1 /************************************************************************** 2 * 3 * Copyright (c) 2006-2007 Tungsten Graphics, Inc., Cedar Park, TX., USA 4 * All Rights Reserved. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the 8 * "Software"), to deal in the Software without restriction, including 9 * without limitation the rights to use, copy, modify, merge, publish, 10 * distribute, sub license, and/or sell copies of the Software, and to 11 * permit persons to whom the Software is furnished to do so, subject to 12 * the following conditions: 13 * 14 * The above copyright notice and this permission notice (including the 15 * next paragraph) shall be included in all copies or substantial portions 16 * of the Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, 22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 24 * USE OR OTHER DEALINGS IN THE SOFTWARE. 25 * 26 **************************************************************************/ 27 /* 28 * Authors: Thomas Hellström <thomas-at-tungstengraphics-dot-com> 29 */ 30 31 #include <linux/export.h> 32 #include <drm/drmP.h> 33 #include <asm/cpufeature.h> 34 35 /* 36 * clflushopt is an unordered instruction which needs fencing with mfence or 37 * sfence to avoid ordering issues. For drm_clflush_page this fencing happens 38 * in the caller. 39 */ 40 static void 41 drm_clflush_page(struct page *page) 42 { 43 uint8_t *page_virtual; 44 unsigned int i; 45 const int size = cpu_clflush_line_size; 46 47 if (unlikely(page == NULL)) 48 return; 49 50 page_virtual = kmap_atomic(page); 51 for (i = 0; i < PAGE_SIZE; i += size) 52 clflushopt(page_virtual + i); 53 kunmap_atomic(page_virtual); 54 } 55 56 static void drm_cache_flush_clflush(struct page *pages[], 57 unsigned long num_pages) 58 { 59 unsigned long i; 60 61 mb(); 62 for (i = 0; i < num_pages; i++) 63 drm_clflush_page(*pages++); 64 mb(); 65 } 66 67 void 68 drm_clflush_pages(struct page *pages[], unsigned long num_pages) 69 { 70 pmap_invalidate_cache_pages((struct vm_page **)pages, num_pages); 71 72 if (static_cpu_has(X86_FEATURE_CLFLUSH)) { 73 drm_cache_flush_clflush(pages, num_pages); 74 return; 75 } 76 77 cpu_wbinvd_on_all_cpus(); 78 } 79 EXPORT_SYMBOL(drm_clflush_pages); 80 81 void 82 drm_clflush_sg(struct sg_table *st) 83 { 84 if (static_cpu_has(X86_FEATURE_CLFLUSH)) { 85 struct sg_page_iter sg_iter; 86 87 mb(); 88 for_each_sg_page(st->sgl, &sg_iter, st->nents, 0) 89 drm_clflush_page(sg_page_iter_page(&sg_iter)); 90 mb(); 91 92 return; 93 } 94 95 cpu_wbinvd_on_all_cpus(); 96 } 97 EXPORT_SYMBOL(drm_clflush_sg); 98 99 void 100 drm_clflush_virt_range(void *in_addr, unsigned long length) 101 { 102 char *addr = in_addr; 103 104 if (static_cpu_has(X86_FEATURE_CLFLUSH)) { 105 const int size = cpu_clflush_line_size; 106 char *end = addr + length; 107 addr = (void *)(((unsigned long)addr) & -size); 108 mb(); 109 for (; addr < end; addr += size) 110 clflushopt(addr); 111 clflushopt(end - 1); /* force serialisation */ 112 mb(); 113 return; 114 } 115 116 cpu_wbinvd_on_all_cpus(); 117 } 118 EXPORT_SYMBOL(drm_clflush_virt_range); 119