1 /* $NetBSD: drm_cache.c,v 1.2 2014/03/18 18:20:42 riastradh 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 1.2 2014/03/18 18:20:42 riastradh Exp $"); 34 35 #include <sys/types.h> 36 #include <sys/xcall.h> 37 38 #include <uvm/uvm_extern.h> 39 40 #include <machine/cpufunc.h> 41 42 #include <linux/mm_types.h> 43 44 #include <drm/drmP.h> 45 46 static bool drm_md_clflush_finegrained_p(void); 47 static void drm_md_clflush_all(void); 48 static void drm_md_clflush_page(struct page *); 49 static void drm_md_clflush_virt_range(const void *, size_t); 50 51 void 52 drm_clflush_pglist(struct pglist *list) 53 { 54 55 if (drm_md_clflush_finegrained_p()) { 56 struct vm_page *page; 57 58 TAILQ_FOREACH(page, list, pageq.queue) 59 drm_md_clflush_page(container_of(page, struct page, 60 p_vmp)); 61 } else { 62 drm_md_clflush_all(); 63 } 64 } 65 66 void 67 drm_clflush_page(struct page *page) 68 { 69 70 if (drm_md_clflush_finegrained_p()) 71 drm_md_clflush_page(page); 72 else 73 drm_md_clflush_all(); 74 } 75 76 void 77 drm_clflush_virt_range(const void *vaddr, size_t nbytes) 78 { 79 80 if (drm_md_clflush_finegrained_p()) 81 drm_md_clflush_virt_range(vaddr, nbytes); 82 else 83 drm_md_clflush_all(); 84 } 85 86 #if defined(__i386__) || defined(__x86_64__) 87 88 static bool 89 drm_md_clflush_finegrained_p(void) 90 { 91 return ISSET(cpu_info_primary.ci_feat_val[0], CPUID_CFLUSH); 92 } 93 94 static void 95 drm_x86_clflush_cpu(void) 96 { 97 asm volatile ("wbinvd"); 98 } 99 100 static void 101 drm_x86_clflush(const void *vaddr) 102 { 103 asm volatile ("clflush %0" : : "m" (*(const char *)vaddr)); 104 } 105 106 static size_t 107 drm_x86_clflush_size(void) 108 { 109 KASSERT(drm_md_clflush_finegrained_p()); 110 return cpu_info_primary.ci_cflush_lsize; 111 } 112 113 static void 114 drm_x86_clflush_xc(void *arg0 __unused, void *arg1 __unused) 115 { 116 drm_x86_clflush_cpu(); 117 } 118 119 static void 120 drm_md_clflush_all(void) 121 { 122 xc_wait(xc_broadcast(0, &drm_x86_clflush_xc, NULL, NULL)); 123 } 124 125 static void 126 drm_md_clflush_page(struct page *page) 127 { 128 void *const vaddr = kmap_atomic(page); 129 130 drm_md_clflush_virt_range(vaddr, PAGE_SIZE); 131 132 kunmap_atomic(vaddr); 133 } 134 135 static void 136 drm_md_clflush_virt_range(const void *vaddr, size_t nbytes) 137 138 { 139 const char *const start = vaddr, *const end = (start + nbytes); 140 const char *p; 141 const unsigned int clflush_size = drm_x86_clflush_size(); 142 143 KASSERT(drm_md_clflush_finegrained_p()); 144 for (p = start; p < end; p += clflush_size) 145 drm_x86_clflush(p); 146 } 147 148 #endif /* defined(__i386__) || defined(__x86_64__) */ 149