1/*	$NetBSD: ttm_agp_backend.c,v 1.3 2021/12/18 23:45:44 riastradh Exp $	*/
2
3/* SPDX-License-Identifier: GPL-2.0 OR MIT */
4/**************************************************************************
5 *
6 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
7 * All Rights Reserved.
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a
10 * copy of this software and associated documentation files (the
11 * "Software"), to deal in the Software without restriction, including
12 * without limitation the rights to use, copy, modify, merge, publish,
13 * distribute, sub license, and/or sell copies of the Software, and to
14 * permit persons to whom the Software is furnished to do so, subject to
15 * the following conditions:
16 *
17 * The above copyright notice and this permission notice (including the
18 * next paragraph) shall be included in all copies or substantial portions
19 * of the Software.
20 *
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
22 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
24 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
25 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
26 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
27 * USE OR OTHER DEALINGS IN THE SOFTWARE.
28 *
29 **************************************************************************/
30/*
31 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
32 *          Keith Packard.
33 */
34
35#include <sys/cdefs.h>
36__KERNEL_RCSID(0, "$NetBSD: ttm_agp_backend.c,v 1.3 2021/12/18 23:45:44 riastradh Exp $");
37
38#define pr_fmt(fmt) "[TTM] " fmt
39
40#include <drm/ttm/ttm_module.h>
41#include <drm/ttm/ttm_bo_driver.h>
42#include <drm/ttm/ttm_page_alloc.h>
43#include <drm/ttm/ttm_placement.h>
44#include <linux/agp_backend.h>
45#include <linux/module.h>
46#include <linux/slab.h>
47#include <linux/io.h>
48#include <asm/agp.h>
49
50struct ttm_agp_backend {
51	struct ttm_tt ttm;
52	struct agp_memory *mem;
53	struct agp_bridge_data *bridge;
54};
55
56static int ttm_agp_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
57{
58	struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);
59	struct page *dummy_read_page = ttm_bo_glob.dummy_read_page;
60	struct drm_mm_node *node = bo_mem->mm_node;
61	struct agp_memory *mem;
62	int ret, cached = (bo_mem->placement & TTM_PL_FLAG_CACHED);
63	unsigned i;
64
65	mem = agp_allocate_memory(agp_be->bridge, ttm->num_pages, AGP_USER_MEMORY);
66	if (unlikely(mem == NULL))
67		return -ENOMEM;
68
69	mem->page_count = 0;
70	for (i = 0; i < ttm->num_pages; i++) {
71		struct page *page = ttm->pages[i];
72
73		if (!page)
74			page = dummy_read_page;
75
76		mem->pages[mem->page_count++] = page;
77	}
78	agp_be->mem = mem;
79
80	mem->is_flushed = 1;
81	mem->type = (cached) ? AGP_USER_CACHED_MEMORY : AGP_USER_MEMORY;
82
83	ret = agp_bind_memory(mem, node->start);
84	if (ret)
85		pr_err("AGP Bind memory failed\n");
86
87	return ret;
88}
89
90static int ttm_agp_unbind(struct ttm_tt *ttm)
91{
92	struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);
93
94	if (agp_be->mem) {
95		if (agp_be->mem->is_bound)
96			return agp_unbind_memory(agp_be->mem);
97		agp_free_memory(agp_be->mem);
98		agp_be->mem = NULL;
99	}
100	return 0;
101}
102
103static void ttm_agp_destroy(struct ttm_tt *ttm)
104{
105	struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);
106
107	if (agp_be->mem)
108		ttm_agp_unbind(ttm);
109	ttm_tt_fini(ttm);
110	kfree(agp_be);
111}
112
113static struct ttm_backend_func ttm_agp_func = {
114	.bind = ttm_agp_bind,
115	.unbind = ttm_agp_unbind,
116	.destroy = ttm_agp_destroy,
117};
118
119struct ttm_tt *ttm_agp_tt_create(struct ttm_buffer_object *bo,
120				 struct agp_bridge_data *bridge,
121				 uint32_t page_flags)
122{
123	struct ttm_agp_backend *agp_be;
124
125	agp_be = kmalloc(sizeof(*agp_be), GFP_KERNEL);
126	if (!agp_be)
127		return NULL;
128
129	agp_be->mem = NULL;
130	agp_be->bridge = bridge;
131	agp_be->ttm.func = &ttm_agp_func;
132
133	if (ttm_tt_init(&agp_be->ttm, bo, page_flags)) {
134		kfree(agp_be);
135		return NULL;
136	}
137
138	return &agp_be->ttm;
139}
140EXPORT_SYMBOL(ttm_agp_tt_create);
141
142int ttm_agp_tt_populate(struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
143{
144	if (ttm->state != tt_unpopulated)
145		return 0;
146
147	return ttm_pool_populate(ttm, ctx);
148}
149EXPORT_SYMBOL(ttm_agp_tt_populate);
150
151void ttm_agp_tt_unpopulate(struct ttm_tt *ttm)
152{
153	ttm_pool_unpopulate(ttm);
154}
155EXPORT_SYMBOL(ttm_agp_tt_unpopulate);
156