linux_kmap.c revision 1.4.10.2
1 1.4.10.2 tls /* $NetBSD: linux_kmap.c,v 1.4.10.2 2014/08/20 00:04:22 tls Exp $ */ 2 1.4.10.2 tls 3 1.4.10.2 tls /*- 4 1.4.10.2 tls * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 1.4.10.2 tls * All rights reserved. 6 1.4.10.2 tls * 7 1.4.10.2 tls * This code is derived from software contributed to The NetBSD Foundation 8 1.4.10.2 tls * by Taylor R. Campbell. 9 1.4.10.2 tls * 10 1.4.10.2 tls * Redistribution and use in source and binary forms, with or without 11 1.4.10.2 tls * modification, are permitted provided that the following conditions 12 1.4.10.2 tls * are met: 13 1.4.10.2 tls * 1. Redistributions of source code must retain the above copyright 14 1.4.10.2 tls * notice, this list of conditions and the following disclaimer. 15 1.4.10.2 tls * 2. Redistributions in binary form must reproduce the above copyright 16 1.4.10.2 tls * notice, this list of conditions and the following disclaimer in the 17 1.4.10.2 tls * documentation and/or other materials provided with the distribution. 18 1.4.10.2 tls * 19 1.4.10.2 tls * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 1.4.10.2 tls * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.4.10.2 tls * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.4.10.2 tls * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 1.4.10.2 tls * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 1.4.10.2 tls * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 1.4.10.2 tls * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 1.4.10.2 tls * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 1.4.10.2 tls * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 1.4.10.2 tls * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 1.4.10.2 tls * POSSIBILITY OF SUCH DAMAGE. 30 1.4.10.2 tls */ 31 1.4.10.2 tls 32 1.4.10.2 tls #include <sys/cdefs.h> 33 1.4.10.2 tls __KERNEL_RCSID(0, "$NetBSD: linux_kmap.c,v 1.4.10.2 2014/08/20 00:04:22 tls Exp $"); 34 1.4.10.2 tls 35 1.4.10.2 tls #include <sys/types.h> 36 1.4.10.2 tls #include <sys/kmem.h> 37 1.4.10.2 tls #include <sys/mutex.h> 38 1.4.10.2 tls #include <sys/rbtree.h> 39 1.4.10.2 tls 40 1.4.10.2 tls #include <uvm/uvm_extern.h> 41 1.4.10.2 tls 42 1.4.10.2 tls #include <linux/highmem.h> 43 1.4.10.2 tls 44 1.4.10.2 tls /* 45 1.4.10.2 tls * XXX Kludgerific implementation of Linux kmap_atomic, which is 46 1.4.10.2 tls * required not to fail. To accomodate this, we reserve one page of 47 1.4.10.2 tls * kva at boot (or load) and limit the system to at most kmap_atomic in 48 1.4.10.2 tls * use at a time. 49 1.4.10.2 tls */ 50 1.4.10.2 tls 51 1.4.10.2 tls /* 52 1.4.10.2 tls * XXX Use direct-mapped physical pages where available, e.g. amd64. 53 1.4.10.2 tls * 54 1.4.10.2 tls * XXX ...or add an abstraction to uvm for this. (uvm_emap?) 55 1.4.10.2 tls */ 56 1.4.10.2 tls 57 1.4.10.2 tls static kmutex_t linux_kmap_atomic_lock; 58 1.4.10.2 tls static vaddr_t linux_kmap_atomic_vaddr; 59 1.4.10.2 tls 60 1.4.10.2 tls static kmutex_t linux_kmap_lock; 61 1.4.10.2 tls static rb_tree_t linux_kmap_entries; 62 1.4.10.2 tls 63 1.4.10.2 tls struct linux_kmap_entry { 64 1.4.10.2 tls paddr_t lke_paddr; 65 1.4.10.2 tls vaddr_t lke_vaddr; 66 1.4.10.2 tls unsigned int lke_refcnt; 67 1.4.10.2 tls rb_node_t lke_node; 68 1.4.10.2 tls }; 69 1.4.10.2 tls 70 1.4.10.2 tls static int 71 1.4.10.2 tls lke_compare_nodes(void *ctx __unused, const void *an, const void *bn) 72 1.4.10.2 tls { 73 1.4.10.2 tls const struct linux_kmap_entry *const a = an; 74 1.4.10.2 tls const struct linux_kmap_entry *const b = bn; 75 1.4.10.2 tls 76 1.4.10.2 tls if (a->lke_paddr < b->lke_paddr) 77 1.4.10.2 tls return -1; 78 1.4.10.2 tls else if (a->lke_paddr > b->lke_paddr) 79 1.4.10.2 tls return +1; 80 1.4.10.2 tls else 81 1.4.10.2 tls return 0; 82 1.4.10.2 tls } 83 1.4.10.2 tls 84 1.4.10.2 tls static int 85 1.4.10.2 tls lke_compare_key(void *ctx __unused, const void *node, const void *key) 86 1.4.10.2 tls { 87 1.4.10.2 tls const struct linux_kmap_entry *const lke = node; 88 1.4.10.2 tls const paddr_t *const paddrp = key; 89 1.4.10.2 tls 90 1.4.10.2 tls if (lke->lke_paddr < *paddrp) 91 1.4.10.2 tls return -1; 92 1.4.10.2 tls else if (lke->lke_paddr > *paddrp) 93 1.4.10.2 tls return +1; 94 1.4.10.2 tls else 95 1.4.10.2 tls return 0; 96 1.4.10.2 tls } 97 1.4.10.2 tls 98 1.4.10.2 tls static const rb_tree_ops_t linux_kmap_entry_ops = { 99 1.4.10.2 tls .rbto_compare_nodes = &lke_compare_nodes, 100 1.4.10.2 tls .rbto_compare_key = &lke_compare_key, 101 1.4.10.2 tls .rbto_node_offset = offsetof(struct linux_kmap_entry, lke_node), 102 1.4.10.2 tls .rbto_context = NULL, 103 1.4.10.2 tls }; 104 1.4.10.2 tls 105 1.4.10.2 tls int 106 1.4.10.2 tls linux_kmap_init(void) 107 1.4.10.2 tls { 108 1.4.10.2 tls 109 1.4.10.2 tls /* IPL_VM is needed to block pmap_kenter_pa. */ 110 1.4.10.2 tls mutex_init(&linux_kmap_atomic_lock, MUTEX_DEFAULT, IPL_VM); 111 1.4.10.2 tls 112 1.4.10.2 tls linux_kmap_atomic_vaddr = uvm_km_alloc(kernel_map, PAGE_SIZE, 0, 113 1.4.10.2 tls (UVM_KMF_VAONLY | UVM_KMF_WAITVA)); 114 1.4.10.2 tls 115 1.4.10.2 tls KASSERT(linux_kmap_atomic_vaddr != 0); 116 1.4.10.2 tls KASSERT(!pmap_extract(pmap_kernel(), linux_kmap_atomic_vaddr, NULL)); 117 1.4.10.2 tls 118 1.4.10.2 tls mutex_init(&linux_kmap_lock, MUTEX_DEFAULT, IPL_VM); 119 1.4.10.2 tls rb_tree_init(&linux_kmap_entries, &linux_kmap_entry_ops); 120 1.4.10.2 tls 121 1.4.10.2 tls return 0; 122 1.4.10.2 tls } 123 1.4.10.2 tls 124 1.4.10.2 tls void 125 1.4.10.2 tls linux_kmap_fini(void) 126 1.4.10.2 tls { 127 1.4.10.2 tls 128 1.4.10.2 tls KASSERT(rb_tree_iterate(&linux_kmap_entries, NULL, RB_DIR_RIGHT) == 129 1.4.10.2 tls NULL); 130 1.4.10.2 tls #if 0 /* XXX no rb_tree_destroy*/ 131 1.4.10.2 tls rb_tree_destroy(&linux_kmap_entries); 132 1.4.10.2 tls #endif 133 1.4.10.2 tls mutex_destroy(&linux_kmap_lock); 134 1.4.10.2 tls 135 1.4.10.2 tls KASSERT(linux_kmap_atomic_vaddr != 0); 136 1.4.10.2 tls KASSERT(!pmap_extract(pmap_kernel(), linux_kmap_atomic_vaddr, NULL)); 137 1.4.10.2 tls 138 1.4.10.2 tls uvm_km_free(kernel_map, linux_kmap_atomic_vaddr, PAGE_SIZE, 139 1.4.10.2 tls (UVM_KMF_VAONLY | UVM_KMF_WAITVA)); 140 1.4.10.2 tls 141 1.4.10.2 tls mutex_destroy(&linux_kmap_atomic_lock); 142 1.4.10.2 tls } 143 1.4.10.2 tls 144 1.4.10.2 tls void * 145 1.4.10.2 tls kmap_atomic(struct page *page) 146 1.4.10.2 tls { 147 1.4.10.2 tls const paddr_t paddr = uvm_vm_page_to_phys(&page->p_vmp); 148 1.4.10.2 tls 149 1.4.10.2 tls mutex_spin_enter(&linux_kmap_atomic_lock); 150 1.4.10.2 tls 151 1.4.10.2 tls KASSERT(linux_kmap_atomic_vaddr != 0); 152 1.4.10.2 tls KASSERT(!pmap_extract(pmap_kernel(), linux_kmap_atomic_vaddr, NULL)); 153 1.4.10.2 tls 154 1.4.10.2 tls const vaddr_t vaddr = linux_kmap_atomic_vaddr; 155 1.4.10.2 tls const int prot = (VM_PROT_READ | VM_PROT_WRITE); 156 1.4.10.2 tls const int flags = 0; 157 1.4.10.2 tls pmap_kenter_pa(vaddr, paddr, prot, flags); 158 1.4.10.2 tls pmap_update(pmap_kernel()); 159 1.4.10.2 tls 160 1.4.10.2 tls return (void *)vaddr; 161 1.4.10.2 tls } 162 1.4.10.2 tls 163 1.4.10.2 tls void 164 1.4.10.2 tls kunmap_atomic(void *addr) 165 1.4.10.2 tls { 166 1.4.10.2 tls const vaddr_t vaddr = (vaddr_t)addr; 167 1.4.10.2 tls 168 1.4.10.2 tls KASSERT(mutex_owned(&linux_kmap_atomic_lock)); 169 1.4.10.2 tls KASSERT(linux_kmap_atomic_vaddr == vaddr); 170 1.4.10.2 tls KASSERT(pmap_extract(pmap_kernel(), vaddr, NULL)); 171 1.4.10.2 tls 172 1.4.10.2 tls pmap_kremove(vaddr, PAGE_SIZE); 173 1.4.10.2 tls pmap_update(pmap_kernel()); 174 1.4.10.2 tls 175 1.4.10.2 tls mutex_spin_exit(&linux_kmap_atomic_lock); 176 1.4.10.2 tls } 177 1.4.10.2 tls 178 1.4.10.2 tls void * 179 1.4.10.2 tls kmap(struct page *page) 180 1.4.10.2 tls { 181 1.4.10.2 tls const paddr_t paddr = VM_PAGE_TO_PHYS(&page->p_vmp); 182 1.4.10.2 tls const vaddr_t vaddr = uvm_km_alloc(kernel_map, PAGE_SIZE, 0, 183 1.4.10.2 tls (UVM_KMF_VAONLY | UVM_KMF_WAITVA)); 184 1.4.10.2 tls KASSERT(vaddr != 0); 185 1.4.10.2 tls 186 1.4.10.2 tls struct linux_kmap_entry *const lke = kmem_alloc(sizeof(*lke), 187 1.4.10.2 tls KM_SLEEP); 188 1.4.10.2 tls lke->lke_paddr = paddr; 189 1.4.10.2 tls lke->lke_vaddr = vaddr; 190 1.4.10.2 tls 191 1.4.10.2 tls mutex_spin_enter(&linux_kmap_lock); 192 1.4.10.2 tls struct linux_kmap_entry *const collision __unused = 193 1.4.10.2 tls rb_tree_insert_node(&linux_kmap_entries, lke); 194 1.4.10.2 tls KASSERT(collision == lke); 195 1.4.10.2 tls mutex_spin_exit(&linux_kmap_lock); 196 1.4.10.2 tls 197 1.4.10.2 tls KASSERT(!pmap_extract(pmap_kernel(), vaddr, NULL)); 198 1.4.10.2 tls const int prot = (VM_PROT_READ | VM_PROT_WRITE); 199 1.4.10.2 tls const int flags = 0; 200 1.4.10.2 tls pmap_kenter_pa(vaddr, paddr, prot, flags); 201 1.4.10.2 tls pmap_update(pmap_kernel()); 202 1.4.10.2 tls 203 1.4.10.2 tls return (void *)vaddr; 204 1.4.10.2 tls } 205 1.4.10.2 tls 206 1.4.10.2 tls void 207 1.4.10.2 tls kunmap(struct page *page) 208 1.4.10.2 tls { 209 1.4.10.2 tls const paddr_t paddr = VM_PAGE_TO_PHYS(&page->p_vmp); 210 1.4.10.2 tls 211 1.4.10.2 tls mutex_spin_enter(&linux_kmap_lock); 212 1.4.10.2 tls struct linux_kmap_entry *const lke = 213 1.4.10.2 tls rb_tree_find_node(&linux_kmap_entries, &paddr); 214 1.4.10.2 tls KASSERT(lke != NULL); 215 1.4.10.2 tls rb_tree_remove_node(&linux_kmap_entries, lke); 216 1.4.10.2 tls mutex_spin_exit(&linux_kmap_lock); 217 1.4.10.2 tls 218 1.4.10.2 tls const vaddr_t vaddr = lke->lke_vaddr; 219 1.4.10.2 tls kmem_free(lke, sizeof(*lke)); 220 1.4.10.2 tls 221 1.4.10.2 tls KASSERT(pmap_extract(pmap_kernel(), vaddr, NULL)); 222 1.4.10.2 tls 223 1.4.10.2 tls pmap_kremove(vaddr, PAGE_SIZE); 224 1.4.10.2 tls pmap_update(pmap_kernel()); 225 1.4.10.2 tls 226 1.4.10.2 tls uvm_km_free(kernel_map, vaddr, PAGE_SIZE, UVM_KMF_VAONLY); 227 1.4.10.2 tls } 228
Indexes created Fri Sep 26 08:10:20 GMT 2025