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 size_t hw_sz = sizeof(struct msc_block_desc) - 662 offsetof(struct msc_block_desc, hw_tag); 663 664 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) { 665 struct msc_block_desc *bdesc = sg_virt(sg); 666 667 memset(&bdesc->hw_tag, 0, hw_sz); 668 } 669 } 670} 671 672static int intel_th_msu_init(struct msc *msc) 673{ 674 u32 mintctl, msusts; 675 676 if (!msc->do_irq) 677 return 0; 678 679 if (!msc->mbuf) 680 return 0; 681 682 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"); 687 msc->do_irq = 0; 688 return 0; 689 } 690 691 msusts = ioread32(msc->msu_base + REG_MSU_MSUSTS); 692 iowrite32(msusts, msc->msu_base + REG_MSU_MSUSTS); 693 694 return 0; 695} 696 697static void intel_th_msu_deinit(struct msc *msc) 698{ 699 u32 mintctl; 700 701 if (!msc->do_irq) 702 return; 703 704 mintctl = ioread32(msc->msu_base + REG_MSU_MINTCTL); 705 mintctl &= msc->index ? ~M1BLIE : ~M0BLIE; 706 iowrite32(mintctl, msc->msu_base + REG_MSU_MINTCTL); 707} 708 709static int msc_win_set_lockout(struct msc_window *win, 710 enum lockout_state expect, 711 enum lockout_state new) 712{ 713 enum lockout_state old; 714 unsigned long flags; 715 int ret = 0; 716 717 if (!win->msc->mbuf) 718 return 0; 719 720 spin_lock_irqsave(&win->lo_lock, flags); 721 old = win->lockout; 722 723 if (old != expect) { 724 ret = -EINVAL; 725 goto unlock; 726 } 727 728 win->lockout = new; 729 730 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); 734 735unlock: 736 spin_unlock_irqrestore(&win->lo_lock, flags); 737 738 if (ret) { 739 if (expect == WIN_READY && old == WIN_LOCKED) 740 return -EBUSY; 741 742 /* from intel_th_msc_window_unlock(), don't warn if not locked */ 743 if (expect == WIN_LOCKED && old == new) 744 return 0; 745 746 dev_warn_ratelimited(msc_dev(win->msc), 747 "expected lockout state %d, got %d\n", 748 expect, old); 749 } 750 751 return ret; 752} 753/** 754 * msc_configure() - set up MSC hardware 755 * @msc: the MSC device to configure 756 * 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. 760 */ 761static int msc_configure(struct msc *msc) 762{ 763 u32 reg; 764 765 lockdep_assert_held(&msc->buf_mutex); 766 767 if (msc->mode > MSC_MODE_MULTI) 768 return -EINVAL; 769 770 if (msc->mode == MSC_MODE_MULTI) { 771 if (msc_win_set_lockout(msc->cur_win, WIN_READY, WIN_INUSE)) 772 return -EBUSY; 773 774 msc_buffer_clear_hw_header(msc); 775 } 776 777 msc->orig_addr = ioread32(msc->reg_base + REG_MSU_MSC0BAR); 778 msc->orig_sz = ioread32(msc->reg_base + REG_MSU_MSC0SIZE); 779 780 reg = msc->base_addr >> PAGE_SHIFT; 781 iowrite32(reg, msc->reg_base + REG_MSU_MSC0BAR); 782 783 if (msc->mode == MSC_MODE_SINGLE) { 784 reg = msc->nr_pages; 785 iowrite32(reg, msc->reg_base + REG_MSU_MSC0SIZE); 786 } 787 788 reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL); 789 reg &= ~(MSC_MODE | MSC_WRAPEN | MSC_EN | MSC_RD_HDR_OVRD); 790 791 reg |= MSC_EN; 792 reg |= msc->mode << __ffs(MSC_MODE); 793 reg |= msc->burst_len << __ffs(MSC_LEN); 794 795 if (msc->wrap) 796 reg |= MSC_WRAPEN; 797 798 iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL); 799 800 intel_th_msu_init(msc); 801 802 msc->thdev->output.multiblock = msc->mode == MSC_MODE_MULTI; 803 intel_th_trace_enable(msc->thdev); 804 msc->enabled = 1; 805 806 if (msc->mbuf && msc->mbuf->activate) 807 msc->mbuf->activate(msc->mbuf_priv); 808 809 return 0; 810} 811 812/** 813 * msc_disable() - disable MSC hardware 814 * @msc: MSC device to disable 815 * 816 * If @msc is enabled, disable tracing on the switch and then disable MSC 817 * storage. Caller must hold msc::buf_mutex. 818 */ 819static void msc_disable(struct msc *msc) 820{ 821 struct msc_window *win = msc->cur_win; 822 u32 reg; 823 824 lockdep_assert_held(&msc->buf_mutex); 825 826 if (msc->mode == MSC_MODE_MULTI) 827 msc_win_set_lockout(win, WIN_INUSE, WIN_LOCKED); 828 829 if (msc->mbuf && msc->mbuf->deactivate) 830 msc->mbuf->deactivate(msc->mbuf_priv); 831 intel_th_msu_deinit(msc); 832 intel_th_trace_disable(msc->thdev); 833 834 if (msc->mode == MSC_MODE_SINGLE) { 835 reg = ioread32(msc->reg_base + REG_MSU_MSC0STS); 836 msc->single_wrap = !!(reg & MSCSTS_WRAPSTAT); 837 838 reg = ioread32(msc->reg_base + REG_MSU_MSC0MWP); 839 msc->single_sz = reg & ((msc->nr_pages << PAGE_SHIFT) - 1); 840 dev_dbg(msc_dev(msc), "MSCnMWP: %08x/%08lx, wrap: %d\n", 841 reg, msc->single_sz, msc->single_wrap); 842 } 843 844 reg = ioread32(msc->reg_base + REG_MSU_MSC0CTL); 845 reg &= ~MSC_EN; 846 iowrite32(reg, msc->reg_base + REG_MSU_MSC0CTL); 847 848 if (msc->mbuf && msc->mbuf->ready) 849 msc->mbuf->ready(msc->mbuf_priv, win->sgt, 850 msc_win_total_sz(win)); 851 852 msc->enabled = 0; 853 854 iowrite32(msc->orig_addr, msc->reg_base + REG_MSU_MSC0BAR); 855 iowrite32(msc->orig_sz, msc->reg_base + REG_MSU_MSC0SIZE); 856 857 dev_dbg(msc_dev(msc), "MSCnNWSA: %08x\n", 858 ioread32(msc->reg_base + REG_MSU_MSC0NWSA)); 859 860 reg = ioread32(msc->reg_base + REG_MSU_MSC0STS); 861 dev_dbg(msc_dev(msc), "MSCnSTS: %08x\n", reg); 862 863 reg = ioread32(msc->reg_base + REG_MSU_MSUSTS); 864 reg &= msc->index ? MSUSTS_MSC1BLAST : MSUSTS_MSC0BLAST; 865 iowrite32(reg, msc->reg_base + REG_MSU_MSUSTS); 866} 867 868static int intel_th_msc_activate(struct intel_th_device *thdev) 869{ 870 struct msc *msc = dev_get_drvdata(&thdev->dev); 871 int ret = -EBUSY; 872 873 if (!atomic_inc_unless_negative(&msc->user_count)) 874 return -ENODEV; 875 876 mutex_lock(&msc->buf_mutex); 877 878 /* if there are readers, refuse */ 879 if (list_empty(&msc->iter_list)) 880 ret = msc_configure(msc); 881 882 mutex_unlock(&msc->buf_mutex); 883 884 if (ret) 885 atomic_dec(&msc->user_count); 886 887 return ret; 888} 889 890static void intel_th_msc_deactivate(struct intel_th_device *thdev) 891{ 892 struct msc *msc = dev_get_drvdata(&thdev->dev); 893 894 mutex_lock(&msc->buf_mutex); 895 if (msc->enabled) { 896 msc_disable(msc); 897 atomic_dec(&msc->user_count); 898 } 899 mutex_unlock(&msc->buf_mutex); 900} 901 902/** 903 * msc_buffer_contig_alloc() - allocate a contiguous buffer for SINGLE mode 904 * @msc: MSC device 905 * @size: allocation size in bytes 906 * 907 * This modifies msc::base, which requires msc::buf_mutex to serialize, so the 908 * caller is expected to hold it. 909 * 910 * Return: 0 on success, -errno otherwise. 911 */ 912static int msc_buffer_contig_alloc(struct msc *msc, unsigned long size) 913{ 914 unsigned long nr_pages = size >> PAGE_SHIFT; 915 unsigned int order = get_order(size); 916 struct page *page; 917 int ret; 918 919 if (!size) 920 return 0; 921 922 ret = sg_alloc_table(&msc->single_sgt, 1, GFP_KERNEL); 923 if (ret) 924 goto err_out; 925 926 ret = -ENOMEM; 927 page = alloc_pages(GFP_KERNEL | __GFP_ZERO | GFP_DMA32, order); 928 if (!page) 929 goto err_free_sgt; 930 931 split_page(page, order); 932 sg_set_buf(msc->single_sgt.sgl, page_address(page), size); 933 934 ret = dma_map_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl, 1, 935 DMA_FROM_DEVICE); 936 if (ret < 0) 937 goto err_free_pages; 938 939 msc->nr_pages = nr_pages; 940 msc->base = page_address(page); 941 msc->base_addr = sg_dma_address(msc->single_sgt.sgl); 942 943 return 0; 944 945err_free_pages: 946 __free_pages(page, order); 947 948err_free_sgt: 949 sg_free_table(&msc->single_sgt); 950 951err_out: 952 return ret; 953} 954 955/** 956 * msc_buffer_contig_free() - free a contiguous buffer 957 * @msc: MSC configured in SINGLE mode 958 */ 959static void msc_buffer_contig_free(struct msc *msc) 960{ 961 unsigned long off; 962 963 dma_unmap_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl, 964 1, DMA_FROM_DEVICE); 965 sg_free_table(&msc->single_sgt); 966 967 for (off = 0; off < msc->nr_pages << PAGE_SHIFT; off += PAGE_SIZE) { 968 struct page *page = virt_to_page(msc->base + off); 969 970 page->mapping = NULL; 971 __free_page(page); 972 } 973 974 msc->nr_pages = 0; 975} 976 977/** 978 * msc_buffer_contig_get_page() - find a page at a given offset 979 * @msc: MSC configured in SINGLE mode 980 * @pgoff: page offset 981 * 982 * Return: page, if @pgoff is within the range, NULL otherwise. 983 */ 984static struct page *msc_buffer_contig_get_page(struct msc *msc, 985 unsigned long pgoff) 986{ 987 if (pgoff >= msc->nr_pages) 988 return NULL; 989 990 return virt_to_page(msc->base + (pgoff << PAGE_SHIFT)); 991} 992 993static int __msc_buffer_win_alloc(struct msc_window *win, 994 unsigned int nr_segs) 995{ 996 struct scatterlist *sg_ptr; 997 void *block; 998 int i, ret; 999 1000 ret = sg_alloc_table(win->sgt, nr_segs, GFP_KERNEL); 1001 if (ret) 1002 return -ENOMEM; 1003 1004 for_each_sg(win->sgt->sgl, sg_ptr, nr_segs, i) { 1005 block = dma_alloc_coherent(msc_dev(win->msc)->parent->parent, 1006 PAGE_SIZE, &sg_dma_address(sg_ptr), 1007 GFP_KERNEL); 1008 if (!block) 1009 goto err_nomem; 1010 1011 sg_set_buf(sg_ptr, block, PAGE_SIZE); 1012 } 1013 1014 return nr_segs; 1015 1016err_nomem: 1017 for_each_sg(win->sgt->sgl, sg_ptr, i, ret) 1018 dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE, 1019 sg_virt(sg_ptr), sg_dma_address(sg_ptr)); 1020 1021 sg_free_table(win->sgt); 1022 1023 return -ENOMEM; 1024} 1025 1026#ifdef CONFIG_X86 1027static void msc_buffer_set_uc(struct msc_window *win, unsigned int nr_segs) 1028{ 1029 struct scatterlist *sg_ptr; 1030 int i; 1031 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)); 1036 } 1037} 1038 1039static void msc_buffer_set_wb(struct msc_window *win) 1040{ 1041 struct scatterlist *sg_ptr; 1042 int i; 1043 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)); 1048 } 1049} 1050#else /* !X86 */ 1051static inline void 1052msc_buffer_set_uc(struct msc_window *win, unsigned int nr_segs) {} 1053static inline void msc_buffer_set_wb(struct msc_window *win) {} 1054#endif /* CONFIG_X86 */ 1055 1056static struct page *msc_sg_page(struct scatterlist *sg) 1057{ 1058 void *addr = sg_virt(sg); 1059 1060 if (is_vmalloc_addr(addr)) 1061 return vmalloc_to_page(addr); 1062 1063 return sg_page(sg); 1064} 1065 1066/** 1067 * msc_buffer_win_alloc() - alloc a window for a multiblock mode 1068 * @msc: MSC device 1069 * @nr_blocks: number of pages in this window 1070 * 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. 1073 * 1074 * Return: 0 on success, -errno otherwise. 1075 */ 1076static int msc_buffer_win_alloc(struct msc *msc, unsigned int nr_blocks) 1077{ 1078 struct msc_window *win; 1079 int ret = -ENOMEM; 1080 1081 if (!nr_blocks) 1082 return 0; 1083 1084 win = kzalloc(sizeof(*win), GFP_KERNEL); 1085 if (!win) 1086 return -ENOMEM; 1087 1088 win->msc = msc; 1089 win->sgt = &win->_sgt; 1090 win->lockout = WIN_READY; 1091 spin_lock_init(&win->lo_lock); 1092 1093 if (!list_empty(&msc->win_list)) { 1094 struct msc_window *prev = list_last_entry(&msc->win_list, 1095 struct msc_window, 1096 entry); 1097 1098 win->pgoff = prev->pgoff + prev->nr_blocks; 1099 } 1100 1101 if (msc->mbuf && msc->mbuf->alloc_window) 1102 ret = msc->mbuf->alloc_window(msc->mbuf_priv, &win->sgt, 1103 nr_blocks << PAGE_SHIFT); 1104 else 1105 ret = __msc_buffer_win_alloc(win, nr_blocks); 1106 1107 if (ret <= 0) 1108 goto err_nomem; 1109 1110 msc_buffer_set_uc(win, ret); 1111 1112 win->nr_segs = ret; 1113 win->nr_blocks = nr_blocks; 1114 1115 if (list_empty(&msc->win_list)) { 1116 msc->base = msc_win_base(win); 1117 msc->base_addr = msc_win_base_dma(win); 1118 msc->cur_win = win; 1119 } 1120 1121 list_add_tail(&win->entry, &msc->win_list); 1122 msc->nr_pages += nr_blocks; 1123 1124 return 0; 1125 1126err_nomem: 1127 kfree(win); 1128 1129 return ret; 1130} 1131 1132static void __msc_buffer_win_free(struct msc *msc, struct msc_window *win) 1133{ 1134 struct scatterlist *sg; 1135 int i; 1136 1137 for_each_sg(win->sgt->sgl, sg, win->nr_segs, i) { 1138 struct page *page = msc_sg_page(sg); 1139 1140 page->mapping = NULL; 1141 dma_free_coherent(msc_dev(win->msc)->parent->parent, PAGE_SIZE, 1142 sg_virt(sg), sg_dma_address(sg)); 1143 } 1144 sg_free_table(win->sgt); 1145} 1146 1147/** 1148 * msc_buffer_win_free() - free a window from MSC's window list 1149 * @msc: MSC device 1150 * @win: window to free 1151 * 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. 1154 */ 1155static void msc_buffer_win_free(struct msc *msc, struct msc_window *win) 1156{ 1157 msc->nr_pages -= win->nr_blocks; 1158 1159 list_del(&win->entry); 1160 if (list_empty(&msc->win_list)) { 1161 msc->base = NULL; 1162 msc->base_addr = 0; 1163 } 1164 1165 msc_buffer_set_wb(win); 1166 1167 if (msc->mbuf && msc->mbuf->free_window) 1168 msc->mbuf->free_window(msc->mbuf_priv, win->sgt); 1169 else 1170 __msc_buffer_win_free(msc, win); 1171 1172 kfree(win); 1173} 1174 1175/** 1176 * msc_buffer_relink() - set up block descriptors for multiblock mode 1177 * @msc: MSC device 1178 * 1179 * This traverses msc::win_list, which requires msc::buf_mutex to serialize, 1180 * so the caller is expected to hold it. 1181 */ 1182static void msc_buffer_relink(struct msc *msc) 1183{ 1184 struct msc_window *win, *next_win; 1185 1186 /* call with msc::mutex locked */ 1187 list_for_each_entry(win, &msc->win_list, entry) { 1188 struct scatterlist *sg; 1189 unsigned int blk; 1190 u32 sw_tag = 0; 1191 1192 /* 1193 * Last window's next_win should point to the first window 1194 * and MSC_SW_TAG_LASTWIN should be set. 1195 */ 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); 1200 } else { 1201 next_win = list_next_entry(win, entry); 1202 } 1203 1204 for_each_sg(win->sgt->sgl, sg, win->nr_segs, blk) { 1205 struct msc_block_desc *bdesc = sg_virt(sg); 1206 1207 memset(bdesc, 0, sizeof(*bdesc)); 1208 1209 bdesc->next_win = msc_win_base_pfn(next_win); 1210 1211 /* 1212 * Similarly to last window, last block should point 1213 * to the first one. 1214 */ 1215 if (blk == win->nr_segs - 1) { 1216 sw_tag |= MSC_SW_TAG_LASTBLK; 1217 bdesc->next_blk = msc_win_base_pfn(win); 1218 } else { 1219 dma_addr_t addr = sg_dma_address(sg_next(sg)); 1220 1221 bdesc->next_blk = PFN_DOWN(addr); 1222 } 1223 1224 bdesc->sw_tag = sw_tag; 1225 bdesc->block_sz = sg->length / 64; 1226 } 1227 } 1228 1229 /* 1230 * Make the above writes globally visible before tracing is 1231 * enabled to make sure hardware sees them coherently. 1232 */ 1233 wmb(); 1234} 1235 1236static void msc_buffer_multi_free(struct msc *msc) 1237{ 1238 struct msc_window *win, *iter; 1239 1240 list_for_each_entry_safe(win, iter, &msc->win_list, entry) 1241 msc_buffer_win_free(msc, win); 1242} 1243 1244static int msc_buffer_multi_alloc(struct msc *msc, unsigned long *nr_pages, 1245 unsigned int nr_wins) 1246{ 1247 int ret, i; 1248 1249 for (i = 0; i < nr_wins; i++) { 1250 ret = msc_buffer_win_alloc(msc, nr_pages[i]); 1251 if (ret) { 1252 msc_buffer_multi_free(msc); 1253 return ret; 1254 } 1255 } 1256 1257 msc_buffer_relink(msc); 1258 1259 return 0; 1260} 1261 1262/** 1263 * msc_buffer_free() - free buffers for MSC 1264 * @msc: MSC device 1265 * 1266 * Free MSC's storage buffers. 1267 * 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. 1270 */ 1271static void msc_buffer_free(struct msc *msc) 1272{ 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); 1277} 1278 1279/** 1280 * msc_buffer_alloc() - allocate a buffer for MSC 1281 * @msc: MSC device 1282 * @size: allocation size in bytes 1283 * 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. 1289 * 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. 1292 * 1293 * Return: 0 on success, -errno otherwise. 1294 */ 1295static int msc_buffer_alloc(struct msc *msc, unsigned long *nr_pages, 1296 unsigned int nr_wins) 1297{ 1298 int ret; 1299 1300 /* -1: buffer not allocated */ 1301 if (atomic_read(&msc->user_count) != -1) 1302 return -EBUSY; 1303 1304 if (msc->mode == MSC_MODE_SINGLE) { 1305 if (nr_wins != 1) 1306 return -EINVAL; 1307 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); 1311 } else { 1312 ret = -EINVAL; 1313 } 1314 1315 if (!ret) { 1316 /* allocation should be visible before the counter goes to 0 */ 1317 smp_mb__before_atomic(); 1318 1319 if (WARN_ON_ONCE(atomic_cmpxchg(&msc->user_count, -1, 0) != -1)) 1320 return -EINVAL; 1321 } 1322 1323 return ret; 1324} 1325 1326/** 1327 * msc_buffer_unlocked_free_unless_used() - free a buffer unless it's in use 1328 * @msc: MSC device 1329 * 1330 * This will free MSC buffer unless it is in use or there is no allocated 1331 * buffer. 1332 * Caller needs to hold msc::buf_mutex. 1333 * 1334 * Return: 0 on successful deallocation or if there was no buffer to 1335 * deallocate, -EBUSY if there are active users. 1336 */ 1337static int msc_buffer_unlocked_free_unless_used(struct msc *msc) 1338{ 1339 int count, ret = 0; 1340 1341 count = atomic_cmpxchg(&msc->user_count, 0, -1); 1342 1343 /* > 0: buffer is allocated and has users */ 1344 if (count > 0) 1345 ret = -EBUSY; 1346 /* 0: buffer is allocated, no users */ 1347 else if (!count) 1348 msc_buffer_free(msc); 1349 /* < 0: no buffer, nothing to do */ 1350 1351 return ret; 1352} 1353 1354/** 1355 * msc_buffer_free_unless_used() - free a buffer unless it's in use 1356 * @msc: MSC device 1357 * 1358 * This is a locked version of msc_buffer_unlocked_free_unless_used(). 1359 */ 1360static int msc_buffer_free_unless_used(struct msc *msc) 1361{ 1362 int ret; 1363 1364 mutex_lock(&msc->buf_mutex); 1365 ret = msc_buffer_unlocked_free_unless_used(msc); 1366 mutex_unlock(&msc->buf_mutex); 1367 1368 return ret; 1369} 1370 1371/** 1372 * msc_buffer_get_page() - get MSC buffer page at a given offset 1373 * @msc: MSC device 1374 * @pgoff: page offset into the storage buffer 1375 * 1376 * This traverses msc::win_list, so holding msc::buf_mutex is expected from 1377 * the caller. 1378 * 1379 * Return: page if @pgoff corresponds to a valid buffer page or NULL. 1380 */ 1381static struct page *msc_buffer_get_page(struct msc *msc, unsigned long pgoff) 1382{ 1383 struct msc_window *win; 1384 struct scatterlist *sg; 1385 unsigned int blk; 1386 1387 if (msc->mode == MSC_MODE_SINGLE) 1388 return msc_buffer_contig_get_page(msc, pgoff); 1389 1390 list_for_each_entry(win, &msc->win_list, entry) 1391 if (pgoff >= win->pgoff && pgoff < win->pgoff + win->nr_blocks) 1392 goto found; 1393 1394 return NULL; 1395 1396found: 1397 pgoff -= win->pgoff; 1398 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); 1402 1403 if (pgoff < pgsz) 1404 return page + pgoff; 1405 1406 pgoff -= pgsz; 1407 } 1408 1409 return NULL; 1410} 1411 1412/** 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 1416 */ 1417struct msc_win_to_user_struct { 1418 char __user *buf; 1419 unsigned long offset; 1420}; 1421 1422/** 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 1427 */ 1428static unsigned long msc_win_to_user(void *data, void *src, size_t len) 1429{ 1430 struct msc_win_to_user_struct *u = data; 1431 unsigned long ret; 1432 1433 ret = copy_to_user(u->buf + u->offset, src, len); 1434 u->offset += len - ret; 1435 1436 return ret; 1437} 1438 1439 1440/* 1441 * file operations' callbacks 1442 */ 1443 1444static int intel_th_msc_open(struct inode *inode, struct file *file) 1445{ 1446 struct intel_th_device *thdev = file->private_data; 1447 struct msc *msc = dev_get_drvdata(&thdev->dev); 1448 struct msc_iter *iter; 1449 1450 if (!capable(CAP_SYS_RAWIO)) 1451 return -EPERM; 1452 1453 iter = msc_iter_install(msc); 1454 if (IS_ERR(iter)) 1455 return PTR_ERR(iter); 1456 1457 file->private_data = iter; 1458 1459 return nonseekable_open(inode, file); 1460} 1461 1462static int intel_th_msc_release(struct inode *inode, struct file *file) 1463{ 1464 struct msc_iter *iter = file->private_data; 1465 struct msc *msc = iter->msc; 1466 1467 msc_iter_remove(iter, msc); 1468 1469 return 0; 1470} 1471 1472static ssize_t 1473msc_single_to_user(struct msc *msc, char __user *buf, loff_t off, size_t len) 1474{ 1475 unsigned long size = msc->nr_pages << PAGE_SHIFT, rem = len; 1476 unsigned long start = off, tocopy = 0; 1477 1478 if (msc->single_wrap) { 1479 start += msc->single_sz; 1480 if (start < size) { 1481 tocopy = min(rem, size - start); 1482 if (copy_to_user(buf, msc->base + start, tocopy)) 1483 return -EFAULT; 1484 1485 buf += tocopy; 1486 rem -= tocopy; 1487 start += tocopy; 1488 } 1489 1490 start &= size - 1; 1491 if (rem) { 1492 tocopy = min(rem, msc->single_sz - start); 1493 if (copy_to_user(buf, msc->base + start, tocopy)) 1494 return -EFAULT; 1495 1496 rem -= tocopy; 1497 } 1498 1499 return len - rem; 1500 } 1501 1502 if (copy_to_user(buf, msc->base + start, rem)) 1503 return -EFAULT; 1504 1505 return len; 1506} 1507 1508static ssize_t intel_th_msc_read(struct file *file, char __user *buf, 1509 size_t len, loff_t *ppos) 1510{ 1511 struct msc_iter *iter = file->private_data; 1512 struct msc *msc = iter->msc; 1513 size_t size; 1514 loff_t off = *ppos; 1515 ssize_t ret = 0; 1516 1517 if (!atomic_inc_unless_negative(&msc->user_count)) 1518 return 0; 1519 1520 if (msc->mode == MSC_MODE_SINGLE && !msc->single_wrap) 1521 size = msc->single_sz; 1522 else 1523 size = msc->nr_pages << PAGE_SHIFT; 1524 1525 if (!size) 1526 goto put_count; 1527 1528 if (off >= size) 1529 goto put_count; 1530 1531 if (off + len >= size) 1532 len = size - off; 1533 1534 if (msc->mode == MSC_MODE_SINGLE) { 1535 ret = msc_single_to_user(msc, buf, off, len); 1536 if (ret >= 0) 1537 *ppos += ret; 1538 } else if (msc->mode == MSC_MODE_MULTI) { 1539 struct msc_win_to_user_struct u = { 1540 .buf = buf, 1541 .offset = 0, 1542 }; 1543 1544 ret = msc_buffer_iterate(iter, len, &u, msc_win_to_user); 1545 if (ret >= 0) 1546 *ppos = iter->offset; 1547 } else { 1548 ret = -EINVAL; 1549 } 1550 1551put_count: 1552 atomic_dec(&msc->user_count); 1553 1554 return ret; 1555} 1556 1557/* 1558 * vm operations callbacks (vm_ops) 1559 */ 1560 1561static void msc_mmap_open(struct vm_area_struct *vma) 1562{ 1563 struct msc_iter *iter = vma->vm_file->private_data; 1564 struct msc *msc = iter->msc; 1565 1566 atomic_inc(&msc->mmap_count); 1567} 1568 1569static void msc_mmap_close(struct vm_area_struct *vma) 1570{ 1571 struct msc_iter *iter = vma->vm_file->private_data; 1572 struct msc *msc = iter->msc; 1573 unsigned long pg; 1574 1575 if (!atomic_dec_and_mutex_lock(&msc->mmap_count, &msc->buf_mutex)) 1576 return; 1577 1578 /* drop page _refcounts */ 1579 for (pg = 0; pg < msc->nr_pages; pg++) { 1580 struct page *page = msc_buffer_get_page(msc, pg); 1581 1582 if (WARN_ON_ONCE(!page)) 1583 continue; 1584 1585 if (page->mapping) 1586 page->mapping = NULL; 1587 } 1588 1589 /* last mapping -- drop user_count */ 1590 atomic_dec(&msc->user_count); 1591 mutex_unlock(&msc->buf_mutex); 1592} 1593 1594static vm_fault_t msc_mmap_fault(struct vm_fault *vmf) 1595{ 1596 struct msc_iter *iter = vmf->vma->vm_file->private_data; 1597 struct msc *msc = iter->msc; 1598 1599 vmf->page = msc_buffer_get_page(msc, vmf->pgoff); 1600 if (!vmf->page) 1601 return VM_FAULT_SIGBUS; 1602 1603 get_page(vmf->page); 1604 vmf->page->mapping = vmf->vma->vm_file->f_mapping; 1605 vmf->page->index = vmf->pgoff; 1606 1607 return 0; 1608} 1609 1610static const struct vm_operations_struct msc_mmap_ops = { 1611 .open = msc_mmap_open, 1612 .close = msc_mmap_close, 1613 .fault = msc_mmap_fault, 1614}; 1615 1616static int intel_th_msc_mmap(struct file *file, struct vm_area_struct *vma) 1617{ 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; 1621 int ret = -EINVAL; 1622 1623 if (!size || offset_in_page(size)) 1624 return -EINVAL; 1625 1626 if (vma->vm_pgoff) 1627 return -EINVAL; 1628 1629 /* grab user_count once per mmap; drop in msc_mmap_close() */ 1630 if (!atomic_inc_unless_negative(&msc->user_count)) 1631 return -EINVAL; 1632 1633 if (msc->mode != MSC_MODE_SINGLE && 1634 msc->mode != MSC_MODE_MULTI) 1635 goto out; 1636 1637 if (size >> PAGE_SHIFT != msc->nr_pages) 1638 goto out; 1639 1640 atomic_set(&msc->mmap_count, 1); 1641 ret = 0; 1642 1643out: 1644 if (ret) 1645 atomic_dec(&msc->user_count); 1646 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; 1650 return ret; 1651} 1652 1653static 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, 1660}; 1661 1662static void intel_th_msc_wait_empty(struct intel_th_device *thdev) 1663{ 1664 struct msc *msc = dev_get_drvdata(&thdev->dev); 1665 unsigned long count; 1666 u32 reg; 1667 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); 1671 cpu_relax(); 1672 } 1673 1674 if (!count) 1675 dev_dbg(msc_dev(msc), "timeout waiting for MSC0 PLE\n"); 1676} 1677 1678static int intel_th_msc_init(struct msc *msc) 1679{ 1680 atomic_set(&msc->user_count, -1); 1681 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); 1686 1687 msc->burst_len = 1688 (ioread32(msc->reg_base + REG_MSU_MSC0CTL) & MSC_LEN) >> 1689 __ffs(MSC_LEN); 1690 1691 return 0; 1692} 1693 1694static int msc_win_switch(struct msc *msc) 1695{ 1696 struct msc_window *first; 1697 1698 if (list_empty(&msc->win_list)) 1699 return -EINVAL; 1700 1701 first = list_first_entry(&msc->win_list, struct msc_window, entry); 1702 1703 if (msc_is_last_win(msc->cur_win)) 1704 msc->cur_win = first; 1705 else 1706 msc->cur_win = list_next_entry(msc->cur_win, entry); 1707 1708 msc->base = msc_win_base(msc->cur_win); 1709 msc->base_addr = msc_win_base_dma(msc->cur_win); 1710 1711 intel_th_trace_switch(msc->thdev); 1712 1713 return 0; 1714} 1715 1716/** 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 1720 */ 1721void intel_th_msc_window_unlock(struct device *dev, struct sg_table *sgt) 1722{ 1723 struct msc *msc = dev_get_drvdata(dev); 1724 struct msc_window *win; 1725 1726 if (!sgt) 1727 return; 1728 1729 win = msc_find_window(msc, sgt, false); 1730 if (!win) 1731 return; 1732 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); 1737 } 1738} 1739EXPORT_SYMBOL_GPL(intel_th_msc_window_unlock); 1740 1741static void msc_work(struct work_struct *work) 1742{ 1743 struct msc *msc = container_of(work, struct msc, work); 1744 1745 intel_th_msc_deactivate(msc->thdev); 1746} 1747 1748static irqreturn_t intel_th_msc_interrupt(struct intel_th_device *thdev) 1749{ 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; 1754 1755 if (!msc->do_irq || !msc->mbuf) 1756 return IRQ_NONE; 1757 1758 msusts &= mask; 1759 1760 if (!msusts) 1761 return msc->enabled ? IRQ_HANDLED : IRQ_NONE; 1762 1763 iowrite32(msusts, msc->msu_base + REG_MSU_MSUSTS); 1764 1765 if (!msc->enabled) 1766 return IRQ_NONE; 1767 1768 /* grab the window before we do the switch */ 1769 win = msc->cur_win; 1770 if (!win) 1771 return IRQ_HANDLED; 1772 next_win = msc_next_window(win); 1773 if (!next_win) 1774 return IRQ_HANDLED; 1775 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); 1780 else 1781 msc->switch_on_unlock = next_win; 1782 1783 return IRQ_HANDLED; 1784 } 1785 1786 /* current window: INUSE -> LOCKED */ 1787 msc_win_set_lockout(win, WIN_INUSE, WIN_LOCKED); 1788 1789 msc_win_switch(msc); 1790 1791 if (msc->mbuf && msc->mbuf->ready) 1792 msc->mbuf->ready(msc->mbuf_priv, win->sgt, 1793 msc_win_total_sz(win)); 1794 1795 return IRQ_HANDLED; 1796} 1797 1798static 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", 1803}; 1804 1805static ssize_t 1806wrap_show(struct device *dev, struct device_attribute *attr, char *buf) 1807{ 1808 struct msc *msc = dev_get_drvdata(dev); 1809 1810 return scnprintf(buf, PAGE_SIZE, "%d\n", msc->wrap); 1811} 1812 1813static ssize_t 1814wrap_store(struct device *dev, struct device_attribute *attr, const char *buf, 1815 size_t size) 1816{ 1817 struct msc *msc = dev_get_drvdata(dev); 1818 unsigned long val; 1819 int ret; 1820 1821 ret = kstrtoul(buf, 10, &val); 1822 if (ret) 1823 return ret; 1824 1825 msc->wrap = !!val; 1826 1827 return size; 1828} 1829 1830static DEVICE_ATTR_RW(wrap); 1831 1832static void msc_buffer_unassign(struct msc *msc) 1833{ 1834 lockdep_assert_held(&msc->buf_mutex); 1835 1836 if (!msc->mbuf) 1837 return; 1838 1839 msc->mbuf->unassign(msc->mbuf_priv); 1840 msu_buffer_put(msc->mbuf); 1841 msc->mbuf_priv = NULL; 1842 msc->mbuf = NULL; 1843} 1844 1845static ssize_t 1846mode_show(struct device *dev, struct device_attribute *attr, char *buf) 1847{ 1848 struct msc *msc = dev_get_drvdata(dev); 1849 const char *mode = msc_mode[msc->mode]; 1850 ssize_t ret; 1851 1852 mutex_lock(&msc->buf_mutex); 1853 if (msc->mbuf) 1854 mode = msc->mbuf->name; 1855 ret = scnprintf(buf, PAGE_SIZE, "%s\n", mode); 1856 mutex_unlock(&msc->buf_mutex); 1857 1858 return ret; 1859} 1860 1861static ssize_t 1862mode_store(struct device *dev, struct device_attribute *attr, const char *buf, 1863 size_t size) 1864{ 1865 const struct msu_buffer *mbuf = NULL; 1866 struct msc *msc = dev_get_drvdata(dev); 1867 size_t len = size; 1868 char *cp, *mode; 1869 int i, ret; 1870 1871 if (!capable(CAP_SYS_RAWIO)) 1872 return -EPERM; 1873 1874 cp = memchr(buf, '\n', len); 1875 if (cp) 1876 len = cp - buf; 1877 1878 mode = kstrndup(buf, len, GFP_KERNEL); 1879 if (!mode) 1880 return -ENOMEM; 1881 1882 i = match_string(msc_mode, ARRAY_SIZE(msc_mode), mode); 1883 if (i >= 0) { 1884 kfree(mode); 1885 goto found; 1886 } 1887 1888 /* Buffer sinks only work with a usable IRQ */ 1889 if (!msc->do_irq) { 1890 kfree(mode); 1891 return -EINVAL; 1892 } 1893 1894 mbuf = msu_buffer_get(mode); 1895 kfree(mode); 1896 if (mbuf) 1897 goto found; 1898 1899 return -EINVAL; 1900 1901found: 1902 if (i == MSC_MODE_MULTI && msc->multi_is_broken) 1903 return -EOPNOTSUPP; 1904 1905 mutex_lock(&msc->buf_mutex); 1906 ret = 0; 1907 1908 /* Same buffer: do nothing */ 1909 if (mbuf && mbuf == msc->mbuf) { 1910 /* put the extra reference we just got */ 1911 msu_buffer_put(mbuf); 1912 goto unlock; 1913 } 1914 1915 ret = msc_buffer_unlocked_free_unless_used(msc); 1916 if (ret) 1917 goto unlock; 1918 1919 if (mbuf) { 1920 void *mbuf_priv = mbuf->assign(dev, &i); 1921 1922 if (!mbuf_priv) { 1923 ret = -ENOMEM; 1924 goto unlock; 1925 } 1926 1927 msc_buffer_unassign(msc); 1928 msc->mbuf_priv = mbuf_priv; 1929 msc->mbuf = mbuf; 1930 } else { 1931 msc_buffer_unassign(msc); 1932 } 1933 1934 msc->mode = i; 1935 1936unlock: 1937 if (ret && mbuf) 1938 msu_buffer_put(mbuf); 1939 mutex_unlock(&msc->buf_mutex); 1940 1941 return ret ? ret : size; 1942} 1943 1944static DEVICE_ATTR_RW(mode); 1945 1946static ssize_t 1947nr_pages_show(struct device *dev, struct device_attribute *attr, char *buf) 1948{ 1949 struct msc *msc = dev_get_drvdata(dev); 1950 struct msc_window *win; 1951 size_t count = 0; 1952 1953 mutex_lock(&msc->buf_mutex); 1954 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' : ','); 1962 } 1963 } else { 1964 count = scnprintf(buf, PAGE_SIZE, "unsupported\n"); 1965 } 1966 1967 mutex_unlock(&msc->buf_mutex); 1968 1969 return count; 1970} 1971 1972static ssize_t 1973nr_pages_store(struct device *dev, struct device_attribute *attr, 1974 const char *buf, size_t size) 1975{ 1976 struct msc *msc = dev_get_drvdata(dev); 1977 unsigned long val, *win = NULL, *rewin; 1978 size_t len = size; 1979 const char *p = buf; 1980 char *end, *s; 1981 int ret, nr_wins = 0; 1982 1983 if (!capable(CAP_SYS_RAWIO)) 1984 return -EPERM; 1985 1986 ret = msc_buffer_free_unless_used(msc); 1987 if (ret) 1988 return ret; 1989 1990 /* scan the comma-separated list of allocation sizes */ 1991 end = memchr(buf, '\n', len); 1992 if (end) 1993 len = end - buf; 1994 1995 do { 1996 end = memchr(p, ',', len); 1997 s = kstrndup(p, end ? end - p : len, GFP_KERNEL); 1998 if (!s) { 1999 ret = -ENOMEM; 2000 goto free_win; 2001 } 2002 2003 ret = kstrtoul(s, 10, &val); 2004 kfree(s); 2005 2006 if (ret || !val) 2007 goto free_win; 2008 2009 if (nr_wins && msc->mode == MSC_MODE_SINGLE) { 2010 ret = -EINVAL; 2011 goto free_win; 2012 } 2013 2014 nr_wins++; 2015 rewin = krealloc(win, sizeof(*win) * nr_wins, GFP_KERNEL); 2016 if (!rewin) { 2017 kfree(win); 2018 return -ENOMEM; 2019 } 2020 2021 win = rewin; 2022 win[nr_wins - 1] = val; 2023 2024 if (!end) 2025 break; 2026 2027 /* consume the number and the following comma, hence +1 */ 2028 len -= end - p + 1; 2029 p = end + 1; 2030 } while (len); 2031 2032 mutex_lock(&msc->buf_mutex); 2033 ret = msc_buffer_alloc(msc, win, nr_wins); 2034 mutex_unlock(&msc->buf_mutex); 2035 2036free_win: 2037 kfree(win); 2038 2039 return ret ? ret : size; 2040} 2041 2042static DEVICE_ATTR_RW(nr_pages); 2043 2044static ssize_t 2045win_switch_store(struct device *dev, struct device_attribute *attr, 2046 const char *buf, size_t size) 2047{ 2048 struct msc *msc = dev_get_drvdata(dev); 2049 unsigned long val; 2050 int ret; 2051 2052 ret = kstrtoul(buf, 10, &val); 2053 if (ret) 2054 return ret; 2055 2056 if (val != 1) 2057 return -EINVAL; 2058 2059 ret = -EINVAL; 2060 mutex_lock(&msc->buf_mutex); 2061 /* 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. 2065 */ 2066 if (msc->mode == MSC_MODE_MULTI && !msc->mbuf) 2067 ret = msc_win_switch(msc); 2068 mutex_unlock(&msc->buf_mutex); 2069 2070 return ret ? ret : size; 2071} 2072 2073static DEVICE_ATTR_WO(win_switch); 2074 2075static ssize_t stop_on_full_show(struct device *dev, 2076 struct device_attribute *attr, char *buf) 2077{ 2078 struct msc *msc = dev_get_drvdata(dev); 2079 2080 return sprintf(buf, "%d\n", msc->stop_on_full); 2081} 2082 2083static ssize_t stop_on_full_store(struct device *dev, 2084 struct device_attribute *attr, 2085 const char *buf, size_t size) 2086{ 2087 struct msc *msc = dev_get_drvdata(dev); 2088 int ret; 2089 2090 ret = kstrtobool(buf, &msc->stop_on_full); 2091 if (ret) 2092 return ret; 2093 2094 return size; 2095} 2096 2097static DEVICE_ATTR_RW(stop_on_full); 2098 2099static 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, 2105 NULL, 2106}; 2107 2108static struct attribute_group msc_output_group = { 2109 .attrs = msc_output_attrs, 2110}; 2111 2112static int intel_th_msc_probe(struct intel_th_device *thdev) 2113{ 2114 struct device *dev = &thdev->dev; 2115 struct resource *res; 2116 struct msc *msc; 2117 void __iomem *base; 2118 int err; 2119 2120 res = intel_th_device_get_resource(thdev, IORESOURCE_MEM, 0); 2121 if (!res) 2122 return -ENODEV; 2123 2124 base = devm_ioremap(dev, res->start, resource_size(res)); 2125 if (!base) 2126 return -ENOMEM; 2127 2128 msc = devm_kzalloc(dev, sizeof(*msc), GFP_KERNEL); 2129 if (!msc) 2130 return -ENOMEM; 2131 2132 res = intel_th_device_get_resource(thdev, IORESOURCE_IRQ, 1); 2133 if (!res) 2134 msc->do_irq = 1; 2135 2136 if (INTEL_TH_CAP(to_intel_th(thdev), multi_is_broken)) 2137 msc->multi_is_broken = 1; 2138 2139 msc->index = thdev->id; 2140 2141 msc->thdev = thdev; 2142 msc->reg_base = base + msc->index * 0x100; 2143 msc->msu_base = base; 2144 2145 INIT_WORK(&msc->work, msc_work); 2146 err = intel_th_msc_init(msc); 2147 if (err) 2148 return err; 2149 2150 dev_set_drvdata(dev, msc); 2151 2152 return 0; 2153} 2154 2155static void intel_th_msc_remove(struct intel_th_device *thdev) 2156{ 2157 struct msc *msc = dev_get_drvdata(&thdev->dev); 2158 int ret; 2159 2160 intel_th_msc_deactivate(thdev); 2161 2162 /* 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. 2166 */ 2167 ret = msc_buffer_free_unless_used(msc); 2168 WARN_ON_ONCE(ret); 2169} 2170 2171static 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, 2180 .driver = { 2181 .name = "msc", 2182 .owner = THIS_MODULE, 2183 }, 2184}; 2185 2186module_driver(intel_th_msc_driver, 2187 intel_th_driver_register, 2188 intel_th_driver_unregister); 2189 2190MODULE_LICENSE("GPL v2"); 2191MODULE_DESCRIPTION("Intel(R) Trace Hub Memory Storage Unit driver"); 2192MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>"); 2193