drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c

   1 /**
   2  * Copyright (c) 2010-2012 Broadcom. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions, and the following disclaimer,
   9  *    without modification.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The names of the above-listed copyright holders may not be used
  14  *    to endorse or promote products derived from this software without
  15  *    specific prior written permission.
  16  *
  17  * ALTERNATIVELY, this software may be distributed under the terms of the
  18  * GNU General Public License ("GPL") version 2, as published by the Free
  19  * Software Foundation.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  22  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  23  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  24  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  25  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  26  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  27  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  28  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  29  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  30  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  31  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <linux/kernel.h>
  35 #include <linux/types.h>
  36 #include <linux/errno.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/pagemap.h>
  39 #include <linux/dma-mapping.h>
  40 #include <linux/io.h>
  41 #include <linux/platform_device.h>
  42 #include <linux/uaccess.h>
  43 #include <linux/mm.h>
  44 #include <linux/of.h>
  45 #include <soc/bcm2835/raspberrypi-firmware.h>
  46
  47 #define TOTAL_SLOTS (VCHIQ_SLOT_ZERO_SLOTS + 2 * 32)
  48
  49 #include "vchiq_arm.h"
  50 #include "vchiq_connected.h"
  51 #include "vchiq_killable.h"
  52 #include "vchiq_pagelist.h"
  53
  54 #define MAX_FRAGMENTS (VCHIQ_NUM_CURRENT_BULKS * 2)
  55
  56 #define VCHIQ_PLATFORM_FRAGMENTS_OFFSET_IDX 0
  57 #define VCHIQ_PLATFORM_FRAGMENTS_COUNT_IDX  1
  58
  59 #define BELL0   0x00
  60 #define BELL2   0x08
  61
  62 typedef struct vchiq_2835_state_struct {
  63         int inited;
  64         VCHIQ_ARM_STATE_T arm_state;
  65 } VCHIQ_2835_ARM_STATE_T;
  66
  67 struct vchiq_pagelist_info {
  68         PAGELIST_T *pagelist;
  69         size_t pagelist_buffer_size;
  70         dma_addr_t dma_addr;
  71         enum dma_data_direction dma_dir;
  72         unsigned int num_pages;
  73         unsigned int pages_need_release;
  74         struct page **pages;
  75         struct scatterlist *scatterlist;
  76         unsigned int scatterlist_mapped;
  77 };
  78
  79 static void __iomem *g_regs;
  80 static unsigned int g_cache_line_size = sizeof(CACHE_LINE_SIZE);
  81 static unsigned int g_fragments_size;
  82 static char *g_fragments_base;
  83 static char *g_free_fragments;
  84 static struct semaphore g_free_fragments_sema;
  85 static struct device *g_dev;
  86
  87 extern int vchiq_arm_log_level;
  88
  89 static DEFINE_SEMAPHORE(g_free_fragments_mutex);
  90
  91 static irqreturn_t
  92 vchiq_doorbell_irq(int irq, void *dev_id);
  93
  94 static struct vchiq_pagelist_info *
  95 create_pagelist(char __user *buf, size_t count, unsigned short type);
  96
  97 static void
  98 free_pagelist(struct vchiq_pagelist_info *pagelistinfo,
  99               int actual);
 100
 101 int vchiq_platform_init(struct platform_device *pdev, VCHIQ_STATE_T *state)
 102 {
 103         struct device *dev = &pdev->dev;
 104         struct rpi_firmware *fw = platform_get_drvdata(pdev);
 105         VCHIQ_SLOT_ZERO_T *vchiq_slot_zero;
 106         struct resource *res;
 107         void *slot_mem;
 108         dma_addr_t slot_phys;
 109         u32 channelbase;
 110         int slot_mem_size, frag_mem_size;
 111         int err, irq, i;
 112
 113         /*
 114          * VCHI messages between the CPU and firmware use
 115          * 32-bit bus addresses.
 116          */
 117         err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
 118
 119         if (err < 0)
 120                 return err;
 121
 122         err = of_property_read_u32(dev->of_node, "cache-line-size",
 123                                    &g_cache_line_size);
 124
 125         if (err) {
 126                 dev_err(dev, "Missing cache-line-size property\n");
 127                 return -ENODEV;
 128         }
 129
 130         g_fragments_size = 2 * g_cache_line_size;
 131
 132         /* Allocate space for the channels in coherent memory */
 133         slot_mem_size = PAGE_ALIGN(TOTAL_SLOTS * VCHIQ_SLOT_SIZE);
 134         frag_mem_size = PAGE_ALIGN(g_fragments_size * MAX_FRAGMENTS);
 135
 136         slot_mem = dmam_alloc_coherent(dev, slot_mem_size + frag_mem_size,
 137                                        &slot_phys, GFP_KERNEL);
 138         if (!slot_mem) {
 139                 dev_err(dev, "could not allocate DMA memory\n");
 140                 return -ENOMEM;
 141         }
 142
 143         WARN_ON(((unsigned long)slot_mem & (PAGE_SIZE - 1)) != 0);
 144
 145         vchiq_slot_zero = vchiq_init_slots(slot_mem, slot_mem_size);
 146         if (!vchiq_slot_zero)
 147                 return -EINVAL;
 148
 149         vchiq_slot_zero->platform_data[VCHIQ_PLATFORM_FRAGMENTS_OFFSET_IDX] =
 150                 (int)slot_phys + slot_mem_size;
 151         vchiq_slot_zero->platform_data[VCHIQ_PLATFORM_FRAGMENTS_COUNT_IDX] =
 152                 MAX_FRAGMENTS;
 153
 154         g_fragments_base = (char *)slot_mem + slot_mem_size;
 155
 156         g_free_fragments = g_fragments_base;
 157         for (i = 0; i < (MAX_FRAGMENTS - 1); i++) {
 158                 *(char **)&g_fragments_base[i*g_fragments_size] =
 159                         &g_fragments_base[(i + 1)*g_fragments_size];
 160         }
 161         *(char **)&g_fragments_base[i * g_fragments_size] = NULL;
 162         sema_init(&g_free_fragments_sema, MAX_FRAGMENTS);
 163
 164         if (vchiq_init_state(state, vchiq_slot_zero, 0) != VCHIQ_SUCCESS)
 165                 return -EINVAL;
 166
 167         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 168         g_regs = devm_ioremap_resource(&pdev->dev, res);
 169         if (IS_ERR(g_regs))
 170                 return PTR_ERR(g_regs);
 171
 172         irq = platform_get_irq(pdev, 0);
 173         if (irq <= 0) {
 174                 dev_err(dev, "failed to get IRQ\n");
 175                 return irq;
 176         }
 177
 178         err = devm_request_irq(dev, irq, vchiq_doorbell_irq, IRQF_IRQPOLL,
 179                                "VCHIQ doorbell", state);
 180         if (err) {
 181                 dev_err(dev, "failed to register irq=%d\n", irq);
 182                 return err;
 183         }
 184
 185         /* Send the base address of the slots to VideoCore */
 186         channelbase = slot_phys;
 187         err = rpi_firmware_property(fw, RPI_FIRMWARE_VCHIQ_INIT,
 188                                     &channelbase, sizeof(channelbase));
 189         if (err || channelbase) {
 190                 dev_err(dev, "failed to set channelbase\n");
 191                 return err ? : -ENXIO;
 192         }
 193
 194         g_dev = dev;
 195         vchiq_log_info(vchiq_arm_log_level,
 196                 "vchiq_init - done (slots %pK, phys %pad)",
 197                 vchiq_slot_zero, &slot_phys);
 198
 199         vchiq_call_connected_callbacks();
 200
 201         return 0;
 202 }
 203
 204 VCHIQ_STATUS_T
 205 vchiq_platform_init_state(VCHIQ_STATE_T *state)
 206 {
 207         VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
 208
 209         state->platform_state = kzalloc(sizeof(VCHIQ_2835_ARM_STATE_T), GFP_KERNEL);
 210         ((VCHIQ_2835_ARM_STATE_T *)state->platform_state)->inited = 1;
 211         status = vchiq_arm_init_state(state, &((VCHIQ_2835_ARM_STATE_T *)state->platform_state)->arm_state);
 212         if (status != VCHIQ_SUCCESS)
 213         {
 214                 ((VCHIQ_2835_ARM_STATE_T *)state->platform_state)->inited = 0;
 215         }
 216         return status;
 217 }
 218
 219 VCHIQ_ARM_STATE_T*
 220 vchiq_platform_get_arm_state(VCHIQ_STATE_T *state)
 221 {
 222         if (!((VCHIQ_2835_ARM_STATE_T *)state->platform_state)->inited)
 223         {
 224                 BUG();
 225         }
 226         return &((VCHIQ_2835_ARM_STATE_T *)state->platform_state)->arm_state;
 227 }
 228
 229 void
 230 remote_event_signal(REMOTE_EVENT_T *event)
 231 {
 232         wmb();
 233
 234         event->fired = 1;
 235
 236         dsb(sy);         /* data barrier operation */
 237
 238         if (event->armed)
 239                 writel(0, g_regs + BELL2); /* trigger vc interrupt */
 240 }
 241
 242 VCHIQ_STATUS_T
 243 vchiq_prepare_bulk_data(VCHIQ_BULK_T *bulk, VCHI_MEM_HANDLE_T memhandle,
 244         void *offset, int size, int dir)
 245 {
 246         struct vchiq_pagelist_info *pagelistinfo;
 247
 248         WARN_ON(memhandle != VCHI_MEM_HANDLE_INVALID);
 249
 250         pagelistinfo = create_pagelist((char __user *)offset, size,
 251                                        (dir == VCHIQ_BULK_RECEIVE)
 252                                        ? PAGELIST_READ
 253                                        : PAGELIST_WRITE);
 254
 255         if (!pagelistinfo)
 256                 return VCHIQ_ERROR;
 257
 258         bulk->handle = memhandle;
 259         bulk->data = (void *)(unsigned long)pagelistinfo->dma_addr;
 260
 261         /*
 262          * Store the pagelistinfo address in remote_data,
 263          * which isn't used by the slave.
 264          */
 265         bulk->remote_data = pagelistinfo;
 266
 267         return VCHIQ_SUCCESS;
 268 }
 269
 270 void
 271 vchiq_complete_bulk(VCHIQ_BULK_T *bulk)
 272 {
 273         if (bulk && bulk->remote_data && bulk->actual)
 274                 free_pagelist((struct vchiq_pagelist_info *)bulk->remote_data,
 275                               bulk->actual);
 276 }
 277
 278 void
 279 vchiq_transfer_bulk(VCHIQ_BULK_T *bulk)
 280 {
 281         /*
 282          * This should only be called on the master (VideoCore) side, but
 283          * provide an implementation to avoid the need for ifdefery.
 284          */
 285         BUG();
 286 }
 287
 288 void
 289 vchiq_dump_platform_state(void *dump_context)
 290 {
 291         char buf[80];
 292         int len;
 293
 294         len = snprintf(buf, sizeof(buf),
 295                 "  Platform: 2835 (VC master)");
 296         vchiq_dump(dump_context, buf, len + 1);
 297 }
 298
 299 VCHIQ_STATUS_T
 300 vchiq_platform_suspend(VCHIQ_STATE_T *state)
 301 {
 302         return VCHIQ_ERROR;
 303 }
 304
 305 VCHIQ_STATUS_T
 306 vchiq_platform_resume(VCHIQ_STATE_T *state)
 307 {
 308         return VCHIQ_SUCCESS;
 309 }
 310
 311 void
 312 vchiq_platform_paused(VCHIQ_STATE_T *state)
 313 {
 314 }
 315
 316 void
 317 vchiq_platform_resumed(VCHIQ_STATE_T *state)
 318 {
 319 }
 320
 321 int
 322 vchiq_platform_videocore_wanted(VCHIQ_STATE_T *state)
 323 {
 324         return 1; // autosuspend not supported - videocore always wanted
 325 }
 326
 327 int
 328 vchiq_platform_use_suspend_timer(void)
 329 {
 330         return 0;
 331 }
 332 void
 333 vchiq_dump_platform_use_state(VCHIQ_STATE_T *state)
 334 {
 335         vchiq_log_info(vchiq_arm_log_level, "Suspend timer not in use");
 336 }
 337 void
 338 vchiq_platform_handle_timeout(VCHIQ_STATE_T *state)
 339 {
 340         (void)state;
 341 }
 342 /*
 343  * Local functions
 344  */
 345
 346 static irqreturn_t
 347 vchiq_doorbell_irq(int irq, void *dev_id)
 348 {
 349         VCHIQ_STATE_T *state = dev_id;
 350         irqreturn_t ret = IRQ_NONE;
 351         unsigned int status;
 352
 353         /* Read (and clear) the doorbell */
 354         status = readl(g_regs + BELL0);
 355
 356         if (status & 0x4) {  /* Was the doorbell rung? */
 357                 remote_event_pollall(state);
 358                 ret = IRQ_HANDLED;
 359         }
 360
 361         return ret;
 362 }
 363
 364 static void
 365 cleanup_pagelistinfo(struct vchiq_pagelist_info *pagelistinfo)
 366 {
 367         if (pagelistinfo->scatterlist_mapped) {
 368                 dma_unmap_sg(g_dev, pagelistinfo->scatterlist,
 369                              pagelistinfo->num_pages, pagelistinfo->dma_dir);
 370         }
 371
 372         if (pagelistinfo->pages_need_release) {
 373                 unsigned int i;
 374
 375                 for (i = 0; i < pagelistinfo->num_pages; i++)
 376                         put_page(pagelistinfo->pages[i]);
 377         }
 378
 379         dma_free_coherent(g_dev, pagelistinfo->pagelist_buffer_size,
 380                           pagelistinfo->pagelist, pagelistinfo->dma_addr);
 381 }
 382
 383 /* There is a potential problem with partial cache lines (pages?)
 384 ** at the ends of the block when reading. If the CPU accessed anything in
 385 ** the same line (page?) then it may have pulled old data into the cache,
 386 ** obscuring the new data underneath. We can solve this by transferring the
 387 ** partial cache lines separately, and allowing the ARM to copy into the
 388 ** cached area.
 389 */
 390
 391 static struct vchiq_pagelist_info *
 392 create_pagelist(char __user *buf, size_t count, unsigned short type)
 393 {
 394         PAGELIST_T *pagelist;
 395         struct vchiq_pagelist_info *pagelistinfo;
 396         struct page **pages;
 397         u32 *addrs;
 398         unsigned int num_pages, offset, i, k;
 399         int actual_pages;
 400         size_t pagelist_size;
 401         struct scatterlist *scatterlist, *sg;
 402         int dma_buffers;
 403         dma_addr_t dma_addr;
 404
 405         offset = ((unsigned int)(unsigned long)buf & (PAGE_SIZE - 1));
 406         num_pages = DIV_ROUND_UP(count + offset, PAGE_SIZE);
 407
 408         pagelist_size = sizeof(PAGELIST_T) +
 409                         (num_pages * sizeof(u32)) +
 410                         (num_pages * sizeof(pages[0]) +
 411                         (num_pages * sizeof(struct scatterlist))) +
 412                         sizeof(struct vchiq_pagelist_info);
 413
 414         /* Allocate enough storage to hold the page pointers and the page
 415         ** list
 416         */
 417         pagelist = dma_zalloc_coherent(g_dev,
 418                                        pagelist_size,
 419                                        &dma_addr,
 420                                        GFP_KERNEL);
 421
 422         vchiq_log_trace(vchiq_arm_log_level, "create_pagelist - %pK",
 423                         pagelist);
 424         if (!pagelist)
 425                 return NULL;
 426
 427         addrs           = pagelist->addrs;
 428         pages           = (struct page **)(addrs + num_pages);
 429         scatterlist     = (struct scatterlist *)(pages + num_pages);
 430         pagelistinfo    = (struct vchiq_pagelist_info *)
 431                           (scatterlist + num_pages);
 432
 433         pagelist->length = count;
 434         pagelist->type = type;
 435         pagelist->offset = offset;
 436
 437         /* Populate the fields of the pagelistinfo structure */
 438         pagelistinfo->pagelist = pagelist;
 439         pagelistinfo->pagelist_buffer_size = pagelist_size;
 440         pagelistinfo->dma_addr = dma_addr;
 441         pagelistinfo->dma_dir =  (type == PAGELIST_WRITE) ?
 442                                   DMA_TO_DEVICE : DMA_FROM_DEVICE;
 443         pagelistinfo->num_pages = num_pages;
 444         pagelistinfo->pages_need_release = 0;
 445         pagelistinfo->pages = pages;
 446         pagelistinfo->scatterlist = scatterlist;
 447         pagelistinfo->scatterlist_mapped = 0;
 448
 449         if (is_vmalloc_addr(buf)) {
 450                 unsigned long length = count;
 451                 unsigned int off = offset;
 452
 453                 for (actual_pages = 0; actual_pages < num_pages;
 454                      actual_pages++) {
 455                         struct page *pg = vmalloc_to_page(buf + (actual_pages *
 456                                                                  PAGE_SIZE));
 457                         size_t bytes = PAGE_SIZE - off;
 458
 459                         if (!pg) {
 460                                 cleanup_pagelistinfo(pagelistinfo);
 461                                 return NULL;
 462                         }
 463
 464                         if (bytes > length)
 465                                 bytes = length;
 466                         pages[actual_pages] = pg;
 467                         length -= bytes;
 468                         off = 0;
 469                 }
 470                 /* do not try and release vmalloc pages */
 471         } else {
 472                 actual_pages = get_user_pages_fast(
 473                                           (unsigned long)buf & PAGE_MASK,
 474                                           num_pages,
 475                                           type == PAGELIST_READ,
 476                                           pages);
 477
 478                 if (actual_pages != num_pages) {
 479                         vchiq_log_info(vchiq_arm_log_level,
 480                                        "create_pagelist - only %d/%d pages locked",
 481                                        actual_pages,
 482                                        num_pages);
 483
 484                         /* This is probably due to the process being killed */
 485                         while (actual_pages > 0)
 486                         {
 487                                 actual_pages--;
 488                                 put_page(pages[actual_pages]);
 489                         }
 490                         cleanup_pagelistinfo(pagelistinfo);
 491                         return NULL;
 492                 }
 493                  /* release user pages */
 494                 pagelistinfo->pages_need_release = 1;
 495         }
 496
 497         /*
 498          * Initialize the scatterlist so that the magic cookie
 499          *  is filled if debugging is enabled
 500          */
 501         sg_init_table(scatterlist, num_pages);
 502         /* Now set the pages for each scatterlist */
 503         for (i = 0; i < num_pages; i++) {
 504                 unsigned int len = PAGE_SIZE - offset;
 505
 506                 if (len > count)
 507                         len = count;
 508                 sg_set_page(scatterlist + i, pages[i], len, offset);
 509                 offset = 0;
 510                 count -= len;
 511         }
 512
 513         dma_buffers = dma_map_sg(g_dev,
 514                                  scatterlist,
 515                                  num_pages,
 516                                  pagelistinfo->dma_dir);
 517
 518         if (dma_buffers == 0) {
 519                 cleanup_pagelistinfo(pagelistinfo);
 520                 return NULL;
 521         }
 522
 523         pagelistinfo->scatterlist_mapped = 1;
 524
 525         /* Combine adjacent blocks for performance */
 526         k = 0;
 527         for_each_sg(scatterlist, sg, dma_buffers, i) {
 528                 u32 len = sg_dma_len(sg);
 529                 u32 addr = sg_dma_address(sg);
 530
 531                 /* Note: addrs is the address + page_count - 1
 532                  * The firmware expects blocks after the first to be page-
 533                  * aligned and a multiple of the page size
 534                  */
 535                 WARN_ON(len == 0);
 536                 WARN_ON(i && (i != (dma_buffers - 1)) && (len & ~PAGE_MASK));
 537                 WARN_ON(i && (addr & ~PAGE_MASK));
 538                 if (k > 0 &&
 539                     ((addrs[k - 1] & PAGE_MASK) +
 540                      (((addrs[k - 1] & ~PAGE_MASK) + 1) << PAGE_SHIFT))
 541                     == (addr & PAGE_MASK))
 542                         addrs[k - 1] += ((len + PAGE_SIZE - 1) >> PAGE_SHIFT);
 543                 else
 544                         addrs[k++] = (addr & PAGE_MASK) |
 545                                 (((len + PAGE_SIZE - 1) >> PAGE_SHIFT) - 1);
 546         }
 547
 548         /* Partial cache lines (fragments) require special measures */
 549         if ((type == PAGELIST_READ) &&
 550                 ((pagelist->offset & (g_cache_line_size - 1)) ||
 551                 ((pagelist->offset + pagelist->length) &
 552                 (g_cache_line_size - 1)))) {
 553                 char *fragments;
 554
 555                 if (down_interruptible(&g_free_fragments_sema) != 0) {
 556                         cleanup_pagelistinfo(pagelistinfo);
 557                         return NULL;
 558                 }
 559
 560                 WARN_ON(g_free_fragments == NULL);
 561
 562                 down(&g_free_fragments_mutex);
 563                 fragments = g_free_fragments;
 564                 WARN_ON(fragments == NULL);
 565                 g_free_fragments = *(char **) g_free_fragments;
 566                 up(&g_free_fragments_mutex);
 567                 pagelist->type = PAGELIST_READ_WITH_FRAGMENTS +
 568                         (fragments - g_fragments_base) / g_fragments_size;
 569         }
 570
 571         return pagelistinfo;
 572 }
 573
 574 static void
 575 free_pagelist(struct vchiq_pagelist_info *pagelistinfo,
 576               int actual)
 577 {
 578         PAGELIST_T *pagelist   = pagelistinfo->pagelist;
 579         struct page **pages    = pagelistinfo->pages;
 580         unsigned int num_pages = pagelistinfo->num_pages;
 581
 582         vchiq_log_trace(vchiq_arm_log_level, "free_pagelist - %pK, %d",
 583                         pagelistinfo->pagelist, actual);
 584
 585         /*
 586          * NOTE: dma_unmap_sg must be called before the
 587          * cpu can touch any of the data/pages.
 588          */
 589         dma_unmap_sg(g_dev, pagelistinfo->scatterlist,
 590                      pagelistinfo->num_pages, pagelistinfo->dma_dir);
 591         pagelistinfo->scatterlist_mapped = 0;
 592
 593         /* Deal with any partial cache lines (fragments) */
 594         if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS) {
 595                 char *fragments = g_fragments_base +
 596                         (pagelist->type - PAGELIST_READ_WITH_FRAGMENTS) *
 597                         g_fragments_size;
 598                 int head_bytes, tail_bytes;
 599
 600                 head_bytes = (g_cache_line_size - pagelist->offset) &
 601                         (g_cache_line_size - 1);
 602                 tail_bytes = (pagelist->offset + actual) &
 603                         (g_cache_line_size - 1);
 604
 605                 if ((actual >= 0) && (head_bytes != 0)) {
 606                         if (head_bytes > actual)
 607                                 head_bytes = actual;
 608
 609                         memcpy((char *)page_address(pages[0]) +
 610                                 pagelist->offset,
 611                                 fragments,
 612                                 head_bytes);
 613                 }
 614                 if ((actual >= 0) && (head_bytes < actual) &&
 615                         (tail_bytes != 0)) {
 616                         memcpy((char *)page_address(pages[num_pages - 1]) +
 617                                 ((pagelist->offset + actual) &
 618                                 (PAGE_SIZE - 1) & ~(g_cache_line_size - 1)),
 619                                 fragments + g_cache_line_size,
 620                                 tail_bytes);
 621                 }
 622
 623                 down(&g_free_fragments_mutex);
 624                 *(char **)fragments = g_free_fragments;
 625                 g_free_fragments = fragments;
 626                 up(&g_free_fragments_mutex);
 627                 up(&g_free_fragments_sema);
 628         }
 629
 630         /* Need to mark all the pages dirty. */
 631         if (pagelist->type != PAGELIST_WRITE &&
 632             pagelistinfo->pages_need_release) {
 633                 unsigned int i;
 634
 635                 for (i = 0; i < num_pages; i++)
 636                         set_page_dirty(pages[i]);
 637         }
 638
 639         cleanup_pagelistinfo(pagelistinfo);
 640 }