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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 */
42struct 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 */
54struct 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 */
75struct 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 */
108struct 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
125 struct mutex iter_mutex;
126 struct list_head iter_list;
127
128 /* config */
129 unsigned int enabled : 1,
130 wrap : 1;
131 unsigned int mode;
132 unsigned int burst_len;
133 unsigned int index;
134};
135
136static inline bool msc_block_is_empty(struct msc_block_desc *bdesc)
137{
138 /* header hasn't been written */
139 if (!bdesc->valid_dw)
140 return true;
141
142 /* valid_dw includes the header */
143 if (!msc_data_sz(bdesc))
144 return true;
145
146 return false;
147}
148
149/**
150 * msc_oldest_window() - locate the window with oldest data
151 * @msc: MSC device
152 *
153 * This should only be used in multiblock mode. Caller should hold the
154 * msc::user_count reference.
155 *
156 * Return: the oldest window with valid data
157 */
158static struct msc_window *msc_oldest_window(struct msc *msc)
159{
160 struct msc_window *win;
161 u32 reg = ioread32(msc->reg_base + REG_MSU_MSC0NWSA);
162 unsigned long win_addr = (unsigned long)reg << PAGE_SHIFT;
163 unsigned int found = 0;
164
165 if (list_empty(&msc->win_list))
166 return NULL;
167
168 /*
169 * we might need a radix tree for this, depending on how
170 * many windows a typical user would allocate; ideally it's
171 * something like 2, in which case we're good
172 */
173 list_for_each_entry(win, &msc->win_list, entry) {
174 if (win->block[0].addr == win_addr)
175 found++;
176
177 /* skip the empty ones */
178 if (msc_block_is_empty(win->block[0].bdesc))
179 continue;
180
181 if (found)
182 return win;
183 }
184
185 return list_entry(msc->win_list.next, struct msc_window, entry);
186}
187
188/**
189 * msc_win_oldest_block() - locate the oldest block in a given window
190 * @win: window to look at
191 *
192 * Return: index of the block with the oldest data
193 */
194static unsigned int msc_win_oldest_block(struct msc_window *win)
195{
196 unsigned int blk;
197 struct msc_block_desc *bdesc = win->block[0].bdesc;
198
199 /* without wrapping, first block is the oldest */
200 if (!msc_block_wrapped(bdesc))
201 return 0;
202
203 /*
204 * with wrapping, last written block contains both the newest and the
205 * oldest data for this window.
206 */
207 for (blk = 0; blk < win->nr_blocks; blk++) {
208 bdesc = win->block[blk].bdesc;
209
210 if (msc_block_last_written(bdesc))
211 return blk;
212 }
213
214 return 0;
215}
216
217/**
218 * msc_is_last_win() - check if a window is the last one for a given MSC
219 * @win: window
220 * Return: true if @win is the last window in MSC's multiblock buffer
221 */
222static inline bool msc_is_last_win(struct msc_window *win)
223{
224 return win->entry.next == &win->msc->win_list;
225}
226
227/**
228 * msc_next_window() - return next window in the multiblock buffer
229 * @win: current window
230 *
231 * Return: window following the current one
232 */
233static struct msc_window *msc_next_window(struct msc_window *win)
234{
235 if (msc_is_last_win(win))
236 return list_entry(win->msc->win_list.next, struct msc_window,
237 entry);
238
239 return list_entry(win->entry.next, struct msc_window, entry);
240}
241
242static struct msc_block_desc *msc_iter_bdesc(struct msc_iter *iter)
243{
244 return iter->win->block[iter->block].bdesc;
245}
246
247static void msc_iter_init(struct msc_iter *iter)
248{
249 memset(iter, 0, sizeof(*iter));
250 iter->start_block = -1;
251 iter->block = -1;
252}
253
254static struct msc_iter *msc_iter_install(struct msc *msc)
255{
256 struct msc_iter *iter;
257
258 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
259 if (!iter)
260 return NULL;
261
262 msc_iter_init(iter);
263 iter->msc = msc;
264
265 mutex_lock(&msc->iter_mutex);
266 list_add_tail(&iter->entry, &msc->iter_list);
267 mutex_unlock(&msc->iter_mutex);
268
269 return iter;
270}
271
272static void msc_iter_remove(struct msc_iter *iter, struct msc *msc)
273{
274 mutex_lock(&msc->iter_mutex);
275 list_del(&iter->entry);
276 mutex_unlock(&msc->iter_mutex);
277
278 kfree(iter);
279}
280
281static void msc_iter_block_start(struct msc_iter *iter)
282{
283 if (iter->start_block != -1)
284 return;
285
286 iter->start_block = msc_win_oldest_block(iter->win);
287 iter->block = iter->start_block;
288 iter->wrap_count = 0;
289
290 /*
291 * start with the block with oldest data; if data has wrapped
292 * in this window, it should be in this block
293 */
294 if (msc_block_wrapped(msc_iter_bdesc(iter)))
295 iter->wrap_count = 2;
296
297}
298
299static int msc_iter_win_start(struct msc_iter *iter, struct msc *msc)
300{
301 /* already started, nothing to do */
302 if (iter->start_win)
303 return 0;
304
305 iter->start_win = msc_oldest_window(msc);
306 if (!iter->start_win)
307 return -EINVAL;
308
309 iter->win = iter->start_win;
310 iter->start_block = -1;
311
312 msc_iter_block_start(iter);
313
314 return 0;
315}
316
317static int msc_iter_win_advance(struct msc_iter *iter)
318{
319 iter->win = msc_next_window(iter->win);
320 iter->start_block = -1;
321
322 if (iter->win == iter->start_win) {
323 iter->eof++;
324 return 1;
325 }
326
327 msc_iter_block_start(iter);
328
329 return 0;
330}
331
332static int msc_iter_block_advance(struct msc_iter *iter)
333{
334 iter->block_off = 0;
335
336 /* wrapping */
337 if (iter->wrap_count && iter->block == iter->start_block) {
338 iter->wrap_count--;
339 if (!iter->wrap_count)
340 /* copied newest data from the wrapped block */
341 return msc_iter_win_advance(iter);
342 }
343
344 /* no wrapping, check for last written block */
345 if (!iter->wrap_count && msc_block_last_written(msc_iter_bdesc(iter)))
346 /* copied newest data for the window */
347 return msc_iter_win_advance(iter);
348
349 /* block advance */
350 if (++iter->block == iter->win->nr_blocks)
351 iter->block = 0;
352
353 /* no wrapping, sanity check in case there is no last written block */
354 if (!iter->wrap_count && iter->block == iter->start_block)
355 return msc_iter_win_advance(iter);
356
357 return 0;
358}
359
360/**
361 * msc_buffer_iterate() - go through multiblock buffer's data
362 * @iter: iterator structure
363 * @size: amount of data to scan
364 * @data: callback's private data
365 * @fn: iterator callback
366 *
367 * This will start at the window which will be written to next (containing
368 * the oldest data) and work its way to the current window, calling @fn
369 * for each chunk of data as it goes.
370 *
371 * Caller should have msc::user_count reference to make sure the buffer
372 * doesn't disappear from under us.
373 *
374 * Return: amount of data actually scanned.
375 */
376static ssize_t
377msc_buffer_iterate(struct msc_iter *iter, size_t size, void *data,
378 unsigned long (*fn)(void *, void *, size_t))
379{
380 struct msc *msc = iter->msc;
381 size_t len = size;
382 unsigned int advance;
383
384 if (iter->eof)
385 return 0;
386
387 /* start with the oldest window */
388 if (msc_iter_win_start(iter, msc))
389 return 0;
390
391 do {
392 unsigned long data_bytes = msc_data_sz(msc_iter_bdesc(iter));
393 void *src = (void *)msc_iter_bdesc(iter) + MSC_BDESC;
394 size_t tocopy = data_bytes, copied = 0;
395 size_t remaining = 0;
396
397 advance = 1;
398
399 /*
400 * If block wrapping happened, we need to visit the last block
401 * twice, because it contains both the oldest and the newest
402 * data in this window.
403 *
404 * First time (wrap_count==2), in the very beginning, to collect
405 * the oldest data, which is in the range
406 * (data_bytes..DATA_IN_PAGE).
407 *
408 * Second time (wrap_count==1), it's just like any other block,
409 * containing data in the range of [MSC_BDESC..data_bytes].
410 */
411 if (iter->block == iter->start_block && iter->wrap_count == 2) {
412 tocopy = DATA_IN_PAGE - data_bytes;
413 src += data_bytes;
414 }
415
416 if (!tocopy)
417 goto next_block;
418
419 tocopy -= iter->block_off;
420 src += iter->block_off;
421
422 if (len < tocopy) {
423 tocopy = len;
424 advance = 0;
425 }
426
427 remaining = fn(data, src, tocopy);
428
429 if (remaining)
430 advance = 0;
431
432 copied = tocopy - remaining;
433 len -= copied;
434 iter->block_off += copied;
435 iter->offset += copied;
436
437 if (!advance)
438 break;
439
440next_block:
441 if (msc_iter_block_advance(iter))
442 break;
443
444 } while (len);
445
446 return size - len;
447}
448
449/**
450 * msc_buffer_clear_hw_header() - clear hw header for multiblock
451 * @msc: MSC device
452 */
453static void msc_buffer_clear_hw_header(struct msc *msc)
454{
455 struct msc_window *win;
456
457 mutex_lock(&msc->buf_mutex);
458 list_for_each_entry(win, &msc->win_list, entry) {
459 unsigned int blk;
460 size_t hw_sz = sizeof(struct msc_block_desc) -
461 offsetof(struct msc_block_desc, hw_tag);
462
463 for (blk = 0; blk < win->nr_blocks; blk++) {
464 struct msc_block_desc *bdesc = win->block[blk].bdesc;
465
466 memset(&bdesc->hw_tag, 0, hw_sz);
467 }
468 }
469 mutex_unlock(&msc->buf_mutex);
470}
471
472/**
473 * msc_configure() - set up MSC hardware
474 * @msc: the MSC device to configure
475 *
476 * Program storage mode, wrapping, burst length and trace buffer address
477 * into a given MSC. If msc::enabled is set, enable the trace, too.
478 */
479static int msc_configure(struct msc *msc)
480{
481 u32 reg;
482
483 if (msc->mode > MSC_MODE_MULTI)
484 return -ENOTSUPP;
485
486 if (msc->mode == MSC_MODE_MULTI)
487 msc_buffer_clear_hw_header(msc);
488
489 reg = msc->base_addr >> PAGE_SHIFT;
490 iowrite32(reg, msc->reg_base + REG_MSU_MSC0BAR);
491
492 if (msc->mode == MSC_MODE_SINGLE) {
493 reg = msc->nr_pages;
494 iowrite32(reg, msc->reg_base + REG_MSU_MSC0SIZE);
495 }
496
497 reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL);
498 reg &= ~(MSC_MODE | MSC_WRAPEN | MSC_EN | MSC_RD_HDR_OVRD);
499
500 reg |= msc->mode << __ffs(MSC_MODE);
501 reg |= msc->burst_len << __ffs(MSC_LEN);
502 /*if (msc->mode == MSC_MODE_MULTI)
503 reg |= MSC_RD_HDR_OVRD; */
504 if (msc->wrap)
505 reg |= MSC_WRAPEN;
506 if (msc->enabled)
507 reg |= MSC_EN;
508
509 iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL);
510
511 if (msc->enabled) {
512 msc->thdev->output.multiblock = msc->mode == MSC_MODE_MULTI;
513 intel_th_trace_enable(msc->thdev);
514 }
515
516 return 0;
517}
518
519/**
520 * msc_disable() - disable MSC hardware
521 * @msc: MSC device to disable
522 *
523 * If @msc is enabled, disable tracing on the switch and then disable MSC
524 * storage.
525 */
526static void msc_disable(struct msc *msc)
527{
528 unsigned long count;
529 u32 reg;
530
531 if (!msc->enabled)
532 return;
533
534 intel_th_trace_disable(msc->thdev);
535
536 for (reg = 0, count = MSC_PLE_WAITLOOP_DEPTH;
537 count && !(reg & MSCSTS_PLE); count--) {
538 reg = ioread32(msc->reg_base + REG_MSU_MSC0STS);
539 cpu_relax();
540 }
541
542 if (!count)
543 dev_dbg(msc_dev(msc), "timeout waiting for MSC0 PLE\n");
544
545 if (msc->mode == MSC_MODE_SINGLE) {
546 msc->single_wrap = !!(reg & MSCSTS_WRAPSTAT);
547
548 reg = ioread32(msc->reg_base + REG_MSU_MSC0MWP);
549 msc->single_sz = reg & ((msc->nr_pages << PAGE_SHIFT) - 1);
550 dev_dbg(msc_dev(msc), "MSCnMWP: %08x/%08lx, wrap: %d\n",
551 reg, msc->single_sz, msc->single_wrap);
552 }
553
554 reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL);
555 reg &= ~MSC_EN;
556 iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL);
557 msc->enabled = 0;
558
559 iowrite32(0, msc->reg_base + REG_MSU_MSC0BAR);
560 iowrite32(0, msc->reg_base + REG_MSU_MSC0SIZE);
561
562 dev_dbg(msc_dev(msc), "MSCnNWSA: %08x\n",
563 ioread32(msc->reg_base + REG_MSU_MSC0NWSA));
564
565 reg = ioread32(msc->reg_base + REG_MSU_MSC0STS);
566 dev_dbg(msc_dev(msc), "MSCnSTS: %08x\n", reg);
567}
568
569static int intel_th_msc_activate(struct intel_th_device *thdev)
570{
571 struct msc *msc = dev_get_drvdata(&thdev->dev);
572 int ret = 0;
573
574 if (!atomic_inc_unless_negative(&msc->user_count))
575 return -ENODEV;
576
577 mutex_lock(&msc->iter_mutex);
578 if (!list_empty(&msc->iter_list))
579 ret = -EBUSY;
580 mutex_unlock(&msc->iter_mutex);
581
582 if (ret) {
583 atomic_dec(&msc->user_count);
584 return ret;
585 }
586
587 msc->enabled = 1;
588
589 return msc_configure(msc);
590}
591
592static void intel_th_msc_deactivate(struct intel_th_device *thdev)
593{
594 struct msc *msc = dev_get_drvdata(&thdev->dev);
595
596 msc_disable(msc);
597
598 atomic_dec(&msc->user_count);
599}
600
601/**
602 * msc_buffer_contig_alloc() - allocate a contiguous buffer for SINGLE mode
603 * @msc: MSC device
604 * @size: allocation size in bytes
605 *
606 * This modifies msc::base, which requires msc::buf_mutex to serialize, so the
607 * caller is expected to hold it.
608 *
609 * Return: 0 on success, -errno otherwise.
610 */
611static int msc_buffer_contig_alloc(struct msc *msc, unsigned long size)
612{
613 unsigned int order = get_order(size);
614 struct page *page;
615
616 if (!size)
617 return 0;
618
619 page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
620 if (!page)
621 return -ENOMEM;
622
623 split_page(page, order);
624 msc->nr_pages = size >> PAGE_SHIFT;
625 msc->base = page_address(page);
626 msc->base_addr = page_to_phys(page);
627
628 return 0;
629}
630
631/**
632 * msc_buffer_contig_free() - free a contiguous buffer
633 * @msc: MSC configured in SINGLE mode
634 */
635static void msc_buffer_contig_free(struct msc *msc)
636{
637 unsigned long off;
638
639 for (off = 0; off < msc->nr_pages << PAGE_SHIFT; off += PAGE_SIZE) {
640 struct page *page = virt_to_page(msc->base + off);
641
642 page->mapping = NULL;
643 __free_page(page);
644 }
645
646 msc->nr_pages = 0;
647}
648
649/**
650 * msc_buffer_contig_get_page() - find a page at a given offset
651 * @msc: MSC configured in SINGLE mode
652 * @pgoff: page offset
653 *
654 * Return: page, if @pgoff is within the range, NULL otherwise.
655 */
656static struct page *msc_buffer_contig_get_page(struct msc *msc,
657 unsigned long pgoff)
658{
659 if (pgoff >= msc->nr_pages)
660 return NULL;
661
662 return virt_to_page(msc->base + (pgoff << PAGE_SHIFT));
663}
664
665/**
666 * msc_buffer_win_alloc() - alloc a window for a multiblock mode
667 * @msc: MSC device
668 * @nr_blocks: number of pages in this window
669 *
670 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex
671 * to serialize, so the caller is expected to hold it.
672 *
673 * Return: 0 on success, -errno otherwise.
674 */
675static int msc_buffer_win_alloc(struct msc *msc, unsigned int nr_blocks)
676{
677 struct msc_window *win;
678 unsigned long size = PAGE_SIZE;
679 int i, ret = -ENOMEM;
680
681 if (!nr_blocks)
682 return 0;
683
684 win = kzalloc(offsetof(struct msc_window, block[nr_blocks]),
685 GFP_KERNEL);
686 if (!win)
687 return -ENOMEM;
688
689 if (!list_empty(&msc->win_list)) {
690 struct msc_window *prev = list_entry(msc->win_list.prev,
691 struct msc_window, entry);
692
693 win->pgoff = prev->pgoff + prev->nr_blocks;
694 }
695
696 for (i = 0; i < nr_blocks; i++) {
697 win->block[i].bdesc = dma_alloc_coherent(msc_dev(msc), size,
698 &win->block[i].addr,
699 GFP_KERNEL);
700
701#ifdef CONFIG_X86
702 /* Set the page as uncached */
703 set_memory_uc((unsigned long)win->block[i].bdesc, 1);
704#endif
705
706 if (!win->block[i].bdesc)
707 goto err_nomem;
708 }
709
710 win->msc = msc;
711 win->nr_blocks = nr_blocks;
712
713 if (list_empty(&msc->win_list)) {
714 msc->base = win->block[0].bdesc;
715 msc->base_addr = win->block[0].addr;
716 }
717
718 list_add_tail(&win->entry, &msc->win_list);
719 msc->nr_pages += nr_blocks;
720
721 return 0;
722
723err_nomem:
724 for (i--; i >= 0; i--) {
725#ifdef CONFIG_X86
726 /* Reset the page to write-back before releasing */
727 set_memory_wb((unsigned long)win->block[i].bdesc, 1);
728#endif
729 dma_free_coherent(msc_dev(msc), size, win->block[i].bdesc,
730 win->block[i].addr);
731 }
732 kfree(win);
733
734 return ret;
735}
736
737/**
738 * msc_buffer_win_free() - free a window from MSC's window list
739 * @msc: MSC device
740 * @win: window to free
741 *
742 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex
743 * to serialize, so the caller is expected to hold it.
744 */
745static void msc_buffer_win_free(struct msc *msc, struct msc_window *win)
746{
747 int i;
748
749 msc->nr_pages -= win->nr_blocks;
750
751 list_del(&win->entry);
752 if (list_empty(&msc->win_list)) {
753 msc->base = NULL;
754 msc->base_addr = 0;
755 }
756
757 for (i = 0; i < win->nr_blocks; i++) {
758 struct page *page = virt_to_page(win->block[i].bdesc);
759
760 page->mapping = NULL;
761#ifdef CONFIG_X86
762 /* Reset the page to write-back before releasing */
763 set_memory_wb((unsigned long)win->block[i].bdesc, 1);
764#endif
765 dma_free_coherent(msc_dev(win->msc), PAGE_SIZE,
766 win->block[i].bdesc, win->block[i].addr);
767 }
768
769 kfree(win);
770}
771
772/**
773 * msc_buffer_relink() - set up block descriptors for multiblock mode
774 * @msc: MSC device
775 *
776 * This traverses msc::win_list, which requires msc::buf_mutex to serialize,
777 * so the caller is expected to hold it.
778 */
779static void msc_buffer_relink(struct msc *msc)
780{
781 struct msc_window *win, *next_win;
782
783 /* call with msc::mutex locked */
784 list_for_each_entry(win, &msc->win_list, entry) {
785 unsigned int blk;
786 u32 sw_tag = 0;
787
788 /*
789 * Last window's next_win should point to the first window
790 * and MSC_SW_TAG_LASTWIN should be set.
791 */
792 if (msc_is_last_win(win)) {
793 sw_tag |= MSC_SW_TAG_LASTWIN;
794 next_win = list_entry(msc->win_list.next,
795 struct msc_window, entry);
796 } else {
797 next_win = list_entry(win->entry.next,
798 struct msc_window, entry);
799 }
800
801 for (blk = 0; blk < win->nr_blocks; blk++) {
802 struct msc_block_desc *bdesc = win->block[blk].bdesc;
803
804 memset(bdesc, 0, sizeof(*bdesc));
805
806 bdesc->next_win = next_win->block[0].addr >> PAGE_SHIFT;
807
808 /*
809 * Similarly to last window, last block should point
810 * to the first one.
811 */
812 if (blk == win->nr_blocks - 1) {
813 sw_tag |= MSC_SW_TAG_LASTBLK;
814 bdesc->next_blk =
815 win->block[0].addr >> PAGE_SHIFT;
816 } else {
817 bdesc->next_blk =
818 win->block[blk + 1].addr >> PAGE_SHIFT;
819 }
820
821 bdesc->sw_tag = sw_tag;
822 bdesc->block_sz = PAGE_SIZE / 64;
823 }
824 }
825
826 /*
827 * Make the above writes globally visible before tracing is
828 * enabled to make sure hardware sees them coherently.
829 */
830 wmb();
831}
832
833static void msc_buffer_multi_free(struct msc *msc)
834{
835 struct msc_window *win, *iter;
836
837 list_for_each_entry_safe(win, iter, &msc->win_list, entry)
838 msc_buffer_win_free(msc, win);
839}
840
841static int msc_buffer_multi_alloc(struct msc *msc, unsigned long *nr_pages,
842 unsigned int nr_wins)
843{
844 int ret, i;
845
846 for (i = 0; i < nr_wins; i++) {
847 ret = msc_buffer_win_alloc(msc, nr_pages[i]);
848 if (ret) {
849 msc_buffer_multi_free(msc);
850 return ret;
851 }
852 }
853
854 msc_buffer_relink(msc);
855
856 return 0;
857}
858
859/**
860 * msc_buffer_free() - free buffers for MSC
861 * @msc: MSC device
862 *
863 * Free MSC's storage buffers.
864 *
865 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex to
866 * serialize, so the caller is expected to hold it.
867 */
868static void msc_buffer_free(struct msc *msc)
869{
870 if (msc->mode == MSC_MODE_SINGLE)
871 msc_buffer_contig_free(msc);
872 else if (msc->mode == MSC_MODE_MULTI)
873 msc_buffer_multi_free(msc);
874}
875
876/**
877 * msc_buffer_alloc() - allocate a buffer for MSC
878 * @msc: MSC device
879 * @size: allocation size in bytes
880 *
881 * Allocate a storage buffer for MSC, depending on the msc::mode, it will be
882 * either done via msc_buffer_contig_alloc() for SINGLE operation mode or
883 * msc_buffer_win_alloc() for multiblock operation. The latter allocates one
884 * window per invocation, so in multiblock mode this can be called multiple
885 * times for the same MSC to allocate multiple windows.
886 *
887 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex
888 * to serialize, so the caller is expected to hold it.
889 *
890 * Return: 0 on success, -errno otherwise.
891 */
892static int msc_buffer_alloc(struct msc *msc, unsigned long *nr_pages,
893 unsigned int nr_wins)
894{
895 int ret;
896
897 /* -1: buffer not allocated */
898 if (atomic_read(&msc->user_count) != -1)
899 return -EBUSY;
900
901 if (msc->mode == MSC_MODE_SINGLE) {
902 if (nr_wins != 1)
903 return -EINVAL;
904
905 ret = msc_buffer_contig_alloc(msc, nr_pages[0] << PAGE_SHIFT);
906 } else if (msc->mode == MSC_MODE_MULTI) {
907 ret = msc_buffer_multi_alloc(msc, nr_pages, nr_wins);
908 } else {
909 ret = -ENOTSUPP;
910 }
911
912 if (!ret) {
913 /* allocation should be visible before the counter goes to 0 */
914 smp_mb__before_atomic();
915
916 if (WARN_ON_ONCE(atomic_cmpxchg(&msc->user_count, -1, 0) != -1))
917 return -EINVAL;
918 }
919
920 return ret;
921}
922
923/**
924 * msc_buffer_unlocked_free_unless_used() - free a buffer unless it's in use
925 * @msc: MSC device
926 *
927 * This will free MSC buffer unless it is in use or there is no allocated
928 * buffer.
929 * Caller needs to hold msc::buf_mutex.
930 *
931 * Return: 0 on successful deallocation or if there was no buffer to
932 * deallocate, -EBUSY if there are active users.
933 */
934static int msc_buffer_unlocked_free_unless_used(struct msc *msc)
935{
936 int count, ret = 0;
937
938 count = atomic_cmpxchg(&msc->user_count, 0, -1);
939
940 /* > 0: buffer is allocated and has users */
941 if (count > 0)
942 ret = -EBUSY;
943 /* 0: buffer is allocated, no users */
944 else if (!count)
945 msc_buffer_free(msc);
946 /* < 0: no buffer, nothing to do */
947
948 return ret;
949}
950
951/**
952 * msc_buffer_free_unless_used() - free a buffer unless it's in use
953 * @msc: MSC device
954 *
955 * This is a locked version of msc_buffer_unlocked_free_unless_used().
956 */
957static int msc_buffer_free_unless_used(struct msc *msc)
958{
959 int ret;
960
961 mutex_lock(&msc->buf_mutex);
962 ret = msc_buffer_unlocked_free_unless_used(msc);
963 mutex_unlock(&msc->buf_mutex);
964
965 return ret;
966}
967
968/**
969 * msc_buffer_get_page() - get MSC buffer page at a given offset
970 * @msc: MSC device
971 * @pgoff: page offset into the storage buffer
972 *
973 * This traverses msc::win_list, so holding msc::buf_mutex is expected from
974 * the caller.
975 *
976 * Return: page if @pgoff corresponds to a valid buffer page or NULL.
977 */
978static struct page *msc_buffer_get_page(struct msc *msc, unsigned long pgoff)
979{
980 struct msc_window *win;
981
982 if (msc->mode == MSC_MODE_SINGLE)
983 return msc_buffer_contig_get_page(msc, pgoff);
984
985 list_for_each_entry(win, &msc->win_list, entry)
986 if (pgoff >= win->pgoff && pgoff < win->pgoff + win->nr_blocks)
987 goto found;
988
989 return NULL;
990
991found:
992 pgoff -= win->pgoff;
993 return virt_to_page(win->block[pgoff].bdesc);
994}
995
996/**
997 * struct msc_win_to_user_struct - data for copy_to_user() callback
998 * @buf: userspace buffer to copy data to
999 * @offset: running offset
1000 */
1001struct msc_win_to_user_struct {
1002 char __user *buf;
1003 unsigned long offset;
1004};
1005
1006/**
1007 * msc_win_to_user() - iterator for msc_buffer_iterate() to copy data to user
1008 * @data: callback's private data
1009 * @src: source buffer
1010 * @len: amount of data to copy from the source buffer
1011 */
1012static unsigned long msc_win_to_user(void *data, void *src, size_t len)
1013{
1014 struct msc_win_to_user_struct *u = data;
1015 unsigned long ret;
1016
1017 ret = copy_to_user(u->buf + u->offset, src, len);
1018 u->offset += len - ret;
1019
1020 return ret;
1021}
1022
1023
1024/*
1025 * file operations' callbacks
1026 */
1027
1028static int intel_th_msc_open(struct inode *inode, struct file *file)
1029{
1030 struct intel_th_device *thdev = file->private_data;
1031 struct msc *msc = dev_get_drvdata(&thdev->dev);
1032 struct msc_iter *iter;
1033
1034 if (!capable(CAP_SYS_RAWIO))
1035 return -EPERM;
1036
1037 iter = msc_iter_install(msc);
1038 if (!iter)
1039 return -ENOMEM;
1040
1041 file->private_data = iter;
1042
1043 return nonseekable_open(inode, file);
1044}
1045
1046static int intel_th_msc_release(struct inode *inode, struct file *file)
1047{
1048 struct msc_iter *iter = file->private_data;
1049 struct msc *msc = iter->msc;
1050
1051 msc_iter_remove(iter, msc);
1052
1053 return 0;
1054}
1055
1056static ssize_t
1057msc_single_to_user(struct msc *msc, char __user *buf, loff_t off, size_t len)
1058{
1059 unsigned long size = msc->nr_pages << PAGE_SHIFT, rem = len;
1060 unsigned long start = off, tocopy = 0;
1061
1062 if (msc->single_wrap) {
1063 start += msc->single_sz;
1064 if (start < size) {
1065 tocopy = min(rem, size - start);
1066 if (copy_to_user(buf, msc->base + start, tocopy))
1067 return -EFAULT;
1068
1069 buf += tocopy;
1070 rem -= tocopy;
1071 start += tocopy;
1072 }
1073
1074 start &= size - 1;
1075 if (rem) {
1076 tocopy = min(rem, msc->single_sz - start);
1077 if (copy_to_user(buf, msc->base + start, tocopy))
1078 return -EFAULT;
1079
1080 rem -= tocopy;
1081 }
1082
1083 return len - rem;
1084 }
1085
1086 if (copy_to_user(buf, msc->base + start, rem))
1087 return -EFAULT;
1088
1089 return len;
1090}
1091
1092static ssize_t intel_th_msc_read(struct file *file, char __user *buf,
1093 size_t len, loff_t *ppos)
1094{
1095 struct msc_iter *iter = file->private_data;
1096 struct msc *msc = iter->msc;
1097 size_t size;
1098 loff_t off = *ppos;
1099 ssize_t ret = 0;
1100
1101 if (!atomic_inc_unless_negative(&msc->user_count))
1102 return 0;
1103
1104 if (msc->enabled) {
1105 ret = -EBUSY;
1106 goto put_count;
1107 }
1108
1109 if (msc->mode == MSC_MODE_SINGLE && !msc->single_wrap)
1110 size = msc->single_sz;
1111 else
1112 size = msc->nr_pages << PAGE_SHIFT;
1113
1114 if (!size)
1115 goto put_count;
1116
1117 if (off >= size)
1118 goto put_count;
1119
1120 if (off + len >= size)
1121 len = size - off;
1122
1123 if (msc->mode == MSC_MODE_SINGLE) {
1124 ret = msc_single_to_user(msc, buf, off, len);
1125 if (ret >= 0)
1126 *ppos += ret;
1127 } else if (msc->mode == MSC_MODE_MULTI) {
1128 struct msc_win_to_user_struct u = {
1129 .buf = buf,
1130 .offset = 0,
1131 };
1132
1133 ret = msc_buffer_iterate(iter, len, &u, msc_win_to_user);
1134 if (ret >= 0)
1135 *ppos = iter->offset;
1136 } else {
1137 ret = -ENOTSUPP;
1138 }
1139
1140put_count:
1141 atomic_dec(&msc->user_count);
1142
1143 return ret;
1144}
1145
1146/*
1147 * vm operations callbacks (vm_ops)
1148 */
1149
1150static void msc_mmap_open(struct vm_area_struct *vma)
1151{
1152 struct msc_iter *iter = vma->vm_file->private_data;
1153 struct msc *msc = iter->msc;
1154
1155 atomic_inc(&msc->mmap_count);
1156}
1157
1158static void msc_mmap_close(struct vm_area_struct *vma)
1159{
1160 struct msc_iter *iter = vma->vm_file->private_data;
1161 struct msc *msc = iter->msc;
1162 unsigned long pg;
1163
1164 if (!atomic_dec_and_mutex_lock(&msc->mmap_count, &msc->buf_mutex))
1165 return;
1166
1167 /* drop page _counts */
1168 for (pg = 0; pg < msc->nr_pages; pg++) {
1169 struct page *page = msc_buffer_get_page(msc, pg);
1170
1171 if (WARN_ON_ONCE(!page))
1172 continue;
1173
1174 if (page->mapping)
1175 page->mapping = NULL;
1176 }
1177
1178 /* last mapping -- drop user_count */
1179 atomic_dec(&msc->user_count);
1180 mutex_unlock(&msc->buf_mutex);
1181}
1182
1183static int msc_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1184{
1185 struct msc_iter *iter = vma->vm_file->private_data;
1186 struct msc *msc = iter->msc;
1187
1188 vmf->page = msc_buffer_get_page(msc, vmf->pgoff);
1189 if (!vmf->page)
1190 return VM_FAULT_SIGBUS;
1191
1192 get_page(vmf->page);
1193 vmf->page->mapping = vma->vm_file->f_mapping;
1194 vmf->page->index = vmf->pgoff;
1195
1196 return 0;
1197}
1198
1199static const struct vm_operations_struct msc_mmap_ops = {
1200 .open = msc_mmap_open,
1201 .close = msc_mmap_close,
1202 .fault = msc_mmap_fault,
1203};
1204
1205static int intel_th_msc_mmap(struct file *file, struct vm_area_struct *vma)
1206{
1207 unsigned long size = vma->vm_end - vma->vm_start;
1208 struct msc_iter *iter = vma->vm_file->private_data;
1209 struct msc *msc = iter->msc;
1210 int ret = -EINVAL;
1211
1212 if (!size || offset_in_page(size))
1213 return -EINVAL;
1214
1215 if (vma->vm_pgoff)
1216 return -EINVAL;
1217
1218 /* grab user_count once per mmap; drop in msc_mmap_close() */
1219 if (!atomic_inc_unless_negative(&msc->user_count))
1220 return -EINVAL;
1221
1222 if (msc->mode != MSC_MODE_SINGLE &&
1223 msc->mode != MSC_MODE_MULTI)
1224 goto out;
1225
1226 if (size >> PAGE_SHIFT != msc->nr_pages)
1227 goto out;
1228
1229 atomic_set(&msc->mmap_count, 1);
1230 ret = 0;
1231
1232out:
1233 if (ret)
1234 atomic_dec(&msc->user_count);
1235
1236 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1237 vma->vm_flags |= VM_DONTEXPAND | VM_DONTCOPY;
1238 vma->vm_ops = &msc_mmap_ops;
1239 return ret;
1240}
1241
1242static const struct file_operations intel_th_msc_fops = {
1243 .open = intel_th_msc_open,
1244 .release = intel_th_msc_release,
1245 .read = intel_th_msc_read,
1246 .mmap = intel_th_msc_mmap,
1247 .llseek = no_llseek,
1248};
1249
1250static int intel_th_msc_init(struct msc *msc)
1251{
1252 atomic_set(&msc->user_count, -1);
1253
1254 msc->mode = MSC_MODE_MULTI;
1255 mutex_init(&msc->buf_mutex);
1256 INIT_LIST_HEAD(&msc->win_list);
1257
1258 mutex_init(&msc->iter_mutex);
1259 INIT_LIST_HEAD(&msc->iter_list);
1260
1261 msc->burst_len =
1262 (ioread32(msc->reg_base + REG_MSU_MSC0CTL) & MSC_LEN) >>
1263 __ffs(MSC_LEN);
1264
1265 return 0;
1266}
1267
1268static const char * const msc_mode[] = {
1269 [MSC_MODE_SINGLE] = "single",
1270 [MSC_MODE_MULTI] = "multi",
1271 [MSC_MODE_EXI] = "ExI",
1272 [MSC_MODE_DEBUG] = "debug",
1273};
1274
1275static ssize_t
1276wrap_show(struct device *dev, struct device_attribute *attr, char *buf)
1277{
1278 struct msc *msc = dev_get_drvdata(dev);
1279
1280 return scnprintf(buf, PAGE_SIZE, "%d\n", msc->wrap);
1281}
1282
1283static ssize_t
1284wrap_store(struct device *dev, struct device_attribute *attr, const char *buf,
1285 size_t size)
1286{
1287 struct msc *msc = dev_get_drvdata(dev);
1288 unsigned long val;
1289 int ret;
1290
1291 ret = kstrtoul(buf, 10, &val);
1292 if (ret)
1293 return ret;
1294
1295 msc->wrap = !!val;
1296
1297 return size;
1298}
1299
1300static DEVICE_ATTR_RW(wrap);
1301
1302static ssize_t
1303mode_show(struct device *dev, struct device_attribute *attr, char *buf)
1304{
1305 struct msc *msc = dev_get_drvdata(dev);
1306
1307 return scnprintf(buf, PAGE_SIZE, "%s\n", msc_mode[msc->mode]);
1308}
1309
1310static ssize_t
1311mode_store(struct device *dev, struct device_attribute *attr, const char *buf,
1312 size_t size)
1313{
1314 struct msc *msc = dev_get_drvdata(dev);
1315 size_t len = size;
1316 char *cp;
1317 int i, ret;
1318
1319 if (!capable(CAP_SYS_RAWIO))
1320 return -EPERM;
1321
1322 cp = memchr(buf, '\n', len);
1323 if (cp)
1324 len = cp - buf;
1325
1326 for (i = 0; i < ARRAY_SIZE(msc_mode); i++)
1327 if (!strncmp(msc_mode[i], buf, len))
1328 goto found;
1329
1330 return -EINVAL;
1331
1332found:
1333 mutex_lock(&msc->buf_mutex);
1334 ret = msc_buffer_unlocked_free_unless_used(msc);
1335 if (!ret)
1336 msc->mode = i;
1337 mutex_unlock(&msc->buf_mutex);
1338
1339 return ret ? ret : size;
1340}
1341
1342static DEVICE_ATTR_RW(mode);
1343
1344static ssize_t
1345nr_pages_show(struct device *dev, struct device_attribute *attr, char *buf)
1346{
1347 struct msc *msc = dev_get_drvdata(dev);
1348 struct msc_window *win;
1349 size_t count = 0;
1350
1351 mutex_lock(&msc->buf_mutex);
1352
1353 if (msc->mode == MSC_MODE_SINGLE)
1354 count = scnprintf(buf, PAGE_SIZE, "%ld\n", msc->nr_pages);
1355 else if (msc->mode == MSC_MODE_MULTI) {
1356 list_for_each_entry(win, &msc->win_list, entry) {
1357 count += scnprintf(buf + count, PAGE_SIZE - count,
1358 "%d%c", win->nr_blocks,
1359 msc_is_last_win(win) ? '\n' : ',');
1360 }
1361 } else {
1362 count = scnprintf(buf, PAGE_SIZE, "unsupported\n");
1363 }
1364
1365 mutex_unlock(&msc->buf_mutex);
1366
1367 return count;
1368}
1369
1370static ssize_t
1371nr_pages_store(struct device *dev, struct device_attribute *attr,
1372 const char *buf, size_t size)
1373{
1374 struct msc *msc = dev_get_drvdata(dev);
1375 unsigned long val, *win = NULL, *rewin;
1376 size_t len = size;
1377 const char *p = buf;
1378 char *end, *s;
1379 int ret, nr_wins = 0;
1380
1381 if (!capable(CAP_SYS_RAWIO))
1382 return -EPERM;
1383
1384 ret = msc_buffer_free_unless_used(msc);
1385 if (ret)
1386 return ret;
1387
1388 /* scan the comma-separated list of allocation sizes */
1389 end = memchr(buf, '\n', len);
1390 if (end)
1391 len = end - buf;
1392
1393 do {
1394 end = memchr(p, ',', len);
1395 s = kstrndup(p, end ? end - p : len, GFP_KERNEL);
1396 ret = kstrtoul(s, 10, &val);
1397 kfree(s);
1398
1399 if (ret || !val)
1400 goto free_win;
1401
1402 if (nr_wins && msc->mode == MSC_MODE_SINGLE) {
1403 ret = -EINVAL;
1404 goto free_win;
1405 }
1406
1407 nr_wins++;
1408 rewin = krealloc(win, sizeof(*win) * nr_wins, GFP_KERNEL);
1409 if (!rewin) {
1410 kfree(win);
1411 return -ENOMEM;
1412 }
1413
1414 win = rewin;
1415 win[nr_wins - 1] = val;
1416
1417 if (!end)
1418 break;
1419
1420 len -= end - p;
1421 p = end + 1;
1422 } while (len);
1423
1424 mutex_lock(&msc->buf_mutex);
1425 ret = msc_buffer_alloc(msc, win, nr_wins);
1426 mutex_unlock(&msc->buf_mutex);
1427
1428free_win:
1429 kfree(win);
1430
1431 return ret ? ret : size;
1432}
1433
1434static DEVICE_ATTR_RW(nr_pages);
1435
1436static struct attribute *msc_output_attrs[] = {
1437 &dev_attr_wrap.attr,
1438 &dev_attr_mode.attr,
1439 &dev_attr_nr_pages.attr,
1440 NULL,
1441};
1442
1443static struct attribute_group msc_output_group = {
1444 .attrs = msc_output_attrs,
1445};
1446
1447static int intel_th_msc_probe(struct intel_th_device *thdev)
1448{
1449 struct device *dev = &thdev->dev;
1450 struct resource *res;
1451 struct msc *msc;
1452 void __iomem *base;
1453 int err;
1454
1455 res = intel_th_device_get_resource(thdev, IORESOURCE_MEM, 0);
1456 if (!res)
1457 return -ENODEV;
1458
1459 base = devm_ioremap(dev, res->start, resource_size(res));
1460 if (!base)
1461 return -ENOMEM;
1462
1463 msc = devm_kzalloc(dev, sizeof(*msc), GFP_KERNEL);
1464 if (!msc)
1465 return -ENOMEM;
1466
1467 msc->index = thdev->id;
1468
1469 msc->thdev = thdev;
1470 msc->reg_base = base + msc->index * 0x100;
1471
1472 err = intel_th_msc_init(msc);
1473 if (err)
1474 return err;
1475
1476 err = sysfs_create_group(&dev->kobj, &msc_output_group);
1477 if (err)
1478 return err;
1479
1480 dev_set_drvdata(dev, msc);
1481
1482 return 0;
1483}
1484
1485static void intel_th_msc_remove(struct intel_th_device *thdev)
1486{
1487 sysfs_remove_group(&thdev->dev.kobj, &msc_output_group);
1488}
1489
1490static struct intel_th_driver intel_th_msc_driver = {
1491 .probe = intel_th_msc_probe,
1492 .remove = intel_th_msc_remove,
1493 .activate = intel_th_msc_activate,
1494 .deactivate = intel_th_msc_deactivate,
1495 .fops = &intel_th_msc_fops,
1496 .driver = {
1497 .name = "msc",
1498 .owner = THIS_MODULE,
1499 },
1500};
1501
1502module_driver(intel_th_msc_driver,
1503 intel_th_driver_register,
1504 intel_th_driver_unregister);
1505
1506MODULE_LICENSE("GPL v2");
1507MODULE_DESCRIPTION("Intel(R) Trace Hub Memory Storage Unit driver");
1508MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Intel(R) Trace Hub Memory Storage Unit
4 *
5 * Copyright (C) 2014-2015 Intel Corporation.
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/types.h>
11#include <linux/module.h>
12#include <linux/device.h>
13#include <linux/uaccess.h>
14#include <linux/sizes.h>
15#include <linux/printk.h>
16#include <linux/slab.h>
17#include <linux/mm.h>
18#include <linux/fs.h>
19#include <linux/io.h>
20#include <linux/workqueue.h>
21#include <linux/dma-mapping.h>
22
23#ifdef CONFIG_X86
24#include <asm/set_memory.h>
25#endif
26
27#include <linux/intel_th.h>
28#include "intel_th.h"
29#include "msu.h"
30
31#define msc_dev(x) (&(x)->thdev->dev)
32
33/*
34 * Lockout state transitions:
35 * READY -> INUSE -+-> LOCKED -+-> READY -> etc.
36 * \-----------/
37 * WIN_READY: window can be used by HW
38 * WIN_INUSE: window is in use
39 * WIN_LOCKED: window is filled up and is being processed by the buffer
40 * handling code
41 *
42 * All state transitions happen automatically, except for the LOCKED->READY,
43 * which needs to be signalled by the buffer code by calling
44 * intel_th_msc_window_unlock().
45 *
46 * When the interrupt handler has to switch to the next window, it checks
47 * whether it's READY, and if it is, it performs the switch and tracing
48 * continues. If it's LOCKED, it stops the trace.
49 */
50enum lockout_state {
51 WIN_READY = 0,
52 WIN_INUSE,
53 WIN_LOCKED
54};
55
56/**
57 * struct msc_window - multiblock mode window descriptor
58 * @entry: window list linkage (msc::win_list)
59 * @pgoff: page offset into the buffer that this window starts at
60 * @lockout: lockout state, see comment below
61 * @lo_lock: lockout state serialization
62 * @nr_blocks: number of blocks (pages) in this window
63 * @nr_segs: number of segments in this window (<= @nr_blocks)
64 * @msc: pointer to the MSC device
65 * @_sgt: array of block descriptors
66 * @sgt: array of block descriptors
67 */
68struct msc_window {
69 struct list_head entry;
70 unsigned long pgoff;
71 enum lockout_state lockout;
72 spinlock_t lo_lock;
73 unsigned int nr_blocks;
74 unsigned int nr_segs;
75 struct msc *msc;
76 struct sg_table _sgt;
77 struct sg_table *sgt;
78};
79
80/**
81 * struct msc_iter - iterator for msc buffer
82 * @entry: msc::iter_list linkage
83 * @msc: pointer to the MSC device
84 * @start_win: oldest window
85 * @win: current window
86 * @offset: current logical offset into the buffer
87 * @start_block: oldest block in the window
88 * @block: block number in the window
89 * @block_off: offset into current block
90 * @wrap_count: block wrapping handling
91 * @eof: end of buffer reached
92 */
93struct msc_iter {
94 struct list_head entry;
95 struct msc *msc;
96 struct msc_window *start_win;
97 struct msc_window *win;
98 unsigned long offset;
99 struct scatterlist *start_block;
100 struct scatterlist *block;
101 unsigned int block_off;
102 unsigned int wrap_count;
103 unsigned int eof;
104};
105
106/**
107 * struct msc - MSC device representation
108 * @reg_base: register window base address
109 * @thdev: intel_th_device pointer
110 * @mbuf: MSU buffer, if assigned
111 * @mbuf_priv MSU buffer's private data, if @mbuf
112 * @win_list: list of windows in multiblock mode
113 * @single_sgt: single mode buffer
114 * @cur_win: current window
115 * @nr_pages: total number of pages allocated for this buffer
116 * @single_sz: amount of data in single mode
117 * @single_wrap: single mode wrap occurred
118 * @base: buffer's base pointer
119 * @base_addr: buffer's base address
120 * @user_count: number of users of the buffer
121 * @mmap_count: number of mappings
122 * @buf_mutex: mutex to serialize access to buffer-related bits
123 * @enabled: MSC is enabled
124 * @wrap: wrapping is enabled
125 * @mode: MSC operating mode
126 * @burst_len: write burst length
127 * @index: number of this MSC in the MSU
128 */
129struct msc {
130 void __iomem *reg_base;
131 void __iomem *msu_base;
132 struct intel_th_device *thdev;
133
134 const struct msu_buffer *mbuf;
135 void *mbuf_priv;
136
137 struct work_struct work;
138 struct list_head win_list;
139 struct sg_table single_sgt;
140 struct msc_window *cur_win;
141 struct msc_window *switch_on_unlock;
142 unsigned long nr_pages;
143 unsigned long single_sz;
144 unsigned int single_wrap : 1;
145 void *base;
146 dma_addr_t base_addr;
147 u32 orig_addr;
148 u32 orig_sz;
149
150 /* <0: no buffer, 0: no users, >0: active users */
151 atomic_t user_count;
152
153 atomic_t mmap_count;
154 struct mutex buf_mutex;
155
156 struct list_head iter_list;
157
158 bool stop_on_full;
159
160 /* config */
161 unsigned int enabled : 1,
162 wrap : 1,
163 do_irq : 1,
164 multi_is_broken : 1;
165 unsigned int mode;
166 unsigned int burst_len;
167 unsigned int index;
168};
169
170static LIST_HEAD(msu_buffer_list);
171static DEFINE_MUTEX(msu_buffer_mutex);
172
173/**
174 * struct msu_buffer_entry - internal MSU buffer bookkeeping
175 * @entry: link to msu_buffer_list
176 * @mbuf: MSU buffer object
177 * @owner: module that provides this MSU buffer
178 */
179struct msu_buffer_entry {
180 struct list_head entry;
181 const struct msu_buffer *mbuf;
182 struct module *owner;
183};
184
185static struct msu_buffer_entry *__msu_buffer_entry_find(const char *name)
186{
187 struct msu_buffer_entry *mbe;
188
189 lockdep_assert_held(&msu_buffer_mutex);
190
191 list_for_each_entry(mbe, &msu_buffer_list, entry) {
192 if (!strcmp(mbe->mbuf->name, name))
193 return mbe;
194 }
195
196 return NULL;
197}
198
199static const struct msu_buffer *
200msu_buffer_get(const char *name)
201{
202 struct msu_buffer_entry *mbe;
203
204 mutex_lock(&msu_buffer_mutex);
205 mbe = __msu_buffer_entry_find(name);
206 if (mbe && !try_module_get(mbe->owner))
207 mbe = NULL;
208 mutex_unlock(&msu_buffer_mutex);
209
210 return mbe ? mbe->mbuf : NULL;
211}
212
213static void msu_buffer_put(const struct msu_buffer *mbuf)
214{
215 struct msu_buffer_entry *mbe;
216
217 mutex_lock(&msu_buffer_mutex);
218 mbe = __msu_buffer_entry_find(mbuf->name);
219 if (mbe)
220 module_put(mbe->owner);
221 mutex_unlock(&msu_buffer_mutex);
222}
223
224int intel_th_msu_buffer_register(const struct msu_buffer *mbuf,
225 struct module *owner)
226{
227 struct msu_buffer_entry *mbe;
228 int ret = 0;
229
230 mbe = kzalloc(sizeof(*mbe), GFP_KERNEL);
231 if (!mbe)
232 return -ENOMEM;
233
234 mutex_lock(&msu_buffer_mutex);
235 if (__msu_buffer_entry_find(mbuf->name)) {
236 ret = -EEXIST;
237 kfree(mbe);
238 goto unlock;
239 }
240
241 mbe->mbuf = mbuf;
242 mbe->owner = owner;
243 list_add_tail(&mbe->entry, &msu_buffer_list);
244unlock:
245 mutex_unlock(&msu_buffer_mutex);
246
247 return ret;
248}
249EXPORT_SYMBOL_GPL(intel_th_msu_buffer_register);
250
251void intel_th_msu_buffer_unregister(const struct msu_buffer *mbuf)
252{
253 struct msu_buffer_entry *mbe;
254
255 mutex_lock(&msu_buffer_mutex);
256 mbe = __msu_buffer_entry_find(mbuf->name);
257 if (mbe) {
258 list_del(&mbe->entry);
259 kfree(mbe);
260 }
261 mutex_unlock(&msu_buffer_mutex);
262}
263EXPORT_SYMBOL_GPL(intel_th_msu_buffer_unregister);
264
265static inline bool msc_block_is_empty(struct msc_block_desc *bdesc)
266{
267 /* header hasn't been written */
268 if (!bdesc->valid_dw)
269 return true;
270
271 /* valid_dw includes the header */
272 if (!msc_data_sz(bdesc))
273 return true;
274
275 return false;
276}
277
278static inline struct scatterlist *msc_win_base_sg(struct msc_window *win)
279{
280 return win->sgt->sgl;
281}
282
283static inline struct msc_block_desc *msc_win_base(struct msc_window *win)
284{
285 return sg_virt(msc_win_base_sg(win));
286}
287
288static inline dma_addr_t msc_win_base_dma(struct msc_window *win)
289{
290 return sg_dma_address(msc_win_base_sg(win));
291}
292
293static inline unsigned long
294msc_win_base_pfn(struct msc_window *win)
295{
296 return PFN_DOWN(msc_win_base_dma(win));
297}
298
299/**
300 * msc_is_last_win() - check if a window is the last one for a given MSC
301 * @win: window
302 * Return: true if @win is the last window in MSC's multiblock buffer
303 */
304static inline bool msc_is_last_win(struct msc_window *win)
305{
306 return win->entry.next == &win->msc->win_list;
307}
308
309/**
310 * msc_next_window() - return next window in the multiblock buffer
311 * @win: current window
312 *
313 * Return: window following the current one
314 */
315static struct msc_window *msc_next_window(struct msc_window *win)
316{
317 if (msc_is_last_win(win))
318 return list_first_entry(&win->msc->win_list, struct msc_window,
319 entry);
320
321 return list_next_entry(win, entry);
322}
323
324static size_t msc_win_total_sz(struct msc_window *win)
325{
326 struct scatterlist *sg;
327 unsigned int blk;
328 size_t size = 0;
329
330 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
331 struct msc_block_desc *bdesc = sg_virt(sg);
332
333 if (msc_block_wrapped(bdesc))
334 return (size_t)win->nr_blocks << PAGE_SHIFT;
335
336 size += msc_total_sz(bdesc);
337 if (msc_block_last_written(bdesc))
338 break;
339 }
340
341 return size;
342}
343
344/**
345 * msc_find_window() - find a window matching a given sg_table
346 * @msc: MSC device
347 * @sgt: SG table of the window
348 * @nonempty: skip over empty windows
349 *
350 * Return: MSC window structure pointer or NULL if the window
351 * could not be found.
352 */
353static struct msc_window *
354msc_find_window(struct msc *msc, struct sg_table *sgt, bool nonempty)
355{
356 struct msc_window *win;
357 unsigned int found = 0;
358
359 if (list_empty(&msc->win_list))
360 return NULL;
361
362 /*
363 * we might need a radix tree for this, depending on how
364 * many windows a typical user would allocate; ideally it's
365 * something like 2, in which case we're good
366 */
367 list_for_each_entry(win, &msc->win_list, entry) {
368 if (win->sgt == sgt)
369 found++;
370
371 /* skip the empty ones */
372 if (nonempty && msc_block_is_empty(msc_win_base(win)))
373 continue;
374
375 if (found)
376 return win;
377 }
378
379 return NULL;
380}
381
382/**
383 * msc_oldest_window() - locate the window with oldest data
384 * @msc: MSC device
385 *
386 * This should only be used in multiblock mode. Caller should hold the
387 * msc::user_count reference.
388 *
389 * Return: the oldest window with valid data
390 */
391static struct msc_window *msc_oldest_window(struct msc *msc)
392{
393 struct msc_window *win;
394
395 if (list_empty(&msc->win_list))
396 return NULL;
397
398 win = msc_find_window(msc, msc_next_window(msc->cur_win)->sgt, true);
399 if (win)
400 return win;
401
402 return list_first_entry(&msc->win_list, struct msc_window, entry);
403}
404
405/**
406 * msc_win_oldest_sg() - locate the oldest block in a given window
407 * @win: window to look at
408 *
409 * Return: index of the block with the oldest data
410 */
411static struct scatterlist *msc_win_oldest_sg(struct msc_window *win)
412{
413 unsigned int blk;
414 struct scatterlist *sg;
415 struct msc_block_desc *bdesc = msc_win_base(win);
416
417 /* without wrapping, first block is the oldest */
418 if (!msc_block_wrapped(bdesc))
419 return msc_win_base_sg(win);
420
421 /*
422 * with wrapping, last written block contains both the newest and the
423 * oldest data for this window.
424 */
425 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
426 struct msc_block_desc *bdesc = sg_virt(sg);
427
428 if (msc_block_last_written(bdesc))
429 return sg;
430 }
431
432 return msc_win_base_sg(win);
433}
434
435static struct msc_block_desc *msc_iter_bdesc(struct msc_iter *iter)
436{
437 return sg_virt(iter->block);
438}
439
440static struct msc_iter *msc_iter_install(struct msc *msc)
441{
442 struct msc_iter *iter;
443
444 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
445 if (!iter)
446 return ERR_PTR(-ENOMEM);
447
448 mutex_lock(&msc->buf_mutex);
449
450 /*
451 * Reading and tracing are mutually exclusive; if msc is
452 * enabled, open() will fail; otherwise existing readers
453 * will prevent enabling the msc and the rest of fops don't
454 * need to worry about it.
455 */
456 if (msc->enabled) {
457 kfree(iter);
458 iter = ERR_PTR(-EBUSY);
459 goto unlock;
460 }
461
462 iter->msc = msc;
463
464 list_add_tail(&iter->entry, &msc->iter_list);
465unlock:
466 mutex_unlock(&msc->buf_mutex);
467
468 return iter;
469}
470
471static void msc_iter_remove(struct msc_iter *iter, struct msc *msc)
472{
473 mutex_lock(&msc->buf_mutex);
474 list_del(&iter->entry);
475 mutex_unlock(&msc->buf_mutex);
476
477 kfree(iter);
478}
479
480static void msc_iter_block_start(struct msc_iter *iter)
481{
482 if (iter->start_block)
483 return;
484
485 iter->start_block = msc_win_oldest_sg(iter->win);
486 iter->block = iter->start_block;
487 iter->wrap_count = 0;
488
489 /*
490 * start with the block with oldest data; if data has wrapped
491 * in this window, it should be in this block
492 */
493 if (msc_block_wrapped(msc_iter_bdesc(iter)))
494 iter->wrap_count = 2;
495
496}
497
498static int msc_iter_win_start(struct msc_iter *iter, struct msc *msc)
499{
500 /* already started, nothing to do */
501 if (iter->start_win)
502 return 0;
503
504 iter->start_win = msc_oldest_window(msc);
505 if (!iter->start_win)
506 return -EINVAL;
507
508 iter->win = iter->start_win;
509 iter->start_block = NULL;
510
511 msc_iter_block_start(iter);
512
513 return 0;
514}
515
516static int msc_iter_win_advance(struct msc_iter *iter)
517{
518 iter->win = msc_next_window(iter->win);
519 iter->start_block = NULL;
520
521 if (iter->win == iter->start_win) {
522 iter->eof++;
523 return 1;
524 }
525
526 msc_iter_block_start(iter);
527
528 return 0;
529}
530
531static int msc_iter_block_advance(struct msc_iter *iter)
532{
533 iter->block_off = 0;
534
535 /* wrapping */
536 if (iter->wrap_count && iter->block == iter->start_block) {
537 iter->wrap_count--;
538 if (!iter->wrap_count)
539 /* copied newest data from the wrapped block */
540 return msc_iter_win_advance(iter);
541 }
542
543 /* no wrapping, check for last written block */
544 if (!iter->wrap_count && msc_block_last_written(msc_iter_bdesc(iter)))
545 /* copied newest data for the window */
546 return msc_iter_win_advance(iter);
547
548 /* block advance */
549 if (sg_is_last(iter->block))
550 iter->block = msc_win_base_sg(iter->win);
551 else
552 iter->block = sg_next(iter->block);
553
554 /* no wrapping, sanity check in case there is no last written block */
555 if (!iter->wrap_count && iter->block == iter->start_block)
556 return msc_iter_win_advance(iter);
557
558 return 0;
559}
560
561/**
562 * msc_buffer_iterate() - go through multiblock buffer's data
563 * @iter: iterator structure
564 * @size: amount of data to scan
565 * @data: callback's private data
566 * @fn: iterator callback
567 *
568 * This will start at the window which will be written to next (containing
569 * the oldest data) and work its way to the current window, calling @fn
570 * for each chunk of data as it goes.
571 *
572 * Caller should have msc::user_count reference to make sure the buffer
573 * doesn't disappear from under us.
574 *
575 * Return: amount of data actually scanned.
576 */
577static ssize_t
578msc_buffer_iterate(struct msc_iter *iter, size_t size, void *data,
579 unsigned long (*fn)(void *, void *, size_t))
580{
581 struct msc *msc = iter->msc;
582 size_t len = size;
583 unsigned int advance;
584
585 if (iter->eof)
586 return 0;
587
588 /* start with the oldest window */
589 if (msc_iter_win_start(iter, msc))
590 return 0;
591
592 do {
593 unsigned long data_bytes = msc_data_sz(msc_iter_bdesc(iter));
594 void *src = (void *)msc_iter_bdesc(iter) + MSC_BDESC;
595 size_t tocopy = data_bytes, copied = 0;
596 size_t remaining = 0;
597
598 advance = 1;
599
600 /*
601 * If block wrapping happened, we need to visit the last block
602 * twice, because it contains both the oldest and the newest
603 * data in this window.
604 *
605 * First time (wrap_count==2), in the very beginning, to collect
606 * the oldest data, which is in the range
607 * (data_bytes..DATA_IN_PAGE).
608 *
609 * Second time (wrap_count==1), it's just like any other block,
610 * containing data in the range of [MSC_BDESC..data_bytes].
611 */
612 if (iter->block == iter->start_block && iter->wrap_count == 2) {
613 tocopy = DATA_IN_PAGE - data_bytes;
614 src += data_bytes;
615 }
616
617 if (!tocopy)
618 goto next_block;
619
620 tocopy -= iter->block_off;
621 src += iter->block_off;
622
623 if (len < tocopy) {
624 tocopy = len;
625 advance = 0;
626 }
627
628 remaining = fn(data, src, tocopy);
629
630 if (remaining)
631 advance = 0;
632
633 copied = tocopy - remaining;
634 len -= copied;
635 iter->block_off += copied;
636 iter->offset += copied;
637
638 if (!advance)
639 break;
640
641next_block:
642 if (msc_iter_block_advance(iter))
643 break;
644
645 } while (len);
646
647 return size - len;
648}
649
650/**
651 * msc_buffer_clear_hw_header() - clear hw header for multiblock
652 * @msc: MSC device
653 */
654static void msc_buffer_clear_hw_header(struct msc *msc)
655{
656 struct msc_window *win;
657 struct scatterlist *sg;
658
659 list_for_each_entry(win, &msc->win_list, entry) {
660 unsigned int blk;
661
662 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
663 struct msc_block_desc *bdesc = sg_virt(sg);
664
665 memset_startat(bdesc, 0, hw_tag);
666 }
667 }
668}
669
670static int intel_th_msu_init(struct msc *msc)
671{
672 u32 mintctl, msusts;
673
674 if (!msc->do_irq)
675 return 0;
676
677 if (!msc->mbuf)
678 return 0;
679
680 mintctl = ioread32(msc->msu_base + REG_MSU_MINTCTL);
681 mintctl |= msc->index ? M1BLIE : M0BLIE;
682 iowrite32(mintctl, msc->msu_base + REG_MSU_MINTCTL);
683 if (mintctl != ioread32(msc->msu_base + REG_MSU_MINTCTL)) {
684 dev_info(msc_dev(msc), "MINTCTL ignores writes: no usable interrupts\n");
685 msc->do_irq = 0;
686 return 0;
687 }
688
689 msusts = ioread32(msc->msu_base + REG_MSU_MSUSTS);
690 iowrite32(msusts, msc->msu_base + REG_MSU_MSUSTS);
691
692 return 0;
693}
694
695static void intel_th_msu_deinit(struct msc *msc)
696{
697 u32 mintctl;
698
699 if (!msc->do_irq)
700 return;
701
702 mintctl = ioread32(msc->msu_base + REG_MSU_MINTCTL);
703 mintctl &= msc->index ? ~M1BLIE : ~M0BLIE;
704 iowrite32(mintctl, msc->msu_base + REG_MSU_MINTCTL);
705}
706
707static int msc_win_set_lockout(struct msc_window *win,
708 enum lockout_state expect,
709 enum lockout_state new)
710{
711 enum lockout_state old;
712 unsigned long flags;
713 int ret = 0;
714
715 if (!win->msc->mbuf)
716 return 0;
717
718 spin_lock_irqsave(&win->lo_lock, flags);
719 old = win->lockout;
720
721 if (old != expect) {
722 ret = -EINVAL;
723 goto unlock;
724 }
725
726 win->lockout = new;
727
728 if (old == expect && new == WIN_LOCKED)
729 atomic_inc(&win->msc->user_count);
730 else if (old == expect && old == WIN_LOCKED)
731 atomic_dec(&win->msc->user_count);
732
733unlock:
734 spin_unlock_irqrestore(&win->lo_lock, flags);
735
736 if (ret) {
737 if (expect == WIN_READY && old == WIN_LOCKED)
738 return -EBUSY;
739
740 /* from intel_th_msc_window_unlock(), don't warn if not locked */
741 if (expect == WIN_LOCKED && old == new)
742 return 0;
743
744 dev_warn_ratelimited(msc_dev(win->msc),
745 "expected lockout state %d, got %d\n",
746 expect, old);
747 }
748
749 return ret;
750}
751/**
752 * msc_configure() - set up MSC hardware
753 * @msc: the MSC device to configure
754 *
755 * Program storage mode, wrapping, burst length and trace buffer address
756 * into a given MSC. Then, enable tracing and set msc::enabled.
757 * The latter is serialized on msc::buf_mutex, so make sure to hold it.
758 *
759 * Return: %0 for success or a negative error code otherwise.
760 */
761static int msc_configure(struct msc *msc)
762{
763 u32 reg;
764
765 lockdep_assert_held(&msc->buf_mutex);
766
767 if (msc->mode > MSC_MODE_MULTI)
768 return -EINVAL;
769
770 if (msc->mode == MSC_MODE_MULTI) {
771 if (msc_win_set_lockout(msc->cur_win, WIN_READY, WIN_INUSE))
772 return -EBUSY;
773
774 msc_buffer_clear_hw_header(msc);
775 }
776
777 msc->orig_addr = ioread32(msc->reg_base + REG_MSU_MSC0BAR);
778 msc->orig_sz = ioread32(msc->reg_base + REG_MSU_MSC0SIZE);
779
780 reg = msc->base_addr >> PAGE_SHIFT;
781 iowrite32(reg, msc->reg_base + REG_MSU_MSC0BAR);
782
783 if (msc->mode == MSC_MODE_SINGLE) {
784 reg = msc->nr_pages;
785 iowrite32(reg, msc->reg_base + REG_MSU_MSC0SIZE);
786 }
787
788 reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL);
789 reg &= ~(MSC_MODE | MSC_WRAPEN | MSC_EN | MSC_RD_HDR_OVRD);
790
791 reg |= MSC_EN;
792 reg |= msc->mode << __ffs(MSC_MODE);
793 reg |= msc->burst_len << __ffs(MSC_LEN);
794
795 if (msc->wrap)
796 reg |= MSC_WRAPEN;
797
798 iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL);
799
800 intel_th_msu_init(msc);
801
802 msc->thdev->output.multiblock = msc->mode == MSC_MODE_MULTI;
803 intel_th_trace_enable(msc->thdev);
804 msc->enabled = 1;
805
806 if (msc->mbuf && msc->mbuf->activate)
807 msc->mbuf->activate(msc->mbuf_priv);
808
809 return 0;
810}
811
812/**
813 * msc_disable() - disable MSC hardware
814 * @msc: MSC device to disable
815 *
816 * If @msc is enabled, disable tracing on the switch and then disable MSC
817 * storage. Caller must hold msc::buf_mutex.
818 */
819static void msc_disable(struct msc *msc)
820{
821 struct msc_window *win = msc->cur_win;
822 u32 reg;
823
824 lockdep_assert_held(&msc->buf_mutex);
825
826 if (msc->mode == MSC_MODE_MULTI)
827 msc_win_set_lockout(win, WIN_INUSE, WIN_LOCKED);
828
829 if (msc->mbuf && msc->mbuf->deactivate)
830 msc->mbuf->deactivate(msc->mbuf_priv);
831 intel_th_msu_deinit(msc);
832 intel_th_trace_disable(msc->thdev);
833
834 if (msc->mode == MSC_MODE_SINGLE) {
835 reg = ioread32(msc->reg_base + REG_MSU_MSC0STS);
836 msc->single_wrap = !!(reg & MSCSTS_WRAPSTAT);
837
838 reg = ioread32(msc->reg_base + REG_MSU_MSC0MWP);
839 msc->single_sz = reg & ((msc->nr_pages << PAGE_SHIFT) - 1);
840 dev_dbg(msc_dev(msc), "MSCnMWP: %08x/%08lx, wrap: %d\n",
841 reg, msc->single_sz, msc->single_wrap);
842 }
843
844 reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL);
845 reg &= ~MSC_EN;
846 iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL);
847
848 if (msc->mbuf && msc->mbuf->ready)
849 msc->mbuf->ready(msc->mbuf_priv, win->sgt,
850 msc_win_total_sz(win));
851
852 msc->enabled = 0;
853
854 iowrite32(msc->orig_addr, msc->reg_base + REG_MSU_MSC0BAR);
855 iowrite32(msc->orig_sz, msc->reg_base + REG_MSU_MSC0SIZE);
856
857 dev_dbg(msc_dev(msc), "MSCnNWSA: %08x\n",
858 ioread32(msc->reg_base + REG_MSU_MSC0NWSA));
859
860 reg = ioread32(msc->reg_base + REG_MSU_MSC0STS);
861 dev_dbg(msc_dev(msc), "MSCnSTS: %08x\n", reg);
862
863 reg = ioread32(msc->reg_base + REG_MSU_MSUSTS);
864 reg &= msc->index ? MSUSTS_MSC1BLAST : MSUSTS_MSC0BLAST;
865 iowrite32(reg, msc->reg_base + REG_MSU_MSUSTS);
866}
867
868static int intel_th_msc_activate(struct intel_th_device *thdev)
869{
870 struct msc *msc = dev_get_drvdata(&thdev->dev);
871 int ret = -EBUSY;
872
873 if (!atomic_inc_unless_negative(&msc->user_count))
874 return -ENODEV;
875
876 mutex_lock(&msc->buf_mutex);
877
878 /* if there are readers, refuse */
879 if (list_empty(&msc->iter_list))
880 ret = msc_configure(msc);
881
882 mutex_unlock(&msc->buf_mutex);
883
884 if (ret)
885 atomic_dec(&msc->user_count);
886
887 return ret;
888}
889
890static void intel_th_msc_deactivate(struct intel_th_device *thdev)
891{
892 struct msc *msc = dev_get_drvdata(&thdev->dev);
893
894 mutex_lock(&msc->buf_mutex);
895 if (msc->enabled) {
896 msc_disable(msc);
897 atomic_dec(&msc->user_count);
898 }
899 mutex_unlock(&msc->buf_mutex);
900}
901
902/**
903 * msc_buffer_contig_alloc() - allocate a contiguous buffer for SINGLE mode
904 * @msc: MSC device
905 * @size: allocation size in bytes
906 *
907 * This modifies msc::base, which requires msc::buf_mutex to serialize, so the
908 * caller is expected to hold it.
909 *
910 * Return: 0 on success, -errno otherwise.
911 */
912static int msc_buffer_contig_alloc(struct msc *msc, unsigned long size)
913{
914 unsigned long nr_pages = size >> PAGE_SHIFT;
915 unsigned int order = get_order(size);
916 struct page *page;
917 int ret;
918
919 if (!size)
920 return 0;
921
922 ret = sg_alloc_table(&msc->single_sgt, 1, GFP_KERNEL);
923 if (ret)
924 goto err_out;
925
926 ret = -ENOMEM;
927 page = alloc_pages(GFP_KERNEL | __GFP_ZERO | GFP_DMA32, order);
928 if (!page)
929 goto err_free_sgt;
930
931 split_page(page, order);
932 sg_set_buf(msc->single_sgt.sgl, page_address(page), size);
933
934 ret = dma_map_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl, 1,
935 DMA_FROM_DEVICE);
936 if (ret < 0)
937 goto err_free_pages;
938
939 msc->nr_pages = nr_pages;
940 msc->base = page_address(page);
941 msc->base_addr = sg_dma_address(msc->single_sgt.sgl);
942
943 return 0;
944
945err_free_pages:
946 __free_pages(page, order);
947
948err_free_sgt:
949 sg_free_table(&msc->single_sgt);
950
951err_out:
952 return ret;
953}
954
955/**
956 * msc_buffer_contig_free() - free a contiguous buffer
957 * @msc: MSC configured in SINGLE mode
958 */
959static void msc_buffer_contig_free(struct msc *msc)
960{
961 unsigned long off;
962
963 dma_unmap_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl,
964 1, DMA_FROM_DEVICE);
965 sg_free_table(&msc->single_sgt);
966
967 for (off = 0; off < msc->nr_pages << PAGE_SHIFT; off += PAGE_SIZE) {
968 struct page *page = virt_to_page(msc->base + off);
969
970 page->mapping = NULL;
971 __free_page(page);
972 }
973
974 msc->nr_pages = 0;
975}
976
977/**
978 * msc_buffer_contig_get_page() - find a page at a given offset
979 * @msc: MSC configured in SINGLE mode
980 * @pgoff: page offset
981 *
982 * Return: page, if @pgoff is within the range, NULL otherwise.
983 */
984static struct page *msc_buffer_contig_get_page(struct msc *msc,
985 unsigned long pgoff)
986{
987 if (pgoff >= msc->nr_pages)
988 return NULL;
989
990 return virt_to_page(msc->base + (pgoff << PAGE_SHIFT));
991}
992
993static int __msc_buffer_win_alloc(struct msc_window *win,
994 unsigned int nr_segs)
995{
996 struct scatterlist *sg_ptr;
997 void *block;
998 int i, ret;
999
1000 ret = sg_alloc_table(win->sgt, nr_segs, GFP_KERNEL);
1001 if (ret)
1002 return -ENOMEM;
1003
1004 for_each_sg(win->sgt->sgl, sg_ptr, nr_segs, i) {
1005 block = dma_alloc_coherent(msc_dev(win->msc)->parent->parent,
1006 PAGE_SIZE, &sg_dma_address(sg_ptr),
1007 GFP_KERNEL);
1008 if (!block)
1009 goto err_nomem;
1010
1011 sg_set_buf(sg_ptr, block, PAGE_SIZE);
1012 }
1013
1014 return nr_segs;
1015
1016err_nomem:
1017 for_each_sg(win->sgt->sgl, sg_ptr, i, ret)
1018 dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE,
1019 sg_virt(sg_ptr), sg_dma_address(sg_ptr));
1020
1021 sg_free_table(win->sgt);
1022
1023 return -ENOMEM;
1024}
1025
1026#ifdef CONFIG_X86
1027static void msc_buffer_set_uc(struct msc *msc)
1028{
1029 struct scatterlist *sg_ptr;
1030 struct msc_window *win;
1031 int i;
1032
1033 if (msc->mode == MSC_MODE_SINGLE) {
1034 set_memory_uc((unsigned long)msc->base, msc->nr_pages);
1035 return;
1036 }
1037
1038 list_for_each_entry(win, &msc->win_list, entry) {
1039 for_each_sg(win->sgt->sgl, sg_ptr, win->nr_segs, i) {
1040 /* Set the page as uncached */
1041 set_memory_uc((unsigned long)sg_virt(sg_ptr),
1042 PFN_DOWN(sg_ptr->length));
1043 }
1044 }
1045}
1046
1047static void msc_buffer_set_wb(struct msc *msc)
1048{
1049 struct scatterlist *sg_ptr;
1050 struct msc_window *win;
1051 int i;
1052
1053 if (msc->mode == MSC_MODE_SINGLE) {
1054 set_memory_wb((unsigned long)msc->base, msc->nr_pages);
1055 return;
1056 }
1057
1058 list_for_each_entry(win, &msc->win_list, entry) {
1059 for_each_sg(win->sgt->sgl, sg_ptr, win->nr_segs, i) {
1060 /* Reset the page to write-back */
1061 set_memory_wb((unsigned long)sg_virt(sg_ptr),
1062 PFN_DOWN(sg_ptr->length));
1063 }
1064 }
1065}
1066#else /* !X86 */
1067static inline void
1068msc_buffer_set_uc(struct msc *msc) {}
1069static inline void msc_buffer_set_wb(struct msc *msc) {}
1070#endif /* CONFIG_X86 */
1071
1072static struct page *msc_sg_page(struct scatterlist *sg)
1073{
1074 void *addr = sg_virt(sg);
1075
1076 if (is_vmalloc_addr(addr))
1077 return vmalloc_to_page(addr);
1078
1079 return sg_page(sg);
1080}
1081
1082/**
1083 * msc_buffer_win_alloc() - alloc a window for a multiblock mode
1084 * @msc: MSC device
1085 * @nr_blocks: number of pages in this window
1086 *
1087 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex
1088 * to serialize, so the caller is expected to hold it.
1089 *
1090 * Return: 0 on success, -errno otherwise.
1091 */
1092static int msc_buffer_win_alloc(struct msc *msc, unsigned int nr_blocks)
1093{
1094 struct msc_window *win;
1095 int ret = -ENOMEM;
1096
1097 if (!nr_blocks)
1098 return 0;
1099
1100 win = kzalloc(sizeof(*win), GFP_KERNEL);
1101 if (!win)
1102 return -ENOMEM;
1103
1104 win->msc = msc;
1105 win->sgt = &win->_sgt;
1106 win->lockout = WIN_READY;
1107 spin_lock_init(&win->lo_lock);
1108
1109 if (!list_empty(&msc->win_list)) {
1110 struct msc_window *prev = list_last_entry(&msc->win_list,
1111 struct msc_window,
1112 entry);
1113
1114 win->pgoff = prev->pgoff + prev->nr_blocks;
1115 }
1116
1117 if (msc->mbuf && msc->mbuf->alloc_window)
1118 ret = msc->mbuf->alloc_window(msc->mbuf_priv, &win->sgt,
1119 nr_blocks << PAGE_SHIFT);
1120 else
1121 ret = __msc_buffer_win_alloc(win, nr_blocks);
1122
1123 if (ret <= 0)
1124 goto err_nomem;
1125
1126 win->nr_segs = ret;
1127 win->nr_blocks = nr_blocks;
1128
1129 if (list_empty(&msc->win_list)) {
1130 msc->base = msc_win_base(win);
1131 msc->base_addr = msc_win_base_dma(win);
1132 msc->cur_win = win;
1133 }
1134
1135 list_add_tail(&win->entry, &msc->win_list);
1136 msc->nr_pages += nr_blocks;
1137
1138 return 0;
1139
1140err_nomem:
1141 kfree(win);
1142
1143 return ret;
1144}
1145
1146static void __msc_buffer_win_free(struct msc *msc, struct msc_window *win)
1147{
1148 struct scatterlist *sg;
1149 int i;
1150
1151 for_each_sg(win->sgt->sgl, sg, win->nr_segs, i) {
1152 struct page *page = msc_sg_page(sg);
1153
1154 page->mapping = NULL;
1155 dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE,
1156 sg_virt(sg), sg_dma_address(sg));
1157 }
1158 sg_free_table(win->sgt);
1159}
1160
1161/**
1162 * msc_buffer_win_free() - free a window from MSC's window list
1163 * @msc: MSC device
1164 * @win: window to free
1165 *
1166 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex
1167 * to serialize, so the caller is expected to hold it.
1168 */
1169static void msc_buffer_win_free(struct msc *msc, struct msc_window *win)
1170{
1171 msc->nr_pages -= win->nr_blocks;
1172
1173 list_del(&win->entry);
1174 if (list_empty(&msc->win_list)) {
1175 msc->base = NULL;
1176 msc->base_addr = 0;
1177 }
1178
1179 if (msc->mbuf && msc->mbuf->free_window)
1180 msc->mbuf->free_window(msc->mbuf_priv, win->sgt);
1181 else
1182 __msc_buffer_win_free(msc, win);
1183
1184 kfree(win);
1185}
1186
1187/**
1188 * msc_buffer_relink() - set up block descriptors for multiblock mode
1189 * @msc: MSC device
1190 *
1191 * This traverses msc::win_list, which requires msc::buf_mutex to serialize,
1192 * so the caller is expected to hold it.
1193 */
1194static void msc_buffer_relink(struct msc *msc)
1195{
1196 struct msc_window *win, *next_win;
1197
1198 /* call with msc::mutex locked */
1199 list_for_each_entry(win, &msc->win_list, entry) {
1200 struct scatterlist *sg;
1201 unsigned int blk;
1202 u32 sw_tag = 0;
1203
1204 /*
1205 * Last window's next_win should point to the first window
1206 * and MSC_SW_TAG_LASTWIN should be set.
1207 */
1208 if (msc_is_last_win(win)) {
1209 sw_tag |= MSC_SW_TAG_LASTWIN;
1210 next_win = list_first_entry(&msc->win_list,
1211 struct msc_window, entry);
1212 } else {
1213 next_win = list_next_entry(win, entry);
1214 }
1215
1216 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
1217 struct msc_block_desc *bdesc = sg_virt(sg);
1218
1219 memset(bdesc, 0, sizeof(*bdesc));
1220
1221 bdesc->next_win = msc_win_base_pfn(next_win);
1222
1223 /*
1224 * Similarly to last window, last block should point
1225 * to the first one.
1226 */
1227 if (blk == win->nr_segs - 1) {
1228 sw_tag |= MSC_SW_TAG_LASTBLK;
1229 bdesc->next_blk = msc_win_base_pfn(win);
1230 } else {
1231 dma_addr_t addr = sg_dma_address(sg_next(sg));
1232
1233 bdesc->next_blk = PFN_DOWN(addr);
1234 }
1235
1236 bdesc->sw_tag = sw_tag;
1237 bdesc->block_sz = sg->length / 64;
1238 }
1239 }
1240
1241 /*
1242 * Make the above writes globally visible before tracing is
1243 * enabled to make sure hardware sees them coherently.
1244 */
1245 wmb();
1246}
1247
1248static void msc_buffer_multi_free(struct msc *msc)
1249{
1250 struct msc_window *win, *iter;
1251
1252 list_for_each_entry_safe(win, iter, &msc->win_list, entry)
1253 msc_buffer_win_free(msc, win);
1254}
1255
1256static int msc_buffer_multi_alloc(struct msc *msc, unsigned long *nr_pages,
1257 unsigned int nr_wins)
1258{
1259 int ret, i;
1260
1261 for (i = 0; i < nr_wins; i++) {
1262 ret = msc_buffer_win_alloc(msc, nr_pages[i]);
1263 if (ret) {
1264 msc_buffer_multi_free(msc);
1265 return ret;
1266 }
1267 }
1268
1269 msc_buffer_relink(msc);
1270
1271 return 0;
1272}
1273
1274/**
1275 * msc_buffer_free() - free buffers for MSC
1276 * @msc: MSC device
1277 *
1278 * Free MSC's storage buffers.
1279 *
1280 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex to
1281 * serialize, so the caller is expected to hold it.
1282 */
1283static void msc_buffer_free(struct msc *msc)
1284{
1285 msc_buffer_set_wb(msc);
1286
1287 if (msc->mode == MSC_MODE_SINGLE)
1288 msc_buffer_contig_free(msc);
1289 else if (msc->mode == MSC_MODE_MULTI)
1290 msc_buffer_multi_free(msc);
1291}
1292
1293/**
1294 * msc_buffer_alloc() - allocate a buffer for MSC
1295 * @msc: MSC device
1296 * @nr_pages: number of pages for each window
1297 * @nr_wins: number of windows
1298 *
1299 * Allocate a storage buffer for MSC, depending on the msc::mode, it will be
1300 * either done via msc_buffer_contig_alloc() for SINGLE operation mode or
1301 * msc_buffer_win_alloc() for multiblock operation. The latter allocates one
1302 * window per invocation, so in multiblock mode this can be called multiple
1303 * times for the same MSC to allocate multiple windows.
1304 *
1305 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex
1306 * to serialize, so the caller is expected to hold it.
1307 *
1308 * Return: 0 on success, -errno otherwise.
1309 */
1310static int msc_buffer_alloc(struct msc *msc, unsigned long *nr_pages,
1311 unsigned int nr_wins)
1312{
1313 int ret;
1314
1315 /* -1: buffer not allocated */
1316 if (atomic_read(&msc->user_count) != -1)
1317 return -EBUSY;
1318
1319 if (msc->mode == MSC_MODE_SINGLE) {
1320 if (nr_wins != 1)
1321 return -EINVAL;
1322
1323 ret = msc_buffer_contig_alloc(msc, nr_pages[0] << PAGE_SHIFT);
1324 } else if (msc->mode == MSC_MODE_MULTI) {
1325 ret = msc_buffer_multi_alloc(msc, nr_pages, nr_wins);
1326 } else {
1327 ret = -EINVAL;
1328 }
1329
1330 if (!ret) {
1331 msc_buffer_set_uc(msc);
1332
1333 /* allocation should be visible before the counter goes to 0 */
1334 smp_mb__before_atomic();
1335
1336 if (WARN_ON_ONCE(atomic_cmpxchg(&msc->user_count, -1, 0) != -1))
1337 return -EINVAL;
1338 }
1339
1340 return ret;
1341}
1342
1343/**
1344 * msc_buffer_unlocked_free_unless_used() - free a buffer unless it's in use
1345 * @msc: MSC device
1346 *
1347 * This will free MSC buffer unless it is in use or there is no allocated
1348 * buffer.
1349 * Caller needs to hold msc::buf_mutex.
1350 *
1351 * Return: 0 on successful deallocation or if there was no buffer to
1352 * deallocate, -EBUSY if there are active users.
1353 */
1354static int msc_buffer_unlocked_free_unless_used(struct msc *msc)
1355{
1356 int count, ret = 0;
1357
1358 count = atomic_cmpxchg(&msc->user_count, 0, -1);
1359
1360 /* > 0: buffer is allocated and has users */
1361 if (count > 0)
1362 ret = -EBUSY;
1363 /* 0: buffer is allocated, no users */
1364 else if (!count)
1365 msc_buffer_free(msc);
1366 /* < 0: no buffer, nothing to do */
1367
1368 return ret;
1369}
1370
1371/**
1372 * msc_buffer_free_unless_used() - free a buffer unless it's in use
1373 * @msc: MSC device
1374 *
1375 * This is a locked version of msc_buffer_unlocked_free_unless_used().
1376 *
1377 * Return: 0 on successful deallocation or if there was no buffer to
1378 * deallocate, -EBUSY if there are active users.
1379 */
1380static int msc_buffer_free_unless_used(struct msc *msc)
1381{
1382 int ret;
1383
1384 mutex_lock(&msc->buf_mutex);
1385 ret = msc_buffer_unlocked_free_unless_used(msc);
1386 mutex_unlock(&msc->buf_mutex);
1387
1388 return ret;
1389}
1390
1391/**
1392 * msc_buffer_get_page() - get MSC buffer page at a given offset
1393 * @msc: MSC device
1394 * @pgoff: page offset into the storage buffer
1395 *
1396 * This traverses msc::win_list, so holding msc::buf_mutex is expected from
1397 * the caller.
1398 *
1399 * Return: page if @pgoff corresponds to a valid buffer page or NULL.
1400 */
1401static struct page *msc_buffer_get_page(struct msc *msc, unsigned long pgoff)
1402{
1403 struct msc_window *win;
1404 struct scatterlist *sg;
1405 unsigned int blk;
1406
1407 if (msc->mode == MSC_MODE_SINGLE)
1408 return msc_buffer_contig_get_page(msc, pgoff);
1409
1410 list_for_each_entry(win, &msc->win_list, entry)
1411 if (pgoff >= win->pgoff && pgoff < win->pgoff + win->nr_blocks)
1412 goto found;
1413
1414 return NULL;
1415
1416found:
1417 pgoff -= win->pgoff;
1418
1419 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
1420 struct page *page = msc_sg_page(sg);
1421 size_t pgsz = PFN_DOWN(sg->length);
1422
1423 if (pgoff < pgsz)
1424 return page + pgoff;
1425
1426 pgoff -= pgsz;
1427 }
1428
1429 return NULL;
1430}
1431
1432/**
1433 * struct msc_win_to_user_struct - data for copy_to_user() callback
1434 * @buf: userspace buffer to copy data to
1435 * @offset: running offset
1436 */
1437struct msc_win_to_user_struct {
1438 char __user *buf;
1439 unsigned long offset;
1440};
1441
1442/**
1443 * msc_win_to_user() - iterator for msc_buffer_iterate() to copy data to user
1444 * @data: callback's private data
1445 * @src: source buffer
1446 * @len: amount of data to copy from the source buffer
1447 *
1448 * Return: >= %0 for success or -errno for error.
1449 */
1450static unsigned long msc_win_to_user(void *data, void *src, size_t len)
1451{
1452 struct msc_win_to_user_struct *u = data;
1453 unsigned long ret;
1454
1455 ret = copy_to_user(u->buf + u->offset, src, len);
1456 u->offset += len - ret;
1457
1458 return ret;
1459}
1460
1461
1462/*
1463 * file operations' callbacks
1464 */
1465
1466static int intel_th_msc_open(struct inode *inode, struct file *file)
1467{
1468 struct intel_th_device *thdev = file->private_data;
1469 struct msc *msc = dev_get_drvdata(&thdev->dev);
1470 struct msc_iter *iter;
1471
1472 if (!capable(CAP_SYS_RAWIO))
1473 return -EPERM;
1474
1475 iter = msc_iter_install(msc);
1476 if (IS_ERR(iter))
1477 return PTR_ERR(iter);
1478
1479 file->private_data = iter;
1480
1481 return nonseekable_open(inode, file);
1482}
1483
1484static int intel_th_msc_release(struct inode *inode, struct file *file)
1485{
1486 struct msc_iter *iter = file->private_data;
1487 struct msc *msc = iter->msc;
1488
1489 msc_iter_remove(iter, msc);
1490
1491 return 0;
1492}
1493
1494static ssize_t
1495msc_single_to_user(struct msc *msc, char __user *buf, loff_t off, size_t len)
1496{
1497 unsigned long size = msc->nr_pages << PAGE_SHIFT, rem = len;
1498 unsigned long start = off, tocopy = 0;
1499
1500 if (msc->single_wrap) {
1501 start += msc->single_sz;
1502 if (start < size) {
1503 tocopy = min(rem, size - start);
1504 if (copy_to_user(buf, msc->base + start, tocopy))
1505 return -EFAULT;
1506
1507 buf += tocopy;
1508 rem -= tocopy;
1509 start += tocopy;
1510 }
1511
1512 start &= size - 1;
1513 if (rem) {
1514 tocopy = min(rem, msc->single_sz - start);
1515 if (copy_to_user(buf, msc->base + start, tocopy))
1516 return -EFAULT;
1517
1518 rem -= tocopy;
1519 }
1520
1521 return len - rem;
1522 }
1523
1524 if (copy_to_user(buf, msc->base + start, rem))
1525 return -EFAULT;
1526
1527 return len;
1528}
1529
1530static ssize_t intel_th_msc_read(struct file *file, char __user *buf,
1531 size_t len, loff_t *ppos)
1532{
1533 struct msc_iter *iter = file->private_data;
1534 struct msc *msc = iter->msc;
1535 size_t size;
1536 loff_t off = *ppos;
1537 ssize_t ret = 0;
1538
1539 if (!atomic_inc_unless_negative(&msc->user_count))
1540 return 0;
1541
1542 if (msc->mode == MSC_MODE_SINGLE && !msc->single_wrap)
1543 size = msc->single_sz;
1544 else
1545 size = msc->nr_pages << PAGE_SHIFT;
1546
1547 if (!size)
1548 goto put_count;
1549
1550 if (off >= size)
1551 goto put_count;
1552
1553 if (off + len >= size)
1554 len = size - off;
1555
1556 if (msc->mode == MSC_MODE_SINGLE) {
1557 ret = msc_single_to_user(msc, buf, off, len);
1558 if (ret >= 0)
1559 *ppos += ret;
1560 } else if (msc->mode == MSC_MODE_MULTI) {
1561 struct msc_win_to_user_struct u = {
1562 .buf = buf,
1563 .offset = 0,
1564 };
1565
1566 ret = msc_buffer_iterate(iter, len, &u, msc_win_to_user);
1567 if (ret >= 0)
1568 *ppos = iter->offset;
1569 } else {
1570 ret = -EINVAL;
1571 }
1572
1573put_count:
1574 atomic_dec(&msc->user_count);
1575
1576 return ret;
1577}
1578
1579/*
1580 * vm operations callbacks (vm_ops)
1581 */
1582
1583static void msc_mmap_open(struct vm_area_struct *vma)
1584{
1585 struct msc_iter *iter = vma->vm_file->private_data;
1586 struct msc *msc = iter->msc;
1587
1588 atomic_inc(&msc->mmap_count);
1589}
1590
1591static void msc_mmap_close(struct vm_area_struct *vma)
1592{
1593 struct msc_iter *iter = vma->vm_file->private_data;
1594 struct msc *msc = iter->msc;
1595 unsigned long pg;
1596
1597 if (!atomic_dec_and_mutex_lock(&msc->mmap_count, &msc->buf_mutex))
1598 return;
1599
1600 /* drop page _refcounts */
1601 for (pg = 0; pg < msc->nr_pages; pg++) {
1602 struct page *page = msc_buffer_get_page(msc, pg);
1603
1604 if (WARN_ON_ONCE(!page))
1605 continue;
1606
1607 if (page->mapping)
1608 page->mapping = NULL;
1609 }
1610
1611 /* last mapping -- drop user_count */
1612 atomic_dec(&msc->user_count);
1613 mutex_unlock(&msc->buf_mutex);
1614}
1615
1616static vm_fault_t msc_mmap_fault(struct vm_fault *vmf)
1617{
1618 struct msc_iter *iter = vmf->vma->vm_file->private_data;
1619 struct msc *msc = iter->msc;
1620
1621 vmf->page = msc_buffer_get_page(msc, vmf->pgoff);
1622 if (!vmf->page)
1623 return VM_FAULT_SIGBUS;
1624
1625 get_page(vmf->page);
1626 vmf->page->mapping = vmf->vma->vm_file->f_mapping;
1627 vmf->page->index = vmf->pgoff;
1628
1629 return 0;
1630}
1631
1632static const struct vm_operations_struct msc_mmap_ops = {
1633 .open = msc_mmap_open,
1634 .close = msc_mmap_close,
1635 .fault = msc_mmap_fault,
1636};
1637
1638static int intel_th_msc_mmap(struct file *file, struct vm_area_struct *vma)
1639{
1640 unsigned long size = vma->vm_end - vma->vm_start;
1641 struct msc_iter *iter = vma->vm_file->private_data;
1642 struct msc *msc = iter->msc;
1643 int ret = -EINVAL;
1644
1645 if (!size || offset_in_page(size))
1646 return -EINVAL;
1647
1648 if (vma->vm_pgoff)
1649 return -EINVAL;
1650
1651 /* grab user_count once per mmap; drop in msc_mmap_close() */
1652 if (!atomic_inc_unless_negative(&msc->user_count))
1653 return -EINVAL;
1654
1655 if (msc->mode != MSC_MODE_SINGLE &&
1656 msc->mode != MSC_MODE_MULTI)
1657 goto out;
1658
1659 if (size >> PAGE_SHIFT != msc->nr_pages)
1660 goto out;
1661
1662 atomic_set(&msc->mmap_count, 1);
1663 ret = 0;
1664
1665out:
1666 if (ret)
1667 atomic_dec(&msc->user_count);
1668
1669 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1670 vm_flags_set(vma, VM_DONTEXPAND | VM_DONTCOPY);
1671 vma->vm_ops = &msc_mmap_ops;
1672 return ret;
1673}
1674
1675static const struct file_operations intel_th_msc_fops = {
1676 .open = intel_th_msc_open,
1677 .release = intel_th_msc_release,
1678 .read = intel_th_msc_read,
1679 .mmap = intel_th_msc_mmap,
1680 .owner = THIS_MODULE,
1681};
1682
1683static void intel_th_msc_wait_empty(struct intel_th_device *thdev)
1684{
1685 struct msc *msc = dev_get_drvdata(&thdev->dev);
1686 unsigned long count;
1687 u32 reg;
1688
1689 for (reg = 0, count = MSC_PLE_WAITLOOP_DEPTH;
1690 count && !(reg & MSCSTS_PLE); count--) {
1691 reg = __raw_readl(msc->reg_base + REG_MSU_MSC0STS);
1692 cpu_relax();
1693 }
1694
1695 if (!count)
1696 dev_dbg(msc_dev(msc), "timeout waiting for MSC0 PLE\n");
1697}
1698
1699static int intel_th_msc_init(struct msc *msc)
1700{
1701 atomic_set(&msc->user_count, -1);
1702
1703 msc->mode = msc->multi_is_broken ? MSC_MODE_SINGLE : MSC_MODE_MULTI;
1704 mutex_init(&msc->buf_mutex);
1705 INIT_LIST_HEAD(&msc->win_list);
1706 INIT_LIST_HEAD(&msc->iter_list);
1707
1708 msc->burst_len =
1709 (ioread32(msc->reg_base + REG_MSU_MSC0CTL) & MSC_LEN) >>
1710 __ffs(MSC_LEN);
1711
1712 return 0;
1713}
1714
1715static int msc_win_switch(struct msc *msc)
1716{
1717 struct msc_window *first;
1718
1719 if (list_empty(&msc->win_list))
1720 return -EINVAL;
1721
1722 first = list_first_entry(&msc->win_list, struct msc_window, entry);
1723
1724 if (msc_is_last_win(msc->cur_win))
1725 msc->cur_win = first;
1726 else
1727 msc->cur_win = list_next_entry(msc->cur_win, entry);
1728
1729 msc->base = msc_win_base(msc->cur_win);
1730 msc->base_addr = msc_win_base_dma(msc->cur_win);
1731
1732 intel_th_trace_switch(msc->thdev);
1733
1734 return 0;
1735}
1736
1737/**
1738 * intel_th_msc_window_unlock - put the window back in rotation
1739 * @dev: MSC device to which this relates
1740 * @sgt: buffer's sg_table for the window, does nothing if NULL
1741 */
1742void intel_th_msc_window_unlock(struct device *dev, struct sg_table *sgt)
1743{
1744 struct msc *msc = dev_get_drvdata(dev);
1745 struct msc_window *win;
1746
1747 if (!sgt)
1748 return;
1749
1750 win = msc_find_window(msc, sgt, false);
1751 if (!win)
1752 return;
1753
1754 msc_win_set_lockout(win, WIN_LOCKED, WIN_READY);
1755 if (msc->switch_on_unlock == win) {
1756 msc->switch_on_unlock = NULL;
1757 msc_win_switch(msc);
1758 }
1759}
1760EXPORT_SYMBOL_GPL(intel_th_msc_window_unlock);
1761
1762static void msc_work(struct work_struct *work)
1763{
1764 struct msc *msc = container_of(work, struct msc, work);
1765
1766 intel_th_msc_deactivate(msc->thdev);
1767}
1768
1769static irqreturn_t intel_th_msc_interrupt(struct intel_th_device *thdev)
1770{
1771 struct msc *msc = dev_get_drvdata(&thdev->dev);
1772 u32 msusts = ioread32(msc->msu_base + REG_MSU_MSUSTS);
1773 u32 mask = msc->index ? MSUSTS_MSC1BLAST : MSUSTS_MSC0BLAST;
1774 struct msc_window *win, *next_win;
1775
1776 if (!msc->do_irq || !msc->mbuf)
1777 return IRQ_NONE;
1778
1779 msusts &= mask;
1780
1781 if (!msusts)
1782 return msc->enabled ? IRQ_HANDLED : IRQ_NONE;
1783
1784 iowrite32(msusts, msc->msu_base + REG_MSU_MSUSTS);
1785
1786 if (!msc->enabled)
1787 return IRQ_NONE;
1788
1789 /* grab the window before we do the switch */
1790 win = msc->cur_win;
1791 if (!win)
1792 return IRQ_HANDLED;
1793 next_win = msc_next_window(win);
1794 if (!next_win)
1795 return IRQ_HANDLED;
1796
1797 /* next window: if READY, proceed, if LOCKED, stop the trace */
1798 if (msc_win_set_lockout(next_win, WIN_READY, WIN_INUSE)) {
1799 if (msc->stop_on_full)
1800 schedule_work(&msc->work);
1801 else
1802 msc->switch_on_unlock = next_win;
1803
1804 return IRQ_HANDLED;
1805 }
1806
1807 /* current window: INUSE -> LOCKED */
1808 msc_win_set_lockout(win, WIN_INUSE, WIN_LOCKED);
1809
1810 msc_win_switch(msc);
1811
1812 if (msc->mbuf && msc->mbuf->ready)
1813 msc->mbuf->ready(msc->mbuf_priv, win->sgt,
1814 msc_win_total_sz(win));
1815
1816 return IRQ_HANDLED;
1817}
1818
1819static const char * const msc_mode[] = {
1820 [MSC_MODE_SINGLE] = "single",
1821 [MSC_MODE_MULTI] = "multi",
1822 [MSC_MODE_EXI] = "ExI",
1823 [MSC_MODE_DEBUG] = "debug",
1824};
1825
1826static ssize_t
1827wrap_show(struct device *dev, struct device_attribute *attr, char *buf)
1828{
1829 struct msc *msc = dev_get_drvdata(dev);
1830
1831 return scnprintf(buf, PAGE_SIZE, "%d\n", msc->wrap);
1832}
1833
1834static ssize_t
1835wrap_store(struct device *dev, struct device_attribute *attr, const char *buf,
1836 size_t size)
1837{
1838 struct msc *msc = dev_get_drvdata(dev);
1839 unsigned long val;
1840 int ret;
1841
1842 ret = kstrtoul(buf, 10, &val);
1843 if (ret)
1844 return ret;
1845
1846 msc->wrap = !!val;
1847
1848 return size;
1849}
1850
1851static DEVICE_ATTR_RW(wrap);
1852
1853static void msc_buffer_unassign(struct msc *msc)
1854{
1855 lockdep_assert_held(&msc->buf_mutex);
1856
1857 if (!msc->mbuf)
1858 return;
1859
1860 msc->mbuf->unassign(msc->mbuf_priv);
1861 msu_buffer_put(msc->mbuf);
1862 msc->mbuf_priv = NULL;
1863 msc->mbuf = NULL;
1864}
1865
1866static ssize_t
1867mode_show(struct device *dev, struct device_attribute *attr, char *buf)
1868{
1869 struct msc *msc = dev_get_drvdata(dev);
1870 const char *mode = msc_mode[msc->mode];
1871 ssize_t ret;
1872
1873 mutex_lock(&msc->buf_mutex);
1874 if (msc->mbuf)
1875 mode = msc->mbuf->name;
1876 ret = scnprintf(buf, PAGE_SIZE, "%s\n", mode);
1877 mutex_unlock(&msc->buf_mutex);
1878
1879 return ret;
1880}
1881
1882static ssize_t
1883mode_store(struct device *dev, struct device_attribute *attr, const char *buf,
1884 size_t size)
1885{
1886 const struct msu_buffer *mbuf = NULL;
1887 struct msc *msc = dev_get_drvdata(dev);
1888 size_t len = size;
1889 char *cp, *mode;
1890 int i, ret;
1891
1892 if (!capable(CAP_SYS_RAWIO))
1893 return -EPERM;
1894
1895 cp = memchr(buf, '\n', len);
1896 if (cp)
1897 len = cp - buf;
1898
1899 mode = kstrndup(buf, len, GFP_KERNEL);
1900 if (!mode)
1901 return -ENOMEM;
1902
1903 i = match_string(msc_mode, ARRAY_SIZE(msc_mode), mode);
1904 if (i >= 0) {
1905 kfree(mode);
1906 goto found;
1907 }
1908
1909 /* Buffer sinks only work with a usable IRQ */
1910 if (!msc->do_irq) {
1911 kfree(mode);
1912 return -EINVAL;
1913 }
1914
1915 mbuf = msu_buffer_get(mode);
1916 kfree(mode);
1917 if (mbuf)
1918 goto found;
1919
1920 return -EINVAL;
1921
1922found:
1923 if (i == MSC_MODE_MULTI && msc->multi_is_broken)
1924 return -EOPNOTSUPP;
1925
1926 mutex_lock(&msc->buf_mutex);
1927 ret = 0;
1928
1929 /* Same buffer: do nothing */
1930 if (mbuf && mbuf == msc->mbuf) {
1931 /* put the extra reference we just got */
1932 msu_buffer_put(mbuf);
1933 goto unlock;
1934 }
1935
1936 ret = msc_buffer_unlocked_free_unless_used(msc);
1937 if (ret)
1938 goto unlock;
1939
1940 if (mbuf) {
1941 void *mbuf_priv = mbuf->assign(dev, &i);
1942
1943 if (!mbuf_priv) {
1944 ret = -ENOMEM;
1945 goto unlock;
1946 }
1947
1948 msc_buffer_unassign(msc);
1949 msc->mbuf_priv = mbuf_priv;
1950 msc->mbuf = mbuf;
1951 } else {
1952 msc_buffer_unassign(msc);
1953 }
1954
1955 msc->mode = i;
1956
1957unlock:
1958 if (ret && mbuf)
1959 msu_buffer_put(mbuf);
1960 mutex_unlock(&msc->buf_mutex);
1961
1962 return ret ? ret : size;
1963}
1964
1965static DEVICE_ATTR_RW(mode);
1966
1967static ssize_t
1968nr_pages_show(struct device *dev, struct device_attribute *attr, char *buf)
1969{
1970 struct msc *msc = dev_get_drvdata(dev);
1971 struct msc_window *win;
1972 size_t count = 0;
1973
1974 mutex_lock(&msc->buf_mutex);
1975
1976 if (msc->mode == MSC_MODE_SINGLE)
1977 count = scnprintf(buf, PAGE_SIZE, "%ld\n", msc->nr_pages);
1978 else if (msc->mode == MSC_MODE_MULTI) {
1979 list_for_each_entry(win, &msc->win_list, entry) {
1980 count += scnprintf(buf + count, PAGE_SIZE - count,
1981 "%d%c", win->nr_blocks,
1982 msc_is_last_win(win) ? '\n' : ',');
1983 }
1984 } else {
1985 count = scnprintf(buf, PAGE_SIZE, "unsupported\n");
1986 }
1987
1988 mutex_unlock(&msc->buf_mutex);
1989
1990 return count;
1991}
1992
1993static ssize_t
1994nr_pages_store(struct device *dev, struct device_attribute *attr,
1995 const char *buf, size_t size)
1996{
1997 struct msc *msc = dev_get_drvdata(dev);
1998 unsigned long val, *win = NULL, *rewin;
1999 size_t len = size;
2000 const char *p = buf;
2001 char *end, *s;
2002 int ret, nr_wins = 0;
2003
2004 if (!capable(CAP_SYS_RAWIO))
2005 return -EPERM;
2006
2007 ret = msc_buffer_free_unless_used(msc);
2008 if (ret)
2009 return ret;
2010
2011 /* scan the comma-separated list of allocation sizes */
2012 end = memchr(buf, '\n', len);
2013 if (end)
2014 len = end - buf;
2015
2016 do {
2017 end = memchr(p, ',', len);
2018 s = kstrndup(p, end ? end - p : len, GFP_KERNEL);
2019 if (!s) {
2020 ret = -ENOMEM;
2021 goto free_win;
2022 }
2023
2024 ret = kstrtoul(s, 10, &val);
2025 kfree(s);
2026
2027 if (ret || !val)
2028 goto free_win;
2029
2030 if (nr_wins && msc->mode == MSC_MODE_SINGLE) {
2031 ret = -EINVAL;
2032 goto free_win;
2033 }
2034
2035 nr_wins++;
2036 rewin = krealloc_array(win, nr_wins, sizeof(*win), GFP_KERNEL);
2037 if (!rewin) {
2038 kfree(win);
2039 return -ENOMEM;
2040 }
2041
2042 win = rewin;
2043 win[nr_wins - 1] = val;
2044
2045 if (!end)
2046 break;
2047
2048 /* consume the number and the following comma, hence +1 */
2049 len -= end - p + 1;
2050 p = end + 1;
2051 } while (len);
2052
2053 mutex_lock(&msc->buf_mutex);
2054 ret = msc_buffer_alloc(msc, win, nr_wins);
2055 mutex_unlock(&msc->buf_mutex);
2056
2057free_win:
2058 kfree(win);
2059
2060 return ret ? ret : size;
2061}
2062
2063static DEVICE_ATTR_RW(nr_pages);
2064
2065static ssize_t
2066win_switch_store(struct device *dev, struct device_attribute *attr,
2067 const char *buf, size_t size)
2068{
2069 struct msc *msc = dev_get_drvdata(dev);
2070 unsigned long val;
2071 int ret;
2072
2073 ret = kstrtoul(buf, 10, &val);
2074 if (ret)
2075 return ret;
2076
2077 if (val != 1)
2078 return -EINVAL;
2079
2080 ret = -EINVAL;
2081 mutex_lock(&msc->buf_mutex);
2082 /*
2083 * Window switch can only happen in the "multi" mode.
2084 * If a external buffer is engaged, they have the full
2085 * control over window switching.
2086 */
2087 if (msc->mode == MSC_MODE_MULTI && !msc->mbuf)
2088 ret = msc_win_switch(msc);
2089 mutex_unlock(&msc->buf_mutex);
2090
2091 return ret ? ret : size;
2092}
2093
2094static DEVICE_ATTR_WO(win_switch);
2095
2096static ssize_t stop_on_full_show(struct device *dev,
2097 struct device_attribute *attr, char *buf)
2098{
2099 struct msc *msc = dev_get_drvdata(dev);
2100
2101 return sprintf(buf, "%d\n", msc->stop_on_full);
2102}
2103
2104static ssize_t stop_on_full_store(struct device *dev,
2105 struct device_attribute *attr,
2106 const char *buf, size_t size)
2107{
2108 struct msc *msc = dev_get_drvdata(dev);
2109 int ret;
2110
2111 ret = kstrtobool(buf, &msc->stop_on_full);
2112 if (ret)
2113 return ret;
2114
2115 return size;
2116}
2117
2118static DEVICE_ATTR_RW(stop_on_full);
2119
2120static struct attribute *msc_output_attrs[] = {
2121 &dev_attr_wrap.attr,
2122 &dev_attr_mode.attr,
2123 &dev_attr_nr_pages.attr,
2124 &dev_attr_win_switch.attr,
2125 &dev_attr_stop_on_full.attr,
2126 NULL,
2127};
2128
2129static const struct attribute_group msc_output_group = {
2130 .attrs = msc_output_attrs,
2131};
2132
2133static int intel_th_msc_probe(struct intel_th_device *thdev)
2134{
2135 struct device *dev = &thdev->dev;
2136 struct resource *res;
2137 struct msc *msc;
2138 void __iomem *base;
2139 int err;
2140
2141 res = intel_th_device_get_resource(thdev, IORESOURCE_MEM, 0);
2142 if (!res)
2143 return -ENODEV;
2144
2145 base = devm_ioremap(dev, res->start, resource_size(res));
2146 if (!base)
2147 return -ENOMEM;
2148
2149 msc = devm_kzalloc(dev, sizeof(*msc), GFP_KERNEL);
2150 if (!msc)
2151 return -ENOMEM;
2152
2153 res = intel_th_device_get_resource(thdev, IORESOURCE_IRQ, 1);
2154 if (!res)
2155 msc->do_irq = 1;
2156
2157 if (INTEL_TH_CAP(to_intel_th(thdev), multi_is_broken))
2158 msc->multi_is_broken = 1;
2159
2160 msc->index = thdev->id;
2161
2162 msc->thdev = thdev;
2163 msc->reg_base = base + msc->index * 0x100;
2164 msc->msu_base = base;
2165
2166 INIT_WORK(&msc->work, msc_work);
2167 err = intel_th_msc_init(msc);
2168 if (err)
2169 return err;
2170
2171 dev_set_drvdata(dev, msc);
2172
2173 return 0;
2174}
2175
2176static void intel_th_msc_remove(struct intel_th_device *thdev)
2177{
2178 struct msc *msc = dev_get_drvdata(&thdev->dev);
2179 int ret;
2180
2181 intel_th_msc_deactivate(thdev);
2182
2183 /*
2184 * Buffers should not be used at this point except if the
2185 * output character device is still open and the parent
2186 * device gets detached from its bus, which is a FIXME.
2187 */
2188 ret = msc_buffer_free_unless_used(msc);
2189 WARN_ON_ONCE(ret);
2190}
2191
2192static struct intel_th_driver intel_th_msc_driver = {
2193 .probe = intel_th_msc_probe,
2194 .remove = intel_th_msc_remove,
2195 .irq = intel_th_msc_interrupt,
2196 .wait_empty = intel_th_msc_wait_empty,
2197 .activate = intel_th_msc_activate,
2198 .deactivate = intel_th_msc_deactivate,
2199 .fops = &intel_th_msc_fops,
2200 .attr_group = &msc_output_group,
2201 .driver = {
2202 .name = "msc",
2203 .owner = THIS_MODULE,
2204 },
2205};
2206
2207module_driver(intel_th_msc_driver,
2208 intel_th_driver_register,
2209 intel_th_driver_unregister);
2210
2211MODULE_LICENSE("GPL v2");
2212MODULE_DESCRIPTION("Intel(R) Trace Hub Memory Storage Unit driver");
2213MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");