1 /* $NetBSD: drm_cache.c,v 1.8 2015/10/17 21:11:56 jmcneill Exp $ */ 2 3 /*- 4 * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Taylor R. Campbell. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: drm_cache.c,v 1.8 2015/10/17 21:11:56 jmcneill Exp $"); 34 35 #include <sys/param.h> 36 #include <sys/types.h> 37 #include <sys/xcall.h> 38 39 #include <uvm/uvm_extern.h> 40 41 #include <linux/mm_types.h> 42 43 #include <drm/drmP.h> 44 45 #if !defined(__arm__) 46 #define DRM_CLFLUSH 1 47 #endif 48 49 #if defined(DRM_CLFLUSH) 50 static bool drm_md_clflush_finegrained_p(void); 51 static void drm_md_clflush_all(void); 52 static void drm_md_clflush_page(struct page *); 53 static void drm_md_clflush_virt_range(const void *, size_t); 54 #endif 55 56 void 57 drm_clflush_pages(struct page **pages, unsigned long npages) 58 { 59 #if defined(DRM_CLFLUSH) 60 if (drm_md_clflush_finegrained_p()) { 61 while (npages--) 62 drm_md_clflush_page(pages[npages]); 63 } else { 64 drm_md_clflush_all(); 65 } 66 #endif 67 } 68 69 void 70 drm_clflush_pglist(struct pglist *list) 71 { 72 #if defined(DRM_CLFLUSH) 73 if (drm_md_clflush_finegrained_p()) { 74 struct vm_page *page; 75 76 TAILQ_FOREACH(page, list, pageq.queue) 77 drm_md_clflush_page(container_of(page, struct page, 78 p_vmp)); 79 } else { 80 drm_md_clflush_all(); 81 } 82 #endif 83 } 84 85 void 86 drm_clflush_page(struct page *page) 87 { 88 #if defined(DRM_CLFLUSH) 89 if (drm_md_clflush_finegrained_p()) 90 drm_md_clflush_page(page); 91 else 92 drm_md_clflush_all(); 93 #endif 94 } 95 96 void 97 drm_clflush_virt_range(const void *vaddr, size_t nbytes) 98 { 99 #if defined(DRM_CLFLUSH) 100 if (drm_md_clflush_finegrained_p()) 101 drm_md_clflush_virt_range(vaddr, nbytes); 102 else 103 drm_md_clflush_all(); 104 #endif 105 } 106 107 #if defined(__i386__) || defined(__x86_64__) 108 109 #include <machine/cpufunc.h> 110 111 static bool 112 drm_md_clflush_finegrained_p(void) 113 { 114 return ISSET(cpu_info_primary.ci_feat_val[0], CPUID_CFLUSH); 115 } 116 117 static void 118 drm_x86_clflush(const void *vaddr) 119 { 120 asm volatile ("clflush %0" : : "m" (*(const char *)vaddr)); 121 } 122 123 static size_t 124 drm_x86_clflush_size(void) 125 { 126 KASSERT(drm_md_clflush_finegrained_p()); 127 return cpu_info_primary.ci_cflush_lsize; 128 } 129 130 static void 131 drm_x86_clflush_xc(void *arg0 __unused, void *arg1 __unused) 132 { 133 wbinvd(); 134 } 135 136 static void 137 drm_md_clflush_all(void) 138 { 139 xc_wait(xc_broadcast(0, &drm_x86_clflush_xc, NULL, NULL)); 140 } 141 142 static void 143 drm_md_clflush_page(struct page *page) 144 { 145 void *const vaddr = kmap_atomic(page); 146 147 drm_md_clflush_virt_range(vaddr, PAGE_SIZE); 148 149 kunmap_atomic(vaddr); 150 } 151 152 static void 153 drm_md_clflush_virt_range(const void *vaddr, size_t nbytes) 154 { 155 const unsigned clflush_size = drm_x86_clflush_size(); 156 const vaddr_t va = (vaddr_t)vaddr; 157 const char *const start = (const void *)rounddown(va, clflush_size); 158 const char *const end = (const void *)roundup(va + nbytes, 159 clflush_size); 160 const char *p; 161 162 /* Support for CLFLUSH implies support for MFENCE. */ 163 KASSERT(drm_md_clflush_finegrained_p()); 164 x86_mfence(); 165 for (p = start; p < end; p += clflush_size) 166 drm_x86_clflush(p); 167 x86_mfence(); 168 } 169 170 #endif /* defined(__i386__) || defined(__x86_64__) */ 171