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); 191