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
agp_remap(unsigned long offset,unsigned long size,struct drm_device * dev)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() */
drm_free_agp(struct agp_memory * handle,int pages)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() */
drm_bind_agp(struct agp_memory * handle,unsigned int start)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() */
drm_unbind_agp(struct agp_memory * handle)115 int drm_unbind_agp(struct agp_memory *handle)
116 {
117 return agp_unbind_memory(handle);
118 }
119
120 #else /* CONFIG_AGP */
agp_remap(unsigned long offset,unsigned long size,struct drm_device * dev)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
drm_legacy_ioremap(struct drm_local_map * map,struct drm_device * dev)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
drm_legacy_ioremap_wc(struct drm_local_map * map,struct drm_device * dev)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
drm_legacy_ioremapfree(struct drm_local_map * map,struct drm_device * dev)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
drm_need_swiotlb(int dma_bits)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
