xref: /linux/drivers/gpu/drm/ttm/ttm_agp_backend.c (revision e058a84bfddc42ba356a2316f2cf1141974625c9)
1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
2 /**************************************************************************
3  *
4  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
5  * All Rights Reserved.
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a
8  * copy of this software and associated documentation files (the
9  * "Software"), to deal in the Software without restriction, including
10  * without limitation the rights to use, copy, modify, merge, publish,
11  * distribute, sub license, and/or sell copies of the Software, and to
12  * permit persons to whom the Software is furnished to do so, subject to
13  * the following conditions:
14  *
15  * The above copyright notice and this permission notice (including the
16  * next paragraph) shall be included in all copies or substantial portions
17  * of the Software.
18  *
19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
22  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
23  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
24  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
25  * USE OR OTHER DEALINGS IN THE SOFTWARE.
26  *
27  **************************************************************************/
28 /*
29  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
30  *          Keith Packard.
31  */
32 
33 #define pr_fmt(fmt) "[TTM] " fmt
34 
35 #include <drm/ttm/ttm_device.h>
36 #include <drm/ttm/ttm_tt.h>
37 #include <drm/ttm/ttm_resource.h>
38 #include <linux/agp_backend.h>
39 #include <linux/module.h>
40 #include <linux/slab.h>
41 #include <linux/io.h>
42 #include <asm/agp.h>
43 
44 struct ttm_agp_backend {
45 	struct ttm_tt ttm;
46 	struct agp_memory *mem;
47 	struct agp_bridge_data *bridge;
48 };
49 
50 int ttm_agp_bind(struct ttm_tt *ttm, struct ttm_resource *bo_mem)
51 {
52 	struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);
53 	struct page *dummy_read_page = ttm_glob.dummy_read_page;
54 	struct agp_memory *mem;
55 	int ret, cached = ttm->caching == ttm_cached;
56 	unsigned i;
57 
58 	if (agp_be->mem)
59 		return 0;
60 
61 	mem = agp_allocate_memory(agp_be->bridge, ttm->num_pages, AGP_USER_MEMORY);
62 	if (unlikely(mem == NULL))
63 		return -ENOMEM;
64 
65 	mem->page_count = 0;
66 	for (i = 0; i < ttm->num_pages; i++) {
67 		struct page *page = ttm->pages[i];
68 
69 		if (!page)
70 			page = dummy_read_page;
71 
72 		mem->pages[mem->page_count++] = page;
73 	}
74 	agp_be->mem = mem;
75 
76 	mem->is_flushed = 1;
77 	mem->type = (cached) ? AGP_USER_CACHED_MEMORY : AGP_USER_MEMORY;
78 
79 	ret = agp_bind_memory(mem, bo_mem->start);
80 	if (ret)
81 		pr_err("AGP Bind memory failed\n");
82 
83 	return ret;
84 }
85 EXPORT_SYMBOL(ttm_agp_bind);
86 
87 void ttm_agp_unbind(struct ttm_tt *ttm)
88 {
89 	struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);
90 
91 	if (agp_be->mem) {
92 		if (agp_be->mem->is_bound) {
93 			agp_unbind_memory(agp_be->mem);
94 			return;
95 		}
96 		agp_free_memory(agp_be->mem);
97 		agp_be->mem = NULL;
98 	}
99 }
100 EXPORT_SYMBOL(ttm_agp_unbind);
101 
102 bool ttm_agp_is_bound(struct ttm_tt *ttm)
103 {
104 	struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);
105 
106 	if (!ttm)
107 		return false;
108 
109 	return (agp_be->mem != NULL);
110 }
111 EXPORT_SYMBOL(ttm_agp_is_bound);
112 
113 void ttm_agp_destroy(struct ttm_tt *ttm)
114 {
115 	struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);
116 
117 	if (agp_be->mem)
118 		ttm_agp_unbind(ttm);
119 	ttm_tt_fini(ttm);
120 	kfree(agp_be);
121 }
122 EXPORT_SYMBOL(ttm_agp_destroy);
123 
124 struct ttm_tt *ttm_agp_tt_create(struct ttm_buffer_object *bo,
125 				 struct agp_bridge_data *bridge,
126 				 uint32_t page_flags)
127 {
128 	struct ttm_agp_backend *agp_be;
129 
130 	agp_be = kmalloc(sizeof(*agp_be), GFP_KERNEL);
131 	if (!agp_be)
132 		return NULL;
133 
134 	agp_be->mem = NULL;
135 	agp_be->bridge = bridge;
136 
137 	if (ttm_tt_init(&agp_be->ttm, bo, page_flags, ttm_write_combined)) {
138 		kfree(agp_be);
139 		return NULL;
140 	}
141 
142 	return &agp_be->ttm;
143 }
144 EXPORT_SYMBOL(ttm_agp_tt_create);
145