mem.c revision 104908
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 * $FreeBSD: head/sys/i386/i386/mem.c 104908 2002-10-11 14:58:34Z mike $ 42 */ 43 44/* 45 * Memory special file 46 */ 47 48#include <sys/param.h> 49#include <sys/conf.h> 50#include <sys/fcntl.h> 51#include <sys/ioccom.h> 52#include <sys/kernel.h> 53#include <sys/lock.h> 54#include <sys/malloc.h> 55#include <sys/memrange.h> 56#include <sys/mutex.h> 57#include <sys/proc.h> 58#include <sys/signalvar.h> 59#include <sys/systm.h> 60#include <sys/uio.h> 61 62#include <machine/db_machdep.h> 63#include <machine/frame.h> 64#include <machine/psl.h> 65#include <machine/specialreg.h> 66 67#include <vm/vm.h> 68#include <vm/pmap.h> 69#include <vm/vm_extern.h> 70 71static dev_t memdev, kmemdev, iodev; 72 73static d_open_t mmopen; 74static d_close_t mmclose; 75static d_read_t mmrw; 76static d_ioctl_t mmioctl; 77static d_mmap_t memmmap; 78 79#define CDEV_MAJOR 2 80static struct cdevsw mem_cdevsw = { 81 /* open */ mmopen, 82 /* close */ mmclose, 83 /* read */ mmrw, 84 /* write */ mmrw, 85 /* ioctl */ mmioctl, 86 /* poll */ (d_poll_t *)seltrue, 87 /* mmap */ memmmap, 88 /* strategy */ nostrategy, 89 /* name */ "mem", 90 /* maj */ CDEV_MAJOR, 91 /* dump */ nodump, 92 /* psize */ nopsize, 93 /* flags */ D_MEM, 94}; 95 96MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 97 98struct mem_range_softc mem_range_softc; 99 100static int 101mmclose(dev_t dev, int flags, int fmt, struct thread *td) 102{ 103 switch (minor(dev)) { 104 case 14: 105 td->td_frame->tf_eflags &= ~PSL_IOPL; 106 } 107 return (0); 108} 109 110static int 111mmopen(dev_t dev, int flags, int fmt, struct thread *td) 112{ 113 int error; 114 115 switch (minor(dev)) { 116 case 0: 117 case 1: 118 if (flags & FWRITE) { 119 error = securelevel_gt(td->td_ucred, 0); 120 if (error != 0) 121 return (error); 122 } 123 break; 124 case 14: 125 error = suser(td); 126 if (error != 0) 127 return (error); 128 error = securelevel_gt(td->td_ucred, 0); 129 if (error != 0) 130 return (error); 131 td->td_frame->tf_eflags |= PSL_IOPL; 132 break; 133 } 134 return (0); 135} 136 137/*ARGSUSED*/ 138static int 139mmrw(dev_t dev, struct uio *uio, int flags) 140{ 141 int o; 142 u_int c = 0, v; 143 struct iovec *iov; 144 int error = 0; 145 vm_offset_t addr, eaddr; 146 147 GIANT_REQUIRED; 148 149 while (uio->uio_resid > 0 && error == 0) { 150 iov = uio->uio_iov; 151 if (iov->iov_len == 0) { 152 uio->uio_iov++; 153 uio->uio_iovcnt--; 154 if (uio->uio_iovcnt < 0) 155 panic("mmrw"); 156 continue; 157 } 158 switch (minor(dev)) { 159 160/* minor device 0 is physical memory */ 161 case 0: 162 v = uio->uio_offset; 163 v &= ~PAGE_MASK; 164 pmap_kenter((vm_offset_t)ptvmmap, v); 165 o = (int)uio->uio_offset & PAGE_MASK; 166 c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK)); 167 c = min(c, (u_int)(PAGE_SIZE - o)); 168 c = min(c, (u_int)iov->iov_len); 169 error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio); 170 pmap_qremove((vm_offset_t)ptvmmap, 1); 171 continue; 172 173/* minor device 1 is kernel memory */ 174 case 1: 175 c = iov->iov_len; 176 177 /* 178 * Make sure that all of the pages are currently resident so 179 * that we don't create any zero-fill pages. 180 */ 181 addr = trunc_page(uio->uio_offset); 182 eaddr = round_page(uio->uio_offset + c); 183 184 if (addr < (vm_offset_t)VADDR(PTDPTDI, 0)) 185 return (EFAULT); 186 if (eaddr >= (vm_offset_t)VADDR(APTDPTDI, 0)) 187 return (EFAULT); 188 for (; addr < eaddr; addr += PAGE_SIZE) 189 if (pmap_extract(kernel_pmap, addr) == 0) 190 return (EFAULT); 191 192 if (!kernacc((caddr_t)(int)uio->uio_offset, c, 193 uio->uio_rw == UIO_READ ? 194 VM_PROT_READ : VM_PROT_WRITE)) 195 return (EFAULT); 196 error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio); 197 continue; 198 } 199 200 if (error) 201 break; 202 iov->iov_base = (char *)iov->iov_base + c; 203 iov->iov_len -= c; 204 uio->uio_offset += c; 205 uio->uio_resid -= c; 206 } 207 return (error); 208} 209 210/*******************************************************\ 211* allow user processes to MMAP some memory sections * 212* instead of going through read/write * 213\*******************************************************/ 214static int 215memmmap(dev_t dev, vm_offset_t offset, int prot) 216{ 217 switch (minor(dev)) 218 { 219 220 /* minor device 0 is physical memory */ 221 case 0: 222 return (i386_btop(offset)); 223 224 /* minor device 1 is kernel memory */ 225 case 1: 226 return (i386_btop(vtophys(offset))); 227 228 default: 229 return (-1); 230 } 231} 232 233/* 234 * Operations for changing memory attributes. 235 * 236 * This is basically just an ioctl shim for mem_range_attr_get 237 * and mem_range_attr_set. 238 */ 239static int 240mmioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td) 241{ 242 int nd, error = 0; 243 struct mem_range_op *mo = (struct mem_range_op *)data; 244 struct mem_range_desc *md; 245 246 /* is this for us? */ 247 if ((cmd != MEMRANGE_GET) && 248 (cmd != MEMRANGE_SET)) 249 return (ENOTTY); 250 251 /* any chance we can handle this? */ 252 if (mem_range_softc.mr_op == NULL) 253 return (EOPNOTSUPP); 254 255 /* do we have any descriptors? */ 256 if (mem_range_softc.mr_ndesc == 0) 257 return (ENXIO); 258 259 switch (cmd) { 260 case MEMRANGE_GET: 261 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 262 if (nd > 0) { 263 md = (struct mem_range_desc *) 264 malloc(nd * sizeof(struct mem_range_desc), 265 M_MEMDESC, M_WAITOK); 266 error = mem_range_attr_get(md, &nd); 267 if (!error) 268 error = copyout(md, mo->mo_desc, 269 nd * sizeof(struct mem_range_desc)); 270 free(md, M_MEMDESC); 271 } 272 else 273 nd = mem_range_softc.mr_ndesc; 274 mo->mo_arg[0] = nd; 275 break; 276 277 case MEMRANGE_SET: 278 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), 279 M_MEMDESC, M_WAITOK); 280 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 281 /* clamp description string */ 282 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 283 if (error == 0) 284 error = mem_range_attr_set(md, &mo->mo_arg[0]); 285 free(md, M_MEMDESC); 286 break; 287 } 288 return (error); 289} 290 291/* 292 * Implementation-neutral, kernel-callable functions for manipulating 293 * memory range attributes. 294 */ 295int 296mem_range_attr_get(struct mem_range_desc *mrd, int *arg) 297{ 298 /* can we handle this? */ 299 if (mem_range_softc.mr_op == NULL) 300 return (EOPNOTSUPP); 301 302 if (*arg == 0) 303 *arg = mem_range_softc.mr_ndesc; 304 else 305 bcopy(mem_range_softc.mr_desc, mrd, 306 (*arg) * sizeof(struct mem_range_desc)); 307 return (0); 308} 309 310int 311mem_range_attr_set(struct mem_range_desc *mrd, int *arg) 312{ 313 /* can we handle this? */ 314 if (mem_range_softc.mr_op == NULL) 315 return (EOPNOTSUPP); 316 317 return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg)); 318} 319 320#ifdef SMP 321void 322mem_range_AP_init(void) 323{ 324 if (mem_range_softc.mr_op && mem_range_softc.mr_op->initAP) 325 (mem_range_softc.mr_op->initAP(&mem_range_softc)); 326} 327#endif 328 329static int 330mem_modevent(module_t mod, int type, void *data) 331{ 332 switch(type) { 333 case MOD_LOAD: 334 if (bootverbose) 335 printf("mem: <memory & I/O>\n"); 336 /* Initialise memory range handling */ 337 if (mem_range_softc.mr_op != NULL) 338 mem_range_softc.mr_op->init(&mem_range_softc); 339 340 memdev = make_dev(&mem_cdevsw, 0, UID_ROOT, GID_KMEM, 341 0640, "mem"); 342 kmemdev = make_dev(&mem_cdevsw, 1, UID_ROOT, GID_KMEM, 343 0640, "kmem"); 344 iodev = make_dev(&mem_cdevsw, 14, UID_ROOT, GID_WHEEL, 345 0600, "io"); 346 return (0); 347 348 case MOD_UNLOAD: 349 destroy_dev(memdev); 350 destroy_dev(kmemdev); 351 destroy_dev(iodev); 352 return (0); 353 354 case MOD_SHUTDOWN: 355 return (0); 356 357 default: 358 return (EOPNOTSUPP); 359 } 360} 361 362DEV_MODULE(mem, mem_modevent, NULL); 363