subr_kmem.c revision 1.4
1 /* $NetBSD: subr_kmem.c,v 1.4 2006/07/08 06:01:53 yamt 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 1.4 2006/07/08 06:01:53 yamt Exp $"); 38 39 #include <sys/param.h> 40 #include <sys/kmem.h> 41 #include <sys/vmem.h> 42 43 #include <lib/libkern/libkern.h> 44 45 #define KMEM_QUANTUM_SIZE (ALIGNBYTES + 1) 46 47 static vmem_t *kmem_arena; 48 49 #if defined(DEBUG) 50 static void kmem_poison_fill(void *, size_t); 51 static void kmem_poison_check(void *, size_t); 52 #else /* defined(DEBUG) */ 53 #define kmem_poison_fill(p, sz) /* nothing */ 54 #define kmem_poison_check(p, sz) /* nothing */ 55 #endif /* defined(DEBUG) */ 56 57 static vmem_addr_t kmem_backend_alloc(vmem_t *, vmem_size_t, vmem_size_t *, 58 vm_flag_t); 59 static void kmem_backend_free(vmem_t *, vmem_addr_t, vmem_size_t); 60 61 static inline vm_flag_t 62 kmf_to_vmf(km_flag_t kmflags) 63 { 64 vm_flag_t vmflags; 65 66 KASSERT((kmflags & (KM_SLEEP|KM_NOSLEEP)) != 0); 67 KASSERT((~kmflags & (KM_SLEEP|KM_NOSLEEP)) != 0); 68 69 vmflags = 0; 70 if ((kmflags & KM_SLEEP) != 0) { 71 vmflags |= VM_SLEEP; 72 } 73 if ((kmflags & KM_NOSLEEP) != 0) { 74 vmflags |= VM_NOSLEEP; 75 } 76 77 return vmflags; 78 } 79 80 /* ---- kmem API */ 81 82 /* 83 * kmem_alloc: allocate wired memory. 84 * 85 * => must not be called from interrupt context. 86 */ 87 88 void * 89 kmem_alloc(size_t size, km_flag_t kmflags) 90 { 91 void *p; 92 93 p = (void *)vmem_alloc(kmem_arena, size, 94 kmf_to_vmf(kmflags) | VM_INSTANTFIT); 95 kmem_poison_check(p, size); 96 return p; 97 } 98 99 /* 100 * kmem_zalloc: allocate wired memory. 101 * 102 * => must not be called from interrupt context. 103 */ 104 105 void * 106 kmem_zalloc(size_t size, km_flag_t kmflags) 107 { 108 void *p; 109 110 p = kmem_alloc(size, kmflags); 111 if (p != NULL) { 112 memset(p, 0, size); 113 } 114 return p; 115 } 116 117 /* 118 * kmem_free: free wired memory allocated by kmem_alloc. 119 * 120 * => must not be called from interrupt context. 121 */ 122 123 void 124 kmem_free(void *p, size_t size) 125 { 126 127 kmem_poison_fill(p, size); 128 vmem_free(kmem_arena, (vmem_addr_t)p, size); 129 } 130 131 void 132 kmem_init(void) 133 { 134 135 kmem_arena = vmem_create("kmem", 0, 0, KMEM_QUANTUM_SIZE, 136 kmem_backend_alloc, kmem_backend_free, NULL, 0, VM_SLEEP); 137 } 138 139 size_t 140 kmem_roundup_size(size_t size) 141 { 142 143 return vmem_roundup_size(kmem_arena, size); 144 } 145 146 /* ---- uvm glue */ 147 148 #include <uvm/uvm_extern.h> 149 150 static vmem_addr_t 151 kmem_backend_alloc(vmem_t *dummy, vmem_size_t size, vmem_size_t *resultsize, 152 vm_flag_t vmflags) 153 { 154 uvm_flag_t uflags; 155 vaddr_t va; 156 157 KASSERT(dummy == NULL); 158 KASSERT(size != 0); 159 KASSERT((vmflags & (VM_SLEEP|VM_NOSLEEP)) != 0); 160 KASSERT((~vmflags & (VM_SLEEP|VM_NOSLEEP)) != 0); 161 162 if ((vmflags & VM_NOSLEEP) != 0) { 163 uflags = UVM_KMF_TRYLOCK | UVM_KMF_NOWAIT; 164 } else { 165 uflags = UVM_KMF_WAITVA; 166 } 167 *resultsize = size = round_page(size); 168 va = uvm_km_alloc(kernel_map, size, 0, 169 uflags | UVM_KMF_WIRED | UVM_KMF_CANFAIL); 170 kmem_poison_fill((void *)va, size); 171 return (vmem_addr_t)va; 172 } 173 174 static void 175 kmem_backend_free(vmem_t *dummy, vmem_addr_t addr, vmem_size_t size) 176 { 177 178 KASSERT(dummy == NULL); 179 KASSERT(addr != 0); 180 KASSERT(size != 0); 181 KASSERT(size == round_page(size)); 182 183 kmem_poison_check((void *)addr, size); 184 uvm_km_free(kernel_map, (vaddr_t)addr, size, UVM_KMF_WIRED); 185 } 186 187 /* ---- debug */ 188 189 #if defined(DEBUG) 190 191 #if defined(_LP64) 192 #define PRIME 0x9e37fffffffc0001UL 193 #else /* defined(_LP64) */ 194 #define PRIME 0x9e3779b1 195 #endif /* defined(_LP64) */ 196 197 static inline uint8_t 198 kmem_poison_pattern(const void *p) 199 { 200 201 return (uint8_t)((((uintptr_t)p) * PRIME) 202 >> ((sizeof(uintptr_t) - sizeof(uint8_t))) * CHAR_BIT); 203 } 204 205 static void 206 kmem_poison_fill(void *p, size_t sz) 207 { 208 uint8_t *cp; 209 const uint8_t *ep; 210 211 cp = p; 212 ep = cp + sz; 213 while (cp < ep) { 214 *cp = kmem_poison_pattern(cp); 215 cp++; 216 } 217 } 218 219 static void 220 kmem_poison_check(void *p, size_t sz) 221 { 222 uint8_t *cp; 223 const uint8_t *ep; 224 225 cp = p; 226 ep = cp + sz; 227 while (cp < ep) { 228 const uint8_t expected = kmem_poison_pattern(cp); 229 230 if (*cp != expected) { 231 panic("%s: %p: 0x%02x != 0x%02x\n", 232 __func__, cp, *cp, expected); 233 } 234 cp++; 235 } 236 } 237 238 #endif /* defined(DEBUG) */ 239
Indexes created Sun Sep 21 18:09:52 GMT 2025