xref: /openbmc/linux/drivers/gpu/drm/drm_memory.c (revision a5907065)
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_agpsupport.h>
42 #include <drm/drm_cache.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 
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 #else /*  CONFIG_AGP  */
103 static inline void *agp_remap(unsigned long offset, unsigned long size,
104 			      struct drm_device *dev)
105 {
106 	return NULL;
107 }
108 
109 #endif /* CONFIG_AGP */
110 
111 void drm_legacy_ioremap(struct drm_local_map *map, struct drm_device *dev)
112 {
113 	if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
114 		map->handle = agp_remap(map->offset, map->size, dev);
115 	else
116 		map->handle = ioremap(map->offset, map->size);
117 }
118 EXPORT_SYMBOL(drm_legacy_ioremap);
119 
120 void drm_legacy_ioremap_wc(struct drm_local_map *map, struct drm_device *dev)
121 {
122 	if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
123 		map->handle = agp_remap(map->offset, map->size, dev);
124 	else
125 		map->handle = ioremap_wc(map->offset, map->size);
126 }
127 EXPORT_SYMBOL(drm_legacy_ioremap_wc);
128 
129 void drm_legacy_ioremapfree(struct drm_local_map *map, struct drm_device *dev)
130 {
131 	if (!map->handle || !map->size)
132 		return;
133 
134 	if (dev->agp && dev->agp->cant_use_aperture && map->type == _DRM_AGP)
135 		vunmap(map->handle);
136 	else
137 		iounmap(map->handle);
138 }
139 EXPORT_SYMBOL(drm_legacy_ioremapfree);
140