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 */ 35 enum 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 55 pgprot_t ttm_prot_from_caching(enum ttm_caching caching, pgprot_t tmp); 56 57 #endif 58