1 /* $NetBSD: drm_memory.c,v 1.3 2021/12/18 23:44:57 riastradh Exp $ */
2
3 /*
4 * \file drm_memory.c
5 * Memory management wrappers for DRM
6 *
7 * \author Rickard E. (Rik) Faith <faith@valinux.com>
8 * \author Gareth Hughes <gareth@valinux.com>
9 */
10
11 /*
12 * Created: Thu Feb 4 14:00:34 1999 by faith@valinux.com
13 *
14 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
15 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
16 * All Rights Reserved.
17 *
18 * Permission is hereby granted, free of charge, to any person obtaining a
19 * copy of this software and associated documentation files (the "Software"),
20 * to deal in the Software without restriction, including without limitation
21 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
22 * and/or sell copies of the Software, and to permit persons to whom the
23 * Software is furnished to do so, subject to the following conditions:
24 *
25 * The above copyright notice and this permission notice (including the next
26 * paragraph) shall be included in all copies or substantial portions of the
27 * Software.
28 *
29 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
30 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
31 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
32 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
33 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
34 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
35 * OTHER DEALINGS IN THE SOFTWARE.
36 */
37
38 #include <sys/cdefs.h>
39 __KERNEL_RCSID(0, "$NetBSD: drm_memory.c,v 1.3 2021/12/18 23:44:57 riastradh Exp $");
40
41 #include <linux/export.h>
42 #include <linux/highmem.h>
43 #include <linux/pci.h>
44 #include <linux/vmalloc.h>
45 #include <xen/xen.h>
46
47 #include <drm/drm_agpsupport.h>
48 #include <drm/drm_cache.h>
49 #include <drm/drm_device.h>
50
51 #include "drm_legacy.h"
52
53 #if IS_ENABLED(CONFIG_AGP)
54
55 #ifdef HAVE_PAGE_AGP
56 # include <asm/agp.h>
57 #else
58 # ifdef __powerpc__
59 # define PAGE_AGP pgprot_noncached_wc(PAGE_KERNEL)
60 # else
61 # define PAGE_AGP PAGE_KERNEL
62 # endif
63 #endif
64
agp_remap(unsigned long offset,unsigned long size,struct drm_device * dev)65 static void *agp_remap(unsigned long offset, unsigned long size,
66 struct drm_device *dev)
67 {
68 unsigned long i, num_pages =
69 PAGE_ALIGN(size) / PAGE_SIZE;
70 struct drm_agp_mem *agpmem;
71 struct page **page_map;
72 struct page **phys_page_map;
73 void *addr;
74
75 size = PAGE_ALIGN(size);
76
77 #ifdef __alpha__
78 offset -= dev->hose->mem_space->start;
79 #endif
80
81 list_for_each_entry(agpmem, &dev->agp->memory, head)
82 if (agpmem->bound <= offset
83 && (agpmem->bound + (agpmem->pages << PAGE_SHIFT)) >=
84 (offset + size))
85 break;
86 if (&agpmem->head == &dev->agp->memory)
87 return NULL;
88
89 /*
90 * OK, we're mapping AGP space on a chipset/platform on which memory accesses by
91 * the CPU do not get remapped by the GART. We fix this by using the kernel's
92 * page-table instead (that's probably faster anyhow...).
93 */
94 /* note: use vmalloc() because num_pages could be large... */
95 page_map = vmalloc(array_size(num_pages, sizeof(struct page *)));
96 if (!page_map)
97 return NULL;
98
99 phys_page_map = (agpmem->memory->pages + (offset - agpmem->bound) / PAGE_SIZE);
100 for (i = 0; i < num_pages; ++i)
101 page_map[i] = phys_page_map[i];
102 addr = vmap(page_map, num_pages, VM_IOREMAP, PAGE_AGP);
103 vfree(page_map);
104
105 return addr;
106 }
107
108 /** Wrapper around agp_free_memory() */
drm_free_agp(struct agp_memory * handle,int pages)109 void drm_free_agp(struct agp_memory *handle, int pages)
110 {
111 agp_free_memory(handle);
112 }
113
114 /** Wrapper around agp_bind_memory() */
drm_bind_agp(struct agp_memory * handle,unsigned int start)115 int drm_bind_agp(struct agp_memory *handle, unsigned int start)
116 {
117 return agp_bind_memory(handle, start);
118 }
119
120 /** Wrapper around agp_unbind_memory() */
drm_unbind_agp(struct agp_memory * handle)121 int drm_unbind_agp(struct agp_memory *handle)
122 {
123 return agp_unbind_memory(handle);
124 }
125
126 #else /* CONFIG_AGP */
agp_remap(unsigned long offset,unsigned long size,struct drm_device * dev)127 static inline void *agp_remap(unsigned long offset, unsigned long size,
128 struct drm_device *dev)
129 {
130 return NULL;
131 }
132
133 #endif /* CONFIG_AGP */
134
drm_legacy_ioremap(struct drm_local_map * map,struct drm_device * dev)135 void drm_legacy_ioremap(struct drm_local_map *map, struct drm_device *dev)
136 {
137 if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
138 map->handle = agp_remap(map->offset, map->size, dev);
139 else
140 map->handle = ioremap(map->offset, map->size);
141 }
142 EXPORT_SYMBOL(drm_legacy_ioremap);
143
drm_legacy_ioremap_wc(struct drm_local_map * map,struct drm_device * dev)144 void drm_legacy_ioremap_wc(struct drm_local_map *map, struct drm_device *dev)
145 {
146 if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
147 map->handle = agp_remap(map->offset, map->size, dev);
148 else
149 map->handle = ioremap_wc(map->offset, map->size);
150 }
151 EXPORT_SYMBOL(drm_legacy_ioremap_wc);
152
drm_legacy_ioremapfree(struct drm_local_map * map,struct drm_device * dev)153 void drm_legacy_ioremapfree(struct drm_local_map *map, struct drm_device *dev)
154 {
155 if (!map->handle || !map->size)
156 return;
157
158 if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
159 vunmap(map->handle);
160 else
161 iounmap(map->handle);
162 }
163 EXPORT_SYMBOL(drm_legacy_ioremapfree);
164
drm_need_swiotlb(int dma_bits)165 bool drm_need_swiotlb(int dma_bits)
166 {
167 struct resource *tmp;
168 resource_size_t max_iomem = 0;
169
170 /*
171 * Xen paravirtual hosts require swiotlb regardless of requested dma
172 * transfer size.
173 *
174 * NOTE: Really, what it requires is use of the dma_alloc_coherent
175 * allocator used in ttm_dma_populate() instead of
176 * ttm_populate_and_map_pages(), which bounce buffers so much in
177 * Xen it leads to swiotlb buffer exhaustion.
178 */
179 if (xen_pv_domain())
180 return true;
181
182 /*
183 * Enforce dma_alloc_coherent when memory encryption is active as well
184 * for the same reasons as for Xen paravirtual hosts.
185 */
186 if (mem_encrypt_active())
187 return true;
188
189 for (tmp = iomem_resource.child; tmp; tmp = tmp->sibling) {
190 max_iomem = max(max_iomem, tmp->end);
191 }
192
193 return max_iomem > ((u64)1 << dma_bits);
194 }
195 EXPORT_SYMBOL(drm_need_swiotlb);
196