drivers/gpu/drm/drm_cache.c

   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 Hellström <thomas-at-tungstengraphics-dot-com>
  29  */
  30
  31 #include "drmP.h"
  32
  33 #if defined(CONFIG_X86)
  34 static void
  35 drm_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
  50 void
  51 drm_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 }
  69 EXPORT_SYMBOL(drm_clflush_pages);