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 * @single_sgt: single mode buffer
94 * @nr_pages: total number of pages allocated for this buffer
95 * @single_sz: amount of data in single mode
96 * @single_wrap: single mode wrap occurred
97 * @base: buffer's base pointer
98 * @base_addr: buffer's base address
99 * @user_count: number of users of the buffer
100 * @mmap_count: number of mappings
101 * @buf_mutex: mutex to serialize access to buffer-related bits
102
103 * @enabled: MSC is enabled
104 * @wrap: wrapping is enabled
105 * @mode: MSC operating mode
106 * @burst_len: write burst length
107 * @index: number of this MSC in the MSU
108 */
109 struct msc {
110 void __iomem *reg_base;
111 struct intel_th_device *thdev;
112
113 struct list_head win_list;
114 struct sg_table single_sgt;
115 unsigned long nr_pages;
116 unsigned long single_sz;
117 unsigned int single_wrap : 1;
118 void *base;
119 dma_addr_t base_addr;
120
121 /* <0: no buffer, 0: no users, >0: active users */
122 atomic_t user_count;
123
124 atomic_t mmap_count;
125 struct mutex buf_mutex;
126
127 struct mutex iter_mutex;
128 struct list_head iter_list;
129
130 /* config */
131 unsigned int enabled : 1,
132 wrap : 1;
133 unsigned int mode;
134 unsigned int burst_len;
135 unsigned int index;
136 };
137
msc_block_is_empty(struct msc_block_desc * bdesc)138 static inline bool msc_block_is_empty(struct msc_block_desc *bdesc)
139 {
140 /* header hasn't been written */
141 if (!bdesc->valid_dw)
142 return true;
143
144 /* valid_dw includes the header */
145 if (!msc_data_sz(bdesc))
146 return true;
147
148 return false;
149 }
150
151 /**
152 * msc_oldest_window() - locate the window with oldest data
153 * @msc: MSC device
154 *
155 * This should only be used in multiblock mode. Caller should hold the
156 * msc::user_count reference.
157 *
158 * Return: the oldest window with valid data
159 */
msc_oldest_window(struct msc * msc)160 static struct msc_window *msc_oldest_window(struct msc *msc)
161 {
162 struct msc_window *win;
163 u32 reg = ioread32(msc->reg_base + REG_MSU_MSC0NWSA);
164 unsigned long win_addr = (unsigned long)reg << PAGE_SHIFT;
165 unsigned int found = 0;
166
167 if (list_empty(&msc->win_list))
168 return NULL;
169
170 /*
171 * we might need a radix tree for this, depending on how
172 * many windows a typical user would allocate; ideally it's
173 * something like 2, in which case we're good
174 */
175 list_for_each_entry(win, &msc->win_list, entry) {
176 if (win->block[0].addr == win_addr)
177 found++;
178
179 /* skip the empty ones */
180 if (msc_block_is_empty(win->block[0].bdesc))
181 continue;
182
183 if (found)
184 return win;
185 }
186
187 return list_entry(msc->win_list.next, struct msc_window, entry);
188 }
189
190 /**
191 * msc_win_oldest_block() - locate the oldest block in a given window
192 * @win: window to look at
193 *
194 * Return: index of the block with the oldest data
195 */
msc_win_oldest_block(struct msc_window * win)196 static unsigned int msc_win_oldest_block(struct msc_window *win)
197 {
198 unsigned int blk;
199 struct msc_block_desc *bdesc = win->block[0].bdesc;
200
201 /* without wrapping, first block is the oldest */
202 if (!msc_block_wrapped(bdesc))
203 return 0;
204
205 /*
206 * with wrapping, last written block contains both the newest and the
207 * oldest data for this window.
208 */
209 for (blk = 0; blk < win->nr_blocks; blk++) {
210 bdesc = win->block[blk].bdesc;
211
212 if (msc_block_last_written(bdesc))
213 return blk;
214 }
215
216 return 0;
217 }
218
219 /**
220 * msc_is_last_win() - check if a window is the last one for a given MSC
221 * @win: window
222 * Return: true if @win is the last window in MSC's multiblock buffer
223 */
msc_is_last_win(struct msc_window * win)224 static inline bool msc_is_last_win(struct msc_window *win)
225 {
226 return win->entry.next == &win->msc->win_list;
227 }
228
229 /**
230 * msc_next_window() - return next window in the multiblock buffer
231 * @win: current window
232 *
233 * Return: window following the current one
234 */
msc_next_window(struct msc_window * win)235 static struct msc_window *msc_next_window(struct msc_window *win)
236 {
237 if (msc_is_last_win(win))
238 return list_entry(win->msc->win_list.next, struct msc_window,
239 entry);
240
241 return list_entry(win->entry.next, struct msc_window, entry);
242 }
243
msc_iter_bdesc(struct msc_iter * iter)244 static struct msc_block_desc *msc_iter_bdesc(struct msc_iter *iter)
245 {
246 return iter->win->block[iter->block].bdesc;
247 }
248
msc_iter_init(struct msc_iter * iter)249 static void msc_iter_init(struct msc_iter *iter)
250 {
251 memset(iter, 0, sizeof(*iter));
252 iter->start_block = -1;
253 iter->block = -1;
254 }
255
msc_iter_install(struct msc * msc)256 static struct msc_iter *msc_iter_install(struct msc *msc)
257 {
258 struct msc_iter *iter;
259
260 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
261 if (!iter)
262 return NULL;
263
264 msc_iter_init(iter);
265 iter->msc = msc;
266
267 mutex_lock(&msc->iter_mutex);
268 list_add_tail(&iter->entry, &msc->iter_list);
269 mutex_unlock(&msc->iter_mutex);
270
271 return iter;
272 }
273
msc_iter_remove(struct msc_iter * iter,struct msc * msc)274 static void msc_iter_remove(struct msc_iter *iter, struct msc *msc)
275 {
276 mutex_lock(&msc->iter_mutex);
277 list_del(&iter->entry);
278 mutex_unlock(&msc->iter_mutex);
279
280 kfree(iter);
281 }
282
msc_iter_block_start(struct msc_iter * iter)283 static void msc_iter_block_start(struct msc_iter *iter)
284 {
285 if (iter->start_block != -1)
286 return;
287
288 iter->start_block = msc_win_oldest_block(iter->win);
289 iter->block = iter->start_block;
290 iter->wrap_count = 0;
291
292 /*
293 * start with the block with oldest data; if data has wrapped
294 * in this window, it should be in this block
295 */
296 if (msc_block_wrapped(msc_iter_bdesc(iter)))
297 iter->wrap_count = 2;
298
299 }
300
msc_iter_win_start(struct msc_iter * iter,struct msc * msc)301 static int msc_iter_win_start(struct msc_iter *iter, struct msc *msc)
302 {
303 /* already started, nothing to do */
304 if (iter->start_win)
305 return 0;
306
307 iter->start_win = msc_oldest_window(msc);
308 if (!iter->start_win)
309 return -EINVAL;
310
311 iter->win = iter->start_win;
312 iter->start_block = -1;
313
314 msc_iter_block_start(iter);
315
316 return 0;
317 }
318
msc_iter_win_advance(struct msc_iter * iter)319 static int msc_iter_win_advance(struct msc_iter *iter)
320 {
321 iter->win = msc_next_window(iter->win);
322 iter->start_block = -1;
323
324 if (iter->win == iter->start_win) {
325 iter->eof++;
326 return 1;
327 }
328
329 msc_iter_block_start(iter);
330
331 return 0;
332 }
333
msc_iter_block_advance(struct msc_iter * iter)334 static int msc_iter_block_advance(struct msc_iter *iter)
335 {
336 iter->block_off = 0;
337
338 /* wrapping */
339 if (iter->wrap_count && iter->block == iter->start_block) {
340 iter->wrap_count--;
341 if (!iter->wrap_count)
342 /* copied newest data from the wrapped block */
343 return msc_iter_win_advance(iter);
344 }
345
346 /* no wrapping, check for last written block */
347 if (!iter->wrap_count && msc_block_last_written(msc_iter_bdesc(iter)))
348 /* copied newest data for the window */
349 return msc_iter_win_advance(iter);
350
351 /* block advance */
352 if (++iter->block == iter->win->nr_blocks)
353 iter->block = 0;
354
355 /* no wrapping, sanity check in case there is no last written block */
356 if (!iter->wrap_count && iter->block == iter->start_block)
357 return msc_iter_win_advance(iter);
358
359 return 0;
360 }
361
362 /**
363 * msc_buffer_iterate() - go through multiblock buffer's data
364 * @iter: iterator structure
365 * @size: amount of data to scan
366 * @data: callback's private data
367 * @fn: iterator callback
368 *
369 * This will start at the window which will be written to next (containing
370 * the oldest data) and work its way to the current window, calling @fn
371 * for each chunk of data as it goes.
372 *
373 * Caller should have msc::user_count reference to make sure the buffer
374 * doesn't disappear from under us.
375 *
376 * Return: amount of data actually scanned.
377 */
378 static ssize_t
msc_buffer_iterate(struct msc_iter * iter,size_t size,void * data,unsigned long (* fn)(void *,void *,size_t))379 msc_buffer_iterate(struct msc_iter *iter, size_t size, void *data,
380 unsigned long (*fn)(void *, void *, size_t))
381 {
382 struct msc *msc = iter->msc;
383 size_t len = size;
384 unsigned int advance;
385
386 if (iter->eof)
387 return 0;
388
389 /* start with the oldest window */
390 if (msc_iter_win_start(iter, msc))
391 return 0;
392
393 do {
394 unsigned long data_bytes = msc_data_sz(msc_iter_bdesc(iter));
395 void *src = (void *)msc_iter_bdesc(iter) + MSC_BDESC;
396 size_t tocopy = data_bytes, copied = 0;
397 size_t remaining = 0;
398
399 advance = 1;
400
401 /*
402 * If block wrapping happened, we need to visit the last block
403 * twice, because it contains both the oldest and the newest
404 * data in this window.
405 *
406 * First time (wrap_count==2), in the very beginning, to collect
407 * the oldest data, which is in the range
408 * (data_bytes..DATA_IN_PAGE).
409 *
410 * Second time (wrap_count==1), it's just like any other block,
411 * containing data in the range of [MSC_BDESC..data_bytes].
412 */
413 if (iter->block == iter->start_block && iter->wrap_count) {
414 tocopy = DATA_IN_PAGE - data_bytes;
415 src += data_bytes;
416 }
417
418 if (!tocopy)
419 goto next_block;
420
421 tocopy -= iter->block_off;
422 src += iter->block_off;
423
424 if (len < tocopy) {
425 tocopy = len;
426 advance = 0;
427 }
428
429 remaining = fn(data, src, tocopy);
430
431 if (remaining)
432 advance = 0;
433
434 copied = tocopy - remaining;
435 len -= copied;
436 iter->block_off += copied;
437 iter->offset += copied;
438
439 if (!advance)
440 break;
441
442 next_block:
443 if (msc_iter_block_advance(iter))
444 break;
445
446 } while (len);
447
448 return size - len;
449 }
450
451 /**
452 * msc_buffer_clear_hw_header() - clear hw header for multiblock
453 * @msc: MSC device
454 */
msc_buffer_clear_hw_header(struct msc * msc)455 static void msc_buffer_clear_hw_header(struct msc *msc)
456 {
457 struct msc_window *win;
458
459 mutex_lock(&msc->buf_mutex);
460 list_for_each_entry(win, &msc->win_list, entry) {
461 unsigned int blk;
462 size_t hw_sz = sizeof(struct msc_block_desc) -
463 offsetof(struct msc_block_desc, hw_tag);
464
465 for (blk = 0; blk < win->nr_blocks; blk++) {
466 struct msc_block_desc *bdesc = win->block[blk].bdesc;
467
468 memset(&bdesc->hw_tag, 0, hw_sz);
469 }
470 }
471 mutex_unlock(&msc->buf_mutex);
472 }
473
474 /**
475 * msc_configure() - set up MSC hardware
476 * @msc: the MSC device to configure
477 *
478 * Program storage mode, wrapping, burst length and trace buffer address
479 * into a given MSC. If msc::enabled is set, enable the trace, too.
480 */
msc_configure(struct msc * msc)481 static int msc_configure(struct msc *msc)
482 {
483 u32 reg;
484
485 if (msc->mode > MSC_MODE_MULTI)
486 return -EINVAL;
487
488 if (msc->mode == MSC_MODE_MULTI)
489 msc_buffer_clear_hw_header(msc);
490
491 reg = msc->base_addr >> PAGE_SHIFT;
492 iowrite32(reg, msc->reg_base + REG_MSU_MSC0BAR);
493
494 if (msc->mode == MSC_MODE_SINGLE) {
495 reg = msc->nr_pages;
496 iowrite32(reg, msc->reg_base + REG_MSU_MSC0SIZE);
497 }
498
499 reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL);
500 reg &= ~(MSC_MODE | MSC_WRAPEN | MSC_EN | MSC_RD_HDR_OVRD);
501
502 reg |= msc->mode << __ffs(MSC_MODE);
503 reg |= msc->burst_len << __ffs(MSC_LEN);
504 /*if (msc->mode == MSC_MODE_MULTI)
505 reg |= MSC_RD_HDR_OVRD; */
506 if (msc->wrap)
507 reg |= MSC_WRAPEN;
508 if (msc->enabled)
509 reg |= MSC_EN;
510
511 iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL);
512
513 if (msc->enabled) {
514 msc->thdev->output.multiblock = msc->mode == MSC_MODE_MULTI;
515 intel_th_trace_enable(msc->thdev);
516 }
517
518 return 0;
519 }
520
521 /**
522 * msc_disable() - disable MSC hardware
523 * @msc: MSC device to disable
524 *
525 * If @msc is enabled, disable tracing on the switch and then disable MSC
526 * storage.
527 */
msc_disable(struct msc * msc)528 static void msc_disable(struct msc *msc)
529 {
530 unsigned long count;
531 u32 reg;
532
533 if (!msc->enabled)
534 return;
535
536 intel_th_trace_disable(msc->thdev);
537
538 for (reg = 0, count = MSC_PLE_WAITLOOP_DEPTH;
539 count && !(reg & MSCSTS_PLE); count--) {
540 reg = ioread32(msc->reg_base + REG_MSU_MSC0STS);
541 cpu_relax();
542 }
543
544 if (!count)
545 dev_dbg(msc_dev(msc), "timeout waiting for MSC0 PLE\n");
546
547 if (msc->mode == MSC_MODE_SINGLE) {
548 msc->single_wrap = !!(reg & MSCSTS_WRAPSTAT);
549
550 reg = ioread32(msc->reg_base + REG_MSU_MSC0MWP);
551 msc->single_sz = reg & ((msc->nr_pages << PAGE_SHIFT) - 1);
552 dev_dbg(msc_dev(msc), "MSCnMWP: %08x/%08lx, wrap: %d\n",
553 reg, msc->single_sz, msc->single_wrap);
554 }
555
556 reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL);
557 reg &= ~MSC_EN;
558 iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL);
559 msc->enabled = 0;
560
561 iowrite32(0, msc->reg_base + REG_MSU_MSC0BAR);
562 iowrite32(0, msc->reg_base + REG_MSU_MSC0SIZE);
563
564 dev_dbg(msc_dev(msc), "MSCnNWSA: %08x\n",
565 ioread32(msc->reg_base + REG_MSU_MSC0NWSA));
566
567 reg = ioread32(msc->reg_base + REG_MSU_MSC0STS);
568 dev_dbg(msc_dev(msc), "MSCnSTS: %08x\n", reg);
569 }
570
intel_th_msc_activate(struct intel_th_device * thdev)571 static int intel_th_msc_activate(struct intel_th_device *thdev)
572 {
573 struct msc *msc = dev_get_drvdata(&thdev->dev);
574 int ret = 0;
575
576 if (!atomic_inc_unless_negative(&msc->user_count))
577 return -ENODEV;
578
579 mutex_lock(&msc->iter_mutex);
580 if (!list_empty(&msc->iter_list))
581 ret = -EBUSY;
582 mutex_unlock(&msc->iter_mutex);
583
584 if (ret) {
585 atomic_dec(&msc->user_count);
586 return ret;
587 }
588
589 msc->enabled = 1;
590
591 return msc_configure(msc);
592 }
593
intel_th_msc_deactivate(struct intel_th_device * thdev)594 static void intel_th_msc_deactivate(struct intel_th_device *thdev)
595 {
596 struct msc *msc = dev_get_drvdata(&thdev->dev);
597
598 msc_disable(msc);
599
600 atomic_dec(&msc->user_count);
601 }
602
603 /**
604 * msc_buffer_contig_alloc() - allocate a contiguous buffer for SINGLE mode
605 * @msc: MSC device
606 * @size: allocation size in bytes
607 *
608 * This modifies msc::base, which requires msc::buf_mutex to serialize, so the
609 * caller is expected to hold it.
610 *
611 * Return: 0 on success, -errno otherwise.
612 */
msc_buffer_contig_alloc(struct msc * msc,unsigned long size)613 static int msc_buffer_contig_alloc(struct msc *msc, unsigned long size)
614 {
615 unsigned long nr_pages = size >> PAGE_SHIFT;
616 unsigned int order = get_order(size);
617 struct page *page;
618 int ret;
619
620 if (!size)
621 return 0;
622
623 ret = sg_alloc_table(&msc->single_sgt, 1, GFP_KERNEL);
624 if (ret)
625 goto err_out;
626
627 ret = -ENOMEM;
628 page = alloc_pages(GFP_KERNEL | __GFP_ZERO | GFP_DMA32, order);
629 if (!page)
630 goto err_free_sgt;
631
632 split_page(page, order);
633 sg_set_buf(msc->single_sgt.sgl, page_address(page), size);
634
635 ret = dma_map_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl, 1,
636 DMA_FROM_DEVICE);
637 if (ret < 0)
638 goto err_free_pages;
639
640 msc->nr_pages = nr_pages;
641 msc->base = page_address(page);
642 msc->base_addr = sg_dma_address(msc->single_sgt.sgl);
643
644 return 0;
645
646 err_free_pages:
647 __free_pages(page, order);
648
649 err_free_sgt:
650 sg_free_table(&msc->single_sgt);
651
652 err_out:
653 return ret;
654 }
655
656 /**
657 * msc_buffer_contig_free() - free a contiguous buffer
658 * @msc: MSC configured in SINGLE mode
659 */
msc_buffer_contig_free(struct msc * msc)660 static void msc_buffer_contig_free(struct msc *msc)
661 {
662 unsigned long off;
663
664 dma_unmap_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl,
665 1, DMA_FROM_DEVICE);
666 sg_free_table(&msc->single_sgt);
667
668 for (off = 0; off < msc->nr_pages << PAGE_SHIFT; off += PAGE_SIZE) {
669 struct page *page = virt_to_page(msc->base + off);
670
671 page->mapping = NULL;
672 __free_page(page);
673 }
674
675 msc->nr_pages = 0;
676 }
677
678 /**
679 * msc_buffer_contig_get_page() - find a page at a given offset
680 * @msc: MSC configured in SINGLE mode
681 * @pgoff: page offset
682 *
683 * Return: page, if @pgoff is within the range, NULL otherwise.
684 */
msc_buffer_contig_get_page(struct msc * msc,unsigned long pgoff)685 static struct page *msc_buffer_contig_get_page(struct msc *msc,
686 unsigned long pgoff)
687 {
688 if (pgoff >= msc->nr_pages)
689 return NULL;
690
691 return virt_to_page(msc->base + (pgoff << PAGE_SHIFT));
692 }
693
694 /**
695 * msc_buffer_win_alloc() - alloc a window for a multiblock mode
696 * @msc: MSC device
697 * @nr_blocks: number of pages in this window
698 *
699 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex
700 * to serialize, so the caller is expected to hold it.
701 *
702 * Return: 0 on success, -errno otherwise.
703 */
msc_buffer_win_alloc(struct msc * msc,unsigned int nr_blocks)704 static int msc_buffer_win_alloc(struct msc *msc, unsigned int nr_blocks)
705 {
706 struct msc_window *win;
707 unsigned long size = PAGE_SIZE;
708 int i, ret = -ENOMEM;
709
710 if (!nr_blocks)
711 return 0;
712
713 win = kzalloc(offsetof(struct msc_window, block[nr_blocks]),
714 GFP_KERNEL);
715 if (!win)
716 return -ENOMEM;
717
718 if (!list_empty(&msc->win_list)) {
719 struct msc_window *prev = list_entry(msc->win_list.prev,
720 struct msc_window, entry);
721
722 win->pgoff = prev->pgoff + prev->nr_blocks;
723 }
724
725 for (i = 0; i < nr_blocks; i++) {
726 win->block[i].bdesc = dma_alloc_coherent(msc_dev(msc), size,
727 &win->block[i].addr,
728 GFP_KERNEL);
729
730 #ifdef CONFIG_X86
731 /* Set the page as uncached */
732 set_memory_uc((unsigned long)win->block[i].bdesc, 1);
733 #endif
734
735 if (!win->block[i].bdesc)
736 goto err_nomem;
737 }
738
739 win->msc = msc;
740 win->nr_blocks = nr_blocks;
741
742 if (list_empty(&msc->win_list)) {
743 msc->base = win->block[0].bdesc;
744 msc->base_addr = win->block[0].addr;
745 }
746
747 list_add_tail(&win->entry, &msc->win_list);
748 msc->nr_pages += nr_blocks;
749
750 return 0;
751
752 err_nomem:
753 for (i--; i >= 0; i--) {
754 #ifdef CONFIG_X86
755 /* Reset the page to write-back before releasing */
756 set_memory_wb((unsigned long)win->block[i].bdesc, 1);
757 #endif
758 dma_free_coherent(msc_dev(msc), size, win->block[i].bdesc,
759 win->block[i].addr);
760 }
761 kfree(win);
762
763 return ret;
764 }
765
766 /**
767 * msc_buffer_win_free() - free a window from MSC's window list
768 * @msc: MSC device
769 * @win: window to free
770 *
771 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex
772 * to serialize, so the caller is expected to hold it.
773 */
msc_buffer_win_free(struct msc * msc,struct msc_window * win)774 static void msc_buffer_win_free(struct msc *msc, struct msc_window *win)
775 {
776 int i;
777
778 msc->nr_pages -= win->nr_blocks;
779
780 list_del(&win->entry);
781 if (list_empty(&msc->win_list)) {
782 msc->base = NULL;
783 msc->base_addr = 0;
784 }
785
786 for (i = 0; i < win->nr_blocks; i++) {
787 struct page *page = virt_to_page(win->block[i].bdesc);
788
789 page->mapping = NULL;
790 #ifdef CONFIG_X86
791 /* Reset the page to write-back before releasing */
792 set_memory_wb((unsigned long)win->block[i].bdesc, 1);
793 #endif
794 dma_free_coherent(msc_dev(win->msc), PAGE_SIZE,
795 win->block[i].bdesc, win->block[i].addr);
796 }
797
798 kfree(win);
799 }
800
801 /**
802 * msc_buffer_relink() - set up block descriptors for multiblock mode
803 * @msc: MSC device
804 *
805 * This traverses msc::win_list, which requires msc::buf_mutex to serialize,
806 * so the caller is expected to hold it.
807 */
msc_buffer_relink(struct msc * msc)808 static void msc_buffer_relink(struct msc *msc)
809 {
810 struct msc_window *win, *next_win;
811
812 /* call with msc::mutex locked */
813 list_for_each_entry(win, &msc->win_list, entry) {
814 unsigned int blk;
815 u32 sw_tag = 0;
816
817 /*
818 * Last window's next_win should point to the first window
819 * and MSC_SW_TAG_LASTWIN should be set.
820 */
821 if (msc_is_last_win(win)) {
822 sw_tag |= MSC_SW_TAG_LASTWIN;
823 next_win = list_entry(msc->win_list.next,
824 struct msc_window, entry);
825 } else {
826 next_win = list_entry(win->entry.next,
827 struct msc_window, entry);
828 }
829
830 for (blk = 0; blk < win->nr_blocks; blk++) {
831 struct msc_block_desc *bdesc = win->block[blk].bdesc;
832
833 memset(bdesc, 0, sizeof(*bdesc));
834
835 bdesc->next_win = next_win->block[0].addr >> PAGE_SHIFT;
836
837 /*
838 * Similarly to last window, last block should point
839 * to the first one.
840 */
841 if (blk == win->nr_blocks - 1) {
842 sw_tag |= MSC_SW_TAG_LASTBLK;
843 bdesc->next_blk =
844 win->block[0].addr >> PAGE_SHIFT;
845 } else {
846 bdesc->next_blk =
847 win->block[blk + 1].addr >> PAGE_SHIFT;
848 }
849
850 bdesc->sw_tag = sw_tag;
851 bdesc->block_sz = PAGE_SIZE / 64;
852 }
853 }
854
855 /*
856 * Make the above writes globally visible before tracing is
857 * enabled to make sure hardware sees them coherently.
858 */
859 wmb();
860 }
861
msc_buffer_multi_free(struct msc * msc)862 static void msc_buffer_multi_free(struct msc *msc)
863 {
864 struct msc_window *win, *iter;
865
866 list_for_each_entry_safe(win, iter, &msc->win_list, entry)
867 msc_buffer_win_free(msc, win);
868 }
869
msc_buffer_multi_alloc(struct msc * msc,unsigned long * nr_pages,unsigned int nr_wins)870 static int msc_buffer_multi_alloc(struct msc *msc, unsigned long *nr_pages,
871 unsigned int nr_wins)
872 {
873 int ret, i;
874
875 for (i = 0; i < nr_wins; i++) {
876 ret = msc_buffer_win_alloc(msc, nr_pages[i]);
877 if (ret) {
878 msc_buffer_multi_free(msc);
879 return ret;
880 }
881 }
882
883 msc_buffer_relink(msc);
884
885 return 0;
886 }
887
888 /**
889 * msc_buffer_free() - free buffers for MSC
890 * @msc: MSC device
891 *
892 * Free MSC's storage buffers.
893 *
894 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex to
895 * serialize, so the caller is expected to hold it.
896 */
msc_buffer_free(struct msc * msc)897 static void msc_buffer_free(struct msc *msc)
898 {
899 if (msc->mode == MSC_MODE_SINGLE)
900 msc_buffer_contig_free(msc);
901 else if (msc->mode == MSC_MODE_MULTI)
902 msc_buffer_multi_free(msc);
903 }
904
905 /**
906 * msc_buffer_alloc() - allocate a buffer for MSC
907 * @msc: MSC device
908 * @size: allocation size in bytes
909 *
910 * Allocate a storage buffer for MSC, depending on the msc::mode, it will be
911 * either done via msc_buffer_contig_alloc() for SINGLE operation mode or
912 * msc_buffer_win_alloc() for multiblock operation. The latter allocates one
913 * window per invocation, so in multiblock mode this can be called multiple
914 * times for the same MSC to allocate multiple windows.
915 *
916 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex
917 * to serialize, so the caller is expected to hold it.
918 *
919 * Return: 0 on success, -errno otherwise.
920 */
msc_buffer_alloc(struct msc * msc,unsigned long * nr_pages,unsigned int nr_wins)921 static int msc_buffer_alloc(struct msc *msc, unsigned long *nr_pages,
922 unsigned int nr_wins)
923 {
924 int ret;
925
926 /* -1: buffer not allocated */
927 if (atomic_read(&msc->user_count) != -1)
928 return -EBUSY;
929
930 if (msc->mode == MSC_MODE_SINGLE) {
931 if (nr_wins != 1)
932 return -EINVAL;
933
934 ret = msc_buffer_contig_alloc(msc, nr_pages[0] << PAGE_SHIFT);
935 } else if (msc->mode == MSC_MODE_MULTI) {
936 ret = msc_buffer_multi_alloc(msc, nr_pages, nr_wins);
937 } else {
938 ret = -EINVAL;
939 }
940
941 if (!ret) {
942 /* allocation should be visible before the counter goes to 0 */
943 smp_mb__before_atomic();
944
945 if (WARN_ON_ONCE(atomic_cmpxchg(&msc->user_count, -1, 0) != -1))
946 return -EINVAL;
947 }
948
949 return ret;
950 }
951
952 /**
953 * msc_buffer_unlocked_free_unless_used() - free a buffer unless it's in use
954 * @msc: MSC device
955 *
956 * This will free MSC buffer unless it is in use or there is no allocated
957 * buffer.
958 * Caller needs to hold msc::buf_mutex.
959 *
960 * Return: 0 on successful deallocation or if there was no buffer to
961 * deallocate, -EBUSY if there are active users.
962 */
msc_buffer_unlocked_free_unless_used(struct msc * msc)963 static int msc_buffer_unlocked_free_unless_used(struct msc *msc)
964 {
965 int count, ret = 0;
966
967 count = atomic_cmpxchg(&msc->user_count, 0, -1);
968
969 /* > 0: buffer is allocated and has users */
970 if (count > 0)
971 ret = -EBUSY;
972 /* 0: buffer is allocated, no users */
973 else if (!count)
974 msc_buffer_free(msc);
975 /* < 0: no buffer, nothing to do */
976
977 return ret;
978 }
979
980 /**
981 * msc_buffer_free_unless_used() - free a buffer unless it's in use
982 * @msc: MSC device
983 *
984 * This is a locked version of msc_buffer_unlocked_free_unless_used().
985 */
msc_buffer_free_unless_used(struct msc * msc)986 static int msc_buffer_free_unless_used(struct msc *msc)
987 {
988 int ret;
989
990 mutex_lock(&msc->buf_mutex);
991 ret = msc_buffer_unlocked_free_unless_used(msc);
992 mutex_unlock(&msc->buf_mutex);
993
994 return ret;
995 }
996
997 /**
998 * msc_buffer_get_page() - get MSC buffer page at a given offset
999 * @msc: MSC device
1000 * @pgoff: page offset into the storage buffer
1001 *
1002 * This traverses msc::win_list, so holding msc::buf_mutex is expected from
1003 * the caller.
1004 *
1005 * Return: page if @pgoff corresponds to a valid buffer page or NULL.
1006 */
msc_buffer_get_page(struct msc * msc,unsigned long pgoff)1007 static struct page *msc_buffer_get_page(struct msc *msc, unsigned long pgoff)
1008 {
1009 struct msc_window *win;
1010
1011 if (msc->mode == MSC_MODE_SINGLE)
1012 return msc_buffer_contig_get_page(msc, pgoff);
1013
1014 list_for_each_entry(win, &msc->win_list, entry)
1015 if (pgoff >= win->pgoff && pgoff < win->pgoff + win->nr_blocks)
1016 goto found;
1017
1018 return NULL;
1019
1020 found:
1021 pgoff -= win->pgoff;
1022 return virt_to_page(win->block[pgoff].bdesc);
1023 }
1024
1025 /**
1026 * struct msc_win_to_user_struct - data for copy_to_user() callback
1027 * @buf: userspace buffer to copy data to
1028 * @offset: running offset
1029 */
1030 struct msc_win_to_user_struct {
1031 char __user *buf;
1032 unsigned long offset;
1033 };
1034
1035 /**
1036 * msc_win_to_user() - iterator for msc_buffer_iterate() to copy data to user
1037 * @data: callback's private data
1038 * @src: source buffer
1039 * @len: amount of data to copy from the source buffer
1040 */
msc_win_to_user(void * data,void * src,size_t len)1041 static unsigned long msc_win_to_user(void *data, void *src, size_t len)
1042 {
1043 struct msc_win_to_user_struct *u = data;
1044 unsigned long ret;
1045
1046 ret = copy_to_user(u->buf + u->offset, src, len);
1047 u->offset += len - ret;
1048
1049 return ret;
1050 }
1051
1052
1053 /*
1054 * file operations' callbacks
1055 */
1056
intel_th_msc_open(struct inode * inode,struct file * file)1057 static int intel_th_msc_open(struct inode *inode, struct file *file)
1058 {
1059 struct intel_th_device *thdev = file->private_data;
1060 struct msc *msc = dev_get_drvdata(&thdev->dev);
1061 struct msc_iter *iter;
1062
1063 if (!capable(CAP_SYS_RAWIO))
1064 return -EPERM;
1065
1066 iter = msc_iter_install(msc);
1067 if (!iter)
1068 return -ENOMEM;
1069
1070 file->private_data = iter;
1071
1072 return nonseekable_open(inode, file);
1073 }
1074
intel_th_msc_release(struct inode * inode,struct file * file)1075 static int intel_th_msc_release(struct inode *inode, struct file *file)
1076 {
1077 struct msc_iter *iter = file->private_data;
1078 struct msc *msc = iter->msc;
1079
1080 msc_iter_remove(iter, msc);
1081
1082 return 0;
1083 }
1084
1085 static ssize_t
msc_single_to_user(struct msc * msc,char __user * buf,loff_t off,size_t len)1086 msc_single_to_user(struct msc *msc, char __user *buf, loff_t off, size_t len)
1087 {
1088 unsigned long size = msc->nr_pages << PAGE_SHIFT, rem = len;
1089 unsigned long start = off, tocopy = 0;
1090
1091 if (msc->single_wrap) {
1092 start += msc->single_sz;
1093 if (start < size) {
1094 tocopy = min(rem, size - start);
1095 if (copy_to_user(buf, msc->base + start, tocopy))
1096 return -EFAULT;
1097
1098 buf += tocopy;
1099 rem -= tocopy;
1100 start += tocopy;
1101 }
1102
1103 start &= size - 1;
1104 if (rem) {
1105 tocopy = min(rem, msc->single_sz - start);
1106 if (copy_to_user(buf, msc->base + start, tocopy))
1107 return -EFAULT;
1108
1109 rem -= tocopy;
1110 }
1111
1112 return len - rem;
1113 }
1114
1115 if (copy_to_user(buf, msc->base + start, rem))
1116 return -EFAULT;
1117
1118 return len;
1119 }
1120
intel_th_msc_read(struct file * file,char __user * buf,size_t len,loff_t * ppos)1121 static ssize_t intel_th_msc_read(struct file *file, char __user *buf,
1122 size_t len, loff_t *ppos)
1123 {
1124 struct msc_iter *iter = file->private_data;
1125 struct msc *msc = iter->msc;
1126 size_t size;
1127 loff_t off = *ppos;
1128 ssize_t ret = 0;
1129
1130 if (!atomic_inc_unless_negative(&msc->user_count))
1131 return 0;
1132
1133 if (msc->enabled) {
1134 ret = -EBUSY;
1135 goto put_count;
1136 }
1137
1138 if (msc->mode == MSC_MODE_SINGLE && !msc->single_wrap)
1139 size = msc->single_sz;
1140 else
1141 size = msc->nr_pages << PAGE_SHIFT;
1142
1143 if (!size)
1144 return 0;
1145
1146 if (off >= size) {
1147 len = 0;
1148 goto put_count;
1149 }
1150 if (off + len >= size)
1151 len = size - off;
1152
1153 if (msc->mode == MSC_MODE_SINGLE) {
1154 ret = msc_single_to_user(msc, buf, off, len);
1155 if (ret >= 0)
1156 *ppos += ret;
1157 } else if (msc->mode == MSC_MODE_MULTI) {
1158 struct msc_win_to_user_struct u = {
1159 .buf = buf,
1160 .offset = 0,
1161 };
1162
1163 ret = msc_buffer_iterate(iter, len, &u, msc_win_to_user);
1164 if (ret >= 0)
1165 *ppos = iter->offset;
1166 } else {
1167 ret = -EINVAL;
1168 }
1169
1170 put_count:
1171 atomic_dec(&msc->user_count);
1172
1173 return ret;
1174 }
1175
1176 /*
1177 * vm operations callbacks (vm_ops)
1178 */
1179
msc_mmap_open(struct vm_area_struct * vma)1180 static void msc_mmap_open(struct vm_area_struct *vma)
1181 {
1182 struct msc_iter *iter = vma->vm_file->private_data;
1183 struct msc *msc = iter->msc;
1184
1185 atomic_inc(&msc->mmap_count);
1186 }
1187
msc_mmap_close(struct vm_area_struct * vma)1188 static void msc_mmap_close(struct vm_area_struct *vma)
1189 {
1190 struct msc_iter *iter = vma->vm_file->private_data;
1191 struct msc *msc = iter->msc;
1192 unsigned long pg;
1193
1194 if (!atomic_dec_and_mutex_lock(&msc->mmap_count, &msc->buf_mutex))
1195 return;
1196
1197 /* drop page _counts */
1198 for (pg = 0; pg < msc->nr_pages; pg++) {
1199 struct page *page = msc_buffer_get_page(msc, pg);
1200
1201 if (WARN_ON_ONCE(!page))
1202 continue;
1203
1204 if (page->mapping)
1205 page->mapping = NULL;
1206 }
1207
1208 /* last mapping -- drop user_count */
1209 atomic_dec(&msc->user_count);
1210 mutex_unlock(&msc->buf_mutex);
1211 }
1212
msc_mmap_fault(struct vm_area_struct * vma,struct vm_fault * vmf)1213 static int msc_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1214 {
1215 struct msc_iter *iter = vma->vm_file->private_data;
1216 struct msc *msc = iter->msc;
1217
1218 vmf->page = msc_buffer_get_page(msc, vmf->pgoff);
1219 if (!vmf->page)
1220 return VM_FAULT_SIGBUS;
1221
1222 get_page(vmf->page);
1223 vmf->page->mapping = vma->vm_file->f_mapping;
1224 vmf->page->index = vmf->pgoff;
1225
1226 return 0;
1227 }
1228
1229 static const struct vm_operations_struct msc_mmap_ops = {
1230 .open = msc_mmap_open,
1231 .close = msc_mmap_close,
1232 .fault = msc_mmap_fault,
1233 };
1234
intel_th_msc_mmap(struct file * file,struct vm_area_struct * vma)1235 static int intel_th_msc_mmap(struct file *file, struct vm_area_struct *vma)
1236 {
1237 unsigned long size = vma->vm_end - vma->vm_start;
1238 struct msc_iter *iter = vma->vm_file->private_data;
1239 struct msc *msc = iter->msc;
1240 int ret = -EINVAL;
1241
1242 if (!size || offset_in_page(size))
1243 return -EINVAL;
1244
1245 if (vma->vm_pgoff)
1246 return -EINVAL;
1247
1248 /* grab user_count once per mmap; drop in msc_mmap_close() */
1249 if (!atomic_inc_unless_negative(&msc->user_count))
1250 return -EINVAL;
1251
1252 if (msc->mode != MSC_MODE_SINGLE &&
1253 msc->mode != MSC_MODE_MULTI)
1254 goto out;
1255
1256 if (size >> PAGE_SHIFT != msc->nr_pages)
1257 goto out;
1258
1259 atomic_set(&msc->mmap_count, 1);
1260 ret = 0;
1261
1262 out:
1263 if (ret)
1264 atomic_dec(&msc->user_count);
1265
1266 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1267 vma->vm_flags |= VM_DONTEXPAND | VM_DONTCOPY;
1268 vma->vm_ops = &msc_mmap_ops;
1269 return ret;
1270 }
1271
1272 static const struct file_operations intel_th_msc_fops = {
1273 .open = intel_th_msc_open,
1274 .release = intel_th_msc_release,
1275 .read = intel_th_msc_read,
1276 .mmap = intel_th_msc_mmap,
1277 .llseek = no_llseek,
1278 };
1279
intel_th_msc_init(struct msc * msc)1280 static int intel_th_msc_init(struct msc *msc)
1281 {
1282 atomic_set(&msc->user_count, -1);
1283
1284 msc->mode = MSC_MODE_MULTI;
1285 mutex_init(&msc->buf_mutex);
1286 INIT_LIST_HEAD(&msc->win_list);
1287
1288 mutex_init(&msc->iter_mutex);
1289 INIT_LIST_HEAD(&msc->iter_list);
1290
1291 msc->burst_len =
1292 (ioread32(msc->reg_base + REG_MSU_MSC0CTL) & MSC_LEN) >>
1293 __ffs(MSC_LEN);
1294
1295 return 0;
1296 }
1297
1298 static const char * const msc_mode[] = {
1299 [MSC_MODE_SINGLE] = "single",
1300 [MSC_MODE_MULTI] = "multi",
1301 [MSC_MODE_EXI] = "ExI",
1302 [MSC_MODE_DEBUG] = "debug",
1303 };
1304
1305 static ssize_t
wrap_show(struct device * dev,struct device_attribute * attr,char * buf)1306 wrap_show(struct device *dev, struct device_attribute *attr, char *buf)
1307 {
1308 struct msc *msc = dev_get_drvdata(dev);
1309
1310 return scnprintf(buf, PAGE_SIZE, "%d\n", msc->wrap);
1311 }
1312
1313 static ssize_t
wrap_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)1314 wrap_store(struct device *dev, struct device_attribute *attr, const char *buf,
1315 size_t size)
1316 {
1317 struct msc *msc = dev_get_drvdata(dev);
1318 unsigned long val;
1319 int ret;
1320
1321 ret = kstrtoul(buf, 10, &val);
1322 if (ret)
1323 return ret;
1324
1325 msc->wrap = !!val;
1326
1327 return size;
1328 }
1329
1330 static DEVICE_ATTR_RW(wrap);
1331
1332 static ssize_t
mode_show(struct device * dev,struct device_attribute * attr,char * buf)1333 mode_show(struct device *dev, struct device_attribute *attr, char *buf)
1334 {
1335 struct msc *msc = dev_get_drvdata(dev);
1336
1337 return scnprintf(buf, PAGE_SIZE, "%s\n", msc_mode[msc->mode]);
1338 }
1339
1340 static ssize_t
mode_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)1341 mode_store(struct device *dev, struct device_attribute *attr, const char *buf,
1342 size_t size)
1343 {
1344 struct msc *msc = dev_get_drvdata(dev);
1345 size_t len = size;
1346 char *cp;
1347 int i, ret;
1348
1349 if (!capable(CAP_SYS_RAWIO))
1350 return -EPERM;
1351
1352 cp = memchr(buf, '\n', len);
1353 if (cp)
1354 len = cp - buf;
1355
1356 for (i = 0; i < ARRAY_SIZE(msc_mode); i++)
1357 if (!strncmp(msc_mode[i], buf, len))
1358 goto found;
1359
1360 return -EINVAL;
1361
1362 found:
1363 mutex_lock(&msc->buf_mutex);
1364 ret = msc_buffer_unlocked_free_unless_used(msc);
1365 if (!ret)
1366 msc->mode = i;
1367 mutex_unlock(&msc->buf_mutex);
1368
1369 return ret ? ret : size;
1370 }
1371
1372 static DEVICE_ATTR_RW(mode);
1373
1374 static ssize_t
nr_pages_show(struct device * dev,struct device_attribute * attr,char * buf)1375 nr_pages_show(struct device *dev, struct device_attribute *attr, char *buf)
1376 {
1377 struct msc *msc = dev_get_drvdata(dev);
1378 struct msc_window *win;
1379 size_t count = 0;
1380
1381 mutex_lock(&msc->buf_mutex);
1382
1383 if (msc->mode == MSC_MODE_SINGLE)
1384 count = scnprintf(buf, PAGE_SIZE, "%ld\n", msc->nr_pages);
1385 else if (msc->mode == MSC_MODE_MULTI) {
1386 list_for_each_entry(win, &msc->win_list, entry) {
1387 count += scnprintf(buf + count, PAGE_SIZE - count,
1388 "%d%c", win->nr_blocks,
1389 msc_is_last_win(win) ? '\n' : ',');
1390 }
1391 } else {
1392 count = scnprintf(buf, PAGE_SIZE, "unsupported\n");
1393 }
1394
1395 mutex_unlock(&msc->buf_mutex);
1396
1397 return count;
1398 }
1399
1400 static ssize_t
nr_pages_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)1401 nr_pages_store(struct device *dev, struct device_attribute *attr,
1402 const char *buf, size_t size)
1403 {
1404 struct msc *msc = dev_get_drvdata(dev);
1405 unsigned long val, *win = NULL, *rewin;
1406 size_t len = size;
1407 const char *p = buf;
1408 char *end, *s;
1409 int ret, nr_wins = 0;
1410
1411 if (!capable(CAP_SYS_RAWIO))
1412 return -EPERM;
1413
1414 ret = msc_buffer_free_unless_used(msc);
1415 if (ret)
1416 return ret;
1417
1418 /* scan the comma-separated list of allocation sizes */
1419 end = memchr(buf, '\n', len);
1420 if (end)
1421 len = end - buf;
1422
1423 do {
1424 end = memchr(p, ',', len);
1425 s = kstrndup(p, end ? end - p : len, GFP_KERNEL);
1426 ret = kstrtoul(s, 10, &val);
1427 kfree(s);
1428
1429 if (ret || !val)
1430 goto free_win;
1431
1432 if (nr_wins && msc->mode == MSC_MODE_SINGLE) {
1433 ret = -EINVAL;
1434 goto free_win;
1435 }
1436
1437 nr_wins++;
1438 rewin = krealloc(win, sizeof(*win) * nr_wins, GFP_KERNEL);
1439 if (!rewin) {
1440 kfree(win);
1441 return -ENOMEM;
1442 }
1443
1444 win = rewin;
1445 win[nr_wins - 1] = val;
1446
1447 if (!end)
1448 break;
1449
1450 /* consume the number and the following comma, hence +1 */
1451 len -= end - p + 1;
1452 p = end + 1;
1453 } while (len);
1454
1455 mutex_lock(&msc->buf_mutex);
1456 ret = msc_buffer_alloc(msc, win, nr_wins);
1457 mutex_unlock(&msc->buf_mutex);
1458
1459 free_win:
1460 kfree(win);
1461
1462 return ret ? ret : size;
1463 }
1464
1465 static DEVICE_ATTR_RW(nr_pages);
1466
1467 static struct attribute *msc_output_attrs[] = {
1468 &dev_attr_wrap.attr,
1469 &dev_attr_mode.attr,
1470 &dev_attr_nr_pages.attr,
1471 NULL,
1472 };
1473
1474 static struct attribute_group msc_output_group = {
1475 .attrs = msc_output_attrs,
1476 };
1477
intel_th_msc_probe(struct intel_th_device * thdev)1478 static int intel_th_msc_probe(struct intel_th_device *thdev)
1479 {
1480 struct device *dev = &thdev->dev;
1481 struct resource *res;
1482 struct msc *msc;
1483 void __iomem *base;
1484 int err;
1485
1486 res = intel_th_device_get_resource(thdev, IORESOURCE_MEM, 0);
1487 if (!res)
1488 return -ENODEV;
1489
1490 base = devm_ioremap(dev, res->start, resource_size(res));
1491 if (!base)
1492 return -ENOMEM;
1493
1494 msc = devm_kzalloc(dev, sizeof(*msc), GFP_KERNEL);
1495 if (!msc)
1496 return -ENOMEM;
1497
1498 msc->index = thdev->id;
1499
1500 msc->thdev = thdev;
1501 msc->reg_base = base + msc->index * 0x100;
1502
1503 err = intel_th_msc_init(msc);
1504 if (err)
1505 return err;
1506
1507 err = sysfs_create_group(&dev->kobj, &msc_output_group);
1508 if (err)
1509 return err;
1510
1511 dev_set_drvdata(dev, msc);
1512
1513 return 0;
1514 }
1515
intel_th_msc_remove(struct intel_th_device * thdev)1516 static void intel_th_msc_remove(struct intel_th_device *thdev)
1517 {
1518 sysfs_remove_group(&thdev->dev.kobj, &msc_output_group);
1519 }
1520
1521 static struct intel_th_driver intel_th_msc_driver = {
1522 .probe = intel_th_msc_probe,
1523 .remove = intel_th_msc_remove,
1524 .activate = intel_th_msc_activate,
1525 .deactivate = intel_th_msc_deactivate,
1526 .fops = &intel_th_msc_fops,
1527 .driver = {
1528 .name = "msc",
1529 .owner = THIS_MODULE,
1530 },
1531 };
1532
1533 module_driver(intel_th_msc_driver,
1534 intel_th_driver_register,
1535 intel_th_driver_unregister);
1536
1537 MODULE_LICENSE("GPL v2");
1538 MODULE_DESCRIPTION("Intel(R) Trace Hub Memory Storage Unit driver");
1539 MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");
1540