root/drivers/gpu/drm/drm_memory.c

DEFINITIONS

1. agp_remap
2. drm_free_agp
3. drm_bind_agp
4. drm_unbind_agp
5. agp_remap
6. drm_legacy_ioremap
7. drm_legacy_ioremap_wc
8. drm_legacy_ioremapfree
9. drm_need_swiotlb

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