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 #include <asm/cpufeature.h>
  34
  35 /*
  36  * clflushopt is an unordered instruction which needs fencing with mfence or
  37  * sfence to avoid ordering issues.  For drm_clflush_page this fencing happens
  38  * in the caller.
  39  */
  40 static void
  41 drm_clflush_page(struct page *page)
  42 {
  43         uint8_t *page_virtual;
  44         unsigned int i;
  45         const int size = cpu_clflush_line_size;
  46
  47         if (unlikely(page == NULL))
  48                 return;
  49
  50         page_virtual = kmap_atomic(page);
  51         for (i = 0; i < PAGE_SIZE; i += size)
  52                 clflushopt(page_virtual + i);
  53         kunmap_atomic(page_virtual);
  54 }
  55
  56 static void drm_cache_flush_clflush(struct page *pages[],
  57                                     unsigned long num_pages)
  58 {
  59         unsigned long i;
  60
  61         mb();
  62         for (i = 0; i < num_pages; i++)
  63                 drm_clflush_page(*pages++);
  64         mb();
  65 }
  66
  67 void
  68 drm_clflush_pages(struct page *pages[], unsigned long num_pages)
  69 {
  70         pmap_invalidate_cache_pages((struct vm_page **)pages, num_pages);
  71
  72         if (static_cpu_has(X86_FEATURE_CLFLUSH)) {
  73                 drm_cache_flush_clflush(pages, num_pages);
  74                 return;
  75         }
  76
  77         cpu_wbinvd_on_all_cpus();
  78 }
  79 EXPORT_SYMBOL(drm_clflush_pages);
  80
  81 void
  82 drm_clflush_sg(struct sg_table *st)
  83 {
  84         if (static_cpu_has(X86_FEATURE_CLFLUSH)) {
  85                 struct sg_page_iter sg_iter;
  86
  87                 mb();
  88                 for_each_sg_page(st->sgl, &sg_iter, st->nents, 0)
  89                         drm_clflush_page(sg_page_iter_page(&sg_iter));
  90                 mb();
  91
  92                 return;
  93         }
  94
  95         cpu_wbinvd_on_all_cpus();
  96 }
  97 EXPORT_SYMBOL(drm_clflush_sg);
  98
  99 void
 100 drm_clflush_virt_range(void *in_addr, unsigned long length)
 101 {
 102         char *addr = in_addr;
 103
 104         if (static_cpu_has(X86_FEATURE_CLFLUSH)) {
 105                 const int size = cpu_clflush_line_size;
 106                 char *end = addr + length;
 107                 addr = (void *)(((unsigned long)addr) & -size);
 108                 mb();
 109                 for (; addr < end; addr += size)
 110                         clflushopt(addr);
 111                 clflushopt(end - 1); /* force serialisation */
 112                 mb();
 113                 return;
 114         }
 115
 116         cpu_wbinvd_on_all_cpus();
 117 }
 118 EXPORT_SYMBOL(drm_clflush_virt_range);