1 /* $NetBSD: linux_writecomb.c,v 1.2 2014/11/04 11:27:31 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: linux_writecomb.c,v 1.2 2014/11/04 11:27:31 jmcneill Exp $"); 34 35 #ifdef _KERNEL_OPT 36 #include "opt_mtrr.h" 37 #endif 38 39 #include <sys/kmem.h> 40 #include <sys/mutex.h> 41 42 #include <machine/mtrr.h> 43 44 #include <linux/idr.h> 45 #include <linux/io.h> 46 47 static struct { 48 kmutex_t lock; 49 struct idr idr; 50 } linux_writecomb __cacheline_aligned; 51 52 int 53 linux_writecomb_init(void) 54 { 55 56 mutex_init(&linux_writecomb.lock, MUTEX_DEFAULT, IPL_SCHED); 57 idr_init(&linux_writecomb.idr); 58 59 return 0; 60 } 61 62 void 63 linux_writecomb_fini(void) 64 { 65 66 KASSERT(idr_is_empty(&linux_writecomb.idr)); 67 idr_destroy(&linux_writecomb.idr); 68 mutex_destroy(&linux_writecomb.lock); 69 } 70 71 int 72 arch_phys_wc_add(unsigned long base, unsigned long size) 73 { 74 struct mtrr *mtrr; 75 int n = 1; 76 int id; 77 int ret; 78 79 mtrr = kmem_alloc(sizeof(*mtrr), KM_SLEEP); 80 mtrr->base = base; 81 mtrr->len = size; 82 mtrr->type = MTRR_TYPE_WC; 83 mtrr->flags = MTRR_VALID; 84 85 /* XXX errno NetBSD->Linux */ 86 ret = -mtrr_set(mtrr, &n, NULL, MTRR_GETSET_KERNEL); 87 if (ret) { 88 KASSERT(n == 0); 89 goto fail0; 90 } 91 KASSERT(n == 1); 92 93 idr_preload(GFP_KERNEL); 94 mutex_spin_enter(&linux_writecomb.lock); 95 id = idr_alloc(&linux_writecomb.idr, mtrr, 0, 0, GFP_NOWAIT); 96 mutex_spin_exit(&linux_writecomb.lock); 97 idr_preload_end(); 98 if (id < 0) 99 goto fail1; 100 101 return id; 102 103 fail1: KASSERT(id < 0); 104 mtrr->type = 0; 105 mtrr->flags = 0; 106 /* XXX errno NetBSD->Linux */ 107 ret = -mtrr_set(mtrr, &n, NULL, MTRR_GETSET_KERNEL); 108 KASSERT(ret == 0); 109 KASSERT(n == 1); 110 ret = id; 111 fail0: KASSERT(ret < 0); 112 kmem_free(mtrr, sizeof(*mtrr)); 113 return ret; 114 } 115 116 void 117 arch_phys_wc_del(int id) 118 { 119 struct mtrr *mtrr; 120 int n; 121 int ret __diagused; 122 123 KASSERT(0 <= id); 124 125 mutex_spin_enter(&linux_writecomb.lock); 126 mtrr = idr_find(&linux_writecomb.idr, id); 127 idr_remove(&linux_writecomb.idr, id); 128 mutex_spin_enter(&linux_writecomb.lock); 129 130 if (mtrr != NULL) { 131 mtrr->type = 0; 132 mtrr->flags = 0; 133 /* XXX errno NetBSD->Linux */ 134 ret = -mtrr_set(mtrr, &n, NULL, MTRR_GETSET_KERNEL); 135 KASSERT(ret == 0); 136 KASSERT(n == 1); 137 kmem_free(mtrr, sizeof(*mtrr)); 138 } 139 } 140 141 int 142 phys_wc_to_mtrr_index(int handle) 143 { 144 145 /* XXX Actually implement this...requires changes to our MTRR API. */ 146 return handle; 147 } 148