1 /* $NetBSD: drm_cache.c,v 1.4 2021/12/19 01:24:25 riastradh Exp $ */ 2 3 /************************************************************************** 4 * 5 * Copyright (c) 2006-2007 Tungsten Graphics, Inc., Cedar Park, TX., USA 6 * All Rights Reserved. 7 * 8 * Permission is hereby granted, free of charge, to any person obtaining a 9 * copy of this software and associated documentation files (the 10 * "Software"), to deal in the Software without restriction, including 11 * without limitation the rights to use, copy, modify, merge, publish, 12 * distribute, sub license, and/or sell copies of the Software, and to 13 * permit persons to whom the Software is furnished to do so, subject to 14 * the following conditions: 15 * 16 * The above copyright notice and this permission notice (including the 17 * next paragraph) shall be included in all copies or substantial portions 18 * of the Software. 19 * 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 23 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, 24 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 25 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 26 * USE OR OTHER DEALINGS IN THE SOFTWARE. 27 * 28 **************************************************************************/ 29 /* 30 * Authors: Thomas Hellstrm <thomas-at-tungstengraphics-dot-com> 31 */ 32 33 #include <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: drm_cache.c,v 1.4 2021/12/19 01:24:25 riastradh Exp $"); 35 36 #include <linux/export.h> 37 #include <linux/highmem.h> 38 39 #include <drm/drm_cache.h> 40 41 #if defined(CONFIG_X86) 42 #include <asm/smp.h> 43 44 /* 45 * clflushopt is an unordered instruction which needs fencing with mfence or 46 * sfence to avoid ordering issues. For drm_clflush_page this fencing happens 47 * in the caller. 48 */ 49 static void 50 drm_clflush_page(struct page *page) 51 { 52 uint8_t *page_virtual; 53 unsigned int i; 54 const int size = boot_cpu_data.x86_clflush_size; 55 56 if (unlikely(page == NULL)) 57 return; 58 59 page_virtual = kmap_atomic(page); 60 for (i = 0; i < PAGE_SIZE; i += size) 61 clflushopt(page_virtual + i); 62 kunmap_atomic(page_virtual); 63 } 64 65 static void drm_cache_flush_clflush(struct page *pages[], 66 unsigned long num_pages) 67 { 68 unsigned long i; 69 70 mb(); /*Full memory barrier used before so that CLFLUSH is ordered*/ 71 for (i = 0; i < num_pages; i++) 72 drm_clflush_page(*pages++); 73 mb(); /*Also used after CLFLUSH so that all cache is flushed*/ 74 } 75 #endif 76 77 /** 78 * drm_clflush_pages - Flush dcache lines of a set of pages. 79 * @pages: List of pages to be flushed. 80 * @num_pages: Number of pages in the array. 81 * 82 * Flush every data cache line entry that points to an address belonging 83 * to a page in the array. 84 */ 85 void 86 drm_clflush_pages(struct page *pages[], unsigned long num_pages) 87 { 88 89 #if defined(CONFIG_X86) 90 if (static_cpu_has(X86_FEATURE_CLFLUSH)) { 91 drm_cache_flush_clflush(pages, num_pages); 92 return; 93 } 94 95 if (wbinvd_on_all_cpus()) 96 pr_err("Timed out waiting for cache flush\n"); 97 98 #elif defined(__powerpc__) 99 unsigned long i; 100 101 for (i = 0; i < num_pages; i++) { 102 struct page *page = pages[i]; 103 void *page_virtual; 104 105 if (unlikely(page == NULL)) 106 continue; 107 108 page_virtual = kmap_atomic(page); 109 flush_dcache_range((unsigned long)page_virtual, 110 (unsigned long)page_virtual + PAGE_SIZE); 111 kunmap_atomic(page_virtual); 112 } 113 #else 114 pr_err("Architecture has no drm_cache.c support\n"); 115 WARN_ON_ONCE(1); 116 #endif 117 } 118 EXPORT_SYMBOL(drm_clflush_pages); 119 120 /** 121 * drm_clflush_sg - Flush dcache lines pointing to a scather-gather. 122 * @st: struct sg_table. 123 * 124 * Flush every data cache line entry that points to an address in the 125 * sg. 126 */ 127 void 128 drm_clflush_sg(struct sg_table *st) 129 { 130 #if defined(CONFIG_X86) 131 if (static_cpu_has(X86_FEATURE_CLFLUSH)) { 132 struct sg_page_iter sg_iter; 133 134 mb(); /*CLFLUSH is ordered only by using memory barriers*/ 135 for_each_sg_page(st->sgl, &sg_iter, st->nents, 0) 136 drm_clflush_page(sg_page_iter_page(&sg_iter)); 137 mb(); /*Make sure that all cache line entry is flushed*/ 138 139 return; 140 } 141 142 if (wbinvd_on_all_cpus()) 143 pr_err("Timed out waiting for cache flush\n"); 144 #else 145 pr_err("Architecture has no drm_cache.c support\n"); 146 WARN_ON_ONCE(1); 147 #endif 148 } 149 EXPORT_SYMBOL(drm_clflush_sg); 150 151 /** 152 * drm_clflush_virt_range - Flush dcache lines of a region 153 * @addr: Initial kernel memory address. 154 * @length: Region size. 155 * 156 * Flush every data cache line entry that points to an address in the 157 * region requested. 158 */ 159 void 160 drm_clflush_virt_range(void *addr, unsigned long length) 161 { 162 #if defined(CONFIG_X86) 163 if (static_cpu_has(X86_FEATURE_CLFLUSH)) { 164 #ifdef __NetBSD__ 165 const int size = cpu_info_primary.ci_cflush_lsize; 166 #else 167 const int size = boot_cpu_data.x86_clflush_size; 168 #endif 169 void *end = addr + length; 170 171 addr = (void *)(((unsigned long)addr) & -size); 172 mb(); /*CLFLUSH is only ordered with a full memory barrier*/ 173 for (; addr < end; addr += size) 174 clflushopt(addr); 175 clflushopt(end - 1); /* force serialisation */ 176 mb(); /*Ensure that evry data cache line entry is flushed*/ 177 return; 178 } 179 180 if (wbinvd_on_all_cpus()) 181 pr_err("Timed out waiting for cache flush\n"); 182 #else 183 pr_err("Architecture has no drm_cache.c support\n"); 184 WARN_ON_ONCE(1); 185 #endif 186 } 187 EXPORT_SYMBOL(drm_clflush_virt_range); 188
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