subr_kmem.c revision 1.16.8.2
1 /* $NetBSD: subr_kmem.c,v 1.16.8.2 2008/01/09 01:56:16 matt Exp $ */ 2 3 /*- 4 * Copyright (c)2006 YAMAMOTO Takashi, 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 /* 30 * allocator of kernel wired memory. 31 * 32 * TODO: 33 * - worth to have "intrsafe" version? maybe.. 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.16.8.2 2008/01/09 01:56:16 matt Exp $"); 38 39 #include <sys/param.h> 40 #include <sys/callback.h> 41 #include <sys/kmem.h> 42 #include <sys/vmem.h> 43 #include <sys/debug.h> 44 #include <sys/lockdebug.h> 45 46 #include <uvm/uvm_extern.h> 47 #include <uvm/uvm_map.h> 48 49 #include <lib/libkern/libkern.h> 50 51 #define KMEM_QUANTUM_SIZE (ALIGNBYTES + 1) 52 53 static vmem_t *kmem_arena; 54 static struct callback_entry kmem_kva_reclaim_entry; 55 56 #if defined(DEBUG) 57 static void *kmem_freecheck; 58 static void kmem_poison_fill(void *, size_t); 59 static void kmem_poison_check(void *, size_t); 60 #else /* defined(DEBUG) */ 61 #define kmem_poison_fill(p, sz) /* nothing */ 62 #define kmem_poison_check(p, sz) /* nothing */ 63 #endif /* defined(DEBUG) */ 64 65 static vmem_addr_t kmem_backend_alloc(vmem_t *, vmem_size_t, vmem_size_t *, 66 vm_flag_t); 67 static void kmem_backend_free(vmem_t *, vmem_addr_t, vmem_size_t); 68 static int kmem_kva_reclaim_callback(struct callback_entry *, void *, void *); 69 70 static inline vm_flag_t 71 kmf_to_vmf(km_flag_t kmflags) 72 { 73 vm_flag_t vmflags; 74 75 KASSERT((kmflags & (KM_SLEEP|KM_NOSLEEP)) != 0); 76 KASSERT((~kmflags & (KM_SLEEP|KM_NOSLEEP)) != 0); 77 78 vmflags = 0; 79 if ((kmflags & KM_SLEEP) != 0) { 80 vmflags |= VM_SLEEP; 81 } 82 if ((kmflags & KM_NOSLEEP) != 0) { 83 vmflags |= VM_NOSLEEP; 84 } 85 86 return vmflags; 87 } 88 89 /* ---- kmem API */ 90 91 /* 92 * kmem_alloc: allocate wired memory. 93 * 94 * => must not be called from interrupt context. 95 */ 96 97 void * 98 kmem_alloc(size_t size, km_flag_t kmflags) 99 { 100 void *p; 101 102 p = (void *)vmem_alloc(kmem_arena, size, 103 kmf_to_vmf(kmflags) | VM_INSTANTFIT); 104 if (p != NULL) { 105 kmem_poison_check(p, kmem_roundup_size(size)); 106 FREECHECK_OUT(&kmem_freecheck, p); 107 } 108 return p; 109 } 110 111 /* 112 * kmem_zalloc: allocate wired memory. 113 * 114 * => must not be called from interrupt context. 115 */ 116 117 void * 118 kmem_zalloc(size_t size, km_flag_t kmflags) 119 { 120 void *p; 121 122 p = kmem_alloc(size, kmflags); 123 if (p != NULL) { 124 memset(p, 0, size); 125 } 126 return p; 127 } 128 129 /* 130 * kmem_free: free wired memory allocated by kmem_alloc. 131 * 132 * => must not be called from interrupt context. 133 */ 134 135 void 136 kmem_free(void *p, size_t size) 137 { 138 139 FREECHECK_IN(&kmem_freecheck, p); 140 LOCKDEBUG_MEM_CHECK(p, size); 141 kmem_poison_check((char *)p + size, kmem_roundup_size(size) - size); 142 kmem_poison_fill(p, size); 143 vmem_free(kmem_arena, (vmem_addr_t)p, size); 144 } 145 146 void 147 kmem_init(void) 148 { 149 150 kmem_arena = vmem_create("kmem", 0, 0, KMEM_QUANTUM_SIZE, 151 kmem_backend_alloc, kmem_backend_free, NULL, 152 KMEM_QUANTUM_SIZE * 32, VM_SLEEP, IPL_NONE); 153 callback_register(&vm_map_to_kernel(kernel_map)->vmk_reclaim_callback, 154 &kmem_kva_reclaim_entry, kmem_arena, kmem_kva_reclaim_callback); 155 } 156 157 size_t 158 kmem_roundup_size(size_t size) 159 { 160 161 return vmem_roundup_size(kmem_arena, size); 162 } 163 164 /* ---- uvm glue */ 165 166 static vmem_addr_t 167 kmem_backend_alloc(vmem_t *dummy, vmem_size_t size, vmem_size_t *resultsize, 168 vm_flag_t vmflags) 169 { 170 uvm_flag_t uflags; 171 vaddr_t va; 172 173 KASSERT(dummy == NULL); 174 KASSERT(size != 0); 175 KASSERT((vmflags & (VM_SLEEP|VM_NOSLEEP)) != 0); 176 KASSERT((~vmflags & (VM_SLEEP|VM_NOSLEEP)) != 0); 177 178 if ((vmflags & VM_NOSLEEP) != 0) { 179 uflags = UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT; 180 } else { 181 uflags = UVM_KMF_WAITVA; 182 } 183 *resultsize = size = round_page(size); 184 va = uvm_km_alloc(kernel_map, size, 0, 185 uflags | UVM_KMF_WIRED | UVM_KMF_CANFAIL); 186 if (va != 0) { 187 kmem_poison_fill((void *)va, size); 188 } 189 return (vmem_addr_t)va; 190 } 191 192 static void 193 kmem_backend_free(vmem_t *dummy, vmem_addr_t addr, vmem_size_t size) 194 { 195 196 KASSERT(dummy == NULL); 197 KASSERT(addr != 0); 198 KASSERT(size != 0); 199 KASSERT(size == round_page(size)); 200 201 kmem_poison_check((void *)addr, size); 202 uvm_km_free(kernel_map, (vaddr_t)addr, size, UVM_KMF_WIRED); 203 } 204 205 static int 206 kmem_kva_reclaim_callback(struct callback_entry *ce, void *obj, void *arg) 207 { 208 vmem_t *vm = obj; 209 210 vmem_reap(vm); 211 return CALLBACK_CHAIN_CONTINUE; 212 } 213 214 /* ---- debug */ 215 216 #if defined(DEBUG) 217 218 #if defined(_LP64) 219 #define PRIME 0x9e37fffffffc0001UL 220 #else /* defined(_LP64) */ 221 #define PRIME 0x9e3779b1 222 #endif /* defined(_LP64) */ 223 224 static inline uint8_t 225 kmem_poison_pattern(const void *p) 226 { 227 228 return (uint8_t)((((uintptr_t)p) * PRIME) 229 >> ((sizeof(uintptr_t) - sizeof(uint8_t))) * CHAR_BIT); 230 } 231 232 static void 233 kmem_poison_fill(void *p, size_t sz) 234 { 235 uint8_t *cp; 236 const uint8_t *ep; 237 238 cp = p; 239 ep = cp + sz; 240 while (cp < ep) { 241 *cp = kmem_poison_pattern(cp); 242 cp++; 243 } 244 } 245 246 static void 247 kmem_poison_check(void *p, size_t sz) 248 { 249 uint8_t *cp; 250 const uint8_t *ep; 251 252 cp = p; 253 ep = cp + sz; 254 while (cp < ep) { 255 const uint8_t expected = kmem_poison_pattern(cp); 256 257 if (*cp != expected) { 258 panic("%s: %p: 0x%02x != 0x%02x\n", 259 __func__, cp, *cp, expected); 260 } 261 cp++; 262 } 263 } 264 265 #endif /* defined(DEBUG) */ 266
Indexes created Sat Sep 20 22:09:52 GMT 2025