1 /* $NetBSD: subr_kmem.c,v 1.10 2006/10/12 01:32:18 christos 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 1.10 2006/10/12 01:32:18 christos Exp $"); 38 39 #include <sys/param.h> 40 #include <sys/callback.h> 41 #include <sys/kmem.h> 42 #include <sys/vmem.h> 43 44 #include <uvm/uvm_extern.h> 45 #include <uvm/uvm_map.h> 46 47 #include <lib/libkern/libkern.h> 48 49 #define KMEM_QUANTUM_SIZE (ALIGNBYTES + 1) 50 51 static vmem_t *kmem_arena; 52 static struct callback_entry kmem_kva_reclaim_entry; 53 54 #if defined(DEBUG) 55 static void kmem_poison_fill(void *, size_t); 56 static void kmem_poison_check(void *, size_t); 57 #else /* defined(DEBUG) */ 58 #define kmem_poison_fill(p, sz) /* nothing */ 59 #define kmem_poison_check(p, sz) /* nothing */ 60 #endif /* defined(DEBUG) */ 61 62 static vmem_addr_t kmem_backend_alloc(vmem_t *, vmem_size_t, vmem_size_t *, 63 vm_flag_t); 64 static void kmem_backend_free(vmem_t *, vmem_addr_t, vmem_size_t); 65 static int kmem_kva_reclaim_callback(struct callback_entry *, void *, void *); 66 67 static inline vm_flag_t 68 kmf_to_vmf(km_flag_t kmflags) 69 { 70 vm_flag_t vmflags; 71 72 KASSERT((kmflags & (KM_SLEEP|KM_NOSLEEP)) != 0); 73 KASSERT((~kmflags & (KM_SLEEP|KM_NOSLEEP)) != 0); 74 75 vmflags = 0; 76 if ((kmflags & KM_SLEEP) != 0) { 77 vmflags |= VM_SLEEP; 78 } 79 if ((kmflags & KM_NOSLEEP) != 0) { 80 vmflags |= VM_NOSLEEP; 81 } 82 83 return vmflags; 84 } 85 86 /* ---- kmem API */ 87 88 /* 89 * kmem_alloc: allocate wired memory. 90 * 91 * => must not be called from interrupt context. 92 */ 93 94 void * 95 kmem_alloc(size_t size, km_flag_t kmflags) 96 { 97 void *p; 98 99 p = (void *)vmem_alloc(kmem_arena, size, 100 kmf_to_vmf(kmflags) | VM_INSTANTFIT); 101 kmem_poison_check(p, size); 102 return p; 103 } 104 105 /* 106 * kmem_zalloc: allocate wired memory. 107 * 108 * => must not be called from interrupt context. 109 */ 110 111 void * 112 kmem_zalloc(size_t size, km_flag_t kmflags) 113 { 114 void *p; 115 116 p = kmem_alloc(size, kmflags); 117 if (p != NULL) { 118 memset(p, 0, size); 119 } 120 return p; 121 } 122 123 /* 124 * kmem_free: free wired memory allocated by kmem_alloc. 125 * 126 * => must not be called from interrupt context. 127 */ 128 129 void 130 kmem_free(void *p, size_t size) 131 { 132 133 kmem_poison_fill(p, size); 134 vmem_free(kmem_arena, (vmem_addr_t)p, size); 135 } 136 137 void 138 kmem_init(void) 139 { 140 141 kmem_arena = vmem_create("kmem", 0, 0, KMEM_QUANTUM_SIZE, 142 kmem_backend_alloc, kmem_backend_free, NULL, 143 KMEM_QUANTUM_SIZE * 32, VM_SLEEP); 144 callback_register(&vm_map_to_kernel(kernel_map)->vmk_reclaim_callback, 145 &kmem_kva_reclaim_entry, kmem_arena, kmem_kva_reclaim_callback); 146 } 147 148 size_t 149 kmem_roundup_size(size_t size) 150 { 151 152 return vmem_roundup_size(kmem_arena, size); 153 } 154 155 /* ---- uvm glue */ 156 157 #include <uvm/uvm_extern.h> 158 159 static vmem_addr_t 160 kmem_backend_alloc(vmem_t *dummy __unused, vmem_size_t size, 161 vmem_size_t *resultsize, vm_flag_t vmflags) 162 { 163 uvm_flag_t uflags; 164 vaddr_t va; 165 166 KASSERT(dummy == NULL); 167 KASSERT(size != 0); 168 KASSERT((vmflags & (VM_SLEEP|VM_NOSLEEP)) != 0); 169 KASSERT((~vmflags & (VM_SLEEP|VM_NOSLEEP)) != 0); 170 171 if ((vmflags & VM_NOSLEEP) != 0) { 172 uflags = UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT; 173 } else { 174 uflags = UVM_KMF_WAITVA; 175 } 176 *resultsize = size = round_page(size); 177 va = uvm_km_alloc(kernel_map, size, 0, 178 uflags | UVM_KMF_WIRED | UVM_KMF_CANFAIL); 179 kmem_poison_fill((void *)va, size); 180 return (vmem_addr_t)va; 181 } 182 183 static void 184 kmem_backend_free(vmem_t *dummy __unused, vmem_addr_t addr, vmem_size_t size) 185 { 186 187 KASSERT(dummy == NULL); 188 KASSERT(addr != 0); 189 KASSERT(size != 0); 190 KASSERT(size == round_page(size)); 191 192 kmem_poison_check((void *)addr, size); 193 uvm_km_free(kernel_map, (vaddr_t)addr, size, UVM_KMF_WIRED); 194 } 195 196 static int 197 kmem_kva_reclaim_callback(struct callback_entry *ce __unused, void *obj, 198 void *arg __unused) 199 { 200 vmem_t *vm = obj; 201 202 vmem_reap(vm); 203 return CALLBACK_CHAIN_CONTINUE; 204 } 205 206 /* ---- debug */ 207 208 #if defined(DEBUG) 209 210 #if defined(_LP64) 211 #define PRIME 0x9e37fffffffc0001UL 212 #else /* defined(_LP64) */ 213 #define PRIME 0x9e3779b1 214 #endif /* defined(_LP64) */ 215 216 static inline uint8_t 217 kmem_poison_pattern(const void *p) 218 { 219 220 return (uint8_t)((((uintptr_t)p) * PRIME) 221 >> ((sizeof(uintptr_t) - sizeof(uint8_t))) * CHAR_BIT); 222 } 223 224 static void 225 kmem_poison_fill(void *p, size_t sz) 226 { 227 uint8_t *cp; 228 const uint8_t *ep; 229 230 cp = p; 231 ep = cp + sz; 232 while (cp < ep) { 233 *cp = kmem_poison_pattern(cp); 234 cp++; 235 } 236 } 237 238 static void 239 kmem_poison_check(void *p, size_t sz) 240 { 241 uint8_t *cp; 242 const uint8_t *ep; 243 244 cp = p; 245 ep = cp + sz; 246 while (cp < ep) { 247 const uint8_t expected = kmem_poison_pattern(cp); 248 249 if (*cp != expected) { 250 panic("%s: %p: 0x%02x != 0x%02x\n", 251 __func__, cp, *cp, expected); 252 } 253 cp++; 254 } 255 } 256 257 #endif /* defined(DEBUG) */ 258