1 // SPDX-License-Identifier: GPL-2.0
3 * Intel(R) Trace Hub Memory Storage Unit
5 * Copyright (C) 2014-2015 Intel Corporation.
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
20 #include <linux/workqueue.h>
21 #include <linux/dma-mapping.h>
24 #include <asm/set_memory.h>
27 #include <linux/intel_th.h>
31 #define msc_dev(x) (&(x)->thdev->dev)
34 * Lockout state transitions:
35 * READY -> INUSE -+-> LOCKED -+-> READY -> etc.
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
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().
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.
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 * @_sgt: array of block descriptors
65 * @sgt: array of block descriptors
68 struct list_head entry;
70 enum lockout_state lockout;
72 unsigned int nr_blocks;
80 * struct msc_iter - iterator for msc buffer
81 * @entry: msc::iter_list linkage
82 * @msc: pointer to the MSC device
83 * @start_win: oldest window
84 * @win: current window
85 * @offset: current logical offset into the buffer
86 * @start_block: oldest block in the window
87 * @block: block number in the window
88 * @block_off: offset into current block
89 * @wrap_count: block wrapping handling
90 * @eof: end of buffer reached
93 struct list_head entry;
95 struct msc_window *start_win;
96 struct msc_window *win;
98 struct scatterlist *start_block;
99 struct scatterlist *block;
100 unsigned int block_off;
101 unsigned int wrap_count;
106 * struct msc - MSC device representation
107 * @reg_base: register window base address
108 * @thdev: intel_th_device pointer
109 * @mbuf: MSU buffer, if assigned
110 * @mbuf_priv MSU buffer's private data, if @mbuf
111 * @win_list: list of windows in multiblock mode
112 * @single_sgt: single mode buffer
113 * @cur_win: current window
114 * @nr_pages: total number of pages allocated for this buffer
115 * @single_sz: amount of data in single mode
116 * @single_wrap: single mode wrap occurred
117 * @base: buffer's base pointer
118 * @base_addr: buffer's base address
119 * @user_count: number of users of the buffer
120 * @mmap_count: number of mappings
121 * @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
130 void __iomem *reg_base;
131 void __iomem *msu_base;
132 struct intel_th_device *thdev;
134 const struct msu_buffer *mbuf;
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;
146 dma_addr_t base_addr;
150 /* <0: no buffer, 0: no users, >0: active users */
154 struct mutex buf_mutex;
156 struct list_head iter_list;
161 unsigned int enabled : 1,
166 unsigned int burst_len;
170 static LIST_HEAD(msu_buffer_list);
171 static DEFINE_MUTEX(msu_buffer_mutex);
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
179 struct msu_buffer_entry {
180 struct list_head entry;
181 const struct msu_buffer *mbuf;
182 struct module *owner;
185 static struct msu_buffer_entry *__msu_buffer_entry_find(const char *name)
187 struct msu_buffer_entry *mbe;
189 lockdep_assert_held(&msu_buffer_mutex);
191 list_for_each_entry(mbe, &msu_buffer_list, entry) {
192 if (!strcmp(mbe->mbuf->name, name))
199 static const struct msu_buffer *
200 msu_buffer_get(const char *name)
202 struct msu_buffer_entry *mbe;
204 mutex_lock(&msu_buffer_mutex);
205 mbe = __msu_buffer_entry_find(name);
206 if (mbe && !try_module_get(mbe->owner))
208 mutex_unlock(&msu_buffer_mutex);
210 return mbe ? mbe->mbuf : NULL;
213 static void msu_buffer_put(const struct msu_buffer *mbuf)
215 struct msu_buffer_entry *mbe;
217 mutex_lock(&msu_buffer_mutex);
218 mbe = __msu_buffer_entry_find(mbuf->name);
220 module_put(mbe->owner);
221 mutex_unlock(&msu_buffer_mutex);
224 int intel_th_msu_buffer_register(const struct msu_buffer *mbuf,
225 struct module *owner)
227 struct msu_buffer_entry *mbe;
230 mbe = kzalloc(sizeof(*mbe), GFP_KERNEL);
234 mutex_lock(&msu_buffer_mutex);
235 if (__msu_buffer_entry_find(mbuf->name)) {
243 list_add_tail(&mbe->entry, &msu_buffer_list);
245 mutex_unlock(&msu_buffer_mutex);
249 EXPORT_SYMBOL_GPL(intel_th_msu_buffer_register);
251 void intel_th_msu_buffer_unregister(const struct msu_buffer *mbuf)
253 struct msu_buffer_entry *mbe;
255 mutex_lock(&msu_buffer_mutex);
256 mbe = __msu_buffer_entry_find(mbuf->name);
258 list_del(&mbe->entry);
261 mutex_unlock(&msu_buffer_mutex);
263 EXPORT_SYMBOL_GPL(intel_th_msu_buffer_unregister);
265 static inline bool msc_block_is_empty(struct msc_block_desc *bdesc)
267 /* header hasn't been written */
268 if (!bdesc->valid_dw)
271 /* valid_dw includes the header */
272 if (!msc_data_sz(bdesc))
278 static inline struct scatterlist *msc_win_base_sg(struct msc_window *win)
280 return win->sgt->sgl;
283 static inline struct msc_block_desc *msc_win_base(struct msc_window *win)
285 return sg_virt(msc_win_base_sg(win));
288 static inline dma_addr_t msc_win_base_dma(struct msc_window *win)
290 return sg_dma_address(msc_win_base_sg(win));
293 static inline unsigned long
294 msc_win_base_pfn(struct msc_window *win)
296 return PFN_DOWN(msc_win_base_dma(win));
300 * msc_is_last_win() - check if a window is the last one for a given MSC
302 * Return: true if @win is the last window in MSC's multiblock buffer
304 static inline bool msc_is_last_win(struct msc_window *win)
306 return win->entry.next == &win->msc->win_list;
310 * msc_next_window() - return next window in the multiblock buffer
311 * @win: current window
313 * Return: window following the current one
315 static struct msc_window *msc_next_window(struct msc_window *win)
317 if (msc_is_last_win(win))
318 return list_first_entry(&win->msc->win_list, struct msc_window,
321 return list_next_entry(win, entry);
324 static size_t msc_win_total_sz(struct msc_window *win)
326 struct scatterlist *sg;
330 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
331 struct msc_block_desc *bdesc = sg_virt(sg);
333 if (msc_block_wrapped(bdesc))
334 return (size_t)win->nr_blocks << PAGE_SHIFT;
336 size += msc_total_sz(bdesc);
337 if (msc_block_last_written(bdesc))
345 * msc_find_window() - find a window matching a given sg_table
347 * @sgt: SG table of the window
348 * @nonempty: skip over empty windows
350 * Return: MSC window structure pointer or NULL if the window
351 * could not be found.
353 static struct msc_window *
354 msc_find_window(struct msc *msc, struct sg_table *sgt, bool nonempty)
356 struct msc_window *win;
357 unsigned int found = 0;
359 if (list_empty(&msc->win_list))
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
367 list_for_each_entry(win, &msc->win_list, entry) {
371 /* skip the empty ones */
372 if (nonempty && msc_block_is_empty(msc_win_base(win)))
383 * msc_oldest_window() - locate the window with oldest data
386 * This should only be used in multiblock mode. Caller should hold the
387 * msc::user_count reference.
389 * Return: the oldest window with valid data
391 static struct msc_window *msc_oldest_window(struct msc *msc)
393 struct msc_window *win;
395 if (list_empty(&msc->win_list))
398 win = msc_find_window(msc, msc_next_window(msc->cur_win)->sgt, true);
402 return list_first_entry(&msc->win_list, struct msc_window, entry);
406 * msc_win_oldest_sg() - locate the oldest block in a given window
407 * @win: window to look at
409 * Return: index of the block with the oldest data
411 static struct scatterlist *msc_win_oldest_sg(struct msc_window *win)
414 struct scatterlist *sg;
415 struct msc_block_desc *bdesc = msc_win_base(win);
417 /* without wrapping, first block is the oldest */
418 if (!msc_block_wrapped(bdesc))
419 return msc_win_base_sg(win);
422 * with wrapping, last written block contains both the newest and the
423 * oldest data for this window.
425 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
426 struct msc_block_desc *bdesc = sg_virt(sg);
428 if (msc_block_last_written(bdesc))
432 return msc_win_base_sg(win);
435 static struct msc_block_desc *msc_iter_bdesc(struct msc_iter *iter)
437 return sg_virt(iter->block);
440 static struct msc_iter *msc_iter_install(struct msc *msc)
442 struct msc_iter *iter;
444 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
446 return ERR_PTR(-ENOMEM);
448 mutex_lock(&msc->buf_mutex);
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.
458 iter = ERR_PTR(-EBUSY);
464 list_add_tail(&iter->entry, &msc->iter_list);
466 mutex_unlock(&msc->buf_mutex);
471 static void msc_iter_remove(struct msc_iter *iter, struct msc *msc)
473 mutex_lock(&msc->buf_mutex);
474 list_del(&iter->entry);
475 mutex_unlock(&msc->buf_mutex);
480 static void msc_iter_block_start(struct msc_iter *iter)
482 if (iter->start_block)
485 iter->start_block = msc_win_oldest_sg(iter->win);
486 iter->block = iter->start_block;
487 iter->wrap_count = 0;
490 * start with the block with oldest data; if data has wrapped
491 * in this window, it should be in this block
493 if (msc_block_wrapped(msc_iter_bdesc(iter)))
494 iter->wrap_count = 2;
498 static int msc_iter_win_start(struct msc_iter *iter, struct msc *msc)
500 /* already started, nothing to do */
504 iter->start_win = msc_oldest_window(msc);
505 if (!iter->start_win)
508 iter->win = iter->start_win;
509 iter->start_block = NULL;
511 msc_iter_block_start(iter);
516 static int msc_iter_win_advance(struct msc_iter *iter)
518 iter->win = msc_next_window(iter->win);
519 iter->start_block = NULL;
521 if (iter->win == iter->start_win) {
526 msc_iter_block_start(iter);
531 static int msc_iter_block_advance(struct msc_iter *iter)
536 if (iter->wrap_count && iter->block == iter->start_block) {
538 if (!iter->wrap_count)
539 /* copied newest data from the wrapped block */
540 return msc_iter_win_advance(iter);
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);
549 if (sg_is_last(iter->block))
550 iter->block = msc_win_base_sg(iter->win);
552 iter->block = sg_next(iter->block);
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);
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
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.
572 * Caller should have msc::user_count reference to make sure the buffer
573 * doesn't disappear from under us.
575 * Return: amount of data actually scanned.
578 msc_buffer_iterate(struct msc_iter *iter, size_t size, void *data,
579 unsigned long (*fn)(void *, void *, size_t))
581 struct msc *msc = iter->msc;
583 unsigned int advance;
588 /* start with the oldest window */
589 if (msc_iter_win_start(iter, msc))
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;
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.
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).
609 * Second time (wrap_count==1), it's just like any other block,
610 * containing data in the range of [MSC_BDESC..data_bytes].
612 if (iter->block == iter->start_block && iter->wrap_count == 2) {
613 tocopy = DATA_IN_PAGE - data_bytes;
620 tocopy -= iter->block_off;
621 src += iter->block_off;
628 remaining = fn(data, src, tocopy);
633 copied = tocopy - remaining;
635 iter->block_off += copied;
636 iter->offset += copied;
642 if (msc_iter_block_advance(iter))
651 * msc_buffer_clear_hw_header() - clear hw header for multiblock
654 static void msc_buffer_clear_hw_header(struct msc *msc)
656 struct msc_window *win;
657 struct scatterlist *sg;
659 list_for_each_entry(win, &msc->win_list, entry) {
661 size_t hw_sz = sizeof(struct msc_block_desc) -
662 offsetof(struct msc_block_desc, hw_tag);
664 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
665 struct msc_block_desc *bdesc = sg_virt(sg);
667 memset(&bdesc->hw_tag, 0, hw_sz);
672 static int intel_th_msu_init(struct msc *msc)
682 mintctl = ioread32(msc->msu_base + REG_MSU_MINTCTL);
683 mintctl |= msc->index ? M1BLIE : M0BLIE;
684 iowrite32(mintctl, msc->msu_base + REG_MSU_MINTCTL);
685 if (mintctl != ioread32(msc->msu_base + REG_MSU_MINTCTL)) {
686 dev_info(msc_dev(msc), "MINTCTL ignores writes: no usable interrupts\n");
691 msusts = ioread32(msc->msu_base + REG_MSU_MSUSTS);
692 iowrite32(msusts, msc->msu_base + REG_MSU_MSUSTS);
697 static void intel_th_msu_deinit(struct msc *msc)
704 mintctl = ioread32(msc->msu_base + REG_MSU_MINTCTL);
705 mintctl &= msc->index ? ~M1BLIE : ~M0BLIE;
706 iowrite32(mintctl, msc->msu_base + REG_MSU_MINTCTL);
709 static int msc_win_set_lockout(struct msc_window *win,
710 enum lockout_state expect,
711 enum lockout_state new)
713 enum lockout_state old;
720 spin_lock_irqsave(&win->lo_lock, flags);
730 if (old == expect && new == WIN_LOCKED)
731 atomic_inc(&win->msc->user_count);
732 else if (old == expect && old == WIN_LOCKED)
733 atomic_dec(&win->msc->user_count);
736 spin_unlock_irqrestore(&win->lo_lock, flags);
739 if (expect == WIN_READY && old == WIN_LOCKED)
742 /* from intel_th_msc_window_unlock(), don't warn if not locked */
743 if (expect == WIN_LOCKED && old == new)
746 dev_warn_ratelimited(msc_dev(win->msc),
747 "expected lockout state %d, got %d\n",
754 * msc_configure() - set up MSC hardware
755 * @msc: the MSC device to configure
757 * Program storage mode, wrapping, burst length and trace buffer address
758 * into a given MSC. Then, enable tracing and set msc::enabled.
759 * The latter is serialized on msc::buf_mutex, so make sure to hold it.
761 static int msc_configure(struct msc *msc)
765 lockdep_assert_held(&msc->buf_mutex);
767 if (msc->mode > MSC_MODE_MULTI)
770 if (msc->mode == MSC_MODE_MULTI) {
771 if (msc_win_set_lockout(msc->cur_win, WIN_READY, WIN_INUSE))
774 msc_buffer_clear_hw_header(msc);
777 msc->orig_addr = ioread32(msc->reg_base + REG_MSU_MSC0BAR);
778 msc->orig_sz = ioread32(msc->reg_base + REG_MSU_MSC0SIZE);
780 reg = msc->base_addr >> PAGE_SHIFT;
781 iowrite32(reg, msc->reg_base + REG_MSU_MSC0BAR);
783 if (msc->mode == MSC_MODE_SINGLE) {
785 iowrite32(reg, msc->reg_base + REG_MSU_MSC0SIZE);
788 reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL);
789 reg &= ~(MSC_MODE | MSC_WRAPEN | MSC_EN | MSC_RD_HDR_OVRD);
792 reg |= msc->mode << __ffs(MSC_MODE);
793 reg |= msc->burst_len << __ffs(MSC_LEN);
798 iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL);
800 intel_th_msu_init(msc);
802 msc->thdev->output.multiblock = msc->mode == MSC_MODE_MULTI;
803 intel_th_trace_enable(msc->thdev);
806 if (msc->mbuf && msc->mbuf->activate)
807 msc->mbuf->activate(msc->mbuf_priv);
813 * msc_disable() - disable MSC hardware
814 * @msc: MSC device to disable
816 * If @msc is enabled, disable tracing on the switch and then disable MSC
817 * storage. Caller must hold msc::buf_mutex.
819 static void msc_disable(struct msc *msc)
821 struct msc_window *win = msc->cur_win;
824 lockdep_assert_held(&msc->buf_mutex);
826 if (msc->mode == MSC_MODE_MULTI)
827 msc_win_set_lockout(win, WIN_INUSE, WIN_LOCKED);
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);
834 if (msc->mode == MSC_MODE_SINGLE) {
835 reg = ioread32(msc->reg_base + REG_MSU_MSC0STS);
836 msc->single_wrap = !!(reg & MSCSTS_WRAPSTAT);
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);
844 reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL);
846 iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL);
848 if (msc->mbuf && msc->mbuf->ready)
849 msc->mbuf->ready(msc->mbuf_priv, win->sgt,
850 msc_win_total_sz(win));
854 iowrite32(msc->orig_addr, msc->reg_base + REG_MSU_MSC0BAR);
855 iowrite32(msc->orig_sz, msc->reg_base + REG_MSU_MSC0SIZE);
857 dev_dbg(msc_dev(msc), "MSCnNWSA: %08x\n",
858 ioread32(msc->reg_base + REG_MSU_MSC0NWSA));
860 reg = ioread32(msc->reg_base + REG_MSU_MSC0STS);
861 dev_dbg(msc_dev(msc), "MSCnSTS: %08x\n", reg);
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);
868 static int intel_th_msc_activate(struct intel_th_device *thdev)
870 struct msc *msc = dev_get_drvdata(&thdev->dev);
873 if (!atomic_inc_unless_negative(&msc->user_count))
876 mutex_lock(&msc->buf_mutex);
878 /* if there are readers, refuse */
879 if (list_empty(&msc->iter_list))
880 ret = msc_configure(msc);
882 mutex_unlock(&msc->buf_mutex);
885 atomic_dec(&msc->user_count);
890 static void intel_th_msc_deactivate(struct intel_th_device *thdev)
892 struct msc *msc = dev_get_drvdata(&thdev->dev);
894 mutex_lock(&msc->buf_mutex);
897 atomic_dec(&msc->user_count);
899 mutex_unlock(&msc->buf_mutex);
903 * msc_buffer_contig_alloc() - allocate a contiguous buffer for SINGLE mode
905 * @size: allocation size in bytes
907 * This modifies msc::base, which requires msc::buf_mutex to serialize, so the
908 * caller is expected to hold it.
910 * Return: 0 on success, -errno otherwise.
912 static int msc_buffer_contig_alloc(struct msc *msc, unsigned long size)
914 unsigned long nr_pages = size >> PAGE_SHIFT;
915 unsigned int order = get_order(size);
922 ret = sg_alloc_table(&msc->single_sgt, 1, GFP_KERNEL);
927 page = alloc_pages(GFP_KERNEL | __GFP_ZERO | GFP_DMA32, order);
931 split_page(page, order);
932 sg_set_buf(msc->single_sgt.sgl, page_address(page), size);
934 ret = dma_map_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl, 1,
939 msc->nr_pages = nr_pages;
940 msc->base = page_address(page);
941 msc->base_addr = sg_dma_address(msc->single_sgt.sgl);
946 __free_pages(page, order);
949 sg_free_table(&msc->single_sgt);
956 * msc_buffer_contig_free() - free a contiguous buffer
957 * @msc: MSC configured in SINGLE mode
959 static void msc_buffer_contig_free(struct msc *msc)
963 dma_unmap_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl,
965 sg_free_table(&msc->single_sgt);
967 for (off = 0; off < msc->nr_pages << PAGE_SHIFT; off += PAGE_SIZE) {
968 struct page *page = virt_to_page(msc->base + off);
970 page->mapping = NULL;
978 * msc_buffer_contig_get_page() - find a page at a given offset
979 * @msc: MSC configured in SINGLE mode
980 * @pgoff: page offset
982 * Return: page, if @pgoff is within the range, NULL otherwise.
984 static struct page *msc_buffer_contig_get_page(struct msc *msc,
987 if (pgoff >= msc->nr_pages)
990 return virt_to_page(msc->base + (pgoff << PAGE_SHIFT));
993 static int __msc_buffer_win_alloc(struct msc_window *win,
994 unsigned int nr_segs)
996 struct scatterlist *sg_ptr;
1000 ret = sg_alloc_table(win->sgt, nr_segs, GFP_KERNEL);
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),
1011 sg_set_buf(sg_ptr, block, PAGE_SIZE);
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));
1021 sg_free_table(win->sgt);
1027 static void msc_buffer_set_uc(struct msc_window *win, unsigned int nr_segs)
1029 struct scatterlist *sg_ptr;
1032 for_each_sg(win->sgt->sgl, sg_ptr, nr_segs, i) {
1033 /* Set the page as uncached */
1034 set_memory_uc((unsigned long)sg_virt(sg_ptr),
1035 PFN_DOWN(sg_ptr->length));
1039 static void msc_buffer_set_wb(struct msc_window *win)
1041 struct scatterlist *sg_ptr;
1044 for_each_sg(win->sgt->sgl, sg_ptr, win->nr_segs, i) {
1045 /* Reset the page to write-back */
1046 set_memory_wb((unsigned long)sg_virt(sg_ptr),
1047 PFN_DOWN(sg_ptr->length));
1052 msc_buffer_set_uc(struct msc_window *win, unsigned int nr_segs) {}
1053 static inline void msc_buffer_set_wb(struct msc_window *win) {}
1054 #endif /* CONFIG_X86 */
1056 static struct page *msc_sg_page(struct scatterlist *sg)
1058 void *addr = sg_virt(sg);
1060 if (is_vmalloc_addr(addr))
1061 return vmalloc_to_page(addr);
1067 * msc_buffer_win_alloc() - alloc a window for a multiblock mode
1069 * @nr_blocks: number of pages in this window
1071 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex
1072 * to serialize, so the caller is expected to hold it.
1074 * Return: 0 on success, -errno otherwise.
1076 static int msc_buffer_win_alloc(struct msc *msc, unsigned int nr_blocks)
1078 struct msc_window *win;
1084 win = kzalloc(sizeof(*win), GFP_KERNEL);
1089 win->sgt = &win->_sgt;
1090 win->lockout = WIN_READY;
1091 spin_lock_init(&win->lo_lock);
1093 if (!list_empty(&msc->win_list)) {
1094 struct msc_window *prev = list_last_entry(&msc->win_list,
1098 win->pgoff = prev->pgoff + prev->nr_blocks;
1101 if (msc->mbuf && msc->mbuf->alloc_window)
1102 ret = msc->mbuf->alloc_window(msc->mbuf_priv, &win->sgt,
1103 nr_blocks << PAGE_SHIFT);
1105 ret = __msc_buffer_win_alloc(win, nr_blocks);
1110 msc_buffer_set_uc(win, ret);
1113 win->nr_blocks = nr_blocks;
1115 if (list_empty(&msc->win_list)) {
1116 msc->base = msc_win_base(win);
1117 msc->base_addr = msc_win_base_dma(win);
1121 list_add_tail(&win->entry, &msc->win_list);
1122 msc->nr_pages += nr_blocks;
1132 static void __msc_buffer_win_free(struct msc *msc, struct msc_window *win)
1134 struct scatterlist *sg;
1137 for_each_sg(win->sgt->sgl, sg, win->nr_segs, i) {
1138 struct page *page = msc_sg_page(sg);
1140 page->mapping = NULL;
1141 dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE,
1142 sg_virt(sg), sg_dma_address(sg));
1144 sg_free_table(win->sgt);
1148 * msc_buffer_win_free() - free a window from MSC's window list
1150 * @win: window to free
1152 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex
1153 * to serialize, so the caller is expected to hold it.
1155 static void msc_buffer_win_free(struct msc *msc, struct msc_window *win)
1157 msc->nr_pages -= win->nr_blocks;
1159 list_del(&win->entry);
1160 if (list_empty(&msc->win_list)) {
1165 msc_buffer_set_wb(win);
1167 if (msc->mbuf && msc->mbuf->free_window)
1168 msc->mbuf->free_window(msc->mbuf_priv, win->sgt);
1170 __msc_buffer_win_free(msc, win);
1176 * msc_buffer_relink() - set up block descriptors for multiblock mode
1179 * This traverses msc::win_list, which requires msc::buf_mutex to serialize,
1180 * so the caller is expected to hold it.
1182 static void msc_buffer_relink(struct msc *msc)
1184 struct msc_window *win, *next_win;
1186 /* call with msc::mutex locked */
1187 list_for_each_entry(win, &msc->win_list, entry) {
1188 struct scatterlist *sg;
1193 * Last window's next_win should point to the first window
1194 * and MSC_SW_TAG_LASTWIN should be set.
1196 if (msc_is_last_win(win)) {
1197 sw_tag |= MSC_SW_TAG_LASTWIN;
1198 next_win = list_first_entry(&msc->win_list,
1199 struct msc_window, entry);
1201 next_win = list_next_entry(win, entry);
1204 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
1205 struct msc_block_desc *bdesc = sg_virt(sg);
1207 memset(bdesc, 0, sizeof(*bdesc));
1209 bdesc->next_win = msc_win_base_pfn(next_win);
1212 * Similarly to last window, last block should point
1215 if (blk == win->nr_segs - 1) {
1216 sw_tag |= MSC_SW_TAG_LASTBLK;
1217 bdesc->next_blk = msc_win_base_pfn(win);
1219 dma_addr_t addr = sg_dma_address(sg_next(sg));
1221 bdesc->next_blk = PFN_DOWN(addr);
1224 bdesc->sw_tag = sw_tag;
1225 bdesc->block_sz = sg->length / 64;
1230 * Make the above writes globally visible before tracing is
1231 * enabled to make sure hardware sees them coherently.
1236 static void msc_buffer_multi_free(struct msc *msc)
1238 struct msc_window *win, *iter;
1240 list_for_each_entry_safe(win, iter, &msc->win_list, entry)
1241 msc_buffer_win_free(msc, win);
1244 static int msc_buffer_multi_alloc(struct msc *msc, unsigned long *nr_pages,
1245 unsigned int nr_wins)
1249 for (i = 0; i < nr_wins; i++) {
1250 ret = msc_buffer_win_alloc(msc, nr_pages[i]);
1252 msc_buffer_multi_free(msc);
1257 msc_buffer_relink(msc);
1263 * msc_buffer_free() - free buffers for MSC
1266 * Free MSC's storage buffers.
1268 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex to
1269 * serialize, so the caller is expected to hold it.
1271 static void msc_buffer_free(struct msc *msc)
1273 if (msc->mode == MSC_MODE_SINGLE)
1274 msc_buffer_contig_free(msc);
1275 else if (msc->mode == MSC_MODE_MULTI)
1276 msc_buffer_multi_free(msc);
1280 * msc_buffer_alloc() - allocate a buffer for MSC
1282 * @size: allocation size in bytes
1284 * Allocate a storage buffer for MSC, depending on the msc::mode, it will be
1285 * either done via msc_buffer_contig_alloc() for SINGLE operation mode or
1286 * msc_buffer_win_alloc() for multiblock operation. The latter allocates one
1287 * window per invocation, so in multiblock mode this can be called multiple
1288 * times for the same MSC to allocate multiple windows.
1290 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex
1291 * to serialize, so the caller is expected to hold it.
1293 * Return: 0 on success, -errno otherwise.
1295 static int msc_buffer_alloc(struct msc *msc, unsigned long *nr_pages,
1296 unsigned int nr_wins)
1300 /* -1: buffer not allocated */
1301 if (atomic_read(&msc->user_count) != -1)
1304 if (msc->mode == MSC_MODE_SINGLE) {
1308 ret = msc_buffer_contig_alloc(msc, nr_pages[0] << PAGE_SHIFT);
1309 } else if (msc->mode == MSC_MODE_MULTI) {
1310 ret = msc_buffer_multi_alloc(msc, nr_pages, nr_wins);
1316 /* allocation should be visible before the counter goes to 0 */
1317 smp_mb__before_atomic();
1319 if (WARN_ON_ONCE(atomic_cmpxchg(&msc->user_count, -1, 0) != -1))
1327 * msc_buffer_unlocked_free_unless_used() - free a buffer unless it's in use
1330 * This will free MSC buffer unless it is in use or there is no allocated
1332 * Caller needs to hold msc::buf_mutex.
1334 * Return: 0 on successful deallocation or if there was no buffer to
1335 * deallocate, -EBUSY if there are active users.
1337 static int msc_buffer_unlocked_free_unless_used(struct msc *msc)
1341 count = atomic_cmpxchg(&msc->user_count, 0, -1);
1343 /* > 0: buffer is allocated and has users */
1346 /* 0: buffer is allocated, no users */
1348 msc_buffer_free(msc);
1349 /* < 0: no buffer, nothing to do */
1355 * msc_buffer_free_unless_used() - free a buffer unless it's in use
1358 * This is a locked version of msc_buffer_unlocked_free_unless_used().
1360 static int msc_buffer_free_unless_used(struct msc *msc)
1364 mutex_lock(&msc->buf_mutex);
1365 ret = msc_buffer_unlocked_free_unless_used(msc);
1366 mutex_unlock(&msc->buf_mutex);
1372 * msc_buffer_get_page() - get MSC buffer page at a given offset
1374 * @pgoff: page offset into the storage buffer
1376 * This traverses msc::win_list, so holding msc::buf_mutex is expected from
1379 * Return: page if @pgoff corresponds to a valid buffer page or NULL.
1381 static struct page *msc_buffer_get_page(struct msc *msc, unsigned long pgoff)
1383 struct msc_window *win;
1384 struct scatterlist *sg;
1387 if (msc->mode == MSC_MODE_SINGLE)
1388 return msc_buffer_contig_get_page(msc, pgoff);
1390 list_for_each_entry(win, &msc->win_list, entry)
1391 if (pgoff >= win->pgoff && pgoff < win->pgoff + win->nr_blocks)
1397 pgoff -= win->pgoff;
1399 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) {
1400 struct page *page = msc_sg_page(sg);
1401 size_t pgsz = PFN_DOWN(sg->length);
1404 return page + pgoff;
1413 * struct msc_win_to_user_struct - data for copy_to_user() callback
1414 * @buf: userspace buffer to copy data to
1415 * @offset: running offset
1417 struct msc_win_to_user_struct {
1419 unsigned long offset;
1423 * msc_win_to_user() - iterator for msc_buffer_iterate() to copy data to user
1424 * @data: callback's private data
1425 * @src: source buffer
1426 * @len: amount of data to copy from the source buffer
1428 static unsigned long msc_win_to_user(void *data, void *src, size_t len)
1430 struct msc_win_to_user_struct *u = data;
1433 ret = copy_to_user(u->buf + u->offset, src, len);
1434 u->offset += len - ret;
1441 * file operations' callbacks
1444 static int intel_th_msc_open(struct inode *inode, struct file *file)
1446 struct intel_th_device *thdev = file->private_data;
1447 struct msc *msc = dev_get_drvdata(&thdev->dev);
1448 struct msc_iter *iter;
1450 if (!capable(CAP_SYS_RAWIO))
1453 iter = msc_iter_install(msc);
1455 return PTR_ERR(iter);
1457 file->private_data = iter;
1459 return nonseekable_open(inode, file);
1462 static int intel_th_msc_release(struct inode *inode, struct file *file)
1464 struct msc_iter *iter = file->private_data;
1465 struct msc *msc = iter->msc;
1467 msc_iter_remove(iter, msc);
1473 msc_single_to_user(struct msc *msc, char __user *buf, loff_t off, size_t len)
1475 unsigned long size = msc->nr_pages << PAGE_SHIFT, rem = len;
1476 unsigned long start = off, tocopy = 0;
1478 if (msc->single_wrap) {
1479 start += msc->single_sz;
1481 tocopy = min(rem, size - start);
1482 if (copy_to_user(buf, msc->base + start, tocopy))
1492 tocopy = min(rem, msc->single_sz - start);
1493 if (copy_to_user(buf, msc->base + start, tocopy))
1502 if (copy_to_user(buf, msc->base + start, rem))
1508 static ssize_t intel_th_msc_read(struct file *file, char __user *buf,
1509 size_t len, loff_t *ppos)
1511 struct msc_iter *iter = file->private_data;
1512 struct msc *msc = iter->msc;
1517 if (!atomic_inc_unless_negative(&msc->user_count))
1520 if (msc->mode == MSC_MODE_SINGLE && !msc->single_wrap)
1521 size = msc->single_sz;
1523 size = msc->nr_pages << PAGE_SHIFT;
1531 if (off + len >= size)
1534 if (msc->mode == MSC_MODE_SINGLE) {
1535 ret = msc_single_to_user(msc, buf, off, len);
1538 } else if (msc->mode == MSC_MODE_MULTI) {
1539 struct msc_win_to_user_struct u = {
1544 ret = msc_buffer_iterate(iter, len, &u, msc_win_to_user);
1546 *ppos = iter->offset;
1552 atomic_dec(&msc->user_count);
1558 * vm operations callbacks (vm_ops)
1561 static void msc_mmap_open(struct vm_area_struct *vma)
1563 struct msc_iter *iter = vma->vm_file->private_data;
1564 struct msc *msc = iter->msc;
1566 atomic_inc(&msc->mmap_count);
1569 static void msc_mmap_close(struct vm_area_struct *vma)
1571 struct msc_iter *iter = vma->vm_file->private_data;
1572 struct msc *msc = iter->msc;
1575 if (!atomic_dec_and_mutex_lock(&msc->mmap_count, &msc->buf_mutex))
1578 /* drop page _refcounts */
1579 for (pg = 0; pg < msc->nr_pages; pg++) {
1580 struct page *page = msc_buffer_get_page(msc, pg);
1582 if (WARN_ON_ONCE(!page))
1586 page->mapping = NULL;
1589 /* last mapping -- drop user_count */
1590 atomic_dec(&msc->user_count);
1591 mutex_unlock(&msc->buf_mutex);
1594 static vm_fault_t msc_mmap_fault(struct vm_fault *vmf)
1596 struct msc_iter *iter = vmf->vma->vm_file->private_data;
1597 struct msc *msc = iter->msc;
1599 vmf->page = msc_buffer_get_page(msc, vmf->pgoff);
1601 return VM_FAULT_SIGBUS;
1603 get_page(vmf->page);
1604 vmf->page->mapping = vmf->vma->vm_file->f_mapping;
1605 vmf->page->index = vmf->pgoff;
1610 static const struct vm_operations_struct msc_mmap_ops = {
1611 .open = msc_mmap_open,
1612 .close = msc_mmap_close,
1613 .fault = msc_mmap_fault,
1616 static int intel_th_msc_mmap(struct file *file, struct vm_area_struct *vma)
1618 unsigned long size = vma->vm_end - vma->vm_start;
1619 struct msc_iter *iter = vma->vm_file->private_data;
1620 struct msc *msc = iter->msc;
1623 if (!size || offset_in_page(size))
1629 /* grab user_count once per mmap; drop in msc_mmap_close() */
1630 if (!atomic_inc_unless_negative(&msc->user_count))
1633 if (msc->mode != MSC_MODE_SINGLE &&
1634 msc->mode != MSC_MODE_MULTI)
1637 if (size >> PAGE_SHIFT != msc->nr_pages)
1640 atomic_set(&msc->mmap_count, 1);
1645 atomic_dec(&msc->user_count);
1647 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1648 vma->vm_flags |= VM_DONTEXPAND | VM_DONTCOPY;
1649 vma->vm_ops = &msc_mmap_ops;
1653 static const struct file_operations intel_th_msc_fops = {
1654 .open = intel_th_msc_open,
1655 .release = intel_th_msc_release,
1656 .read = intel_th_msc_read,
1657 .mmap = intel_th_msc_mmap,
1658 .llseek = no_llseek,
1659 .owner = THIS_MODULE,
1662 static void intel_th_msc_wait_empty(struct intel_th_device *thdev)
1664 struct msc *msc = dev_get_drvdata(&thdev->dev);
1665 unsigned long count;
1668 for (reg = 0, count = MSC_PLE_WAITLOOP_DEPTH;
1669 count && !(reg & MSCSTS_PLE); count--) {
1670 reg = __raw_readl(msc->reg_base + REG_MSU_MSC0STS);
1675 dev_dbg(msc_dev(msc), "timeout waiting for MSC0 PLE\n");
1678 static int intel_th_msc_init(struct msc *msc)
1680 atomic_set(&msc->user_count, -1);
1682 msc->mode = msc->multi_is_broken ? MSC_MODE_SINGLE : MSC_MODE_MULTI;
1683 mutex_init(&msc->buf_mutex);
1684 INIT_LIST_HEAD(&msc->win_list);
1685 INIT_LIST_HEAD(&msc->iter_list);
1688 (ioread32(msc->reg_base + REG_MSU_MSC0CTL) & MSC_LEN) >>
1694 static int msc_win_switch(struct msc *msc)
1696 struct msc_window *first;
1698 if (list_empty(&msc->win_list))
1701 first = list_first_entry(&msc->win_list, struct msc_window, entry);
1703 if (msc_is_last_win(msc->cur_win))
1704 msc->cur_win = first;
1706 msc->cur_win = list_next_entry(msc->cur_win, entry);
1708 msc->base = msc_win_base(msc->cur_win);
1709 msc->base_addr = msc_win_base_dma(msc->cur_win);
1711 intel_th_trace_switch(msc->thdev);
1717 * intel_th_msc_window_unlock - put the window back in rotation
1718 * @dev: MSC device to which this relates
1719 * @sgt: buffer's sg_table for the window, does nothing if NULL
1721 void intel_th_msc_window_unlock(struct device *dev, struct sg_table *sgt)
1723 struct msc *msc = dev_get_drvdata(dev);
1724 struct msc_window *win;
1729 win = msc_find_window(msc, sgt, false);
1733 msc_win_set_lockout(win, WIN_LOCKED, WIN_READY);
1734 if (msc->switch_on_unlock == win) {
1735 msc->switch_on_unlock = NULL;
1736 msc_win_switch(msc);
1739 EXPORT_SYMBOL_GPL(intel_th_msc_window_unlock);
1741 static void msc_work(struct work_struct *work)
1743 struct msc *msc = container_of(work, struct msc, work);
1745 intel_th_msc_deactivate(msc->thdev);
1748 static irqreturn_t intel_th_msc_interrupt(struct intel_th_device *thdev)
1750 struct msc *msc = dev_get_drvdata(&thdev->dev);
1751 u32 msusts = ioread32(msc->msu_base + REG_MSU_MSUSTS);
1752 u32 mask = msc->index ? MSUSTS_MSC1BLAST : MSUSTS_MSC0BLAST;
1753 struct msc_window *win, *next_win;
1755 if (!msc->do_irq || !msc->mbuf)
1761 return msc->enabled ? IRQ_HANDLED : IRQ_NONE;
1763 iowrite32(msusts, msc->msu_base + REG_MSU_MSUSTS);
1768 /* grab the window before we do the switch */
1772 next_win = msc_next_window(win);
1776 /* next window: if READY, proceed, if LOCKED, stop the trace */
1777 if (msc_win_set_lockout(next_win, WIN_READY, WIN_INUSE)) {
1778 if (msc->stop_on_full)
1779 schedule_work(&msc->work);
1781 msc->switch_on_unlock = next_win;
1786 /* current window: INUSE -> LOCKED */
1787 msc_win_set_lockout(win, WIN_INUSE, WIN_LOCKED);
1789 msc_win_switch(msc);
1791 if (msc->mbuf && msc->mbuf->ready)
1792 msc->mbuf->ready(msc->mbuf_priv, win->sgt,
1793 msc_win_total_sz(win));
1798 static const char * const msc_mode[] = {
1799 [MSC_MODE_SINGLE] = "single",
1800 [MSC_MODE_MULTI] = "multi",
1801 [MSC_MODE_EXI] = "ExI",
1802 [MSC_MODE_DEBUG] = "debug",
1806 wrap_show(struct device *dev, struct device_attribute *attr, char *buf)
1808 struct msc *msc = dev_get_drvdata(dev);
1810 return scnprintf(buf, PAGE_SIZE, "%d\n", msc->wrap);
1814 wrap_store(struct device *dev, struct device_attribute *attr, const char *buf,
1817 struct msc *msc = dev_get_drvdata(dev);
1821 ret = kstrtoul(buf, 10, &val);
1830 static DEVICE_ATTR_RW(wrap);
1832 static void msc_buffer_unassign(struct msc *msc)
1834 lockdep_assert_held(&msc->buf_mutex);
1839 msc->mbuf->unassign(msc->mbuf_priv);
1840 msu_buffer_put(msc->mbuf);
1841 msc->mbuf_priv = NULL;
1846 mode_show(struct device *dev, struct device_attribute *attr, char *buf)
1848 struct msc *msc = dev_get_drvdata(dev);
1849 const char *mode = msc_mode[msc->mode];
1852 mutex_lock(&msc->buf_mutex);
1854 mode = msc->mbuf->name;
1855 ret = scnprintf(buf, PAGE_SIZE, "%s\n", mode);
1856 mutex_unlock(&msc->buf_mutex);
1862 mode_store(struct device *dev, struct device_attribute *attr, const char *buf,
1865 const struct msu_buffer *mbuf = NULL;
1866 struct msc *msc = dev_get_drvdata(dev);
1871 if (!capable(CAP_SYS_RAWIO))
1874 cp = memchr(buf, '\n', len);
1878 mode = kstrndup(buf, len, GFP_KERNEL);
1882 i = match_string(msc_mode, ARRAY_SIZE(msc_mode), mode);
1888 /* Buffer sinks only work with a usable IRQ */
1894 mbuf = msu_buffer_get(mode);
1902 if (i == MSC_MODE_MULTI && msc->multi_is_broken)
1905 mutex_lock(&msc->buf_mutex);
1908 /* Same buffer: do nothing */
1909 if (mbuf && mbuf == msc->mbuf) {
1910 /* put the extra reference we just got */
1911 msu_buffer_put(mbuf);
1915 ret = msc_buffer_unlocked_free_unless_used(msc);
1920 void *mbuf_priv = mbuf->assign(dev, &i);
1927 msc_buffer_unassign(msc);
1928 msc->mbuf_priv = mbuf_priv;
1931 msc_buffer_unassign(msc);
1938 msu_buffer_put(mbuf);
1939 mutex_unlock(&msc->buf_mutex);
1941 return ret ? ret : size;
1944 static DEVICE_ATTR_RW(mode);
1947 nr_pages_show(struct device *dev, struct device_attribute *attr, char *buf)
1949 struct msc *msc = dev_get_drvdata(dev);
1950 struct msc_window *win;
1953 mutex_lock(&msc->buf_mutex);
1955 if (msc->mode == MSC_MODE_SINGLE)
1956 count = scnprintf(buf, PAGE_SIZE, "%ld\n", msc->nr_pages);
1957 else if (msc->mode == MSC_MODE_MULTI) {
1958 list_for_each_entry(win, &msc->win_list, entry) {
1959 count += scnprintf(buf + count, PAGE_SIZE - count,
1960 "%d%c", win->nr_blocks,
1961 msc_is_last_win(win) ? '\n' : ',');
1964 count = scnprintf(buf, PAGE_SIZE, "unsupported\n");
1967 mutex_unlock(&msc->buf_mutex);
1973 nr_pages_store(struct device *dev, struct device_attribute *attr,
1974 const char *buf, size_t size)
1976 struct msc *msc = dev_get_drvdata(dev);
1977 unsigned long val, *win = NULL, *rewin;
1979 const char *p = buf;
1981 int ret, nr_wins = 0;
1983 if (!capable(CAP_SYS_RAWIO))
1986 ret = msc_buffer_free_unless_used(msc);
1990 /* scan the comma-separated list of allocation sizes */
1991 end = memchr(buf, '\n', len);
1996 end = memchr(p, ',', len);
1997 s = kstrndup(p, end ? end - p : len, GFP_KERNEL);
2003 ret = kstrtoul(s, 10, &val);
2009 if (nr_wins && msc->mode == MSC_MODE_SINGLE) {
2015 rewin = krealloc(win, sizeof(*win) * nr_wins, GFP_KERNEL);
2022 win[nr_wins - 1] = val;
2027 /* consume the number and the following comma, hence +1 */
2032 mutex_lock(&msc->buf_mutex);
2033 ret = msc_buffer_alloc(msc, win, nr_wins);
2034 mutex_unlock(&msc->buf_mutex);
2039 return ret ? ret : size;
2042 static DEVICE_ATTR_RW(nr_pages);
2045 win_switch_store(struct device *dev, struct device_attribute *attr,
2046 const char *buf, size_t size)
2048 struct msc *msc = dev_get_drvdata(dev);
2052 ret = kstrtoul(buf, 10, &val);
2060 mutex_lock(&msc->buf_mutex);
2062 * Window switch can only happen in the "multi" mode.
2063 * If a external buffer is engaged, they have the full
2064 * control over window switching.
2066 if (msc->mode == MSC_MODE_MULTI && !msc->mbuf)
2067 ret = msc_win_switch(msc);
2068 mutex_unlock(&msc->buf_mutex);
2070 return ret ? ret : size;
2073 static DEVICE_ATTR_WO(win_switch);
2075 static ssize_t stop_on_full_show(struct device *dev,
2076 struct device_attribute *attr, char *buf)
2078 struct msc *msc = dev_get_drvdata(dev);
2080 return sprintf(buf, "%d\n", msc->stop_on_full);
2083 static ssize_t stop_on_full_store(struct device *dev,
2084 struct device_attribute *attr,
2085 const char *buf, size_t size)
2087 struct msc *msc = dev_get_drvdata(dev);
2090 ret = kstrtobool(buf, &msc->stop_on_full);
2097 static DEVICE_ATTR_RW(stop_on_full);
2099 static struct attribute *msc_output_attrs[] = {
2100 &dev_attr_wrap.attr,
2101 &dev_attr_mode.attr,
2102 &dev_attr_nr_pages.attr,
2103 &dev_attr_win_switch.attr,
2104 &dev_attr_stop_on_full.attr,
2108 static struct attribute_group msc_output_group = {
2109 .attrs = msc_output_attrs,
2112 static int intel_th_msc_probe(struct intel_th_device *thdev)
2114 struct device *dev = &thdev->dev;
2115 struct resource *res;
2120 res = intel_th_device_get_resource(thdev, IORESOURCE_MEM, 0);
2124 base = devm_ioremap(dev, res->start, resource_size(res));
2128 msc = devm_kzalloc(dev, sizeof(*msc), GFP_KERNEL);
2132 res = intel_th_device_get_resource(thdev, IORESOURCE_IRQ, 1);
2136 if (INTEL_TH_CAP(to_intel_th(thdev), multi_is_broken))
2137 msc->multi_is_broken = 1;
2139 msc->index = thdev->id;
2142 msc->reg_base = base + msc->index * 0x100;
2143 msc->msu_base = base;
2145 INIT_WORK(&msc->work, msc_work);
2146 err = intel_th_msc_init(msc);
2150 dev_set_drvdata(dev, msc);
2155 static void intel_th_msc_remove(struct intel_th_device *thdev)
2157 struct msc *msc = dev_get_drvdata(&thdev->dev);
2160 intel_th_msc_deactivate(thdev);
2163 * Buffers should not be used at this point except if the
2164 * output character device is still open and the parent
2165 * device gets detached from its bus, which is a FIXME.
2167 ret = msc_buffer_free_unless_used(msc);
2171 static struct intel_th_driver intel_th_msc_driver = {
2172 .probe = intel_th_msc_probe,
2173 .remove = intel_th_msc_remove,
2174 .irq = intel_th_msc_interrupt,
2175 .wait_empty = intel_th_msc_wait_empty,
2176 .activate = intel_th_msc_activate,
2177 .deactivate = intel_th_msc_deactivate,
2178 .fops = &intel_th_msc_fops,
2179 .attr_group = &msc_output_group,
2182 .owner = THIS_MODULE,
2186 module_driver(intel_th_msc_driver,
2187 intel_th_driver_register,
2188 intel_th_driver_unregister);
2190 MODULE_LICENSE("GPL v2");
2191 MODULE_DESCRIPTION("Intel(R) Trace Hub Memory Storage Unit driver");
2192 MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");