1 /* This file contains the device dependent part of the drivers for the 2 * following special files: 3 * /dev/ram - RAM disk 4 * /dev/mem - absolute memory 5 * /dev/kmem - kernel virtual memory 6 * /dev/null - null device (data sink) 7 * /dev/boot - boot device loaded from boot image 8 * /dev/zero - null byte stream generator 9 * /dev/imgrd - boot image RAM disk 10 * 11 * Changes: 12 * Apr 29, 2005 added null byte generator (Jorrit N. Herder) 13 * Apr 09, 2005 added support for boot device (Jorrit N. Herder) 14 * Jul 26, 2004 moved RAM driver to user-space (Jorrit N. Herder) 15 * Apr 20, 1992 device dependent/independent split (Kees J. Bot) 16 */ 17 18 #include <assert.h> 19 #include <minix/drivers.h> 20 #include <minix/chardriver.h> 21 #include <minix/blockdriver.h> 22 #include <sys/ioc_memory.h> 23 #include <minix/ds.h> 24 #include <minix/vm.h> 25 #include <machine/param.h> 26 #include <machine/vmparam.h> 27 #include <sys/mman.h> 28 #include "kernel/const.h" 29 #include "kernel/config.h" 30 #include "kernel/type.h" 31 32 #include <machine/vm.h> 33 34 #include "local.h" 35 36 /* ramdisks (/dev/ram*) */ 37 #define RAMDISKS 6 38 39 #define RAM_DEV_LAST (RAM_DEV_FIRST+RAMDISKS-1) 40 41 #define NR_DEVS (7+RAMDISKS) /* number of minor devices */ 42 43 static struct device m_geom[NR_DEVS]; /* base and size of each device */ 44 static vir_bytes m_vaddrs[NR_DEVS]; 45 46 static int openct[NR_DEVS]; 47 48 static ssize_t m_char_read(devminor_t minor, u64_t position, endpoint_t endpt, 49 cp_grant_id_t grant, size_t size, int flags, cdev_id_t id); 50 static ssize_t m_char_write(devminor_t minor, u64_t position, endpoint_t endpt, 51 cp_grant_id_t grant, size_t size, int flags, cdev_id_t id); 52 static int m_char_open(devminor_t minor, int access, endpoint_t user_endpt); 53 static int m_char_close(devminor_t minor); 54 55 static struct device *m_block_part(devminor_t minor); 56 static ssize_t m_block_transfer(devminor_t minor, int do_write, u64_t position, 57 endpoint_t endpt, iovec_t *iov, unsigned int nr_req, int flags); 58 static int m_block_open(devminor_t minor, int access); 59 static int m_block_close(devminor_t minor); 60 static int m_block_ioctl(devminor_t minor, unsigned long request, endpoint_t 61 endpt, cp_grant_id_t grant, endpoint_t user_endpt); 62 63 /* Entry points to the CHARACTER part of this driver. */ 64 static struct chardriver m_cdtab = { 65 .cdr_open = m_char_open, /* open device */ 66 .cdr_close = m_char_close, /* close device */ 67 .cdr_read = m_char_read, /* read from device */ 68 .cdr_write = m_char_write /* write to device */ 69 }; 70 71 /* Entry points to the BLOCK part of this driver. */ 72 static struct blockdriver m_bdtab = { 73 .bdr_type = BLOCKDRIVER_TYPE_DISK,/* handle partition requests */ 74 .bdr_open = m_block_open, /* open device */ 75 .bdr_close = m_block_close, /* nothing on a close */ 76 .bdr_transfer = m_block_transfer, /* do the I/O */ 77 .bdr_ioctl = m_block_ioctl, /* ram disk I/O control */ 78 .bdr_part = m_block_part /* return partition information */ 79 }; 80 81 /* SEF functions and variables. */ 82 static void sef_local_startup(void); 83 static int sef_cb_init_fresh(int type, sef_init_info_t *info); 84 85 /*===========================================================================* 86 * main * 87 *===========================================================================*/ 88 int main(void) 89 { 90 message msg; 91 int r, ipc_status; 92 93 /* SEF local startup. */ 94 sef_local_startup(); 95 96 /* The receive loop. */ 97 for (;;) { 98 if ((r = driver_receive(ANY, &msg, &ipc_status)) != OK) 99 panic("memory: driver_receive failed (%d)", r); 100 101 if (IS_BDEV_RQ(msg.m_type)) 102 blockdriver_process(&m_bdtab, &msg, ipc_status); 103 else 104 chardriver_process(&m_cdtab, &msg, ipc_status); 105 } 106 107 return(OK); 108 } 109 110 /*===========================================================================* 111 * sef_local_startup * 112 *===========================================================================*/ 113 static void sef_local_startup() 114 { 115 /* Register init callbacks. */ 116 sef_setcb_init_fresh(sef_cb_init_fresh); 117 sef_setcb_init_restart(SEF_CB_INIT_RESTART_STATEFUL); 118 119 /* Let SEF perform startup. */ 120 sef_startup(); 121 } 122 123 /*===========================================================================* 124 * sef_cb_init_fresh * 125 *===========================================================================*/ 126 static int sef_cb_init_fresh(int type, sef_init_info_t *UNUSED(info)) 127 { 128 /* Initialize the memory driver. */ 129 int i; 130 #if 0 131 struct kinfo kinfo; /* kernel information */ 132 int s; 133 134 if (OK != (s=sys_getkinfo(&kinfo))) { 135 panic("Couldn't get kernel information: %d", s); 136 } 137 138 /* Map in kernel memory for /dev/kmem. */ 139 m_geom[KMEM_DEV].dv_base = kinfo.kmem_base; 140 m_geom[KMEM_DEV].dv_size = kinfo.kmem_size; 141 if((m_vaddrs[KMEM_DEV] = vm_map_phys(SELF, (void *) kinfo.kmem_base, 142 kinfo.kmem_size)) == MAP_FAILED) { 143 printf("MEM: Couldn't map in /dev/kmem."); 144 } 145 #endif 146 147 /* Ramdisk image built into the memory driver */ 148 m_geom[IMGRD_DEV].dv_base= 0; 149 m_geom[IMGRD_DEV].dv_size= imgrd_size; 150 m_vaddrs[IMGRD_DEV] = (vir_bytes) imgrd; 151 152 for(i = 0; i < NR_DEVS; i++) 153 openct[i] = 0; 154 155 /* Set up memory range for /dev/mem. */ 156 m_geom[MEM_DEV].dv_base = 0; 157 m_geom[MEM_DEV].dv_size = 0xffffffffULL; 158 159 m_vaddrs[MEM_DEV] = (vir_bytes) MAP_FAILED; /* we are not mapping this in. */ 160 161 chardriver_announce(); 162 blockdriver_announce(type); 163 164 return(OK); 165 } 166 167 /*===========================================================================* 168 * m_is_block * 169 *===========================================================================*/ 170 static int m_is_block(devminor_t minor) 171 { 172 /* Return TRUE iff the given minor device number is for a block device. */ 173 174 switch (minor) { 175 case MEM_DEV: 176 case KMEM_DEV: 177 case NULL_DEV: 178 case ZERO_DEV: 179 return FALSE; 180 181 default: 182 return TRUE; 183 } 184 } 185 186 /*===========================================================================* 187 * m_transfer_kmem * 188 *===========================================================================*/ 189 static ssize_t m_transfer_kmem(devminor_t minor, int do_write, u64_t position, 190 endpoint_t endpt, cp_grant_id_t grant, size_t size) 191 { 192 /* Transfer from or to the KMEM device. */ 193 u64_t dv_size, dev_vaddr; 194 int r; 195 196 dv_size = m_geom[minor].dv_size; 197 dev_vaddr = m_vaddrs[minor]; 198 199 if (!dev_vaddr || dev_vaddr == (vir_bytes) MAP_FAILED) { 200 printf("MEM: dev %d not initialized\n", minor); 201 return EIO; 202 } 203 204 if (position >= dv_size) return 0; /* check for EOF */ 205 if (position + size > dv_size) size = dv_size - position; 206 207 if (!do_write) /* copy actual data */ 208 r = sys_safecopyto(endpt, grant, 0, dev_vaddr + position, size); 209 else 210 r = sys_safecopyfrom(endpt, grant, 0, dev_vaddr + position, size); 211 212 return (r != OK) ? r : size; 213 } 214 215 /*===========================================================================* 216 * m_transfer_mem * 217 *===========================================================================*/ 218 static ssize_t m_transfer_mem(devminor_t minor, int do_write, u64_t position, 219 endpoint_t endpt, cp_grant_id_t grant, size_t size) 220 { 221 /* Transfer from or to the MEM device. */ 222 static int any_mapped = 0; 223 static phys_bytes pagestart_mapped; 224 static char *vaddr; 225 phys_bytes mem_phys, pagestart; 226 size_t off, page_off, subcount; 227 u64_t dv_size; 228 int r; 229 230 dv_size = m_geom[minor].dv_size; 231 if (position >= dv_size) return 0; /* check for EOF */ 232 if (position + size > dv_size) size = dv_size - position; 233 234 /* Physical copying. Only used to access entire memory. 235 * Transfer one 'page window' at a time. 236 */ 237 off = 0; 238 while (off < size) { 239 mem_phys = (phys_bytes) position; 240 241 page_off = (size_t) (mem_phys % PAGE_SIZE); 242 pagestart = mem_phys - page_off; 243 244 /* All memory to the map call has to be page-aligned. 245 * Don't have to map same page over and over. 246 */ 247 if (!any_mapped || pagestart_mapped != pagestart) { 248 if (any_mapped) { 249 if (vm_unmap_phys(SELF, vaddr, PAGE_SIZE) != OK) 250 panic("vm_unmap_phys failed"); 251 any_mapped = 0; 252 } 253 254 vaddr = vm_map_phys(SELF, (void *) pagestart, PAGE_SIZE); 255 if (vaddr == MAP_FAILED) { 256 printf("memory: vm_map_phys failed\n"); 257 return ENOMEM; 258 } 259 any_mapped = 1; 260 pagestart_mapped = pagestart; 261 } 262 263 /* how much to be done within this page. */ 264 subcount = PAGE_SIZE - page_off; 265 if (subcount > size) 266 subcount = size; 267 268 if (!do_write) /* copy data */ 269 r = sys_safecopyto(endpt, grant, off, 270 (vir_bytes) vaddr + page_off, subcount); 271 else 272 r = sys_safecopyfrom(endpt, grant, off, 273 (vir_bytes) vaddr + page_off, subcount); 274 if (r != OK) 275 return r; 276 277 position += subcount; 278 off += subcount; 279 } 280 281 return off; 282 } 283 284 /*===========================================================================* 285 * m_char_read * 286 *===========================================================================*/ 287 static ssize_t m_char_read(devminor_t minor, u64_t position, endpoint_t endpt, 288 cp_grant_id_t grant, size_t size, int UNUSED(flags), 289 cdev_id_t UNUSED(id)) 290 { 291 /* Read from one of the driver's character devices. */ 292 ssize_t r; 293 294 /* Check if the minor device number is ok. */ 295 if (minor < 0 || minor >= NR_DEVS || m_is_block(minor)) return ENXIO; 296 297 switch (minor) { 298 case NULL_DEV: 299 r = 0; /* always at EOF */ 300 break; 301 302 case ZERO_DEV: 303 /* Fill the target area with zeroes. In fact, let the kernel do it! */ 304 if ((r = sys_safememset(endpt, grant, 0, '\0', size)) == OK) 305 r = size; 306 break; 307 308 case KMEM_DEV: 309 r = m_transfer_kmem(minor, FALSE, position, endpt, grant, size); 310 break; 311 312 case MEM_DEV: 313 r = m_transfer_mem(minor, FALSE, position, endpt, grant, size); 314 break; 315 316 default: 317 panic("unknown character device %d", minor); 318 } 319 320 return r; 321 } 322 323 /*===========================================================================* 324 * m_char_write * 325 *===========================================================================*/ 326 static ssize_t m_char_write(devminor_t minor, u64_t position, endpoint_t endpt, 327 cp_grant_id_t grant, size_t size, int UNUSED(flags), 328 cdev_id_t UNUSED(id)) 329 { 330 /* Write to one of the driver's character devices. */ 331 ssize_t r; 332 333 /* Check if the minor device number is ok. */ 334 if (minor < 0 || minor >= NR_DEVS || m_is_block(minor)) return ENXIO; 335 336 switch (minor) { 337 case NULL_DEV: 338 case ZERO_DEV: 339 r = size; /* just eat everything */ 340 break; 341 342 case KMEM_DEV: 343 r = m_transfer_kmem(minor, TRUE, position, endpt, grant, size); 344 break; 345 346 case MEM_DEV: 347 r = m_transfer_mem(minor, TRUE, position, endpt, grant, size); 348 break; 349 350 default: 351 panic("unknown character device %d", minor); 352 } 353 354 return r; 355 } 356 357 /*===========================================================================* 358 * m_char_open * 359 *===========================================================================*/ 360 static int m_char_open(devminor_t minor, int access, endpoint_t user_endpt) 361 { 362 /* Open a memory character device. */ 363 364 /* Check if the minor device number is ok. */ 365 if (minor < 0 || minor >= NR_DEVS || m_is_block(minor)) return ENXIO; 366 367 #if defined(__i386__) 368 if (minor == MEM_DEV) 369 { 370 int r = sys_enable_iop(user_endpt); 371 if (r != OK) 372 { 373 printf("m_char_open: sys_enable_iop failed for %d: %d\n", 374 user_endpt, r); 375 return r; 376 } 377 } 378 #endif 379 380 openct[minor]++; 381 382 return(OK); 383 } 384 385 /*===========================================================================* 386 * m_char_close * 387 *===========================================================================*/ 388 static int m_char_close(devminor_t minor) 389 { 390 /* Close a memory character device. */ 391 392 if (minor < 0 || minor >= NR_DEVS || m_is_block(minor)) return ENXIO; 393 394 if(openct[minor] < 1) { 395 printf("MEMORY: closing unopened device %d\n", minor); 396 return(EINVAL); 397 } 398 openct[minor]--; 399 400 return(OK); 401 } 402 403 /*===========================================================================* 404 * m_block_part * 405 *===========================================================================*/ 406 static struct device *m_block_part(devminor_t minor) 407 { 408 /* Prepare for I/O on a device: check if the minor device number is ok. */ 409 if (minor < 0 || minor >= NR_DEVS || !m_is_block(minor)) return(NULL); 410 411 return(&m_geom[minor]); 412 } 413 414 /*===========================================================================* 415 * m_block_transfer * 416 *===========================================================================*/ 417 static int m_block_transfer( 418 devminor_t minor, /* minor device number */ 419 int do_write, /* read or write? */ 420 u64_t position, /* offset on device to read or write */ 421 endpoint_t endpt, /* process doing the request */ 422 iovec_t *iov, /* pointer to read or write request vector */ 423 unsigned int nr_req, /* length of request vector */ 424 int UNUSED(flags) /* transfer flags */ 425 ) 426 { 427 /* Read or write one the driver's block devices. */ 428 unsigned count; 429 vir_bytes vir_offset = 0; 430 struct device *dv; 431 u64_t dv_size; 432 int r; 433 vir_bytes dev_vaddr; 434 cp_grant_id_t grant; 435 ssize_t total = 0; 436 437 /* Get minor device information. */ 438 if ((dv = m_block_part(minor)) == NULL) return(ENXIO); 439 dv_size = dv->dv_size; 440 dev_vaddr = m_vaddrs[minor]; 441 442 if (ex64hi(position) != 0) 443 return OK; /* Beyond EOF */ 444 445 while (nr_req > 0) { 446 447 /* How much to transfer and where to / from. */ 448 count = iov->iov_size; 449 grant = (cp_grant_id_t) iov->iov_addr; 450 451 /* Virtual copying. For RAM disks and internal FS. */ 452 if(!dev_vaddr || dev_vaddr == (vir_bytes) MAP_FAILED) { 453 printf("MEM: dev %d not initialized\n", minor); 454 return EIO; 455 } 456 if (position >= dv_size) return(total); /* check for EOF */ 457 if (position + count > dv_size) count = dv_size - position; 458 if (!do_write) { /* copy actual data */ 459 r=sys_safecopyto(endpt, grant, vir_offset, 460 dev_vaddr + position, count); 461 } else { 462 r=sys_safecopyfrom(endpt, grant, vir_offset, 463 dev_vaddr + position, count); 464 } 465 if(r != OK) { 466 panic("I/O copy failed: %d", r); 467 } 468 469 /* Book the number of bytes transferred. */ 470 position += count; 471 vir_offset += count; 472 total += count; 473 if ((iov->iov_size -= count) == 0) { iov++; nr_req--; vir_offset = 0; } 474 475 } 476 return(total); 477 } 478 479 /*===========================================================================* 480 * m_block_open * 481 *===========================================================================*/ 482 static int m_block_open(devminor_t minor, int UNUSED(access)) 483 { 484 /* Open a memory block device. */ 485 if (m_block_part(minor) == NULL) return(ENXIO); 486 487 openct[minor]++; 488 489 return(OK); 490 } 491 492 /*===========================================================================* 493 * m_block_close * 494 *===========================================================================*/ 495 static int m_block_close(devminor_t minor) 496 { 497 /* Close a memory block device. */ 498 if (m_block_part(minor) == NULL) return(ENXIO); 499 500 if(openct[minor] < 1) { 501 printf("MEMORY: closing unopened device %d\n", minor); 502 return(EINVAL); 503 } 504 openct[minor]--; 505 506 return(OK); 507 } 508 509 /*===========================================================================* 510 * m_block_ioctl * 511 *===========================================================================*/ 512 static int m_block_ioctl(devminor_t minor, unsigned long request, 513 endpoint_t endpt, cp_grant_id_t grant, endpoint_t UNUSED(user_endpt)) 514 { 515 /* I/O controls for the block devices of the memory driver. Currently there is 516 * one I/O control specific to the memory driver: 517 * - MIOCRAMSIZE: to set the size of the RAM disk. 518 */ 519 struct device *dv; 520 u32_t ramdev_size; 521 int s; 522 void *mem; 523 int is_imgrd = 0; 524 525 if (request != MIOCRAMSIZE) 526 return EINVAL; 527 528 if(minor == IMGRD_DEV) 529 is_imgrd = 1; 530 531 /* Someone wants to create a new RAM disk with the given size. 532 * A ramdisk can be created only once, and only on RAM disk device. 533 */ 534 if ((dv = m_block_part(minor)) == NULL) return ENXIO; 535 if((minor < RAM_DEV_FIRST || minor > RAM_DEV_LAST) && 536 minor != RAM_DEV_OLD && !is_imgrd) { 537 printf("MEM: MIOCRAMSIZE: %d not a ramdisk\n", minor); 538 return EINVAL; 539 } 540 541 /* Get request structure */ 542 s= sys_safecopyfrom(endpt, grant, 0, (vir_bytes)&ramdev_size, 543 sizeof(ramdev_size)); 544 if (s != OK) 545 return s; 546 if(is_imgrd) 547 ramdev_size = 0; 548 if(m_vaddrs[minor] && dv->dv_size == (u64_t) ramdev_size) { 549 return(OK); 550 } 551 /* openct is 1 for the ioctl(). */ 552 if(openct[minor] != 1) { 553 printf("MEM: MIOCRAMSIZE: %d in use (count %d)\n", 554 minor, openct[minor]); 555 return(EBUSY); 556 } 557 if(m_vaddrs[minor]) { 558 u32_t a, o; 559 u64_t size; 560 int r; 561 if(ex64hi(dv->dv_size)) { 562 panic("huge old ramdisk"); 563 } 564 size = dv->dv_size; 565 a = m_vaddrs[minor]; 566 if((o = a % PAGE_SIZE)) { 567 vir_bytes l = PAGE_SIZE - o; 568 a += l; 569 size -= l; 570 } 571 size = rounddown(size, PAGE_SIZE); 572 r = munmap((void *) a, size); 573 if(r != OK) { 574 printf("memory: WARNING: munmap failed: %d\n", r); 575 } 576 m_vaddrs[minor] = (vir_bytes) NULL; 577 dv->dv_size = 0; 578 } 579 580 #if DEBUG 581 printf("MEM:%d: allocating ramdisk of size 0x%x\n", minor, ramdev_size); 582 #endif 583 584 mem = NULL; 585 586 /* Try to allocate a piece of memory for the RAM disk. */ 587 if(ramdev_size > 0 && 588 (mem = mmap(NULL, ramdev_size, PROT_READ|PROT_WRITE, 589 MAP_PREALLOC|MAP_ANON, -1, 0)) == MAP_FAILED) { 590 printf("MEM: failed to get memory for ramdisk\n"); 591 return(ENOMEM); 592 } 593 594 m_vaddrs[minor] = (vir_bytes) mem; 595 596 dv->dv_size = ramdev_size; 597 598 return(OK); 599 } 600