAGE_SIZE, | |
779 | win->block[i].bdesc, win->block[i].addr); | |
780 | } | |
781 | ||
782 | kfree(win); | |
783 | } | |
784 | ||
785 | /** | |
786 | * msc_buffer_relink() - set up block descriptors for multiblock mode | |
787 | * @msc: MSC device | |
788 | * | |
789 | * This traverses msc::win_list, which requires msc::buf_mutex to serialize, | |
790 | * so the caller is expected to hold it. | |
791 | */ | |
792 | static void msc_buffer_relink(struct msc *msc) | |
793 | { | |
794 | struct msc_window *win, *next_win; | |
795 | ||
796 | /* call with msc::mutex locked */ | |
797 | list_for_each_entry(win, &msc->win_list, entry) { | |
798 | unsigned int blk; | |
799 | u32 sw_tag = 0; | |
800 | ||
801 | /* | |
802 | * Last window's next_win should point to the first window | |
803 | * and MSC_SW_TAG_LASTWIN should be set. | |
804 | */ | |
805 | if (msc_is_last_win(win)) { | |
806 | sw_tag |= MSC_SW_TAG_LASTWIN; | |
807 | next_win = list_entry(msc->win_list.next, | |
808 | struct msc_window, entry); | |
809 | } else { | |
810 | next_win = list_entry(win->entry.next, | |
811 | struct msc_window, entry); | |
812 | } | |
813 | ||
814 | for (blk = 0; blk < win->nr_blocks; blk++) { | |
815 | struct msc_block_desc *bdesc = win->block[blk].bdesc; | |
816 | ||
817 | memset(bdesc, 0, sizeof(*bdesc)); | |
818 | ||
819 | bdesc->next_win = next_win->block[0].addr >> PAGE_SHIFT; | |
820 | ||
821 | /* | |
822 | * Similarly to last window, last block should point | |
823 | * to the first one. | |
824 | */ | |
825 | if (blk == win->nr_blocks - 1) { | |
826 | sw_tag |= MSC_SW_TAG_LASTBLK; | |
827 | bdesc->next_blk = | |
828 | win->block[0].addr >> PAGE_SHIFT; | |
829 | } else { | |
830 | bdesc->next_blk = | |
831 | win->block[blk + 1].addr >> PAGE_SHIFT; | |
832 | } | |
833 | ||
834 | bdesc->sw_tag = sw_tag; | |
835 | bdesc->block_sz = PAGE_SIZE / 64; | |
836 | } | |
837 | } | |
838 | ||
839 | /* | |
840 | * Make the above writes globally visible before tracing is | |
841 | * enabled to make sure hardware sees them coherently. | |
842 | */ | |
843 | wmb(); | |
844 | } | |
845 | ||
846 | static void msc_buffer_multi_free(struct msc *msc) | |
847 | { | |
848 | struct msc_window *win, *iter; | |
849 | ||
850 | list_for_each_entry_safe(win, iter, &msc->win_list, entry) | |
851 | msc_buffer_win_free(msc, win); | |
852 | } | |
853 | ||
854 | static int msc_buffer_multi_alloc(struct msc *msc, unsigned long *nr_pages, | |
855 | unsigned int nr_wins) | |
856 | { | |
857 | int ret, i; | |
858 | ||
859 | for (i = 0; i < nr_wins; i++) { | |
860 | ret = msc_buffer_win_alloc(msc, nr_pages[i]); | |
861 | if (ret) { | |
862 | msc_buffer_multi_free(msc); | |
863 | return ret; | |
864 | } | |
865 | } | |
866 | ||
867 | msc_buffer_relink(msc); | |
868 | ||
869 | return 0; | |
870 | } | |
871 | ||
872 | /** | |
873 | * msc_buffer_free() - free buffers for MSC | |
874 | * @msc: MSC device | |
875 | * | |
876 | * Free MSC's storage buffers. | |
877 | * | |
878 | * This modifies msc::win_list and msc::base, which requires msc::buf_mutex to | |
879 | * serialize, so the caller is expected to hold it. | |
880 | */ | |
881 | static void msc_buffer_free(struct msc *msc) | |
882 | { | |
883 | if (msc->mode == MSC_MODE_SINGLE) | |
884 | msc_buffer_contig_free(msc); | |
885 | else if (msc->mode == MSC_MODE_MULTI) | |
886 | msc_buffer_multi_free(msc); | |
887 | } | |
888 | ||
889 | /** | |
890 | * msc_buffer_alloc() - allocate a buffer for MSC | |
891 | * @msc: MSC device | |
892 | * @size: allocation size in bytes | |
893 | * | |
894 | * Allocate a storage buffer for MSC, depending on the msc::mode, it will be | |
895 | * either done via msc_buffer_contig_alloc() for SINGLE operation mode or | |
896 | * msc_buffer_win_alloc() for multiblock operation. The latter allocates one | |
897 | * window per invocation, so in multiblock mode this can be called multiple | |
898 | * times for the same MSC to allocate multiple windows. | |
899 | * | |
900 | * This modifies msc::win_list and msc::base, which requires msc::buf_mutex | |
901 | * to serialize, so the caller is expected to hold it. | |
902 | * | |
903 | * Return: 0 on success, -errno otherwise. | |
904 | */ | |
905 | static int msc_buffer_alloc(struct msc *msc, unsigned long *nr_pages, | |
906 | unsigned int nr_wins) | |
907 | { | |
908 | int ret; | |
909 | ||
910 | /* -1: buffer not allocated */ | |
911 | if (atomic_read(&msc->user_count) != -1) | |
912 | return -EBUSY; | |
913 | ||
914 | if (msc->mode == MSC_MODE_SINGLE) { | |
915 | if (nr_wins != 1) | |
916 | return -EINVAL; | |
917 | ||
918 | ret = msc_buffer_contig_alloc(msc, nr_pages[0] << PAGE_SHIFT); | |
919 | } else if (msc->mode == MSC_MODE_MULTI) { | |
920 | ret = msc_buffer_multi_alloc(msc, nr_pages, nr_wins); | |
921 | } else { | |
922 | ret = -ENOTSUPP; | |
923 | } | |
924 | ||
925 | if (!ret) { | |
926 | /* allocation should be visible before the counter goes to 0 */ | |
927 | smp_mb__before_atomic(); | |
928 | ||
929 | if (WARN_ON_ONCE(atomic_cmpxchg(&msc->user_count, -1, 0) != -1)) | |
930 | return -EINVAL; | |
931 | } | |
932 | ||
933 | return ret; | |
934 | } | |
935 | ||
936 | /** | |
937 | * msc_buffer_unlocked_free_unless_used() - free a buffer unless it's in use | |
938 | * @msc: MSC device | |
939 | * | |
940 | * This will free MSC buffer unless it is in use or there is no allocated | |
941 | * buffer. | |
942 | * Caller needs to hold msc::buf_mutex. | |
943 | * | |
944 | * Return: 0 on successful deallocation or if there was no buffer to | |
945 | * deallocate, -EBUSY if there are active users. | |
946 | */ | |
947 | static int msc_buffer_unlocked_free_unless_used(struct msc *msc) | |
948 | { | |
949 | int count, ret = 0; | |
950 | ||
951 | count = atomic_cmpxchg(&msc->user_count, 0, -1); | |
952 | ||
953 | /* > 0: buffer is allocated and has users */ | |
954 | if (count > 0) | |
955 | ret = -EBUSY; | |
956 | /* 0: buffer is allocated, no users */ | |
957 | else if (!count) | |
958 | msc_buffer_free(msc); | |
959 | /* < 0: no buffer, nothing to do */ | |
960 | ||
961 | return ret; | |
962 | } | |
963 | ||
964 | /** | |
965 | * msc_buffer_free_unless_used() - free a buffer unless it's in use | |
966 | * @msc: MSC device | |
967 | * | |
968 | * This is a locked version of msc_buffer_unlocked_free_unless_used(). | |
969 | */ | |
970 | static int msc_buffer_free_unless_used(struct msc *msc) | |
971 | { | |
972 | int ret; | |
973 | ||
974 | mutex_lock(&msc->buf_mutex); | |
975 | ret = msc_buffer_unlocked_free_unless_used(msc); | |
976 | mutex_unlock(&msc->buf_mutex); | |
977 | ||
978 | return ret; | |
979 | } | |
980 | ||
981 | /** | |
982 | * msc_buffer_get_page() - get MSC buffer page at a given offset | |
983 | * @msc: MSC device | |
984 | * @pgoff: page offset into the storage buffer | |
985 | * | |
986 | * This traverses msc::win_list, so holding msc::buf_mutex is expected from | |
987 | * the caller. | |
988 | * | |
989 | * Return: page if @pgoff corresponds to a valid buffer page or NULL. | |
990 | */ | |
991 | static struct page *msc_buffer_get_page(struct msc *msc, unsigned long pgoff) | |
992 | { | |
993 | struct msc_window *win; | |
994 | ||
995 | if (msc->mode == MSC_MODE_SINGLE) | |
996 | return msc_buffer_contig_get_page(msc, pgoff); | |
997 | ||
998 | list_for_each_entry(win, &msc->win_list, entry) | |
999 | if (pgoff >= win->pgoff && pgoff < win->pgoff + win->nr_blocks) | |
1000 | goto found; | |
1001 | ||
1002 | return NULL; | |
1003 | ||
1004 | found: | |
1005 | pgoff -= win->pgoff; | |
1006 | return virt_to_page(win->block[pgoff].bdesc); | |
1007 | } | |
1008 | ||
1009 | /** | |
1010 | * struct msc_win_to_user_struct - data for copy_to_user() callback | |
1011 | * @buf: userspace buffer to copy data to | |
1012 | * @offset: running offset | |
1013 | */ | |
1014 | struct msc_win_to_user_struct { | |
1015 | char __user *buf; | |
1016 | unsigned long offset; | |
1017 | }; | |
1018 | ||
1019 | /** | |
1020 | * msc_win_to_user() - iterator for msc_buffer_iterate() to copy data to user | |
1021 | * @data: callback's private data | |
1022 | * @src: source buffer | |
1023 | * @len: amount of data to copy from the source buffer | |
1024 | */ | |
1025 | static unsigned long msc_win_to_user(void *data, void *src, size_t len) | |
1026 | { | |
1027 | struct msc_win_to_user_struct *u = data; | |
1028 | unsigned long ret; | |
1029 | ||
1030 | ret = copy_to_user(u->buf + u->offset, src, len); | |
1031 | u->offset += len - ret; | |
1032 | ||
1033 | return ret; | |
1034 | } | |
1035 | ||
1036 | ||
1037 | /* | |
1038 | * file operations' callbacks | |
1039 | */ | |
1040 | ||
1041 | static int intel_th_msc_open(struct inode *inode, struct file *file) | |
1042 | { | |
1043 | struct intel_th_device *thdev = file->private_data; | |
1044 | struct msc *msc = dev_get_drvdata(&thdev->dev); | |
1045 | struct msc_iter *iter; | |
1046 | ||
1047 | if (!capable(CAP_SYS_RAWIO)) | |
1048 | return -EPERM; | |
1049 | ||
1050 | iter = msc_iter_install(msc); | |
a45ff6ed AS |
1051 | if (IS_ERR(iter)) |
1052 | return PTR_ERR(iter); | |
ba82664c AS |
1053 | |
1054 | file->private_data = iter; | |
1055 | ||
1056 | return nonseekable_open(inode, file); | |
1057 | } | |
1058 | ||
1059 | static int intel_th_msc_release(struct inode *inode, struct file *file) | |
1060 | { | |
1061 | struct msc_iter *iter = file->private_data; | |
1062 | struct msc *msc = iter->msc; | |
1063 | ||
1064 | msc_iter_remove(iter, msc); | |
1065 | ||
1066 | return 0; | |
1067 | } | |
1068 | ||
1069 | static ssize_t | |
1070 | msc_single_to_user(struct msc *msc, char __user *buf, loff_t off, size_t len) | |
1071 | { | |
ed392688 | 1072 | unsigned long size = msc->nr_pages << PAGE_SHIFT, rem = len; |
ba82664c AS |
1073 | unsigned long start = off, tocopy = 0; |
1074 | ||
1075 | if (msc->single_wrap) { | |
1076 | start += msc->single_sz; | |
1077 | if (start < size) { | |
1078 | tocopy = min(rem, size - start); | |
1079 | if (copy_to_user(buf, msc->base + start, tocopy)) | |
1080 | return -EFAULT; | |
1081 | ||
1082 | buf += tocopy; | |
1083 | rem -= tocopy; | |
1084 | start += tocopy; | |
1085 | } | |
1086 | ||
1087 | start &= size - 1; | |
1088 | if (rem) { | |
1089 | tocopy = min(rem, msc->single_sz - start); | |
1090 | if (copy_to_user(buf, msc->base + start, tocopy)) | |
1091 | return -EFAULT; | |
1092 | ||
1093 | rem -= tocopy; | |
1094 | } | |
1095 | ||
1096 | return len - rem; | |
1097 | } | |
1098 | ||
1099 | if (copy_to_user(buf, msc->base + start, rem)) | |
1100 | return -EFAULT; | |
1101 | ||
1102 | return len; | |
1103 | } | |
1104 | ||
1105 | static ssize_t intel_th_msc_read(struct file *file, char __user *buf, | |
1106 | size_t len, loff_t *ppos) | |
1107 | { | |
1108 | struct msc_iter *iter = file->private_data; | |
1109 | struct msc *msc = iter->msc; | |
1110 | size_t size; | |
1111 | loff_t off = *ppos; | |
1112 | ssize_t ret = 0; | |
1113 | ||
1114 | if (!atomic_inc_unless_negative(&msc->user_count)) | |
1115 | return 0; | |
1116 | ||
ba82664c AS |
1117 | if (msc->mode == MSC_MODE_SINGLE && !msc->single_wrap) |
1118 | size = msc->single_sz; | |
1119 | else | |
1120 | size = msc->nr_pages << PAGE_SHIFT; | |
1121 | ||
1122 | if (!size) | |
2bed074a | 1123 | goto put_count; |
ba82664c | 1124 | |
2bed074a | 1125 | if (off >= size) |
ba82664c | 1126 | goto put_count; |
2bed074a | 1127 | |
ba82664c AS |
1128 | if (off + len >= size) |
1129 | len = size - off; | |
1130 | ||
1131 | if (msc->mode == MSC_MODE_SINGLE) { | |
1132 | ret = msc_single_to_user(msc, buf, off, len); | |
1133 | if (ret >= 0) | |
1134 | *ppos += ret; | |
1135 | } else if (msc->mode == MSC_MODE_MULTI) { | |
1136 | struct msc_win_to_user_struct u = { | |
1137 | .buf = buf, | |
1138 | .offset = 0, | |
1139 | }; | |
1140 | ||
1141 | ret = msc_buffer_iterate(iter, len, &u, msc_win_to_user); | |
1142 | if (ret >= 0) | |
1143 | *ppos = iter->offset; | |
1144 | } else { | |
1145 | ret = -ENOTSUPP; | |
1146 | } | |
1147 | ||
1148 | put_count: | |
1149 | atomic_dec(&msc->user_count); | |
1150 | ||
1151 | return ret; | |
1152 | } | |
1153 | ||
1154 | /* | |
1155 | * vm operations callbacks (vm_ops) | |
1156 | */ | |
1157 | ||
1158 | static void msc_mmap_open(struct vm_area_struct *vma) | |
1159 | { | |
1160 | struct msc_iter *iter = vma->vm_file->private_data; | |
1161 | struct msc *msc = iter->msc; | |
1162 | ||
1163 | atomic_inc(&msc->mmap_count); | |
1164 | } | |
1165 | ||
1166 | static void msc_mmap_close(struct vm_area_struct *vma) | |
1167 | { | |
1168 | struct msc_iter *iter = vma->vm_file->private_data; | |
1169 | struct msc *msc = iter->msc; | |
1170 | unsigned long pg; | |
1171 | ||
1172 | if (!atomic_dec_and_mutex_lock(&msc->mmap_count, &msc->buf_mutex)) | |
1173 | return; | |
1174 | ||
0139aa7b | 1175 | /* drop page _refcounts */ |
ba82664c AS |
1176 | for (pg = 0; pg < msc->nr_pages; pg++) { |
1177 | struct page *page = msc_buffer_get_page(msc, pg); | |
1178 | ||
1179 | if (WARN_ON_ONCE(!page)) | |
1180 | continue; | |
1181 | ||
1182 | if (page->mapping) | |
1183 | page->mapping = NULL; | |
1184 | } | |
1185 | ||
1186 | /* last mapping -- drop user_count */ | |
1187 | atomic_dec(&msc->user_count); | |
1188 | mutex_unlock(&msc->buf_mutex); | |
1189 | } | |
1190 | ||
11bac800 | 1191 | static int msc_mmap_fault(struct vm_fault *vmf) |
ba82664c | 1192 | { |
11bac800 | 1193 | struct msc_iter *iter = vmf->vma->vm_file->private_data; |
ba82664c AS |
1194 | struct msc *msc = iter->msc; |
1195 | ||
1196 | vmf->page = msc_buffer_get_page(msc, vmf->pgoff); | |
1197 | if (!vmf->page) | |
1198 | return VM_FAULT_SIGBUS; | |
1199 | ||
1200 | get_page(vmf->page); | |
11bac800 | 1201 | vmf->page->mapping = vmf->vma->vm_file->f_mapping; |
ba82664c AS |
1202 | vmf->page->index = vmf->pgoff; |
1203 | ||
1204 | return 0; | |
1205 | } | |
1206 | ||
1207 | static const struct vm_operations_struct msc_mmap_ops = { | |
1208 | .open = msc_mmap_open, | |
1209 | .close = msc_mmap_close, | |
1210 | .fault = msc_mmap_fault, | |
1211 | }; | |
1212 | ||
1213 | static int intel_th_msc_mmap(struct file *file, struct vm_area_struct *vma) | |
1214 | { | |
1215 | unsigned long size = vma->vm_end - vma->vm_start; | |
1216 | struct msc_iter *iter = vma->vm_file->private_data; | |
1217 | struct msc *msc = iter->msc; | |
1218 | int ret = -EINVAL; | |
1219 | ||
1220 | if (!size || offset_in_page(size)) | |
1221 | return -EINVAL; | |
1222 | ||
1223 | if (vma->vm_pgoff) | |
1224 | return -EINVAL; | |
1225 | ||
1226 | /* grab user_count once per mmap; drop in msc_mmap_close() */ | |
1227 | if (!atomic_inc_unless_negative(&msc->user_count)) | |
1228 | return -EINVAL; | |
1229 | ||
1230 | if (msc->mode != MSC_MODE_SINGLE && | |
1231 | msc->mode != MSC_MODE_MULTI) | |
1232 | goto out; | |
1233 | ||
1234 | if (size >> PAGE_SHIFT != msc->nr_pages) | |
1235 | goto out; | |
1236 | ||
1237 | atomic_set(&msc->mmap_count, 1); | |
1238 | ret = 0; | |
1239 | ||
1240 | out: | |
1241 | if (ret) | |
1242 | atomic_dec(&msc->user_count); | |
1243 | ||
1244 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); | |
1245 | vma->vm_flags |= VM_DONTEXPAND | VM_DONTCOPY; | |
1246 | vma->vm_ops = &msc_mmap_ops; | |
1247 | return ret; | |
1248 | } | |
1249 | ||
1250 | static const struct file_operations intel_th_msc_fops = { | |
1251 | .open = intel_th_msc_open, | |
1252 | .release = intel_th_msc_release, | |
1253 | .read = intel_th_msc_read, | |
1254 | .mmap = intel_th_msc_mmap, | |
1255 | .llseek = no_llseek, | |
8e9a2beb | 1256 | .owner = THIS_MODULE, |
ba82664c AS |
1257 | }; |
1258 | ||
1259 | static int intel_th_msc_init(struct msc *msc) | |
1260 | { | |
1261 | atomic_set(&msc->user_count, -1); | |
1262 | ||
1263 | msc->mode = MSC_MODE_MULTI; | |
1264 | mutex_init(&msc->buf_mutex); | |
1265 | INIT_LIST_HEAD(&msc->win_list); | |
ba82664c AS |
1266 | INIT_LIST_HEAD(&msc->iter_list); |
1267 | ||
1268 | msc->burst_len = | |
1269 | (ioread32(msc->reg_base + REG_MSU_MSC0CTL) & MSC_LEN) >> | |
1270 | __ffs(MSC_LEN); | |
1271 | ||
1272 | return 0; | |
1273 | } | |
1274 | ||
1275 | static const char * const msc_mode[] = { | |
1276 | [MSC_MODE_SINGLE] = "single", | |
1277 | [MSC_MODE_MULTI] = "multi", | |
1278 | [MSC_MODE_EXI] = "ExI", | |
1279 | [MSC_MODE_DEBUG] = "debug", | |
1280 | }; | |
1281 | ||
1282 | static ssize_t | |
1283 | wrap_show(struct device *dev, struct device_attribute *attr, char *buf) | |
1284 | { | |
1285 | struct msc *msc = dev_get_drvdata(dev); | |
1286 | ||
1287 | return scnprintf(buf, PAGE_SIZE, "%d\n", msc->wrap); | |
1288 | } | |
1289 | ||
1290 | static ssize_t | |
1291 | wrap_store(struct device *dev, struct device_attribute *attr, const char *buf, | |
1292 | size_t size) | |
1293 | { | |
1294 | struct msc *msc = dev_get_drvdata(dev); | |
1295 | unsigned long val; | |
1296 | int ret; | |
1297 | ||
1298 | ret = kstrtoul(buf, 10, &val); | |
1299 | if (ret) | |
1300 | return ret; | |
1301 | ||
1302 | msc->wrap = !!val; | |
1303 | ||
1304 | return size; | |
1305 | } | |
1306 | ||
1307 | static DEVICE_ATTR_RW(wrap); | |
1308 | ||
1309 | static ssize_t | |
1310 | mode_show(struct device *dev, struct device_attribute *attr, char *buf) | |
1311 | { | |
1312 | struct msc *msc = dev_get_drvdata(dev); | |
1313 | ||
1314 | return scnprintf(buf, PAGE_SIZE, "%s\n", msc_mode[msc->mode]); | |
1315 | } | |
1316 | ||
1317 | static ssize_t | |
1318 | mode_store(struct device *dev, struct device_attribute *attr, const char *buf, | |
1319 | size_t size) | |
1320 | { | |
1321 | struct msc *msc = dev_get_drvdata(dev); | |
1322 | size_t len = size; | |
1323 | char *cp; | |
1324 | int i, ret; | |
1325 | ||
1326 | if (!capable(CAP_SYS_RAWIO)) | |
1327 | return -EPERM; | |
1328 | ||
1329 | cp = memchr(buf, '\n', len); | |
1330 | if (cp) | |
1331 | len = cp - buf; | |
1332 | ||
1333 | for (i = 0; i < ARRAY_SIZE(msc_mode); i++) | |
1334 | if (!strncmp(msc_mode[i], buf, len)) | |
1335 | goto found; | |
1336 | ||
1337 | return -EINVAL; | |
1338 | ||
1339 | found: | |
1340 | mutex_lock(&msc->buf_mutex); | |
1341 | ret = msc_buffer_unlocked_free_unless_used(msc); | |
1342 | if (!ret) | |
1343 | msc->mode = i; | |
1344 | mutex_unlock(&msc->buf_mutex); | |
1345 | ||
1346 | return ret ? ret : size; | |
1347 | } | |
1348 | ||
1349 | static DEVICE_ATTR_RW(mode); | |
1350 | ||
1351 | static ssize_t | |
1352 | nr_pages_show(struct device *dev, struct device_attribute *attr, char *buf) | |
1353 | { | |
1354 | struct msc *msc = dev_get_drvdata(dev); | |
1355 | struct msc_window *win; | |
1356 | size_t count = 0; | |
1357 | ||
1358 | mutex_lock(&msc->buf_mutex); | |
1359 | ||
1360 | if (msc->mode == MSC_MODE_SINGLE) | |
1361 | count = scnprintf(buf, PAGE_SIZE, "%ld\n", msc->nr_pages); | |
1362 | else if (msc->mode == MSC_MODE_MULTI) { | |
1363 | list_for_each_entry(win, &msc->win_list, entry) { | |
1364 | count += scnprintf(buf + count, PAGE_SIZE - count, | |
1365 | "%d%c", win->nr_blocks, | |
1366 | msc_is_last_win(win) ? '\n' : ','); | |
1367 | } | |
1368 | } else { | |
1369 | count = scnprintf(buf, PAGE_SIZE, "unsupported\n"); | |
1370 | } | |
1371 | ||
1372 | mutex_unlock(&msc->buf_mutex); | |
1373 | ||
1374 | return count; | |
1375 | } | |
1376 | ||
1377 | static ssize_t | |
1378 | nr_pages_store(struct device *dev, struct device_attribute *attr, | |
1379 | const char *buf, size_t size) | |
1380 | { | |
1381 | struct msc *msc = dev_get_drvdata(dev); | |
1382 | unsigned long val, *win = NULL, *rewin; | |
1383 | size_t len = size; | |
1384 | const char *p = buf; | |
1385 | char *end, *s; | |
1386 | int ret, nr_wins = 0; | |
1387 | ||
1388 | if (!capable(CAP_SYS_RAWIO)) | |
1389 | return -EPERM; | |
1390 | ||
1391 | ret = msc_buffer_free_unless_used(msc); | |
1392 | if (ret) | |
1393 | return ret; | |
1394 | ||
1395 | /* scan the comma-separated list of allocation sizes */ | |
1396 | end = memchr(buf, '\n', len); | |
1397 | if (end) | |
1398 | len = end - buf; | |
1399 | ||
1400 | do { | |
1401 | end = memchr(p, ',', len); | |
1402 | s = kstrndup(p, end ? end - p : len, GFP_KERNEL); | |
6575cbd6 AS |
1403 | if (!s) { |
1404 | ret = -ENOMEM; | |
1405 | goto free_win; | |
1406 | } | |
1407 | ||
ba82664c AS |
1408 | ret = kstrtoul(s, 10, &val); |
1409 | kfree(s); | |
1410 | ||
1411 | if (ret || !val) | |
1412 | goto free_win; | |
1413 | ||
1414 | if (nr_wins && msc->mode == MSC_MODE_SINGLE) { | |
1415 | ret = -EINVAL; | |
1416 | goto free_win; | |
1417 | } | |
1418 | ||
1419 | nr_wins++; | |
1420 | rewin = krealloc(win, sizeof(*win) * nr_wins, GFP_KERNEL); | |
1421 | if (!rewin) { | |
1422 | kfree(win); | |
1423 | return -ENOMEM; | |
1424 | } | |
1425 | ||
1426 | win = rewin; | |
1427 | win[nr_wins - 1] = val; | |
1428 | ||
1429 | if (!end) | |
1430 | break; | |
1431 | ||
1432 | len -= end - p; | |
1433 | p = end + 1; | |
1434 | } while (len); | |
1435 | ||
1436 | mutex_lock(&msc->buf_mutex); | |
1437 | ret = msc_buffer_alloc(msc, win, nr_wins); | |
1438 | mutex_unlock(&msc->buf_mutex); | |
1439 | ||
1440 | free_win: | |
1441 | kfree(win); | |
1442 | ||
1443 | return ret ? ret : size; | |
1444 | } | |
1445 | ||
1446 | static DEVICE_ATTR_RW(nr_pages); | |
1447 | ||
1448 | static struct attribute *msc_output_attrs[] = { | |
1449 | &dev_attr_wrap.attr, | |
1450 | &dev_attr_mode.attr, | |
1451 | &dev_attr_nr_pages.attr, | |
1452 | NULL, | |
1453 | }; | |
1454 | ||
1455 | static struct attribute_group msc_output_group = { | |
1456 | .attrs = msc_output_attrs, | |
1457 | }; | |
1458 | ||
1459 | static int intel_th_msc_probe(struct intel_th_device *thdev) | |
1460 | { | |
1461 | struct device *dev = &thdev->dev; | |
1462 | struct resource *res; | |
1463 | struct msc *msc; | |
1464 | void __iomem *base; | |
1465 | int err; | |
1466 | ||
1467 | res = intel_th_device_get_resource(thdev, IORESOURCE_MEM, 0); | |
1468 | if (!res) | |
1469 | return -ENODEV; | |
1470 | ||
1471 | base = devm_ioremap(dev, res->start, resource_size(res)); | |
73061da0 DC |
1472 | if (!base) |
1473 | return -ENOMEM; | |
ba82664c AS |
1474 | |
1475 | msc = devm_kzalloc(dev, sizeof(*msc), GFP_KERNEL); | |
1476 | if (!msc) | |
1477 | return -ENOMEM; | |
1478 | ||
1479 | msc->index = thdev->id; | |
1480 | ||
1481 | msc->thdev = thdev; | |
1482 | msc->reg_base = base + msc->index * 0x100; | |
1483 | ||
1484 | err = intel_th_msc_init(msc); | |
1485 | if (err) | |
1486 | return err; | |
1487 | ||
ba82664c AS |
1488 | dev_set_drvdata(dev, msc); |
1489 | ||
1490 | return 0; | |
1491 | } | |
1492 | ||
1493 | static void intel_th_msc_remove(struct intel_th_device *thdev) | |
1494 | { | |
f152dfee AS |
1495 | struct msc *msc = dev_get_drvdata(&thdev->dev); |
1496 | int ret; | |
1497 | ||
1498 | intel_th_msc_deactivate(thdev); | |
1499 | ||
1500 | /* | |
1501 | * Buffers should not be used at this point except if the | |
1502 | * output character device is still open and the parent | |
1503 | * device gets detached from its bus, which is a FIXME. | |
1504 | */ | |
1505 | ret = msc_buffer_free_unless_used(msc); | |
1506 | WARN_ON_ONCE(ret); | |
ba82664c AS |
1507 | } |
1508 | ||
1509 | static struct intel_th_driver intel_th_msc_driver = { | |
1510 | .probe = intel_th_msc_probe, | |
1511 | .remove = intel_th_msc_remove, | |
1512 | .activate = intel_th_msc_activate, | |
1513 | .deactivate = intel_th_msc_deactivate, | |
1514 | .fops = &intel_th_msc_fops, | |
9d482aed | 1515 | .attr_group = &msc_output_group, |
ba82664c AS |
1516 | .driver = { |
1517 | .name = "msc", | |
1518 | .owner = THIS_MODULE, | |
1519 | }, | |
1520 | }; | |
1521 | ||
1522 | module_driver(intel_th_msc_driver, | |
1523 | intel_th_driver_register, | |
1524 | intel_th_driver_unregister); | |
1525 | ||
1526 | MODULE_LICENSE("GPL v2"); | |
1527 | MODULE_DESCRIPTION("Intel(R) Trace Hub Memory Storage Unit driver"); | |
1528 | MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>"); |