| 1 | /* $NetBSD: linux_writecomb.c,v 1.4 2015/10/17 21:06:42 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 1.4 2015/10/17 21:06:42 jmcneill 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 | |
| 53 | static struct { |
| 54 | kmutex_t lock; |
| 55 | struct idr idr; |
| 56 | } linux_writecomb __cacheline_aligned; |
| 57 | |
| 58 | int |
| 59 | linux_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 | |
| 68 | void |
| 69 | linux_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 | |
| 77 | int |
| 78 | arch_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 | |
| 110 | fail1: 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; |
| 118 | fail0: KASSERT(ret < 0); |
| 119 | kmem_free(mtrr, sizeof(*mtrr)); |
| 120 | return ret; |
| 121 | #else |
| 122 | return -1; |
| 123 | #endif |
| 124 | } |
| 125 | |
| 126 | void |
| 127 | arch_phys_wc_del(int id) |
| 128 | { |
| 129 | #if defined(MTRR) |
| 130 | struct mtrr *mtrr; |
| 131 | int n; |
| 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_enter(&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 | |
| 153 | int |
| 154 | phys_wc_to_mtrr_index(int handle) |
| 155 | { |
| 156 | |
| 157 | /* XXX Actually implement this...requires changes to our MTRR API. */ |
| 158 | return handle; |
| 159 | } |
| 160 | |