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 <linux/highmem.h>
33
34 #include <drm/drm_cache.h>
35
36 #if defined(CONFIG_X86)
37 #include <asm/smp.h>
38
39 /*
40 * clflushopt is an unordered instruction which needs fencing with mfence or
41 * sfence to avoid ordering issues. For drm_clflush_page this fencing happens
42 * in the caller.
43 */
44 static void
45 drm_clflush_page(struct page *page)
46 {
47 uint8_t *page_virtual;
48 unsigned int i;
49 const int size = boot_cpu_data.x86_clflush_size;
50
51 if (unlikely(page == NULL))
52 return;
53
54 page_virtual = kmap_atomic(page);
55 for (i = 0; i < PAGE_SIZE; i += size)
56 clflushopt(page_virtual + i);
57 kunmap_atomic(page_virtual);
58 }
59
60 static void drm_cache_flush_clflush(struct page *pages[],
61 unsigned long num_pages)
62 {
63 unsigned long i;
64
65 mb();
66 for (i = 0; i < num_pages; i++)
67 drm_clflush_page(*pages++);
68 mb();
69 }
70 #endif
71
72 /**
73 * drm_clflush_pages - Flush dcache lines of a set of pages.
74 * @pages: List of pages to be flushed.
75 * @num_pages: Number of pages in the array.
76 *
77 * Flush every data cache line entry that points to an address belonging
78 * to a page in the array.
79 */
80 void
81 drm_clflush_pages(struct page *pages[], unsigned long num_pages)
82 {
83
84 #if defined(CONFIG_X86)
85 if (static_cpu_has(X86_FEATURE_CLFLUSH)) {
86 drm_cache_flush_clflush(pages, num_pages);
87 return;
88 }
89
90 if (wbinvd_on_all_cpus())
91 pr_err("Timed out waiting for cache flush\n");
92
93 #elif defined(__powerpc__)
94 unsigned long i;
95 for (i = 0; i < num_pages; i++) {
96 struct page *page = pages[i];
97 void *page_virtual;
98
99 if (unlikely(page == NULL))
100 continue;
101
102 page_virtual = kmap_atomic(page);
103 flush_dcache_range((unsigned long)page_virtual,
104 (unsigned long)page_virtual + PAGE_SIZE);
105 kunmap_atomic(page_virtual);
106 }
107 #else
108 pr_err("Architecture has no drm_cache.c support\n");
109 WARN_ON_ONCE(1);
110 #endif
111 }
112 EXPORT_SYMBOL(drm_clflush_pages);
113
114 /**
115 * drm_clflush_sg - Flush dcache lines pointing to a scather-gather.
116 * @st: struct sg_table.
117 *
118 * Flush every data cache line entry that points to an address in the
119 * sg.
120 */
121 void
122 drm_clflush_sg(struct sg_table *st)
123 {
124 #if defined(CONFIG_X86)
125 if (static_cpu_has(X86_FEATURE_CLFLUSH)) {
126 struct sg_page_iter sg_iter;
127
128 mb();
129 for_each_sg_page(st->sgl, &sg_iter, st->nents, 0)
130 drm_clflush_page(sg_page_iter_page(&sg_iter));
131 mb();
132
133 return;
134 }
135
136 if (wbinvd_on_all_cpus())
137 pr_err("Timed out waiting for cache flush\n");
138 #else
139 pr_err("Architecture has no drm_cache.c support\n");
140 WARN_ON_ONCE(1);
141 #endif
142 }
143 EXPORT_SYMBOL(drm_clflush_sg);
144
145 /**
146 * drm_clflush_virt_range - Flush dcache lines of a region
147 * @addr: Initial kernel memory address.
148 * @length: Region size.
149 *
150 * Flush every data cache line entry that points to an address in the
151 * region requested.
152 */
153 void
154 drm_clflush_virt_range(void *addr, unsigned long length)
155 {
156 #if defined(CONFIG_X86)
157 if (static_cpu_has(X86_FEATURE_CLFLUSH)) {
158 const int size = boot_cpu_data.x86_clflush_size;
159 void *end = addr + length;
160 addr = (void *)(((unsigned long)addr) & -size);
161 mb();
162 for (; addr < end; addr += size)
163 clflushopt(addr);
164 clflushopt(end - 1); /* force serialisation */
165 mb();
166 return;
167 }
168
169 if (wbinvd_on_all_cpus())
170 pr_err("Timed out waiting for cache flush\n");
171 #else
172 pr_err("Architecture has no drm_cache.c support\n");
173 WARN_ON_ONCE(1);
174 #endif
175 }
176 EXPORT_SYMBOL(drm_clflush_virt_range);