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