drivers/hwtracing/intel

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

DEFINITIONS
