ttm_agp_backend.c

  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/export.h>
 40#include <linux/module.h>
 41#include <linux/slab.h>
 42#include <linux/io.h>
 43#include <asm/agp.h>
 44
 45struct ttm_agp_backend {
 46	struct ttm_tt ttm;
 47	struct agp_memory *mem;
 48	struct agp_bridge_data *bridge;
 49};
 50
 51int ttm_agp_bind(struct ttm_tt *ttm, struct ttm_resource *bo_mem)
 52{
 53	struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);
 54	struct page *dummy_read_page = ttm_glob.dummy_read_page;
 55	struct agp_memory *mem;
 56	int ret, cached = ttm->caching == ttm_cached;
 57	unsigned i;
 58
 59	if (agp_be->mem)
 60		return 0;
 61
 62	mem = agp_allocate_memory(agp_be->bridge, ttm->num_pages, AGP_USER_MEMORY);
 63	if (unlikely(mem == NULL))
 64		return -ENOMEM;
 65
 66	mem->page_count = 0;
 67	for (i = 0; i < ttm->num_pages; i++) {
 68		struct page *page = ttm->pages[i];
 69
 70		if (!page)
 71			page = dummy_read_page;
 72
 73		mem->pages[mem->page_count++] = page;
 74	}
 75	agp_be->mem = mem;
 76
 77	mem->is_flushed = 1;
 78	mem->type = (cached) ? AGP_USER_CACHED_MEMORY : AGP_USER_MEMORY;
 79
 80	ret = agp_bind_memory(mem, bo_mem->start);
 81	if (ret)
 82		pr_err("AGP Bind memory failed\n");
 83
 84	return ret;
 85}
 86EXPORT_SYMBOL(ttm_agp_bind);
 87
 88void ttm_agp_unbind(struct ttm_tt *ttm)
 89{
 90	struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);
 91
 92	if (agp_be->mem) {
 93		if (agp_be->mem->is_bound) {
 94			agp_unbind_memory(agp_be->mem);
 95			return;
 96		}
 97		agp_free_memory(agp_be->mem);
 98		agp_be->mem = NULL;
 99	}
100}
101EXPORT_SYMBOL(ttm_agp_unbind);
102
103bool ttm_agp_is_bound(struct ttm_tt *ttm)
104{
105	struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);
106
107	if (!ttm)
108		return false;
109
110	return (agp_be->mem != NULL);
111}
112EXPORT_SYMBOL(ttm_agp_is_bound);
113
114void ttm_agp_destroy(struct ttm_tt *ttm)
115{
116	struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);
117
118	if (agp_be->mem)
119		ttm_agp_unbind(ttm);
120	ttm_tt_fini(ttm);
121	kfree(agp_be);
122}
123EXPORT_SYMBOL(ttm_agp_destroy);
124
125struct ttm_tt *ttm_agp_tt_create(struct ttm_buffer_object *bo,
126				 struct agp_bridge_data *bridge,
127				 uint32_t page_flags)
128{
129	struct ttm_agp_backend *agp_be;
130
131	agp_be = kmalloc(sizeof(*agp_be), GFP_KERNEL);
132	if (!agp_be)
133		return NULL;
134
135	agp_be->mem = NULL;
136	agp_be->bridge = bridge;
137
138	if (ttm_tt_init(&agp_be->ttm, bo, page_flags, ttm_write_combined, 0)) {
139		kfree(agp_be);
140		return NULL;
141	}
142
143	return &agp_be->ttm;
144}
145EXPORT_SYMBOL(ttm_agp_tt_create);