LXR linux/drivers/gpu/drm/drm

   1/**************************************************************************
   2 *
   3 * Copyright (c) 2006-2007 Tungsten Graphics, Inc., Cedar Park, TX., USA
   4 * All Rights Reserved.
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a
   7 * copy of this software and associated documentation files (the
   8 * "Software"), to deal in the Software without restriction, including
   9 * without limitation the rights to use, copy, modify, merge, publish,
  10 * distribute, sub license, and/or sell copies of the Software, and to
  11 * permit persons to whom the Software is furnished to do so, subject to
  12 * the following conditions:
  13 *
  14 * The above copyright notice and this permission notice (including the
  15 * next paragraph) shall be included in all copies or substantial portions
  16 * of the Software.
  17 *
  18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
  25 *
  26 **************************************************************************/
  27/*
  28 * Authors: Thomas HellstrÃ¶m <thomas-at-tungstengraphics-dot-com>
  29 */
  30
  31#include "drmP.h"
  32
  33#if defined(CONFIG_X86)
  34static void
  35drm_clflush_page(struct page *page)
  36{
  37        uint8_t *page_virtual;
  38        unsigned int i;
  39
  40        if (unlikely(page == NULL))
  41                return;
  42
  43        page_virtual = kmap_atomic(page, KM_USER0);
  44        for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
  45                clflush(page_virtual + i);
  46        kunmap_atomic(page_virtual, KM_USER0);
  47}
  48#endif
  49
  50void
  51drm_clflush_pages(struct page *pages[], unsigned long num_pages)
  52{
  53
  54#if defined(CONFIG_X86)
  55        if (cpu_has_clflush) {
  56                unsigned long i;
  57
  58                mb();
  59                for (i = 0; i < num_pages; ++i)
  60                        drm_clflush_page(*pages++);
  61                mb();
  62
  63                return;
  64        }
  65
  66        wbinvd();
  67#endif
  68}
  69EXPORT_SYMBOL(drm_clflush_pages);
  70