mem.c revision 115683
1/*- 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department, and code derived from software contributed to 9 * Berkeley by William Jolitz. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * from: Utah $Hdr: mem.c 1.13 89/10/08$ 40 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91 41 */ 42 43#include <sys/cdefs.h> 44__FBSDID("$FreeBSD: head/sys/i386/i386/mem.c 115683 2003-06-02 06:43:15Z obrien $"); 45 46/* 47 * Memory special file 48 */ 49 50#include <sys/param.h> 51#include <sys/conf.h> 52#include <sys/fcntl.h> 53#include <sys/ioccom.h> 54#include <sys/kernel.h> 55#include <sys/lock.h> 56#include <sys/malloc.h> 57#include <sys/memrange.h> 58#include <sys/mutex.h> 59#include <sys/proc.h> 60#include <sys/signalvar.h> 61#include <sys/systm.h> 62#include <sys/uio.h> 63 64#include <machine/db_machdep.h> 65#include <machine/frame.h> 66#include <machine/psl.h> 67#include <machine/specialreg.h> 68 69#include <vm/vm.h> 70#include <vm/pmap.h> 71#include <vm/vm_extern.h> 72 73static dev_t memdev, kmemdev, iodev; 74 75static d_open_t mmopen; 76static d_close_t mmclose; 77static d_read_t mmrw; 78static d_ioctl_t mmioctl; 79static d_mmap_t memmmap; 80 81#define CDEV_MAJOR 2 82static struct cdevsw mem_cdevsw = { 83 .d_open = mmopen, 84 .d_close = mmclose, 85 .d_read = mmrw, 86 .d_write = mmrw, 87 .d_ioctl = mmioctl, 88 .d_mmap = memmmap, 89 .d_name = "mem", 90 .d_maj = CDEV_MAJOR, 91 .d_flags = D_MEM, 92}; 93 94MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 95 96struct mem_range_softc mem_range_softc; 97 98static int 99mmclose(dev_t dev, int flags, int fmt, struct thread *td) 100{ 101 switch (minor(dev)) { 102 case 14: 103 td->td_frame->tf_eflags &= ~PSL_IOPL; 104 } 105 return (0); 106} 107 108static int 109mmopen(dev_t dev, int flags, int fmt, struct thread *td) 110{ 111 int error; 112 113 switch (minor(dev)) { 114 case 0: 115 case 1: 116 if (flags & FWRITE) { 117 error = securelevel_gt(td->td_ucred, 0); 118 if (error != 0) 119 return (error); 120 } 121 break; 122 case 14: 123 error = suser(td); 124 if (error != 0) 125 return (error); 126 error = securelevel_gt(td->td_ucred, 0); 127 if (error != 0) 128 return (error); 129 td->td_frame->tf_eflags |= PSL_IOPL; 130 break; 131 } 132 return (0); 133} 134 135/*ARGSUSED*/ 136static int 137mmrw(dev_t dev, struct uio *uio, int flags) 138{ 139 int o; 140 u_int c = 0, v; 141 struct iovec *iov; 142 int error = 0; 143 vm_offset_t addr, eaddr; 144 145 GIANT_REQUIRED; 146 147 while (uio->uio_resid > 0 && error == 0) { 148 iov = uio->uio_iov; 149 if (iov->iov_len == 0) { 150 uio->uio_iov++; 151 uio->uio_iovcnt--; 152 if (uio->uio_iovcnt < 0) 153 panic("mmrw"); 154 continue; 155 } 156 switch (minor(dev)) { 157 158/* minor device 0 is physical memory */ 159 case 0: 160 v = uio->uio_offset; 161 v &= ~PAGE_MASK; 162 pmap_kenter((vm_offset_t)ptvmmap, v); 163 o = (int)uio->uio_offset & PAGE_MASK; 164 c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK)); 165 c = min(c, (u_int)(PAGE_SIZE - o)); 166 c = min(c, (u_int)iov->iov_len); 167 error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio); 168 pmap_qremove((vm_offset_t)ptvmmap, 1); 169 continue; 170 171/* minor device 1 is kernel memory */ 172 case 1: 173 c = iov->iov_len; 174 175 /* 176 * Make sure that all of the pages are currently resident so 177 * that we don't create any zero-fill pages. 178 */ 179 addr = trunc_page(uio->uio_offset); 180 eaddr = round_page(uio->uio_offset + c); 181 182 if (addr < (vm_offset_t)VADDR(PTDPTDI, 0)) 183 return (EFAULT); 184 for (; addr < eaddr; addr += PAGE_SIZE) 185 if (pmap_extract(kernel_pmap, addr) == 0) 186 return (EFAULT); 187 188 if (!kernacc((caddr_t)(int)uio->uio_offset, c, 189 uio->uio_rw == UIO_READ ? 190 VM_PROT_READ : VM_PROT_WRITE)) 191 return (EFAULT); 192 error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio); 193 continue; 194 195 default: 196 return (ENODEV); 197 } 198 199 if (error) 200 break; 201 iov->iov_base = (char *)iov->iov_base + c; 202 iov->iov_len -= c; 203 uio->uio_offset += c; 204 uio->uio_resid -= c; 205 } 206 return (error); 207} 208 209/*******************************************************\ 210* allow user processes to MMAP some memory sections * 211* instead of going through read/write * 212\*******************************************************/ 213static int 214memmmap(dev_t dev, vm_offset_t offset, vm_paddr_t *paddr, int prot) 215{ 216 switch (minor(dev)) 217 { 218 219 /* minor device 0 is physical memory */ 220 case 0: 221 *paddr = offset; 222 break; 223 224 /* minor device 1 is kernel memory */ 225 case 1: 226 *paddr = vtophys(offset); 227 break; 228 229 default: 230 return (-1); 231 } 232 return (0); 233} 234 235/* 236 * Operations for changing memory attributes. 237 * 238 * This is basically just an ioctl shim for mem_range_attr_get 239 * and mem_range_attr_set. 240 */ 241static int 242mmioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td) 243{ 244 int nd, error = 0; 245 struct mem_range_op *mo = (struct mem_range_op *)data; 246 struct mem_range_desc *md; 247 248 /* is this for us? */ 249 if ((cmd != MEMRANGE_GET) && 250 (cmd != MEMRANGE_SET)) 251 return (ENOTTY); 252 253 /* any chance we can handle this? */ 254 if (mem_range_softc.mr_op == NULL) 255 return (EOPNOTSUPP); 256 257 /* do we have any descriptors? */ 258 if (mem_range_softc.mr_ndesc == 0) 259 return (ENXIO); 260 261 switch (cmd) { 262 case MEMRANGE_GET: 263 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 264 if (nd > 0) { 265 md = (struct mem_range_desc *) 266 malloc(nd * sizeof(struct mem_range_desc), 267 M_MEMDESC, M_WAITOK); 268 error = mem_range_attr_get(md, &nd); 269 if (!error) 270 error = copyout(md, mo->mo_desc, 271 nd * sizeof(struct mem_range_desc)); 272 free(md, M_MEMDESC); 273 } 274 else 275 nd = mem_range_softc.mr_ndesc; 276 mo->mo_arg[0] = nd; 277 break; 278 279 case MEMRANGE_SET: 280 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), 281 M_MEMDESC, M_WAITOK); 282 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 283 /* clamp description string */ 284 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 285 if (error == 0) 286 error = mem_range_attr_set(md, &mo->mo_arg[0]); 287 free(md, M_MEMDESC); 288 break; 289 } 290 return (error); 291} 292 293/* 294 * Implementation-neutral, kernel-callable functions for manipulating 295 * memory range attributes. 296 */ 297int 298mem_range_attr_get(struct mem_range_desc *mrd, int *arg) 299{ 300 /* can we handle this? */ 301 if (mem_range_softc.mr_op == NULL) 302 return (EOPNOTSUPP); 303 304 if (*arg == 0) 305 *arg = mem_range_softc.mr_ndesc; 306 else 307 bcopy(mem_range_softc.mr_desc, mrd, 308 (*arg) * sizeof(struct mem_range_desc)); 309 return (0); 310} 311 312int 313mem_range_attr_set(struct mem_range_desc *mrd, int *arg) 314{ 315 /* can we handle this? */ 316 if (mem_range_softc.mr_op == NULL) 317 return (EOPNOTSUPP); 318 319 return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg)); 320} 321 322#ifdef SMP 323void 324mem_range_AP_init(void) 325{ 326 if (mem_range_softc.mr_op && mem_range_softc.mr_op->initAP) 327 (mem_range_softc.mr_op->initAP(&mem_range_softc)); 328} 329#endif 330 331static int 332mem_modevent(module_t mod, int type, void *data) 333{ 334 switch(type) { 335 case MOD_LOAD: 336 if (bootverbose) 337 printf("mem: <memory & I/O>\n"); 338 /* Initialise memory range handling */ 339 if (mem_range_softc.mr_op != NULL) 340 mem_range_softc.mr_op->init(&mem_range_softc); 341 342 memdev = make_dev(&mem_cdevsw, 0, UID_ROOT, GID_KMEM, 343 0640, "mem"); 344 kmemdev = make_dev(&mem_cdevsw, 1, UID_ROOT, GID_KMEM, 345 0640, "kmem"); 346 iodev = make_dev(&mem_cdevsw, 14, UID_ROOT, GID_WHEEL, 347 0600, "io"); 348 return (0); 349 350 case MOD_UNLOAD: 351 destroy_dev(memdev); 352 destroy_dev(kmemdev); 353 destroy_dev(iodev); 354 return (0); 355 356 case MOD_SHUTDOWN: 357 return (0); 358 359 default: 360 return (EOPNOTSUPP); 361 } 362} 363 364DEV_MODULE(mem, mem_modevent, NULL); 365