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
agp_remap(unsigned long offset,unsigned long size,struct drm_device * dev)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() */
drm_free_agp(struct agp_memory * handle,int pages)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() */
drm_bind_agp(struct agp_memory * handle,unsigned int start)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() */
drm_unbind_agp(struct agp_memory * handle)116 int drm_unbind_agp(struct agp_memory *handle)
117 {
118 return agp_unbind_memory(handle);
119 }
120
121 #else /* CONFIG_AGP */
agp_remap(unsigned long offset,unsigned long size,struct drm_device * dev)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
drm_legacy_ioremap(struct drm_local_map * map,struct drm_device * dev)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
drm_legacy_ioremap_wc(struct drm_local_map * map,struct drm_device * dev)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
drm_legacy_ioremapfree(struct drm_local_map * map,struct drm_device * dev)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
drm_need_swiotlb(int dma_bits)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