linux_writecomb.c revision 1.6
1/* $NetBSD: linux_writecomb.c,v 1.6 2018/08/14 14:53:21 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: linux_writecomb.c,v 1.6 2018/08/14 14:53:21 riastradh Exp $"); 34 35#if defined(__i386__) || defined(__x86_64__) 36#define HAS_MTRR 1 37#endif 38 39#if defined(_KERNEL_OPT) && defined(HAS_MTRR) 40#include "opt_mtrr.h" 41#endif 42 43#include <sys/kmem.h> 44#include <sys/mutex.h> 45 46#if defined(MTRR) 47#include <machine/mtrr.h> 48#endif 49 50#include <linux/idr.h> 51#include <linux/io.h> 52 53static struct { 54 kmutex_t lock; 55 struct idr idr; 56} linux_writecomb __cacheline_aligned; 57 58int 59linux_writecomb_init(void) 60{ 61 62 mutex_init(&linux_writecomb.lock, MUTEX_DEFAULT, IPL_VM); 63 idr_init(&linux_writecomb.idr); 64 65 return 0; 66} 67 68void 69linux_writecomb_fini(void) 70{ 71 72 KASSERT(idr_is_empty(&linux_writecomb.idr)); 73 idr_destroy(&linux_writecomb.idr); 74 mutex_destroy(&linux_writecomb.lock); 75} 76 77int 78arch_phys_wc_add(unsigned long base, unsigned long size) 79{ 80#if defined(MTRR) 81 struct mtrr *mtrr; 82 int n = 1; 83 int id; 84 int ret; 85 86 mtrr = kmem_alloc(sizeof(*mtrr), KM_SLEEP); 87 mtrr->base = base; 88 mtrr->len = size; 89 mtrr->type = MTRR_TYPE_WC; 90 mtrr->flags = MTRR_VALID; 91 92 /* XXX errno NetBSD->Linux */ 93 ret = -mtrr_set(mtrr, &n, NULL, MTRR_GETSET_KERNEL); 94 if (ret) { 95 KASSERT(n == 0); 96 goto fail0; 97 } 98 KASSERT(n == 1); 99 100 idr_preload(GFP_KERNEL); 101 mutex_spin_enter(&linux_writecomb.lock); 102 id = idr_alloc(&linux_writecomb.idr, mtrr, 0, 0, GFP_NOWAIT); 103 mutex_spin_exit(&linux_writecomb.lock); 104 idr_preload_end(); 105 if (id < 0) 106 goto fail1; 107 108 return id; 109 110fail1: KASSERT(id < 0); 111 mtrr->type = 0; 112 mtrr->flags = 0; 113 /* XXX errno NetBSD->Linux */ 114 ret = -mtrr_set(mtrr, &n, NULL, MTRR_GETSET_KERNEL); 115 KASSERT(ret == 0); 116 KASSERT(n == 1); 117 ret = id; 118fail0: KASSERT(ret < 0); 119 kmem_free(mtrr, sizeof(*mtrr)); 120 return ret; 121#else 122 return -1; 123#endif 124} 125 126void 127arch_phys_wc_del(int id) 128{ 129#if defined(MTRR) 130 struct mtrr *mtrr; 131 int n = 1; 132 int ret __diagused; 133 134 KASSERT(0 <= id); 135 136 mutex_spin_enter(&linux_writecomb.lock); 137 mtrr = idr_find(&linux_writecomb.idr, id); 138 idr_remove(&linux_writecomb.idr, id); 139 mutex_spin_exit(&linux_writecomb.lock); 140 141 if (mtrr != NULL) { 142 mtrr->type = 0; 143 mtrr->flags = 0; 144 /* XXX errno NetBSD->Linux */ 145 ret = -mtrr_set(mtrr, &n, NULL, MTRR_GETSET_KERNEL); 146 KASSERT(ret == 0); 147 KASSERT(n == 1); 148 kmem_free(mtrr, sizeof(*mtrr)); 149 } 150#endif 151} 152 153int 154phys_wc_to_mtrr_index(int handle) 155{ 156 157 /* XXX Actually implement this...requires changes to our MTRR API. */ 158 return handle; 159} 160