1/*
2 * Copyright 2020 Advanced Micro Devices, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * Authors: Christian König
23 */
24
25#ifndef _TTM_CACHING_H_
26#define _TTM_CACHING_H_
27
28#include <linux/pgtable.h>
29
30#define TTM_NUM_CACHING_TYPES 3
31
32/**
33 * enum ttm_caching - CPU caching and BUS snooping behavior.
34 */
35enum ttm_caching {
36 /**
37 * @ttm_uncached: Most defensive option for device mappings,
38 * don't even allow write combining.
39 */
40 ttm_uncached,
41
42 /**
43 * @ttm_write_combined: Don't cache read accesses, but allow at least
44 * writes to be combined.
45 */
46 ttm_write_combined,
47
48 /**
49 * @ttm_cached: Fully cached like normal system memory, requires that
50 * devices snoop the CPU cache on accesses.
51 */
52 ttm_cached
53};
54
55pgprot_t ttm_prot_from_caching(enum ttm_caching caching, pgprot_t tmp);
56
57#endif
58