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_lu(SEF_CB_INIT_LU_DEFAULT); 118 sef_setcb_init_restart(SEF_CB_INIT_RESTART_STATEFUL); 119 120 /* Let SEF perform startup. */ 121 sef_startup(); 122 } 123 124 /*===========================================================================* 125 * sef_cb_init_fresh * 126 *===========================================================================*/ 127 static int sef_cb_init_fresh(int type, sef_init_info_t *UNUSED(info)) 128 { 129 /* Initialize the memory driver. */ 130 int i; 131 #if 0 132 struct kinfo kinfo; /* kernel information */ 133 int s; 134 135 if (OK != (s=sys_getkinfo(&kinfo))) { 136 panic("Couldn't get kernel information: %d", s); 137 } 138 139 /* Map in kernel memory for /dev/kmem. */ 140 m_geom[KMEM_DEV].dv_base = kinfo.kmem_base; 141 m_geom[KMEM_DEV].dv_size = kinfo.kmem_size; 142 if((m_vaddrs[KMEM_DEV] = vm_map_phys(SELF, (void *) kinfo.kmem_base, 143 kinfo.kmem_size)) == MAP_FAILED) { 144 printf("MEM: Couldn't map in /dev/kmem."); 145 } 146 #endif 147 148 /* Ramdisk image built into the memory driver */ 149 m_geom[IMGRD_DEV].dv_base= 0; 150 m_geom[IMGRD_DEV].dv_size= imgrd_size; 151 m_vaddrs[IMGRD_DEV] = (vir_bytes) imgrd; 152 153 for(i = 0; i < NR_DEVS; i++) 154 openct[i] = 0; 155 156 /* Set up memory range for /dev/mem. */ 157 m_geom[MEM_DEV].dv_base = 0; 158 m_geom[MEM_DEV].dv_size = 0xffffffffULL; 159 160 m_vaddrs[MEM_DEV] = (vir_bytes) MAP_FAILED; /* we are not mapping this in. */ 161 162 chardriver_announce(); 163 blockdriver_announce(type); 164 165 return(OK); 166 } 167 168 /*===========================================================================* 169 * m_is_block * 170 *===========================================================================*/ 171 static int m_is_block(devminor_t minor) 172 { 173 /* Return TRUE iff the given minor device number is for a block device. */ 174 175 switch (minor) { 176 case MEM_DEV: 177 case KMEM_DEV: 178 case NULL_DEV: 179 case ZERO_DEV: 180 return FALSE; 181 182 default: 183 return TRUE; 184 } 185 } 186 187 /*===========================================================================* 188 * m_transfer_kmem * 189 *===========================================================================*/ 190 static ssize_t m_transfer_kmem(devminor_t minor, int do_write, u64_t position, 191 endpoint_t endpt, cp_grant_id_t grant, size_t size) 192 { 193 /* Transfer from or to the KMEM device. */ 194 u64_t dv_size, dev_vaddr; 195 int r; 196 197 dv_size = m_geom[minor].dv_size; 198 dev_vaddr = m_vaddrs[minor]; 199 200 if (!dev_vaddr || dev_vaddr == (vir_bytes) MAP_FAILED) { 201 printf("MEM: dev %d not initialized\n", minor); 202 return EIO; 203 } 204 205 if (position >= dv_size) return 0; /* check for EOF */ 206 if (position + size > dv_size) size = dv_size - position; 207 208 if (!do_write) /* copy actual data */ 209 r = sys_safecopyto(endpt, grant, 0, dev_vaddr + position, size); 210 else 211 r = sys_safecopyfrom(endpt, grant, 0, dev_vaddr + position, size); 212 213 return (r != OK) ? r : size; 214 } 215 216 /*===========================================================================* 217 * m_transfer_mem * 218 *===========================================================================*/ 219 static ssize_t m_transfer_mem(devminor_t minor, int do_write, u64_t position, 220 endpoint_t endpt, cp_grant_id_t grant, size_t size) 221 { 222 /* Transfer from or to the MEM device. */ 223 static int any_mapped = 0; 224 static phys_bytes pagestart_mapped; 225 static char *vaddr; 226 phys_bytes mem_phys, pagestart; 227 size_t off, page_off, subcount; 228 u64_t dv_size; 229 int r; 230 231 dv_size = m_geom[minor].dv_size; 232 if (position >= dv_size) return 0; /* check for EOF */ 233 if (position + size > dv_size) size = dv_size - position; 234 235 /* Physical copying. Only used to access entire memory. 236 * Transfer one 'page window' at a time. 237 */ 238 off = 0; 239 while (off < size) { 240 mem_phys = (phys_bytes) position; 241 242 page_off = (size_t) (mem_phys % PAGE_SIZE); 243 pagestart = mem_phys - page_off; 244 245 /* All memory to the map call has to be page-aligned. 246 * Don't have to map same page over and over. 247 */ 248 if (!any_mapped || pagestart_mapped != pagestart) { 249 if (any_mapped) { 250 if (vm_unmap_phys(SELF, vaddr, PAGE_SIZE) != OK) 251 panic("vm_unmap_phys failed"); 252 any_mapped = 0; 253 } 254 255 vaddr = vm_map_phys(SELF, (void *) pagestart, PAGE_SIZE); 256 if (vaddr == MAP_FAILED) { 257 printf("memory: vm_map_phys failed\n"); 258 return ENOMEM; 259 } 260 any_mapped = 1; 261 pagestart_mapped = pagestart; 262 } 263 264 /* how much to be done within this page. */ 265 subcount = PAGE_SIZE - page_off; 266 if (subcount > size) 267 subcount = size; 268 269 if (!do_write) /* copy data */ 270 r = sys_safecopyto(endpt, grant, off, 271 (vir_bytes) vaddr + page_off, subcount); 272 else 273 r = sys_safecopyfrom(endpt, grant, off, 274 (vir_bytes) vaddr + page_off, subcount); 275 if (r != OK) 276 return r; 277 278 position += subcount; 279 off += subcount; 280 } 281 282 return off; 283 } 284 285 /*===========================================================================* 286 * m_char_read * 287 *===========================================================================*/ 288 static ssize_t m_char_read(devminor_t minor, u64_t position, endpoint_t endpt, 289 cp_grant_id_t grant, size_t size, int UNUSED(flags), 290 cdev_id_t UNUSED(id)) 291 { 292 /* Read from one of the driver's character devices. */ 293 ssize_t r; 294 295 /* Check if the minor device number is ok. */ 296 if (minor < 0 || minor >= NR_DEVS || m_is_block(minor)) return ENXIO; 297 298 switch (minor) { 299 case NULL_DEV: 300 r = 0; /* always at EOF */ 301 break; 302 303 case ZERO_DEV: 304 /* Fill the target area with zeroes. In fact, let the kernel do it! */ 305 if ((r = sys_safememset(endpt, grant, 0, '\0', size)) == OK) 306 r = size; 307 break; 308 309 case KMEM_DEV: 310 r = m_transfer_kmem(minor, FALSE, position, endpt, grant, size); 311 break; 312 313 case MEM_DEV: 314 r = m_transfer_mem(minor, FALSE, position, endpt, grant, size); 315 break; 316 317 default: 318 panic("unknown character device %d", minor); 319 } 320 321 return r; 322 } 323 324 /*===========================================================================* 325 * m_char_write * 326 *===========================================================================*/ 327 static ssize_t m_char_write(devminor_t minor, u64_t position, endpoint_t endpt, 328 cp_grant_id_t grant, size_t size, int UNUSED(flags), 329 cdev_id_t UNUSED(id)) 330 { 331 /* Write to one of the driver's character devices. */ 332 ssize_t r; 333 334 /* Check if the minor device number is ok. */ 335 if (minor < 0 || minor >= NR_DEVS || m_is_block(minor)) return ENXIO; 336 337 switch (minor) { 338 case NULL_DEV: 339 case ZERO_DEV: 340 r = size; /* just eat everything */ 341 break; 342 343 case KMEM_DEV: 344 r = m_transfer_kmem(minor, TRUE, position, endpt, grant, size); 345 break; 346 347 case MEM_DEV: 348 r = m_transfer_mem(minor, TRUE, position, endpt, grant, size); 349 break; 350 351 default: 352 panic("unknown character device %d", minor); 353 } 354 355 return r; 356 } 357 358 /*===========================================================================* 359 * m_char_open * 360 *===========================================================================*/ 361 static int m_char_open(devminor_t minor, int access, endpoint_t user_endpt) 362 { 363 /* Open a memory character device. */ 364 365 /* Check if the minor device number is ok. */ 366 if (minor < 0 || minor >= NR_DEVS || m_is_block(minor)) return ENXIO; 367 368 #if defined(__i386__) 369 if (minor == MEM_DEV) 370 { 371 int r = sys_enable_iop(user_endpt); 372 if (r != OK) 373 { 374 printf("m_char_open: sys_enable_iop failed for %d: %d\n", 375 user_endpt, r); 376 return r; 377 } 378 } 379 #endif 380 381 openct[minor]++; 382 383 return(OK); 384 } 385 386 /*===========================================================================* 387 * m_char_close * 388 *===========================================================================*/ 389 static int m_char_close(devminor_t minor) 390 { 391 /* Close a memory character device. */ 392 393 if (minor < 0 || minor >= NR_DEVS || m_is_block(minor)) return ENXIO; 394 395 if(openct[minor] < 1) { 396 printf("MEMORY: closing unopened device %d\n", minor); 397 return(EINVAL); 398 } 399 openct[minor]--; 400 401 return(OK); 402 } 403 404 /*===========================================================================* 405 * m_block_part * 406 *===========================================================================*/ 407 static struct device *m_block_part(devminor_t minor) 408 { 409 /* Prepare for I/O on a device: check if the minor device number is ok. */ 410 if (minor < 0 || minor >= NR_DEVS || !m_is_block(minor)) return(NULL); 411 412 return(&m_geom[minor]); 413 } 414 415 /*===========================================================================* 416 * m_block_transfer * 417 *===========================================================================*/ 418 static int m_block_transfer( 419 devminor_t minor, /* minor device number */ 420 int do_write, /* read or write? */ 421 u64_t position, /* offset on device to read or write */ 422 endpoint_t endpt, /* process doing the request */ 423 iovec_t *iov, /* pointer to read or write request vector */ 424 unsigned int nr_req, /* length of request vector */ 425 int UNUSED(flags) /* transfer flags */ 426 ) 427 { 428 /* Read or write one the driver's block devices. */ 429 unsigned count; 430 vir_bytes vir_offset = 0; 431 struct device *dv; 432 u64_t dv_size; 433 int r; 434 vir_bytes dev_vaddr; 435 cp_grant_id_t grant; 436 ssize_t total = 0; 437 438 /* Get minor device information. */ 439 if ((dv = m_block_part(minor)) == NULL) return(ENXIO); 440 dv_size = dv->dv_size; 441 dev_vaddr = m_vaddrs[minor]; 442 443 if (ex64hi(position) != 0) 444 return OK; /* Beyond EOF */ 445 446 while (nr_req > 0) { 447 448 /* How much to transfer and where to / from. */ 449 count = iov->iov_size; 450 grant = (cp_grant_id_t) iov->iov_addr; 451 452 /* Virtual copying. For RAM disks and internal FS. */ 453 if(!dev_vaddr || dev_vaddr == (vir_bytes) MAP_FAILED) { 454 printf("MEM: dev %d not initialized\n", minor); 455 return EIO; 456 } 457 if (position >= dv_size) return(total); /* check for EOF */ 458 if (position + count > dv_size) count = dv_size - position; 459 if (!do_write) { /* copy actual data */ 460 r=sys_safecopyto(endpt, grant, vir_offset, 461 dev_vaddr + position, count); 462 } else { 463 r=sys_safecopyfrom(endpt, grant, vir_offset, 464 dev_vaddr + position, count); 465 } 466 if(r != OK) { 467 panic("I/O copy failed: %d", r); 468 } 469 470 /* Book the number of bytes transferred. */ 471 position += count; 472 vir_offset += count; 473 total += count; 474 if ((iov->iov_size -= count) == 0) { iov++; nr_req--; vir_offset = 0; } 475 476 } 477 return(total); 478 } 479 480 /*===========================================================================* 481 * m_block_open * 482 *===========================================================================*/ 483 static int m_block_open(devminor_t minor, int UNUSED(access)) 484 { 485 /* Open a memory block device. */ 486 if (m_block_part(minor) == NULL) return(ENXIO); 487 488 openct[minor]++; 489 490 return(OK); 491 } 492 493 /*===========================================================================* 494 * m_block_close * 495 *===========================================================================*/ 496 static int m_block_close(devminor_t minor) 497 { 498 /* Close a memory block device. */ 499 if (m_block_part(minor) == NULL) return(ENXIO); 500 501 if(openct[minor] < 1) { 502 printf("MEMORY: closing unopened device %d\n", minor); 503 return(EINVAL); 504 } 505 openct[minor]--; 506 507 return(OK); 508 } 509 510 /*===========================================================================* 511 * m_block_ioctl * 512 *===========================================================================*/ 513 static int m_block_ioctl(devminor_t minor, unsigned long request, 514 endpoint_t endpt, cp_grant_id_t grant, endpoint_t UNUSED(user_endpt)) 515 { 516 /* I/O controls for the block devices of the memory driver. Currently there is 517 * one I/O control specific to the memory driver: 518 * - MIOCRAMSIZE: to set the size of the RAM disk. 519 */ 520 struct device *dv; 521 u32_t ramdev_size; 522 int s; 523 void *mem; 524 int is_imgrd = 0; 525 526 if (request != MIOCRAMSIZE) 527 return EINVAL; 528 529 if(minor == IMGRD_DEV) 530 is_imgrd = 1; 531 532 /* Someone wants to create a new RAM disk with the given size. 533 * A ramdisk can be created only once, and only on RAM disk device. 534 */ 535 if ((dv = m_block_part(minor)) == NULL) return ENXIO; 536 if((minor < RAM_DEV_FIRST || minor > RAM_DEV_LAST) && 537 minor != RAM_DEV_OLD && !is_imgrd) { 538 printf("MEM: MIOCRAMSIZE: %d not a ramdisk\n", minor); 539 return EINVAL; 540 } 541 542 /* Get request structure */ 543 s= sys_safecopyfrom(endpt, grant, 0, (vir_bytes)&ramdev_size, 544 sizeof(ramdev_size)); 545 if (s != OK) 546 return s; 547 if(is_imgrd) 548 ramdev_size = 0; 549 if(m_vaddrs[minor] && dv->dv_size == (u64_t) ramdev_size) { 550 return(OK); 551 } 552 /* openct is 1 for the ioctl(). */ 553 if(openct[minor] != 1) { 554 printf("MEM: MIOCRAMSIZE: %d in use (count %d)\n", 555 minor, openct[minor]); 556 return(EBUSY); 557 } 558 if(m_vaddrs[minor]) { 559 u32_t a, o; 560 u64_t size; 561 int r; 562 if(ex64hi(dv->dv_size)) { 563 panic("huge old ramdisk"); 564 } 565 size = dv->dv_size; 566 a = m_vaddrs[minor]; 567 if((o = a % PAGE_SIZE)) { 568 vir_bytes l = PAGE_SIZE - o; 569 a += l; 570 size -= l; 571 } 572 size = rounddown(size, PAGE_SIZE); 573 r = munmap((void *) a, size); 574 if(r != OK) { 575 printf("memory: WARNING: munmap failed: %d\n", r); 576 } 577 m_vaddrs[minor] = (vir_bytes) NULL; 578 dv->dv_size = 0; 579 } 580 581 #if DEBUG 582 printf("MEM:%d: allocating ramdisk of size 0x%x\n", minor, ramdev_size); 583 #endif 584 585 mem = NULL; 586 587 /* Try to allocate a piece of memory for the RAM disk. */ 588 if(ramdev_size > 0 && 589 (mem = mmap(NULL, ramdev_size, PROT_READ|PROT_WRITE, 590 MAP_PREALLOC|MAP_ANON, -1, 0)) == MAP_FAILED) { 591 printf("MEM: failed to get memory for ramdisk\n"); 592 return(ENOMEM); 593 } 594 595 m_vaddrs[minor] = (vir_bytes) mem; 596 597 dv->dv_size = ramdev_size; 598 599 return(OK); 600 } 601