linux/linux-5.18.11/include/drm/ttm/ttm_caching.h

56 lines
1.8 KiB
C

/*
* Copyright 2020 Advanced Micro Devices, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Authors: Christian König
*/
#ifndef _TTM_CACHING_H_
#define _TTM_CACHING_H_
#define TTM_NUM_CACHING_TYPES 3
/**
* enum ttm_caching - CPU caching and BUS snooping behavior.
*/
enum ttm_caching {
/**
* @ttm_uncached: Most defensive option for device mappings,
* don't even allow write combining.
*/
ttm_uncached,
/**
* @ttm_write_combined: Don't cache read accesses, but allow at least
* writes to be combined.
*/
ttm_write_combined,
/**
* @ttm_cached: Fully cached like normal system memory, requires that
* devices snoop the CPU cache on accesses.
*/
ttm_cached
};
pgprot_t ttm_prot_from_caching(enum ttm_caching caching, pgprot_t tmp);
#endif