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