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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
54static 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() */
98void drm_free_agp(struct agp_memory *handle, int pages)
99{
100 agp_free_memory(handle);
101}
102
103/** Wrapper around agp_bind_memory() */
104int 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() */
110int drm_unbind_agp(struct agp_memory *handle)
111{
112 return agp_unbind_memory(handle);
113}
114
115#else /* CONFIG_AGP */
116static 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
124void 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}
131EXPORT_SYMBOL(drm_legacy_ioremap);
132
133void 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}
140EXPORT_SYMBOL(drm_legacy_ioremap_wc);
141
142void 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}
152EXPORT_SYMBOL(drm_legacy_ioremapfree);
153
154bool 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}
184EXPORT_SYMBOL(drm_need_swiotlb);