sys/dev/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 <linux/export.h>
  32 #include <drm/drmP.h>
  33
  34 #include <machine/md_var.h>
  35 #include <machine/cpufunc.h>
  36
  37 #define cpu_has_clflush 1
  38
  39 void
  40 drm_clflush_virt_range(void *in_addr, unsigned long length)
  41 {
  42         char *addr = in_addr;
  43         if (cpu_has_clflush) {
  44                 char *end = addr + length;
  45                 cpu_mfence();
  46                 for (; addr < end; addr += cpu_clflush_line_size)
  47                         clflush((unsigned long)addr);
  48                 clflush((unsigned long)(end - 1));
  49                 cpu_mfence();
  50                 return;
  51         }
  52
  53         cpu_wbinvd_on_all_cpus();
  54 }
  55 EXPORT_SYMBOL(drm_clflush_virt_range);