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 * Jerome Glisse 31 */ 32 #include <linux/module.h> 33 #include <linux/device.h> 34 #include <linux/pgtable.h> 35 #include <linux/sched.h> 36 #include <linux/debugfs.h> 37 #include <drm/ttm/ttm_caching.h> 38 39 #include "ttm_module.h" 40 41 /** 42 * DOC: TTM 43 * 44 * TTM is a memory manager for accelerator devices with dedicated memory. 45 * 46 * The basic idea is that resources are grouped together in buffer objects of 47 * certain size and TTM handles lifetime, movement and CPU mappings of those 48 * objects. 49 * 50 * TODO: Add more design background and information here. 51 */ 52 53 /** 54 * ttm_prot_from_caching - Modify the page protection according to the 55 * ttm cacing mode 56 * @caching: The ttm caching mode 57 * @tmp: The original page protection 58 * 59 * Return: The modified page protection 60 */ 61 pgprot_t ttm_prot_from_caching(enum ttm_caching caching, pgprot_t tmp) 62 { 63 /* Cached mappings need no adjustment */ 64 if (caching == ttm_cached) 65 return tmp; 66 67 #if defined(__i386__) || defined(__x86_64__) 68 if (caching == ttm_write_combined) 69 tmp = pgprot_writecombine(tmp); 70 #ifndef CONFIG_UML 71 else if (boot_cpu_data.x86 > 3) 72 tmp = pgprot_noncached(tmp); 73 #endif /* CONFIG_UML */ 74 #endif /* __i386__ || __x86_64__ */ 75 #if defined(__ia64__) || defined(__arm__) || defined(__aarch64__) || \ 76 defined(__powerpc__) || defined(__mips__) || defined(__loongarch__) || \ 77 defined(__riscv) 78 if (caching == ttm_write_combined) 79 tmp = pgprot_writecombine(tmp); 80 else 81 tmp = pgprot_noncached(tmp); 82 #endif 83 #if defined(__sparc__) 84 tmp = pgprot_noncached(tmp); 85 #endif 86 return tmp; 87 } 88 89 MODULE_AUTHOR("Thomas Hellstrom, Jerome Glisse"); 90 MODULE_DESCRIPTION("TTM memory manager subsystem (for DRM device)"); 91 MODULE_LICENSE("GPL and additional rights"); 92