minix/drivers/storage/memory/memory.c

   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 }