drivers/gpu/drm/drm_memory.c

   1 /**
   2  * \file drm_memory.c
   3  * Memory management wrappers for DRM
   4  *
   5  * \author Rickard E. (Rik) Faith <faith@valinux.com>
   6  * \author Gareth Hughes <gareth@valinux.com>
   7  */
   8
   9 /*
  10  * Created: Thu Feb  4 14:00:34 1999 by faith@valinux.com
  11  *
  12  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
  13  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  14  * All Rights Reserved.
  15  *
  16  * Permission is hereby granted, free of charge, to any person obtaining a
  17  * copy of this software and associated documentation files (the "Software"),
  18  * to deal in the Software without restriction, including without limitation
  19  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  20  * and/or sell copies of the Software, and to permit persons to whom the
  21  * Software is furnished to do so, subject to the following conditions:
  22  *
  23  * The above copyright notice and this permission notice (including the next
  24  * paragraph) shall be included in all copies or substantial portions of the
  25  * Software.
  26  *
  27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  28  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  29  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  30  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  31  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  32  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  33  * OTHER DEALINGS IN THE SOFTWARE.
  34  */
  35
  36 #include <linux/highmem.h>
  37 #include <linux/export.h>
  38 #include <drm/drmP.h>
  39 #include "drm_legacy.h"
  40
  41 #if IS_ENABLED(CONFIG_AGP)
  42
  43 #ifdef HAVE_PAGE_AGP
  44 # include <asm/agp.h>
  45 #else
  46 # ifdef __powerpc__
  47 #  define PAGE_AGP      pgprot_noncached_wc(PAGE_KERNEL)
  48 # else
  49 #  define PAGE_AGP      PAGE_KERNEL
  50 # endif
  51 #endif
  52
  53 static void *agp_remap(unsigned long offset, unsigned long size,
  54                        struct drm_device * dev)
  55 {
  56         unsigned long i, num_pages =
  57             PAGE_ALIGN(size) / PAGE_SIZE;
  58         struct drm_agp_mem *agpmem;
  59         struct page **page_map;
  60         struct page **phys_page_map;
  61         void *addr;
  62
  63         size = PAGE_ALIGN(size);
  64
  65 #ifdef __alpha__
  66         offset -= dev->hose->mem_space->start;
  67 #endif
  68
  69         list_for_each_entry(agpmem, &dev->agp->memory, head)
  70                 if (agpmem->bound <= offset
  71                     && (agpmem->bound + (agpmem->pages << PAGE_SHIFT)) >=
  72                     (offset + size))
  73                         break;
  74         if (&agpmem->head == &dev->agp->memory)
  75                 return NULL;
  76
  77         /*
  78          * OK, we're mapping AGP space on a chipset/platform on which memory accesses by
  79          * the CPU do not get remapped by the GART.  We fix this by using the kernel's
  80          * page-table instead (that's probably faster anyhow...).
  81          */
  82         /* note: use vmalloc() because num_pages could be large... */
  83         page_map = vmalloc(num_pages * sizeof(struct page *));
  84         if (!page_map)
  85                 return NULL;
  86
  87         phys_page_map = (agpmem->memory->pages + (offset - agpmem->bound) / PAGE_SIZE);
  88         for (i = 0; i < num_pages; ++i)
  89                 page_map[i] = phys_page_map[i];
  90         addr = vmap(page_map, num_pages, VM_IOREMAP, PAGE_AGP);
  91         vfree(page_map);
  92
  93         return addr;
  94 }
  95
  96 /** Wrapper around agp_free_memory() */
  97 void drm_free_agp(struct agp_memory * handle, int pages)
  98 {
  99         agp_free_memory(handle);
 100 }
 101
 102 /** Wrapper around agp_bind_memory() */
 103 int drm_bind_agp(struct agp_memory * handle, unsigned int start)
 104 {
 105         return agp_bind_memory(handle, start);
 106 }
 107
 108 /** Wrapper around agp_unbind_memory() */
 109 int drm_unbind_agp(struct agp_memory * handle)
 110 {
 111         return agp_unbind_memory(handle);
 112 }
 113
 114 #else /*  CONFIG_AGP  */
 115 static inline void *agp_remap(unsigned long offset, unsigned long size,
 116                               struct drm_device * dev)
 117 {
 118         return NULL;
 119 }
 120
 121 #endif /* CONFIG_AGP */
 122
 123 void drm_legacy_ioremap(struct drm_local_map *map, struct drm_device *dev)
 124 {
 125         if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
 126                 map->handle = agp_remap(map->offset, map->size, dev);
 127         else
 128                 map->handle = ioremap(map->offset, map->size);
 129 }
 130 EXPORT_SYMBOL(drm_legacy_ioremap);
 131
 132 void drm_legacy_ioremap_wc(struct drm_local_map *map, struct drm_device *dev)
 133 {
 134         if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
 135                 map->handle = agp_remap(map->offset, map->size, dev);
 136         else
 137                 map->handle = ioremap_wc(map->offset, map->size);
 138 }
 139 EXPORT_SYMBOL(drm_legacy_ioremap_wc);
 140
 141 void drm_legacy_ioremapfree(struct drm_local_map *map, struct drm_device *dev)
 142 {
 143         if (!map->handle || !map->size)
 144                 return;
 145
 146         if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
 147                 vunmap(map->handle);
 148         else
 149                 iounmap(map->handle);
 150 }
 151 EXPORT_SYMBOL(drm_legacy_ioremapfree);