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
41#include <drm/drm_cache.h>
42#include <drm/drm_device.h>
43
44#include "drm_legacy.h"
45
46#if IS_ENABLED(CONFIG_AGP)
47
48#ifdef HAVE_PAGE_AGP
49# include <asm/agp.h>
50#else
51# ifdef __powerpc__
52# define PAGE_AGP pgprot_noncached_wc(PAGE_KERNEL)
53# else
54# define PAGE_AGP PAGE_KERNEL
55# endif
56#endif
57
58static void *agp_remap(unsigned long offset, unsigned long size,
59 struct drm_device *dev)
60{
61 unsigned long i, num_pages =
62 PAGE_ALIGN(size) / PAGE_SIZE;
63 struct drm_agp_mem *agpmem;
64 struct page **page_map;
65 struct page **phys_page_map;
66 void *addr;
67
68 size = PAGE_ALIGN(size);
69
70#ifdef __alpha__
71 offset -= dev->hose->mem_space->start;
72#endif
73
74 list_for_each_entry(agpmem, &dev->agp->memory, head)
75 if (agpmem->bound <= offset
76 && (agpmem->bound + (agpmem->pages << PAGE_SHIFT)) >=
77 (offset + size))
78 break;
79 if (&agpmem->head == &dev->agp->memory)
80 return NULL;
81
82 /*
83 * OK, we're mapping AGP space on a chipset/platform on which memory accesses by
84 * the CPU do not get remapped by the GART. We fix this by using the kernel's
85 * page-table instead (that's probably faster anyhow...).
86 */
87 /* note: use vmalloc() because num_pages could be large... */
88 page_map = vmalloc(array_size(num_pages, sizeof(struct page *)));
89 if (!page_map)
90 return NULL;
91
92 phys_page_map = (agpmem->memory->pages + (offset - agpmem->bound) / PAGE_SIZE);
93 for (i = 0; i < num_pages; ++i)
94 page_map[i] = phys_page_map[i];
95 addr = vmap(pages: page_map, count: num_pages, VM_IOREMAP, PAGE_AGP);
96 vfree(addr: page_map);
97
98 return addr;
99}
100
101#else /* CONFIG_AGP */
102static inline void *agp_remap(unsigned long offset, unsigned long size,
103 struct drm_device *dev)
104{
105 return NULL;
106}
107
108#endif /* CONFIG_AGP */
109
110void drm_legacy_ioremap(struct drm_local_map *map, struct drm_device *dev)
111{
112 if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
113 map->handle = agp_remap(offset: map->offset, size: map->size, dev);
114 else
115 map->handle = ioremap(offset: map->offset, size: map->size);
116}
117EXPORT_SYMBOL(drm_legacy_ioremap);
118
119void drm_legacy_ioremap_wc(struct drm_local_map *map, struct drm_device *dev)
120{
121 if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
122 map->handle = agp_remap(offset: map->offset, size: map->size, dev);
123 else
124 map->handle = ioremap_wc(offset: map->offset, size: map->size);
125}
126EXPORT_SYMBOL(drm_legacy_ioremap_wc);
127
128void drm_legacy_ioremapfree(struct drm_local_map *map, struct drm_device *dev)
129{
130 if (!map->handle || !map->size)
131 return;
132
133 if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
134 vunmap(addr: map->handle);
135 else
136 iounmap(addr: map->handle);
137}
138EXPORT_SYMBOL(drm_legacy_ioremapfree);
139

source code of linux/drivers/gpu/drm/drm_memory.c