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 * @_sgt: array of block descriptors 65 * @sgt: array of block descriptors 66 */ 67struct msc_window { 68 struct list_head entry; 69 unsigned long pgoff; 70 enum lockout_state lockout; 71 spinlock_t lo_lock; 72 unsigned int nr_blocks; 73 unsigned int nr_segs; 74 struct msc *msc; 75 struct sg_table _sgt; 76 struct sg_table *sgt; 77}; 78 79/** 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 91 */ 92struct msc_iter { 93 struct list_head entry; 94 struct msc *msc; 95 struct msc_window *start_win; 96 struct msc_window *win; 97 unsigned long offset; 98 struct scatterlist *start_block; 99 struct scatterlist *block; 100 unsigned int block_off; 101 unsigned int wrap_count; 102 unsigned int eof; 103}; 104 105/** 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 122 123 * @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 */ 759static int msc_configure(struct msc *msc) 760{ 761 u32 reg; 762 763 lockdep_assert_held(&msc->buf_mutex); 764 765 if (msc->mode > MSC_MODE_MULTI) 766 return -EINVAL; 767 768 if (msc->mode == MSC_MODE_MULTI) { 769 if (msc_win_set_lockout(msc->cur_win, WIN_READY, WIN_INUSE)) 770 return -EBUSY; 771 772 msc_buffer_clear_hw_header(msc); 773 } 774 775 msc->orig_addr = ioread32(msc->reg_base + REG_MSU_MSC0BAR); 776 msc->orig_sz = ioread32(msc->reg_base + REG_MSU_MSC0SIZE); 777 778 reg = msc->base_addr >> PAGE_SHIFT; 779 iowrite32(reg, msc->reg_base + REG_MSU_MSC0BAR); 780 781 if (msc->mode == MSC_MODE_SINGLE) { 782 reg = msc->nr_pages; 783 iowrite32(reg, msc->reg_base + REG_MSU_MSC0SIZE); 784 } 785 786 reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL); 787 reg &= ~(MSC_MODE | MSC_WRAPEN | MSC_EN | MSC_RD_HDR_OVRD); 788 789 reg |= MSC_EN; 790 reg |= msc->mode << __ffs(MSC_MODE); 791 reg |= msc->burst_len << __ffs(MSC_LEN); 792 793 if (msc->wrap) 794 reg |= MSC_WRAPEN; 795 796 iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL); 797 798 intel_th_msu_init(msc); 799 800 msc->thdev->output.multiblock = msc->mode == MSC_MODE_MULTI; 801 intel_th_trace_enable(msc->thdev); 802 msc->enabled = 1; 803 804 if (msc->mbuf && msc->mbuf->activate) 805 msc->mbuf->activate(msc->mbuf_priv); 806 807 return 0; 808} 809 810/** 811 * msc_disable() - disable MSC hardware 812 * @msc: MSC device to disable 813 * 814 * If @msc is enabled, disable tracing on the switch and then disable MSC 815 * storage. Caller must hold msc::buf_mutex. 816 */ 817static void msc_disable(struct msc *msc) 818{ 819 struct msc_window *win = msc->cur_win; 820 u32 reg; 821 822 lockdep_assert_held(&msc->buf_mutex); 823 824 if (msc->mode == MSC_MODE_MULTI) 825 msc_win_set_lockout(win, WIN_INUSE, WIN_LOCKED); 826 827 if (msc->mbuf && msc->mbuf->deactivate) 828 msc->mbuf->deactivate(msc->mbuf_priv); 829 intel_th_msu_deinit(msc); 830 intel_th_trace_disable(msc->thdev); 831 832 if (msc->mode == MSC_MODE_SINGLE) { 833 reg = ioread32(msc->reg_base + REG_MSU_MSC0STS); 834 msc->single_wrap = !!(reg & MSCSTS_WRAPSTAT); 835 836 reg = ioread32(msc->reg_base + REG_MSU_MSC0MWP); 837 msc->single_sz = reg & ((msc->nr_pages << PAGE_SHIFT) - 1); 838 dev_dbg(msc_dev(msc), "MSCnMWP: %08x/%08lx, wrap: %d\n", 839 reg, msc->single_sz, msc->single_wrap); 840 } 841 842 reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL); 843 reg &= ~MSC_EN; 844 iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL); 845 846 if (msc->mbuf && msc->mbuf->ready) 847 msc->mbuf->ready(msc->mbuf_priv, win->sgt, 848 msc_win_total_sz(win)); 849 850 msc->enabled = 0; 851 852 iowrite32(msc->orig_addr, msc->reg_base + REG_MSU_MSC0BAR); 853 iowrite32(msc->orig_sz, msc->reg_base + REG_MSU_MSC0SIZE); 854 855 dev_dbg(msc_dev(msc), "MSCnNWSA: %08x\n", 856 ioread32(msc->reg_base + REG_MSU_MSC0NWSA)); 857 858 reg = ioread32(msc->reg_base + REG_MSU_MSC0STS); 859 dev_dbg(msc_dev(msc), "MSCnSTS: %08x\n", reg); 860 861 reg = ioread32(msc->reg_base + REG_MSU_MSUSTS); 862 reg &= msc->index ? MSUSTS_MSC1BLAST : MSUSTS_MSC0BLAST; 863 iowrite32(reg, msc->reg_base + REG_MSU_MSUSTS); 864} 865 866static int intel_th_msc_activate(struct intel_th_device *thdev) 867{ 868 struct msc *msc = dev_get_drvdata(&thdev->dev); 869 int ret = -EBUSY; 870 871 if (!atomic_inc_unless_negative(&msc->user_count)) 872 return -ENODEV; 873 874 mutex_lock(&msc->buf_mutex); 875 876 /* if there are readers, refuse */ 877 if (list_empty(&msc->iter_list)) 878 ret = msc_configure(msc); 879 880 mutex_unlock(&msc->buf_mutex); 881 882 if (ret) 883 atomic_dec(&msc->user_count); 884 885 return ret; 886} 887 888static void intel_th_msc_deactivate(struct intel_th_device *thdev) 889{ 890 struct msc *msc = dev_get_drvdata(&thdev->dev); 891 892 mutex_lock(&msc->buf_mutex); 893 if (msc->enabled) { 894 msc_disable(msc); 895 atomic_dec(&msc->user_count); 896 } 897 mutex_unlock(&msc->buf_mutex); 898} 899 900/** 901 * msc_buffer_contig_alloc() - allocate a contiguous buffer for SINGLE mode 902 * @msc: MSC device 903 * @size: allocation size in bytes 904 * 905 * This modifies msc::base, which requires msc::buf_mutex to serialize, so the 906 * caller is expected to hold it. 907 * 908 * Return: 0 on success, -errno otherwise. 909 */ 910static int msc_buffer_contig_alloc(struct msc *msc, unsigned long size) 911{ 912 unsigned long nr_pages = size >> PAGE_SHIFT; 913 unsigned int order = get_order(size); 914 struct page *page; 915 int ret; 916 917 if (!size) 918 return 0; 919 920 ret = sg_alloc_table(&msc->single_sgt, 1, GFP_KERNEL); 921 if (ret) 922 goto err_out; 923 924 ret = -ENOMEM; 925 page = alloc_pages(GFP_KERNEL | __GFP_ZERO | GFP_DMA32, order); 926 if (!page) 927 goto err_free_sgt; 928 929 split_page(page, order); 930 sg_set_buf(msc->single_sgt.sgl, page_address(page), size); 931 932 ret = dma_map_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl, 1, 933 DMA_FROM_DEVICE); 934 if (ret < 0) 935 goto err_free_pages; 936 937 msc->nr_pages = nr_pages; 938 msc->base = page_address(page); 939 msc->base_addr = sg_dma_address(msc->single_sgt.sgl); 940 941 return 0; 942 943err_free_pages: 944 __free_pages(page, order); 945 946err_free_sgt: 947 sg_free_table(&msc->single_sgt); 948 949err_out: 950 return ret; 951} 952 953/** 954 * msc_buffer_contig_free() - free a contiguous buffer 955 * @msc: MSC configured in SINGLE mode 956 */ 957static void msc_buffer_contig_free(struct msc *msc) 958{ 959 unsigned long off; 960 961 dma_unmap_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl, 962 1, DMA_FROM_DEVICE); 963 sg_free_table(&msc->single_sgt); 964 965 for (off = 0; off < msc->nr_pages << PAGE_SHIFT; off += PAGE_SIZE) { 966 struct page *page = virt_to_page(msc->base + off); 967 968 page->mapping = NULL; 969 __free_page(page); 970 } 971 972 msc->nr_pages = 0; 973} 974 975/** 976 * msc_buffer_contig_get_page() - find a page at a given offset 977 * @msc: MSC configured in SINGLE mode 978 * @pgoff: page offset 979 * 980 * Return: page, if @pgoff is within the range, NULL otherwise. 981 */ 982static struct page *msc_buffer_contig_get_page(struct msc *msc, 983 unsigned long pgoff) 984{ 985 if (pgoff >= msc->nr_pages) 986 return NULL; 987 988 return virt_to_page(msc->base + (pgoff << PAGE_SHIFT)); 989} 990 991static int __msc_buffer_win_alloc(struct msc_window *win, 992 unsigned int nr_segs) 993{ 994 struct scatterlist *sg_ptr; 995 void *block; 996 int i, ret; 997 998 ret = sg_alloc_table(win->sgt, nr_segs, GFP_KERNEL); 999 if (ret) 1000 return -ENOMEM; 1001 1002 for_each_sg(win->sgt->sgl, sg_ptr, nr_segs, i) { 1003 block = dma_alloc_coherent(msc_dev(win->msc)->parent->parent, 1004 PAGE_SIZE, &sg_dma_address(sg_ptr), 1005 GFP_KERNEL); 1006 if (!block) 1007 goto err_nomem; 1008 1009 sg_set_buf(sg_ptr, block, PAGE_SIZE); 1010 } 1011 1012 return nr_segs; 1013 1014err_nomem: 1015 for_each_sg(win->sgt->sgl, sg_ptr, i, ret) 1016 dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE, 1017 sg_virt(sg_ptr), sg_dma_address(sg_ptr)); 1018 1019 sg_free_table(win->sgt); 1020 1021 return -ENOMEM; 1022} 1023 1024#ifdef CONFIG_X86 1025static void msc_buffer_set_uc(struct msc *msc) 1026{ 1027 struct scatterlist *sg_ptr; 1028 struct msc_window *win; 1029 int i; 1030 1031 if (msc->mode == MSC_MODE_SINGLE) { 1032 set_memory_uc((unsigned long)msc->base, msc->nr_pages); 1033 return; 1034 } 1035 1036 list_for_each_entry(win, &msc->win_list, entry) { 1037 for_each_sg(win->sgt->sgl, sg_ptr, win->nr_segs, i) { 1038 /* Set the page as uncached */ 1039 set_memory_uc((unsigned long)sg_virt(sg_ptr), 1040 PFN_DOWN(sg_ptr->length)); 1041 } 1042 } 1043} 1044 1045static void msc_buffer_set_wb(struct msc *msc) 1046{ 1047 struct scatterlist *sg_ptr; 1048 struct msc_window *win; 1049 int i; 1050 1051 if (msc->mode == MSC_MODE_SINGLE) { 1052 set_memory_wb((unsigned long)msc->base, msc->nr_pages); 1053 return; 1054 } 1055 1056 list_for_each_entry(win, &msc->win_list, entry) { 1057 for_each_sg(win->sgt->sgl, sg_ptr, win->nr_segs, i) { 1058 /* Reset the page to write-back */ 1059 set_memory_wb((unsigned long)sg_virt(sg_ptr), 1060 PFN_DOWN(sg_ptr->length)); 1061 } 1062 } 1063} 1064#else /* !X86 */ 1065static inline void 1066msc_buffer_set_uc(struct msc *msc) {} 1067static inline void msc_buffer_set_wb(struct msc *msc) {} 1068#endif /* CONFIG_X86 */ 1069 1070static struct page *msc_sg_page(struct scatterlist *sg) 1071{ 1072 void *addr = sg_virt(sg); 1073 1074 if (is_vmalloc_addr(addr)) 1075 return vmalloc_to_page(addr); 1076 1077 return sg_page(sg); 1078} 1079 1080/** 1081 * msc_buffer_win_alloc() - alloc a window for a multiblock mode 1082 * @msc: MSC device 1083 * @nr_blocks: number of pages in this window 1084 * 1085 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex 1086 * to serialize, so the caller is expected to hold it. 1087 * 1088 * Return: 0 on success, -errno otherwise. 1089 */ 1090static int msc_buffer_win_alloc(struct msc *msc, unsigned int nr_blocks) 1091{ 1092 struct msc_window *win; 1093 int ret = -ENOMEM; 1094 1095 if (!nr_blocks) 1096 return 0; 1097 1098 win = kzalloc(sizeof(*win), GFP_KERNEL); 1099 if (!win) 1100 return -ENOMEM; 1101 1102 win->msc = msc; 1103 win->sgt = &win->_sgt; 1104 win->lockout = WIN_READY; 1105 spin_lock_init(&win->lo_lock); 1106 1107 if (!list_empty(&msc->win_list)) { 1108 struct msc_window *prev = list_last_entry(&msc->win_list, 1109 struct msc_window, 1110 entry); 1111 1112 win->pgoff = prev->pgoff + prev->nr_blocks; 1113 } 1114 1115 if (msc->mbuf && msc->mbuf->alloc_window) 1116 ret = msc->mbuf->alloc_window(msc->mbuf_priv, &win->sgt, 1117 nr_blocks << PAGE_SHIFT); 1118 else 1119 ret = __msc_buffer_win_alloc(win, nr_blocks); 1120 1121 if (ret <= 0) 1122 goto err_nomem; 1123 1124 win->nr_segs = ret; 1125 win->nr_blocks = nr_blocks; 1126 1127 if (list_empty(&msc->win_list)) { 1128 msc->base = msc_win_base(win); 1129 msc->base_addr = msc_win_base_dma(win); 1130 msc->cur_win = win; 1131 } 1132 1133 list_add_tail(&win->entry, &msc->win_list); 1134 msc->nr_pages += nr_blocks; 1135 1136 return 0; 1137 1138err_nomem: 1139 kfree(win); 1140 1141 return ret; 1142} 1143 1144static void __msc_buffer_win_free(struct msc *msc, struct msc_window *win) 1145{ 1146 struct scatterlist *sg; 1147 int i; 1148 1149 for_each_sg(win->sgt->sgl, sg, win->nr_segs, i) { 1150 struct page *page = msc_sg_page(sg); 1151 1152 page->mapping = NULL; 1153 dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE, 1154 sg_virt(sg), sg_dma_address(sg)); 1155 } 1156 sg_free_table(win->sgt); 1157} 1158 1159/** 1160 * msc_buffer_win_free() - free a window from MSC's window list 1161 * @msc: MSC device 1162 * @win: window to free 1163 * 1164 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex 1165 * to serialize, so the caller is expected to hold it. 1166 */ 1167static void msc_buffer_win_free(struct msc *msc, struct msc_window *win) 1168{ 1169 msc->nr_pages -= win->nr_blocks; 1170 1171 list_del(&win->entry); 1172 if (list_empty(&msc->win_list)) { 1173 msc->base = NULL; 1174 msc->base_addr = 0; 1175 } 1176 1177 if (msc->mbuf && msc->mbuf->free_window) 1178 msc->mbuf->free_window(msc->mbuf_priv, win->sgt); 1179 else 1180 __msc_buffer_win_free(msc, win); 1181 1182 kfree(win); 1183} 1184 1185/** 1186 * msc_buffer_relink() - set up block descriptors for multiblock mode 1187 * @msc: MSC device 1188 * 1189 * This traverses msc::win_list, which requires msc::buf_mutex to serialize, 1190 * so the caller is expected to hold it. 1191 */ 1192static void msc_buffer_relink(struct msc *msc) 1193{ 1194 struct msc_window *win, *next_win; 1195 1196 /* call with msc::mutex locked */ 1197 list_for_each_entry(win, &msc->win_list, entry) { 1198 struct scatterlist *sg; 1199 unsigned int blk; 1200 u32 sw_tag = 0; 1201 1202 /* 1203 * Last window's next_win should point to the first window 1204 * and MSC_SW_TAG_LASTWIN should be set. 1205 */ 1206 if (msc_is_last_win(win)) { 1207 sw_tag |= MSC_SW_TAG_LASTWIN; 1208 next_win = list_first_entry(&msc->win_list, 1209 struct msc_window, entry); 1210 } else { 1211 next_win = list_next_entry(win, entry); 1212 } 1213 1214 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) { 1215 struct msc_block_desc *bdesc = sg_virt(sg); 1216 1217 memset(bdesc, 0, sizeof(*bdesc)); 1218 1219 bdesc->next_win = msc_win_base_pfn(next_win); 1220 1221 /* 1222 * Similarly to last window, last block should point 1223 * to the first one. 1224 */ 1225 if (blk == win->nr_segs - 1) { 1226 sw_tag |= MSC_SW_TAG_LASTBLK; 1227 bdesc->next_blk = msc_win_base_pfn(win); 1228 } else { 1229 dma_addr_t addr = sg_dma_address(sg_next(sg)); 1230 1231 bdesc->next_blk = PFN_DOWN(addr); 1232 } 1233 1234 bdesc->sw_tag = sw_tag; 1235 bdesc->block_sz = sg->length / 64; 1236 } 1237 } 1238 1239 /* 1240 * Make the above writes globally visible before tracing is 1241 * enabled to make sure hardware sees them coherently. 1242 */ 1243 wmb(); 1244} 1245 1246static void msc_buffer_multi_free(struct msc *msc) 1247{ 1248 struct msc_window *win, *iter; 1249 1250 list_for_each_entry_safe(win, iter, &msc->win_list, entry) 1251 msc_buffer_win_free(msc, win); 1252} 1253 1254static int msc_buffer_multi_alloc(struct msc *msc, unsigned long *nr_pages, 1255 unsigned int nr_wins) 1256{ 1257 int ret, i; 1258 1259 for (i = 0; i < nr_wins; i++) { 1260 ret = msc_buffer_win_alloc(msc, nr_pages[i]); 1261 if (ret) { 1262 msc_buffer_multi_free(msc); 1263 return ret; 1264 } 1265 } 1266 1267 msc_buffer_relink(msc); 1268 1269 return 0; 1270} 1271 1272/** 1273 * msc_buffer_free() - free buffers for MSC 1274 * @msc: MSC device 1275 * 1276 * Free MSC's storage buffers. 1277 * 1278 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex to 1279 * serialize, so the caller is expected to hold it. 1280 */ 1281static void msc_buffer_free(struct msc *msc) 1282{ 1283 msc_buffer_set_wb(msc); 1284 1285 if (msc->mode == MSC_MODE_SINGLE) 1286 msc_buffer_contig_free(msc); 1287 else if (msc->mode == MSC_MODE_MULTI) 1288 msc_buffer_multi_free(msc); 1289} 1290 1291/** 1292 * msc_buffer_alloc() - allocate a buffer for MSC 1293 * @msc: MSC device 1294 * @size: allocation size in bytes 1295 * 1296 * Allocate a storage buffer for MSC, depending on the msc::mode, it will be 1297 * either done via msc_buffer_contig_alloc() for SINGLE operation mode or 1298 * msc_buffer_win_alloc() for multiblock operation. The latter allocates one 1299 * window per invocation, so in multiblock mode this can be called multiple 1300 * times for the same MSC to allocate multiple windows. 1301 * 1302 * This modifies msc::win_list and msc::base, which requires msc::buf_mutex 1303 * to serialize, so the caller is expected to hold it. 1304 * 1305 * Return: 0 on success, -errno otherwise. 1306 */ 1307static int msc_buffer_alloc(struct msc *msc, unsigned long *nr_pages, 1308 unsigned int nr_wins) 1309{ 1310 int ret; 1311 1312 /* -1: buffer not allocated */ 1313 if (atomic_read(&msc->user_count) != -1) 1314 return -EBUSY; 1315 1316 if (msc->mode == MSC_MODE_SINGLE) { 1317 if (nr_wins != 1) 1318 return -EINVAL; 1319 1320 ret = msc_buffer_contig_alloc(msc, nr_pages[0] << PAGE_SHIFT); 1321 } else if (msc->mode == MSC_MODE_MULTI) { 1322 ret = msc_buffer_multi_alloc(msc, nr_pages, nr_wins); 1323 } else { 1324 ret = -EINVAL; 1325 } 1326 1327 if (!ret) { 1328 msc_buffer_set_uc(msc); 1329 1330 /* allocation should be visible before the counter goes to 0 */ 1331 smp_mb__before_atomic(); 1332 1333 if (WARN_ON_ONCE(atomic_cmpxchg(&msc->user_count, -1, 0) != -1)) 1334 return -EINVAL; 1335 } 1336 1337 return ret; 1338} 1339 1340/** 1341 * msc_buffer_unlocked_free_unless_used() - free a buffer unless it's in use 1342 * @msc: MSC device 1343 * 1344 * This will free MSC buffer unless it is in use or there is no allocated 1345 * buffer. 1346 * Caller needs to hold msc::buf_mutex. 1347 * 1348 * Return: 0 on successful deallocation or if there was no buffer to 1349 * deallocate, -EBUSY if there are active users. 1350 */ 1351static int msc_buffer_unlocked_free_unless_used(struct msc *msc) 1352{ 1353 int count, ret = 0; 1354 1355 count = atomic_cmpxchg(&msc->user_count, 0, -1); 1356 1357 /* > 0: buffer is allocated and has users */ 1358 if (count > 0) 1359 ret = -EBUSY; 1360 /* 0: buffer is allocated, no users */ 1361 else if (!count) 1362 msc_buffer_free(msc); 1363 /* < 0: no buffer, nothing to do */ 1364 1365 return ret; 1366} 1367 1368/** 1369 * msc_buffer_free_unless_used() - free a buffer unless it's in use 1370 * @msc: MSC device 1371 * 1372 * This is a locked version of msc_buffer_unlocked_free_unless_used(). 1373 */ 1374static int msc_buffer_free_unless_used(struct msc *msc) 1375{ 1376 int ret; 1377 1378 mutex_lock(&msc->buf_mutex); 1379 ret = msc_buffer_unlocked_free_unless_used(msc); 1380 mutex_unlock(&msc->buf_mutex); 1381 1382 return ret; 1383} 1384 1385/** 1386 * msc_buffer_get_page() - get MSC buffer page at a given offset 1387 * @msc: MSC device 1388 * @pgoff: page offset into the storage buffer 1389 * 1390 * This traverses msc::win_list, so holding msc::buf_mutex is expected from 1391 * the caller. 1392 * 1393 * Return: page if @pgoff corresponds to a valid buffer page or NULL. 1394 */ 1395static struct page *msc_buffer_get_page(struct msc *msc, unsigned long pgoff) 1396{ 1397 struct msc_window *win; 1398 struct scatterlist *sg; 1399 unsigned int blk; 1400 1401 if (msc->mode == MSC_MODE_SINGLE) 1402 return msc_buffer_contig_get_page(msc, pgoff); 1403 1404 list_for_each_entry(win, &msc->win_list, entry) 1405 if (pgoff >= win->pgoff && pgoff < win->pgoff + win->nr_blocks) 1406 goto found; 1407 1408 return NULL; 1409 1410found: 1411 pgoff -= win->pgoff; 1412 1413 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) { 1414 struct page *page = msc_sg_page(sg); 1415 size_t pgsz = PFN_DOWN(sg->length); 1416 1417 if (pgoff < pgsz) 1418 return page + pgoff; 1419 1420 pgoff -= pgsz; 1421 } 1422 1423 return NULL; 1424} 1425 1426/** 1427 * struct msc_win_to_user_struct - data for copy_to_user() callback 1428 * @buf: userspace buffer to copy data to 1429 * @offset: running offset 1430 */ 1431struct msc_win_to_user_struct { 1432 char __user *buf; 1433 unsigned long offset; 1434}; 1435 1436/** 1437 * msc_win_to_user() - iterator for msc_buffer_iterate() to copy data to user 1438 * @data: callback's private data 1439 * @src: source buffer 1440 * @len: amount of data to copy from the source buffer 1441 */ 1442static unsigned long msc_win_to_user(void *data, void *src, size_t len) 1443{ 1444 struct msc_win_to_user_struct *u = data; 1445 unsigned long ret; 1446 1447 ret = copy_to_user(u->buf + u->offset, src, len); 1448 u->offset += len - ret; 1449 1450 return ret; 1451} 1452 1453 1454/* 1455 * file operations' callbacks 1456 */ 1457 1458static int intel_th_msc_open(struct inode *inode, struct file *file) 1459{ 1460 struct intel_th_device *thdev = file->private_data; 1461 struct msc *msc = dev_get_drvdata(&thdev->dev); 1462 struct msc_iter *iter; 1463 1464 if (!capable(CAP_SYS_RAWIO)) 1465 return -EPERM; 1466 1467 iter = msc_iter_install(msc); 1468 if (IS_ERR(iter)) 1469 return PTR_ERR(iter); 1470 1471 file->private_data = iter; 1472 1473 return nonseekable_open(inode, file); 1474} 1475 1476static int intel_th_msc_release(struct inode *inode, struct file *file) 1477{ 1478 struct msc_iter *iter = file->private_data; 1479 struct msc *msc = iter->msc; 1480 1481 msc_iter_remove(iter, msc); 1482 1483 return 0; 1484} 1485 1486static ssize_t 1487msc_single_to_user(struct msc *msc, char __user *buf, loff_t off, size_t len) 1488{ 1489 unsigned long size = msc->nr_pages << PAGE_SHIFT, rem = len; 1490 unsigned long start = off, tocopy = 0; 1491 1492 if (msc->single_wrap) { 1493 start += msc->single_sz; 1494 if (start < size) { 1495 tocopy = min(rem, size - start); 1496 if (copy_to_user(buf, msc->base + start, tocopy)) 1497 return -EFAULT; 1498 1499 buf += tocopy; 1500 rem -= tocopy; 1501 start += tocopy; 1502 } 1503 1504 start &= size - 1; 1505 if (rem) { 1506 tocopy = min(rem, msc->single_sz - start); 1507 if (copy_to_user(buf, msc->base + start, tocopy)) 1508 return -EFAULT; 1509 1510 rem -= tocopy; 1511 } 1512 1513 return len - rem; 1514 } 1515 1516 if (copy_to_user(buf, msc->base + start, rem)) 1517 return -EFAULT; 1518 1519 return len; 1520} 1521 1522static ssize_t intel_th_msc_read(struct file *file, char __user *buf, 1523 size_t len, loff_t *ppos) 1524{ 1525 struct msc_iter *iter = file->private_data; 1526 struct msc *msc = iter->msc; 1527 size_t size; 1528 loff_t off = *ppos; 1529 ssize_t ret = 0; 1530 1531 if (!atomic_inc_unless_negative(&msc->user_count)) 1532 return 0; 1533 1534 if (msc->mode == MSC_MODE_SINGLE && !msc->single_wrap) 1535 size = msc->single_sz; 1536 else 1537 size = msc->nr_pages << PAGE_SHIFT; 1538 1539 if (!size) 1540 goto put_count; 1541 1542 if (off >= size) 1543 goto put_count; 1544 1545 if (off + len >= size) 1546 len = size - off; 1547 1548 if (msc->mode == MSC_MODE_SINGLE) { 1549 ret = msc_single_to_user(msc, buf, off, len); 1550 if (ret >= 0) 1551 *ppos += ret; 1552 } else if (msc->mode == MSC_MODE_MULTI) { 1553 struct msc_win_to_user_struct u = { 1554 .buf = buf, 1555 .offset = 0, 1556 }; 1557 1558 ret = msc_buffer_iterate(iter, len, &u, msc_win_to_user); 1559 if (ret >= 0) 1560 *ppos = iter->offset; 1561 } else { 1562 ret = -EINVAL; 1563 } 1564 1565put_count: 1566 atomic_dec(&msc->user_count); 1567 1568 return ret; 1569} 1570 1571/* 1572 * vm operations callbacks (vm_ops) 1573 */ 1574 1575static void msc_mmap_open(struct vm_area_struct *vma) 1576{ 1577 struct msc_iter *iter = vma->vm_file->private_data; 1578 struct msc *msc = iter->msc; 1579 1580 atomic_inc(&msc->mmap_count); 1581} 1582 1583static void msc_mmap_close(struct vm_area_struct *vma) 1584{ 1585 struct msc_iter *iter = vma->vm_file->private_data; 1586 struct msc *msc = iter->msc; 1587 unsigned long pg; 1588 1589 if (!atomic_dec_and_mutex_lock(&msc->mmap_count, &msc->buf_mutex)) 1590 return; 1591 1592 /* drop page _refcounts */ 1593 for (pg = 0; pg < msc->nr_pages; pg++) { 1594 struct page *page = msc_buffer_get_page(msc, pg); 1595 1596 if (WARN_ON_ONCE(!page)) 1597 continue; 1598 1599 if (page->mapping) 1600 page->mapping = NULL; 1601 } 1602 1603 /* last mapping -- drop user_count */ 1604 atomic_dec(&msc->user_count); 1605 mutex_unlock(&msc->buf_mutex); 1606} 1607 1608static vm_fault_t msc_mmap_fault(struct vm_fault *vmf) 1609{ 1610 struct msc_iter *iter = vmf->vma->vm_file->private_data; 1611 struct msc *msc = iter->msc; 1612 1613 vmf->page = msc_buffer_get_page(msc, vmf->pgoff); 1614 if (!vmf->page) 1615 return VM_FAULT_SIGBUS; 1616 1617 get_page(vmf->page); 1618 vmf->page->mapping = vmf->vma->vm_file->f_mapping; 1619 vmf->page->index = vmf->pgoff; 1620 1621 return 0; 1622} 1623 1624static const struct vm_operations_struct msc_mmap_ops = { 1625 .open = msc_mmap_open, 1626 .close = msc_mmap_close, 1627 .fault = msc_mmap_fault, 1628}; 1629 1630static int intel_th_msc_mmap(struct file *file, struct vm_area_struct *vma) 1631{ 1632 unsigned long size = vma->vm_end - vma->vm_start; 1633 struct msc_iter *iter = vma->vm_file->private_data; 1634 struct msc *msc = iter->msc; 1635 int ret = -EINVAL; 1636 1637 if (!size || offset_in_page(size)) 1638 return -EINVAL; 1639 1640 if (vma->vm_pgoff) 1641 return -EINVAL; 1642 1643 /* grab user_count once per mmap; drop in msc_mmap_close() */ 1644 if (!atomic_inc_unless_negative(&msc->user_count)) 1645 return -EINVAL; 1646 1647 if (msc->mode != MSC_MODE_SINGLE && 1648 msc->mode != MSC_MODE_MULTI) 1649 goto out; 1650 1651 if (size >> PAGE_SHIFT != msc->nr_pages) 1652 goto out; 1653 1654 atomic_set(&msc->mmap_count, 1); 1655 ret = 0; 1656 1657out: 1658 if (ret) 1659 atomic_dec(&msc->user_count); 1660 1661 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 1662 vm_flags_set(vma, VM_DONTEXPAND | VM_DONTCOPY); 1663 vma->vm_ops = &msc_mmap_ops; 1664 return ret; 1665} 1666 1667static const struct file_operations intel_th_msc_fops = { 1668 .open = intel_th_msc_open, 1669 .release = intel_th_msc_release, 1670 .read = intel_th_msc_read, 1671 .mmap = intel_th_msc_mmap, 1672 .llseek = no_llseek, 1673 .owner = THIS_MODULE, 1674}; 1675 1676static void intel_th_msc_wait_empty(struct intel_th_device *thdev) 1677{ 1678 struct msc *msc = dev_get_drvdata(&thdev->dev); 1679 unsigned long count; 1680 u32 reg; 1681 1682 for (reg = 0, count = MSC_PLE_WAITLOOP_DEPTH; 1683 count && !(reg & MSCSTS_PLE); count--) { 1684 reg = __raw_readl(msc->reg_base + REG_MSU_MSC0STS); 1685 cpu_relax(); 1686 } 1687 1688 if (!count) 1689 dev_dbg(msc_dev(msc), "timeout waiting for MSC0 PLE\n"); 1690} 1691 1692static int intel_th_msc_init(struct msc *msc) 1693{ 1694 atomic_set(&msc->user_count, -1); 1695 1696 msc->mode = msc->multi_is_broken ? MSC_MODE_SINGLE : MSC_MODE_MULTI; 1697 mutex_init(&msc->buf_mutex); 1698 INIT_LIST_HEAD(&msc->win_list); 1699 INIT_LIST_HEAD(&msc->iter_list); 1700 1701 msc->burst_len = 1702 (ioread32(msc->reg_base + REG_MSU_MSC0CTL) & MSC_LEN) >> 1703 __ffs(MSC_LEN); 1704 1705 return 0; 1706} 1707 1708static int msc_win_switch(struct msc *msc) 1709{ 1710 struct msc_window *first; 1711 1712 if (list_empty(&msc->win_list)) 1713 return -EINVAL; 1714 1715 first = list_first_entry(&msc->win_list, struct msc_window, entry); 1716 1717 if (msc_is_last_win(msc->cur_win)) 1718 msc->cur_win = first; 1719 else 1720 msc->cur_win = list_next_entry(msc->cur_win, entry); 1721 1722 msc->base = msc_win_base(msc->cur_win); 1723 msc->base_addr = msc_win_base_dma(msc->cur_win); 1724 1725 intel_th_trace_switch(msc->thdev); 1726 1727 return 0; 1728} 1729 1730/** 1731 * intel_th_msc_window_unlock - put the window back in rotation 1732 * @dev: MSC device to which this relates 1733 * @sgt: buffer's sg_table for the window, does nothing if NULL 1734 */ 1735void intel_th_msc_window_unlock(struct device *dev, struct sg_table *sgt) 1736{ 1737 struct msc *msc = dev_get_drvdata(dev); 1738 struct msc_window *win; 1739 1740 if (!sgt) 1741 return; 1742 1743 win = msc_find_window(msc, sgt, false); 1744 if (!win) 1745 return; 1746 1747 msc_win_set_lockout(win, WIN_LOCKED, WIN_READY); 1748 if (msc->switch_on_unlock == win) { 1749 msc->switch_on_unlock = NULL; 1750 msc_win_switch(msc); 1751 } 1752} 1753EXPORT_SYMBOL_GPL(intel_th_msc_window_unlock); 1754 1755static void msc_work(struct work_struct *work) 1756{ 1757 struct msc *msc = container_of(work, struct msc, work); 1758 1759 intel_th_msc_deactivate(msc->thdev); 1760} 1761 1762static irqreturn_t intel_th_msc_interrupt(struct intel_th_device *thdev) 1763{ 1764 struct msc *msc = dev_get_drvdata(&thdev->dev); 1765 u32 msusts = ioread32(msc->msu_base + REG_MSU_MSUSTS); 1766 u32 mask = msc->index ? MSUSTS_MSC1BLAST : MSUSTS_MSC0BLAST; 1767 struct msc_window *win, *next_win; 1768 1769 if (!msc->do_irq || !msc->mbuf) 1770 return IRQ_NONE; 1771 1772 msusts &= mask; 1773 1774 if (!msusts) 1775 return msc->enabled ? IRQ_HANDLED : IRQ_NONE; 1776 1777 iowrite32(msusts, msc->msu_base + REG_MSU_MSUSTS); 1778 1779 if (!msc->enabled) 1780 return IRQ_NONE; 1781 1782 /* grab the window before we do the switch */ 1783 win = msc->cur_win; 1784 if (!win) 1785 return IRQ_HANDLED; 1786 next_win = msc_next_window(win); 1787 if (!next_win) 1788 return IRQ_HANDLED; 1789 1790 /* next window: if READY, proceed, if LOCKED, stop the trace */ 1791 if (msc_win_set_lockout(next_win, WIN_READY, WIN_INUSE)) { 1792 if (msc->stop_on_full) 1793 schedule_work(&msc->work); 1794 else 1795 msc->switch_on_unlock = next_win; 1796 1797 return IRQ_HANDLED; 1798 } 1799 1800 /* current window: INUSE -> LOCKED */ 1801 msc_win_set_lockout(win, WIN_INUSE, WIN_LOCKED); 1802 1803 msc_win_switch(msc); 1804 1805 if (msc->mbuf && msc->mbuf->ready) 1806 msc->mbuf->ready(msc->mbuf_priv, win->sgt, 1807 msc_win_total_sz(win)); 1808 1809 return IRQ_HANDLED; 1810} 1811 1812static const char * const msc_mode[] = { 1813 [MSC_MODE_SINGLE] = "single", 1814 [MSC_MODE_MULTI] = "multi", 1815 [MSC_MODE_EXI] = "ExI", 1816 [MSC_MODE_DEBUG] = "debug", 1817}; 1818 1819static ssize_t 1820wrap_show(struct device *dev, struct device_attribute *attr, char *buf) 1821{ 1822 struct msc *msc = dev_get_drvdata(dev); 1823 1824 return scnprintf(buf, PAGE_SIZE, "%d\n", msc->wrap); 1825} 1826 1827static ssize_t 1828wrap_store(struct device *dev, struct device_attribute *attr, const char *buf, 1829 size_t size) 1830{ 1831 struct msc *msc = dev_get_drvdata(dev); 1832 unsigned long val; 1833 int ret; 1834 1835 ret = kstrtoul(buf, 10, &val); 1836 if (ret) 1837 return ret; 1838 1839 msc->wrap = !!val; 1840 1841 return size; 1842} 1843 1844static DEVICE_ATTR_RW(wrap); 1845 1846static void msc_buffer_unassign(struct msc *msc) 1847{ 1848 lockdep_assert_held(&msc->buf_mutex); 1849 1850 if (!msc->mbuf) 1851 return; 1852 1853 msc->mbuf->unassign(msc->mbuf_priv); 1854 msu_buffer_put(msc->mbuf); 1855 msc->mbuf_priv = NULL; 1856 msc->mbuf = NULL; 1857} 1858 1859static ssize_t 1860mode_show(struct device *dev, struct device_attribute *attr, char *buf) 1861{ 1862 struct msc *msc = dev_get_drvdata(dev); 1863 const char *mode = msc_mode[msc->mode]; 1864 ssize_t ret; 1865 1866 mutex_lock(&msc->buf_mutex); 1867 if (msc->mbuf) 1868 mode = msc->mbuf->name; 1869 ret = scnprintf(buf, PAGE_SIZE, "%s\n", mode); 1870 mutex_unlock(&msc->buf_mutex); 1871 1872 return ret; 1873} 1874 1875static ssize_t 1876mode_store(struct device *dev, struct device_attribute *attr, const char *buf, 1877 size_t size) 1878{ 1879 const struct msu_buffer *mbuf = NULL; 1880 struct msc *msc = dev_get_drvdata(dev); 1881 size_t len = size; 1882 char *cp, *mode; 1883 int i, ret; 1884 1885 if (!capable(CAP_SYS_RAWIO)) 1886 return -EPERM; 1887 1888 cp = memchr(buf, '\n', len); 1889 if (cp) 1890 len = cp - buf; 1891 1892 mode = kstrndup(buf, len, GFP_KERNEL); 1893 if (!mode) 1894 return -ENOMEM; 1895 1896 i = match_string(msc_mode, ARRAY_SIZE(msc_mode), mode); 1897 if (i >= 0) { 1898 kfree(mode); 1899 goto found; 1900 } 1901 1902 /* Buffer sinks only work with a usable IRQ */ 1903 if (!msc->do_irq) { 1904 kfree(mode); 1905 return -EINVAL; 1906 } 1907 1908 mbuf = msu_buffer_get(mode); 1909 kfree(mode); 1910 if (mbuf) 1911 goto found; 1912 1913 return -EINVAL; 1914 1915found: 1916 if (i == MSC_MODE_MULTI && msc->multi_is_broken) 1917 return -EOPNOTSUPP; 1918 1919 mutex_lock(&msc->buf_mutex); 1920 ret = 0; 1921 1922 /* Same buffer: do nothing */ 1923 if (mbuf && mbuf == msc->mbuf) { 1924 /* put the extra reference we just got */ 1925 msu_buffer_put(mbuf); 1926 goto unlock; 1927 } 1928 1929 ret = msc_buffer_unlocked_free_unless_used(msc); 1930 if (ret) 1931 goto unlock; 1932 1933 if (mbuf) { 1934 void *mbuf_priv = mbuf->assign(dev, &i); 1935 1936 if (!mbuf_priv) { 1937 ret = -ENOMEM; 1938 goto unlock; 1939 } 1940 1941 msc_buffer_unassign(msc); 1942 msc->mbuf_priv = mbuf_priv; 1943 msc->mbuf = mbuf; 1944 } else { 1945 msc_buffer_unassign(msc); 1946 } 1947 1948 msc->mode = i; 1949 1950unlock: 1951 if (ret && mbuf) 1952 msu_buffer_put(mbuf); 1953 mutex_unlock(&msc->buf_mutex); 1954 1955 return ret ? ret : size; 1956} 1957 1958static DEVICE_ATTR_RW(mode); 1959 1960static ssize_t 1961nr_pages_show(struct device *dev, struct device_attribute *attr, char *buf) 1962{ 1963 struct msc *msc = dev_get_drvdata(dev); 1964 struct msc_window *win; 1965 size_t count = 0; 1966 1967 mutex_lock(&msc->buf_mutex); 1968 1969 if (msc->mode == MSC_MODE_SINGLE) 1970 count = scnprintf(buf, PAGE_SIZE, "%ld\n", msc->nr_pages); 1971 else if (msc->mode == MSC_MODE_MULTI) { 1972 list_for_each_entry(win, &msc->win_list, entry) { 1973 count += scnprintf(buf + count, PAGE_SIZE - count, 1974 "%d%c", win->nr_blocks, 1975 msc_is_last_win(win) ? '\n' : ','); 1976 } 1977 } else { 1978 count = scnprintf(buf, PAGE_SIZE, "unsupported\n"); 1979 } 1980 1981 mutex_unlock(&msc->buf_mutex); 1982 1983 return count; 1984} 1985 1986static ssize_t 1987nr_pages_store(struct device *dev, struct device_attribute *attr, 1988 const char *buf, size_t size) 1989{ 1990 struct msc *msc = dev_get_drvdata(dev); 1991 unsigned long val, *win = NULL, *rewin; 1992 size_t len = size; 1993 const char *p = buf; 1994 char *end, *s; 1995 int ret, nr_wins = 0; 1996 1997 if (!capable(CAP_SYS_RAWIO)) 1998 return -EPERM; 1999 2000 ret = msc_buffer_free_unless_used(msc); 2001 if (ret) 2002 return ret; 2003 2004 /* scan the comma-separated list of allocation sizes */ 2005 end = memchr(buf, '\n', len); 2006 if (end) 2007 len = end - buf; 2008 2009 do { 2010 end = memchr(p, ',', len); 2011 s = kstrndup(p, end ? end - p : len, GFP_KERNEL); 2012 if (!s) { 2013 ret = -ENOMEM; 2014 goto free_win; 2015 } 2016 2017 ret = kstrtoul(s, 10, &val); 2018 kfree(s); 2019 2020 if (ret || !val) 2021 goto free_win; 2022 2023 if (nr_wins && msc->mode == MSC_MODE_SINGLE) { 2024 ret = -EINVAL; 2025 goto free_win; 2026 } 2027 2028 nr_wins++; 2029 rewin = krealloc_array(win, nr_wins, sizeof(*win), GFP_KERNEL); 2030 if (!rewin) { 2031 kfree(win); 2032 return -ENOMEM; 2033 } 2034 2035 win = rewin; 2036 win[nr_wins - 1] = val; 2037 2038 if (!end) 2039 break; 2040 2041 /* consume the number and the following comma, hence +1 */ 2042 len -= end - p + 1; 2043 p = end + 1; 2044 } while (len); 2045 2046 mutex_lock(&msc->buf_mutex); 2047 ret = msc_buffer_alloc(msc, win, nr_wins); 2048 mutex_unlock(&msc->buf_mutex); 2049 2050free_win: 2051 kfree(win); 2052 2053 return ret ? ret : size; 2054} 2055 2056static DEVICE_ATTR_RW(nr_pages); 2057 2058static ssize_t 2059win_switch_store(struct device *dev, struct device_attribute *attr, 2060 const char *buf, size_t size) 2061{ 2062 struct msc *msc = dev_get_drvdata(dev); 2063 unsigned long val; 2064 int ret; 2065 2066 ret = kstrtoul(buf, 10, &val); 2067 if (ret) 2068 return ret; 2069 2070 if (val != 1) 2071 return -EINVAL; 2072 2073 ret = -EINVAL; 2074 mutex_lock(&msc->buf_mutex); 2075 /* 2076 * Window switch can only happen in the "multi" mode. 2077 * If a external buffer is engaged, they have the full 2078 * control over window switching. 2079 */ 2080 if (msc->mode == MSC_MODE_MULTI && !msc->mbuf) 2081 ret = msc_win_switch(msc); 2082 mutex_unlock(&msc->buf_mutex); 2083 2084 return ret ? ret : size; 2085} 2086 2087static DEVICE_ATTR_WO(win_switch); 2088 2089static ssize_t stop_on_full_show(struct device *dev, 2090 struct device_attribute *attr, char *buf) 2091{ 2092 struct msc *msc = dev_get_drvdata(dev); 2093 2094 return sprintf(buf, "%d\n", msc->stop_on_full); 2095} 2096 2097static ssize_t stop_on_full_store(struct device *dev, 2098 struct device_attribute *attr, 2099 const char *buf, size_t size) 2100{ 2101 struct msc *msc = dev_get_drvdata(dev); 2102 int ret; 2103 2104 ret = kstrtobool(buf, &msc->stop_on_full); 2105 if (ret) 2106 return ret; 2107 2108 return size; 2109} 2110 2111static DEVICE_ATTR_RW(stop_on_full); 2112 2113static struct attribute *msc_output_attrs[] = { 2114 &dev_attr_wrap.attr, 2115 &dev_attr_mode.attr, 2116 &dev_attr_nr_pages.attr, 2117 &dev_attr_win_switch.attr, 2118 &dev_attr_stop_on_full.attr, 2119 NULL, 2120}; 2121 2122static const struct attribute_group msc_output_group = { 2123 .attrs = msc_output_attrs, 2124}; 2125 2126static int intel_th_msc_probe(struct intel_th_device *thdev) 2127{ 2128 struct device *dev = &thdev->dev; 2129 struct resource *res; 2130 struct msc *msc; 2131 void __iomem *base; 2132 int err; 2133 2134 res = intel_th_device_get_resource(thdev, IORESOURCE_MEM, 0); 2135 if (!res) 2136 return -ENODEV; 2137 2138 base = devm_ioremap(dev, res->start, resource_size(res)); 2139 if (!base) 2140 return -ENOMEM; 2141 2142 msc = devm_kzalloc(dev, sizeof(*msc), GFP_KERNEL); 2143 if (!msc) 2144 return -ENOMEM; 2145 2146 res = intel_th_device_get_resource(thdev, IORESOURCE_IRQ, 1); 2147 if (!res) 2148 msc->do_irq = 1; 2149 2150 if (INTEL_TH_CAP(to_intel_th(thdev), multi_is_broken)) 2151 msc->multi_is_broken = 1; 2152 2153 msc->index = thdev->id; 2154 2155 msc->thdev = thdev; 2156 msc->reg_base = base + msc->index * 0x100; 2157 msc->msu_base = base; 2158 2159 INIT_WORK(&msc->work, msc_work); 2160 err = intel_th_msc_init(msc); 2161 if (err) 2162 return err; 2163 2164 dev_set_drvdata(dev, msc); 2165 2166 return 0; 2167} 2168 2169static void intel_th_msc_remove(struct intel_th_device *thdev) 2170{ 2171 struct msc *msc = dev_get_drvdata(&thdev->dev); 2172 int ret; 2173 2174 intel_th_msc_deactivate(thdev); 2175 2176 /* 2177 * Buffers should not be used at this point except if the 2178 * output character device is still open and the parent 2179 * device gets detached from its bus, which is a FIXME. 2180 */ 2181 ret = msc_buffer_free_unless_used(msc); 2182 WARN_ON_ONCE(ret); 2183} 2184 2185static struct intel_th_driver intel_th_msc_driver = { 2186 .probe = intel_th_msc_probe, 2187 .remove = intel_th_msc_remove, 2188 .irq = intel_th_msc_interrupt, 2189 .wait_empty = intel_th_msc_wait_empty, 2190 .activate = intel_th_msc_activate, 2191 .deactivate = intel_th_msc_deactivate, 2192 .fops = &intel_th_msc_fops, 2193 .attr_group = &msc_output_group, 2194 .driver = { 2195 .name = "msc", 2196 .owner = THIS_MODULE, 2197 }, 2198}; 2199 2200module_driver(intel_th_msc_driver, 2201 intel_th_driver_register, 2202 intel_th_driver_unregister); 2203 2204MODULE_LICENSE("GPL v2"); 2205MODULE_DESCRIPTION("Intel(R) Trace Hub Memory Storage Unit driver"); 2206MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>"); 2207