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); 190