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2  *
3  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
4  * All Rights Reserved.
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6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
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11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
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19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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26  **************************************************************************/
27 /*
28  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
29  *          Keith Packard.
30  */
31 
32 #include "ttm/ttm_module.h"
33 #include "ttm/ttm_bo_driver.h"
34 #ifdef TTM_HAS_AGP
35 #include "ttm/ttm_placement.h"
36 #include <linux/agp_backend.h>
37 #include <linux/module.h>
38 #include <linux/io.h>
39 #include <asm/agp.h>
40 
41 struct ttm_agp_backend {
42 	struct ttm_backend backend;
43 	struct agp_memory *mem;
44 	struct agp_bridge_data *bridge;
45 };
46 
47 static int ttm_agp_populate(struct ttm_backend *backend,
48 			    unsigned long num_pages, struct page **pages,
49 			    struct page *dummy_read_page)
50 {
51 	struct ttm_agp_backend *agp_be =
52 	    container_of(backend, struct ttm_agp_backend, backend);
53 	struct page **cur_page, **last_page = pages + num_pages;
54 	struct agp_memory *mem;
55 
56 	mem = agp_allocate_memory(agp_be->bridge, num_pages, AGP_USER_MEMORY);
57 	if (unlikely(mem == NULL))
58 		return -ENOMEM;
59 
60 	mem->page_count = 0;
61 	for (cur_page = pages; cur_page < last_page; ++cur_page) {
62 		struct page *page = *cur_page;
63 		if (!page)
64 			page = dummy_read_page;
65 
66 		mem->pages[mem->page_count++] = page;
67 	}
68 	agp_be->mem = mem;
69 	return 0;
70 }
71 
72 static int ttm_agp_bind(struct ttm_backend *backend, struct ttm_mem_reg *bo_mem)
73 {
74 	struct ttm_agp_backend *agp_be =
75 	    container_of(backend, struct ttm_agp_backend, backend);
76 	struct agp_memory *mem = agp_be->mem;
77 	int cached = (bo_mem->placement & TTM_PL_FLAG_CACHED);
78 	int ret;
79 
80 	mem->is_flushed = 1;
81 	mem->type = (cached) ? AGP_USER_CACHED_MEMORY : AGP_USER_MEMORY;
82 
83 	ret = agp_bind_memory(mem, bo_mem->mm_node->start);
84 	if (ret)
85 		printk(KERN_ERR TTM_PFX "AGP Bind memory failed.\n");
86 
87 	return ret;
88 }
89 
90 static int ttm_agp_unbind(struct ttm_backend *backend)
91 {
92 	struct ttm_agp_backend *agp_be =
93 	    container_of(backend, struct ttm_agp_backend, backend);
94 
95 	if (agp_be->mem->is_bound)
96 		return agp_unbind_memory(agp_be->mem);
97 	else
98 		return 0;
99 }
100 
101 static void ttm_agp_clear(struct ttm_backend *backend)
102 {
103 	struct ttm_agp_backend *agp_be =
104 	    container_of(backend, struct ttm_agp_backend, backend);
105 	struct agp_memory *mem = agp_be->mem;
106 
107 	if (mem) {
108 		ttm_agp_unbind(backend);
109 		agp_free_memory(mem);
110 	}
111 	agp_be->mem = NULL;
112 }
113 
114 static void ttm_agp_destroy(struct ttm_backend *backend)
115 {
116 	struct ttm_agp_backend *agp_be =
117 	    container_of(backend, struct ttm_agp_backend, backend);
118 
119 	if (agp_be->mem)
120 		ttm_agp_clear(backend);
121 	kfree(agp_be);
122 }
123 
124 static struct ttm_backend_func ttm_agp_func = {
125 	.populate = ttm_agp_populate,
126 	.clear = ttm_agp_clear,
127 	.bind = ttm_agp_bind,
128 	.unbind = ttm_agp_unbind,
129 	.destroy = ttm_agp_destroy,
130 };
131 
132 struct ttm_backend *ttm_agp_backend_init(struct ttm_bo_device *bdev,
133 					 struct agp_bridge_data *bridge)
134 {
135 	struct ttm_agp_backend *agp_be;
136 
137 	agp_be = kmalloc(sizeof(*agp_be), GFP_KERNEL);
138 	if (!agp_be)
139 		return NULL;
140 
141 	agp_be->mem = NULL;
142 	agp_be->bridge = bridge;
143 	agp_be->backend.func = &ttm_agp_func;
144 	agp_be->backend.bdev = bdev;
145 	return &agp_be->backend;
146 }
147 EXPORT_SYMBOL(ttm_agp_backend_init);
148 
149 #endif
150