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/export.h>
  37 #include <linux/highmem.h>
  38 #include <linux/pci.h>
  39 #include <linux/vmalloc.h>
  40 #include <xen/xen.h>
  41
  42 #include <drm/drm_agpsupport.h>
  43 #include <drm/drm_cache.h>
  44 #include <drm/drm_device.h>
  45
  46 #include "drm_legacy.h"
  47
  48 #if IS_ENABLED(CONFIG_AGP)
  49
  50 #ifdef HAVE_PAGE_AGP
  51 # include <asm/agp.h>
  52 #else
  53 # ifdef __powerpc__
  54 #  define PAGE_AGP      pgprot_noncached_wc(PAGE_KERNEL)
  55 # else
  56 #  define PAGE_AGP      PAGE_KERNEL
  57 # endif
  58 #endif
  59
  60 static void *agp_remap(unsigned long offset, unsigned long size,
  61                        struct drm_device *dev)
  62 {
  63         unsigned long i, num_pages =
  64             PAGE_ALIGN(size) / PAGE_SIZE;
  65         struct drm_agp_mem *agpmem;
  66         struct page **page_map;
  67         struct page **phys_page_map;
  68         void *addr;
  69
  70         size = PAGE_ALIGN(size);
  71
  72 #ifdef __alpha__
  73         offset -= dev->hose->mem_space->start;
  74 #endif
  75
  76         list_for_each_entry(agpmem, &dev->agp->memory, head)
  77                 if (agpmem->bound <= offset
  78                     && (agpmem->bound + (agpmem->pages << PAGE_SHIFT)) >=
  79                     (offset + size))
  80                         break;
  81         if (&agpmem->head == &dev->agp->memory)
  82                 return NULL;
  83
  84         /*
  85          * OK, we're mapping AGP space on a chipset/platform on which memory accesses by
  86          * the CPU do not get remapped by the GART.  We fix this by using the kernel's
  87          * page-table instead (that's probably faster anyhow...).
  88          */
  89         /* note: use vmalloc() because num_pages could be large... */
  90         page_map = vmalloc(array_size(num_pages, sizeof(struct page *)));
  91         if (!page_map)
  92                 return NULL;
  93
  94         phys_page_map = (agpmem->memory->pages + (offset - agpmem->bound) / PAGE_SIZE);
  95         for (i = 0; i < num_pages; ++i)
  96                 page_map[i] = phys_page_map[i];
  97         addr = vmap(page_map, num_pages, VM_IOREMAP, PAGE_AGP);
  98         vfree(page_map);
  99
 100         return addr;
 101 }
 102
 103 /** Wrapper around agp_free_memory() */
 104 void drm_free_agp(struct agp_memory *handle, int pages)
 105 {
 106         agp_free_memory(handle);
 107 }
 108
 109 /** Wrapper around agp_bind_memory() */
 110 int drm_bind_agp(struct agp_memory *handle, unsigned int start)
 111 {
 112         return agp_bind_memory(handle, start);
 113 }
 114
 115 /** Wrapper around agp_unbind_memory() */
 116 int drm_unbind_agp(struct agp_memory *handle)
 117 {
 118         return agp_unbind_memory(handle);
 119 }
 120
 121 #else /*  CONFIG_AGP  */
 122 static inline void *agp_remap(unsigned long offset, unsigned long size,
 123                               struct drm_device *dev)
 124 {
 125         return NULL;
 126 }
 127
 128 #endif /* CONFIG_AGP */
 129
 130 void drm_legacy_ioremap(struct drm_local_map *map, struct drm_device *dev)
 131 {
 132         if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
 133                 map->handle = agp_remap(map->offset, map->size, dev);
 134         else
 135                 map->handle = ioremap(map->offset, map->size);
 136 }
 137 EXPORT_SYMBOL(drm_legacy_ioremap);
 138
 139 void drm_legacy_ioremap_wc(struct drm_local_map *map, struct drm_device *dev)
 140 {
 141         if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
 142                 map->handle = agp_remap(map->offset, map->size, dev);
 143         else
 144                 map->handle = ioremap_wc(map->offset, map->size);
 145 }
 146 EXPORT_SYMBOL(drm_legacy_ioremap_wc);
 147
 148 void drm_legacy_ioremapfree(struct drm_local_map *map, struct drm_device *dev)
 149 {
 150         if (!map->handle || !map->size)
 151                 return;
 152
 153         if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
 154                 vunmap(map->handle);
 155         else
 156                 iounmap(map->handle);
 157 }
 158 EXPORT_SYMBOL(drm_legacy_ioremapfree);
 159
 160 bool drm_need_swiotlb(int dma_bits)
 161 {
 162         struct resource *tmp;
 163         resource_size_t max_iomem = 0;
 164
 165         /*
 166          * Xen paravirtual hosts require swiotlb regardless of requested dma
 167          * transfer size.
 168          *
 169          * NOTE: Really, what it requires is use of the dma_alloc_coherent
 170          *       allocator used in ttm_dma_populate() instead of
 171          *       ttm_populate_and_map_pages(), which bounce buffers so much in
 172          *       Xen it leads to swiotlb buffer exhaustion.
 173          */
 174         if (xen_pv_domain())
 175                 return true;
 176
 177         /*
 178          * Enforce dma_alloc_coherent when memory encryption is active as well
 179          * for the same reasons as for Xen paravirtual hosts.
 180          */
 181         if (mem_encrypt_active())
 182                 return true;
 183
 184         for (tmp = iomem_resource.child; tmp; tmp = tmp->sibling) {
 185                 max_iomem = max(max_iomem,  tmp->end);
 186         }
 187
 188         return max_iomem > ((u64)1 << dma_bits);
 189 }
 190 EXPORT_SYMBOL(drm_need_swiotlb);