drivers/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 <sys/mman.h>
  27 #include "kernel/const.h"
  28 #include "kernel/config.h"
  29 #include "kernel/type.h"
  30
  31 #include <machine/vm.h>
  32
  33 #include "local.h"
  34
  35 /* ramdisks (/dev/ram*) */
  36 #define RAMDISKS     6
  37
  38 #define RAM_DEV_LAST (RAM_DEV_FIRST+RAMDISKS-1)
  39
  40 #define NR_DEVS            (7+RAMDISKS) /* number of minor devices */
  41
  42 static struct device m_geom[NR_DEVS];  /* base and size of each device */
  43 static vir_bytes m_vaddrs[NR_DEVS];
  44 static dev_t m_device;                  /* current minor character device */
  45
  46 static int openct[NR_DEVS];
  47
  48 static struct device *m_prepare(dev_t device);
  49 static int m_transfer(endpoint_t endpt, int opcode, u64_t position,
  50         iovec_t *iov, unsigned int nr_req, endpoint_t user_endpt, unsigned int
  51         flags);
  52 static int m_do_open(message *m_ptr);
  53 static int m_do_close(message *m_ptr);
  54
  55 static struct device *m_block_part(dev_t minor);
  56 static int m_block_transfer(dev_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(dev_t minor, int access);
  59 static int m_block_close(dev_t minor);
  60 static int m_block_ioctl(dev_t minor, unsigned int request, endpoint_t
  61         endpt, cp_grant_id_t grant);
  62
  63 /* Entry points to the CHARACTER part of this driver. */
  64 static struct chardriver m_cdtab = {
  65   m_do_open,    /* open or mount */
  66   m_do_close,   /* nothing on a close */
  67   nop_ioctl,    /* no I/O control */
  68   m_prepare,    /* prepare for I/O on a given minor device */
  69   m_transfer,   /* do the I/O */
  70   nop_cleanup,  /* no need to clean up */
  71   nop_alarm,    /* no alarms */
  72   nop_cancel,   /* no blocking operations */
  73   nop_select,   /* select not supported */
  74   NULL          /* other messages not supported */
  75 };
  76
  77 /* Entry points to the BLOCK part of this driver. */
  78 static struct blockdriver m_bdtab = {
  79   BLOCKDRIVER_TYPE_DISK,/* handle partition requests */
  80   m_block_open,         /* open or mount */
  81   m_block_close,        /* nothing on a close */
  82   m_block_transfer,     /* do the I/O */
  83   m_block_ioctl,        /* ram disk I/O control */
  84   NULL,                 /* no need to clean up */
  85   m_block_part,         /* return partition information */
  86   NULL,                 /* no geometry */
  87   NULL,                 /* no interrupt processing */
  88   NULL,                 /* no alarm processing */
  89   NULL,                 /* no processing of other messages */
  90   NULL                  /* no threading support */
  91 };
  92
  93 #define click_to_round_k(n) \
  94         ((unsigned) ((((unsigned long) (n) << CLICK_SHIFT) + 512) / 1024))
  95
  96 /* SEF functions and variables. */
  97 static void sef_local_startup(void);
  98 static int sef_cb_init_fresh(int type, sef_init_info_t *info);
  99
 100
 101 /*===========================================================================*
 102  *                                 main                                      *
 103  *===========================================================================*/
 104 int main(void)
 105 {
 106   message msg;
 107   int r, ipc_status;
 108
 109   /* SEF local startup. */
 110   sef_local_startup();
 111
 112   /* The receive loop. */
 113   for (;;) {
 114         if ((r = driver_receive(ANY, &msg, &ipc_status)) != OK)
 115                 panic("memory: driver_receive failed (%d)", r);
 116
 117         if (IS_BDEV_RQ(msg.m_type))
 118                 blockdriver_process(&m_bdtab, &msg, ipc_status);
 119         else
 120                 chardriver_process(&m_cdtab, CHARDRIVER_SYNC, &msg,
 121                         ipc_status);
 122   }
 123
 124   return(OK);
 125 }
 126
 127 /*===========================================================================*
 128  *                             sef_local_startup                             *
 129  *===========================================================================*/
 130 static void sef_local_startup()
 131 {
 132   /* Register init callbacks. */
 133   sef_setcb_init_fresh(sef_cb_init_fresh);
 134   sef_setcb_init_lu(sef_cb_init_fresh);
 135   sef_setcb_init_restart(sef_cb_init_fresh);
 136
 137   /* Register live update callbacks. */
 138   sef_setcb_lu_prepare(sef_cb_lu_prepare_always_ready);
 139   sef_setcb_lu_state_isvalid(sef_cb_lu_state_isvalid_standard);
 140
 141   /* Let SEF perform startup. */
 142   sef_startup();
 143 }
 144
 145 /*===========================================================================*
 146  *                          sef_cb_init_fresh                                *
 147  *===========================================================================*/
 148 static int sef_cb_init_fresh(int UNUSED(type), sef_init_info_t *UNUSED(info))
 149 {
 150 /* Initialize the memory driver. */
 151   int i;
 152 #if 0
 153   struct kinfo kinfo;           /* kernel information */
 154   int s;
 155
 156   if (OK != (s=sys_getkinfo(&kinfo))) {
 157       panic("Couldn't get kernel information: %d", s);
 158   }
 159
 160   /* Map in kernel memory for /dev/kmem. */
 161   m_geom[KMEM_DEV].dv_base = cvul64(kinfo.kmem_base);
 162   m_geom[KMEM_DEV].dv_size = cvul64(kinfo.kmem_size);
 163   if((m_vaddrs[KMEM_DEV] = vm_map_phys(SELF, (void *) kinfo.kmem_base,
 164         kinfo.kmem_size)) == MAP_FAILED) {
 165         printf("MEM: Couldn't map in /dev/kmem.");
 166   }
 167 #endif
 168
 169   /* Ramdisk image built into the memory driver */
 170   m_geom[IMGRD_DEV].dv_base= cvul64(0);
 171   m_geom[IMGRD_DEV].dv_size= cvul64(imgrd_size);
 172   m_vaddrs[IMGRD_DEV] = (vir_bytes) imgrd;
 173
 174   for(i = 0; i < NR_DEVS; i++)
 175         openct[i] = 0;
 176
 177   /* Set up memory range for /dev/mem. */
 178   m_geom[MEM_DEV].dv_base = cvul64(0);
 179   m_geom[MEM_DEV].dv_size = cvul64(0xffffffff);
 180
 181   m_vaddrs[MEM_DEV] = (vir_bytes) MAP_FAILED; /* we are not mapping this in. */
 182
 183   return(OK);
 184 }
 185
 186 /*===========================================================================*
 187  *                              m_is_block                                   *
 188  *===========================================================================*/
 189 static int m_is_block(dev_t minor)
 190 {
 191 /* Return TRUE iff the given minor device number is for a block device. */
 192
 193   switch (minor) {
 194   case MEM_DEV:
 195   case KMEM_DEV:
 196   case NULL_DEV:
 197   case ZERO_DEV:
 198         return FALSE;
 199
 200   default:
 201         return TRUE;
 202   }
 203 }
 204
 205 /*===========================================================================*
 206  *                              m_prepare                                    *
 207  *===========================================================================*/
 208 static struct device *m_prepare(dev_t device)
 209 {
 210 /* Prepare for I/O on a device: check if the minor device number is ok. */
 211   if (device >= NR_DEVS || m_is_block(device)) return(NULL);
 212   m_device = device;
 213
 214   return(&m_geom[device]);
 215 }
 216
 217 /*===========================================================================*
 218  *                              m_transfer                                   *
 219  *===========================================================================*/
 220 static int m_transfer(
 221   endpoint_t endpt,             /* endpoint of grant owner */
 222   int opcode,                   /* DEV_GATHER_S or DEV_SCATTER_S */
 223   u64_t pos64,                  /* offset on device to read or write */
 224   iovec_t *iov,                 /* pointer to read or write request vector */
 225   unsigned int nr_req,          /* length of request vector */
 226   endpoint_t UNUSED(user_endpt),/* endpoint of user process */
 227   unsigned int UNUSED(flags)
 228 )
 229 {
 230 /* Read or write one the driver's character devices. */
 231   unsigned count;
 232   vir_bytes vir_offset = 0;
 233   struct device *dv;
 234   unsigned long dv_size;
 235   int s, r;
 236   off_t position;
 237   cp_grant_id_t grant;
 238   vir_bytes dev_vaddr;
 239
 240   /* ZERO_DEV and NULL_DEV are infinite in size. */
 241   if (m_device != ZERO_DEV && m_device != NULL_DEV && ex64hi(pos64) != 0)
 242         return OK;      /* Beyond EOF */
 243   position= cv64ul(pos64);
 244
 245   /* Get minor device number and check for /dev/null. */
 246   dv = &m_geom[m_device];
 247   dv_size = cv64ul(dv->dv_size);
 248   dev_vaddr = m_vaddrs[m_device];
 249
 250   while (nr_req > 0) {
 251
 252         /* How much to transfer and where to / from. */
 253         count = iov->iov_size;
 254         grant = (cp_grant_id_t) iov->iov_addr;
 255
 256         switch (m_device) {
 257
 258         /* No copying; ignore request. */
 259         case NULL_DEV:
 260             if (opcode == DEV_GATHER_S) return(OK);     /* always at EOF */
 261             break;
 262
 263         /* Virtual copying. For kernel memory. */
 264         default:
 265         case KMEM_DEV:
 266             if(!dev_vaddr || dev_vaddr == (vir_bytes) MAP_FAILED) {
 267                 printf("MEM: dev %d not initialized\n", m_device);
 268                 return EIO;
 269             }
 270             if (position >= dv_size) return(OK);        /* check for EOF */
 271             if (position + count > dv_size) count = dv_size - position;
 272             if (opcode == DEV_GATHER_S) {       /* copy actual data */
 273                 r=sys_safecopyto(endpt, grant, vir_offset,
 274                   dev_vaddr + position, count);
 275             } else {
 276                 r=sys_safecopyfrom(endpt, grant, vir_offset,
 277                   dev_vaddr + position, count);
 278             }
 279             if(r != OK) {
 280               panic("I/O copy failed: %d", r);
 281             }
 282             break;
 283
 284         /* Physical copying. Only used to access entire memory.
 285          * Transfer one 'page window' at a time.
 286          */
 287         case MEM_DEV:
 288         {
 289             u32_t pagestart, page_off;
 290             static u32_t pagestart_mapped;
 291             static int any_mapped = 0;
 292             static char *vaddr;
 293             int r;
 294             u32_t subcount;
 295             phys_bytes mem_phys;
 296
 297             if (position >= dv_size)
 298                 return(OK);     /* check for EOF */
 299             if (position + count > dv_size)
 300                 count = dv_size - position;
 301             mem_phys = position;
 302
 303             page_off = mem_phys % PAGE_SIZE;
 304             pagestart = mem_phys - page_off;
 305
 306             /* All memory to the map call has to be page-aligned.
 307              * Don't have to map same page over and over.
 308              */
 309             if(!any_mapped || pagestart_mapped != pagestart) {
 310              if(any_mapped) {
 311                 if(vm_unmap_phys(SELF, vaddr, PAGE_SIZE) != OK)
 312                         panic("vm_unmap_phys failed");
 313                 any_mapped = 0;
 314              }
 315              vaddr = vm_map_phys(SELF, (void *) pagestart, PAGE_SIZE);
 316              if(vaddr == MAP_FAILED)
 317                 r = ENOMEM;
 318              else
 319                 r = OK;
 320              if(r != OK) {
 321                 printf("memory: vm_map_phys failed\n");
 322                 return r;
 323              }
 324              any_mapped = 1;
 325              pagestart_mapped = pagestart;
 326            }
 327
 328             /* how much to be done within this page. */
 329             subcount = PAGE_SIZE-page_off;
 330             if(subcount > count)
 331                 subcount = count;
 332
 333             if (opcode == DEV_GATHER_S) {                       /* copy data */
 334                    s=sys_safecopyto(endpt, grant,
 335                        vir_offset, (vir_bytes) vaddr+page_off, subcount);
 336             } else {
 337                    s=sys_safecopyfrom(endpt, grant,
 338                        vir_offset, (vir_bytes) vaddr+page_off, subcount);
 339             }
 340             if(s != OK)
 341                 return s;
 342             count = subcount;
 343             break;
 344         }
 345
 346         /* Null byte stream generator. */
 347         case ZERO_DEV:
 348             if (opcode == DEV_GATHER_S)
 349                 if ((s = sys_safememset(endpt, grant, 0, '\0', count)) != OK)
 350                     return s;
 351
 352             break;
 353
 354         }
 355
 356         /* Book the number of bytes transferred. */
 357         position += count;
 358         vir_offset += count;
 359         if ((iov->iov_size -= count) == 0) { iov++; nr_req--; vir_offset = 0; }
 360
 361   }
 362   return(OK);
 363 }
 364
 365 /*===========================================================================*
 366  *                              m_do_open                                    *
 367  *===========================================================================*/
 368 static int m_do_open(message *m_ptr)
 369 {
 370 /* Open a memory character device. */
 371   int r;
 372
 373 /* Check device number on open. */
 374   if (m_prepare(m_ptr->DEVICE) == NULL) return(ENXIO);
 375 #if defined(__i386__)
 376   if (m_device == MEM_DEV)
 377   {
 378         r = sys_enable_iop(m_ptr->USER_ENDPT);
 379         if (r != OK)
 380         {
 381                 printf("m_do_open: sys_enable_iop failed for %d: %d\n",
 382                         m_ptr->USER_ENDPT, r);
 383                 return r;
 384         }
 385   }
 386 #endif
 387
 388   openct[m_device]++;
 389
 390   return(OK);
 391 }
 392
 393 /*===========================================================================*
 394  *                              m_do_close                                   *
 395  *===========================================================================*/
 396 static int m_do_close(message *m_ptr)
 397 {
 398 /* Close a memory character device. */
 399   if (m_prepare(m_ptr->DEVICE) == NULL) return(ENXIO);
 400
 401   if(openct[m_device] < 1) {
 402         printf("MEMORY: closing unopened device %d\n", m_device);
 403         return(EINVAL);
 404   }
 405   openct[m_device]--;
 406
 407   return(OK);
 408 }
 409
 410 /*===========================================================================*
 411  *                              m_block_part                                 *
 412  *===========================================================================*/
 413 static struct device *m_block_part(dev_t minor)
 414 {
 415 /* Prepare for I/O on a device: check if the minor device number is ok. */
 416   if (minor >= NR_DEVS || !m_is_block(minor)) return(NULL);
 417
 418   return(&m_geom[minor]);
 419 }
 420
 421 /*===========================================================================*
 422  *                              m_block_transfer                             *
 423  *===========================================================================*/
 424 static int m_block_transfer(
 425   dev_t minor,                  /* minor device number */
 426   int do_write,                 /* read or write? */
 427   u64_t pos64,                  /* offset on device to read or write */
 428   endpoint_t endpt,             /* process doing the request */
 429   iovec_t *iov,                 /* pointer to read or write request vector */
 430   unsigned int nr_req,          /* length of request vector */
 431   int UNUSED(flags)             /* transfer flags */
 432 )
 433 {
 434 /* Read or write one the driver's block devices. */
 435   unsigned count;
 436   vir_bytes vir_offset = 0;
 437   struct device *dv;
 438   unsigned long dv_size;
 439   int r;
 440   off_t position;
 441   vir_bytes dev_vaddr;
 442   cp_grant_id_t grant;
 443   ssize_t total = 0;
 444
 445   /* Get minor device information. */
 446   if ((dv = m_block_part(minor)) == NULL) return(ENXIO);
 447   dv_size = cv64ul(dv->dv_size);
 448   dev_vaddr = m_vaddrs[minor];
 449
 450   if (ex64hi(pos64) != 0)
 451         return OK;      /* Beyond EOF */
 452   position= cv64ul(pos64);
 453
 454   while (nr_req > 0) {
 455
 456         /* How much to transfer and where to / from. */
 457         count = iov->iov_size;
 458         grant = (cp_grant_id_t) iov->iov_addr;
 459
 460         /* Virtual copying. For RAM disks and internal FS. */
 461         if(!dev_vaddr || dev_vaddr == (vir_bytes) MAP_FAILED) {
 462                 printf("MEM: dev %d not initialized\n", minor);
 463                 return EIO;
 464         }
 465         if (position >= dv_size) return(total); /* check for EOF */
 466         if (position + count > dv_size) count = dv_size - position;
 467         if (!do_write) {        /* copy actual data */
 468                 r=sys_safecopyto(endpt, grant, vir_offset,
 469                   dev_vaddr + position, count);
 470         } else {
 471                 r=sys_safecopyfrom(endpt, grant, vir_offset,
 472                   dev_vaddr + position, count);
 473         }
 474         if(r != OK) {
 475                 panic("I/O copy failed: %d", r);
 476         }
 477
 478         /* Book the number of bytes transferred. */
 479         position += count;
 480         vir_offset += count;
 481         total += count;
 482         if ((iov->iov_size -= count) == 0) { iov++; nr_req--; vir_offset = 0; }
 483
 484   }
 485   return(total);
 486 }
 487
 488 /*===========================================================================*
 489  *                              m_block_open                                 *
 490  *===========================================================================*/
 491 static int m_block_open(dev_t minor, int UNUSED(access))
 492 {
 493 /* Open a memory block device. */
 494   if (m_block_part(minor) == NULL) return(ENXIO);
 495
 496   openct[minor]++;
 497
 498   return(OK);
 499 }
 500
 501 /*===========================================================================*
 502  *                              m_block_close                                *
 503  *===========================================================================*/
 504 static int m_block_close(dev_t minor)
 505 {
 506 /* Close a memory block device. */
 507   if (m_block_part(minor) == NULL) return(ENXIO);
 508
 509   if(openct[minor] < 1) {
 510         printf("MEMORY: closing unopened device %d\n", minor);
 511         return(EINVAL);
 512   }
 513   openct[minor]--;
 514
 515   return(OK);
 516 }
 517
 518 /*===========================================================================*
 519  *                              m_block_ioctl                                *
 520  *===========================================================================*/
 521 static int m_block_ioctl(dev_t minor, unsigned int request, endpoint_t endpt,
 522         cp_grant_id_t grant)
 523 {
 524 /* I/O controls for the block devices of the memory driver. Currently there is
 525  * one I/O control specific to the memory driver:
 526  * - MIOCRAMSIZE: to set the size of the RAM disk.
 527  */
 528   struct device *dv;
 529   u32_t ramdev_size;
 530   int s;
 531   void *mem;
 532   int is_imgrd = 0;
 533
 534   if (request != MIOCRAMSIZE)
 535         return EINVAL;
 536
 537   if(minor == IMGRD_DEV)
 538         is_imgrd = 1;
 539
 540   /* Someone wants to create a new RAM disk with the given size.
 541    * A ramdisk can be created only once, and only on RAM disk device.
 542    */
 543   if ((dv = m_block_part(minor)) == NULL) return ENXIO;
 544   if((minor < RAM_DEV_FIRST || minor > RAM_DEV_LAST) &&
 545         minor != RAM_DEV_OLD && !is_imgrd) {
 546         printf("MEM: MIOCRAMSIZE: %d not a ramdisk\n", minor);
 547         return EINVAL;
 548   }
 549
 550   /* Get request structure */
 551   s= sys_safecopyfrom(endpt, grant, 0, (vir_bytes)&ramdev_size,
 552         sizeof(ramdev_size));
 553   if (s != OK)
 554         return s;
 555   if(is_imgrd)
 556         ramdev_size = 0;
 557   if(m_vaddrs[minor] && !cmp64(dv->dv_size, cvul64(ramdev_size))) {
 558         return(OK);
 559   }
 560   /* openct is 1 for the ioctl(). */
 561   if(openct[minor] != 1) {
 562         printf("MEM: MIOCRAMSIZE: %d in use (count %d)\n",
 563                 minor, openct[minor]);
 564         return(EBUSY);
 565   }
 566   if(m_vaddrs[minor]) {
 567         u32_t a, o;
 568         u64_t size;
 569         int r;
 570         if(ex64hi(dv->dv_size)) {
 571                 panic("huge old ramdisk");
 572         }
 573         size = dv->dv_size;
 574         a = m_vaddrs[minor];
 575         if((o = a % PAGE_SIZE)) {
 576                 vir_bytes l = PAGE_SIZE - o;
 577                 a += l;
 578                 size -= l;
 579         }
 580         size = rounddown(size, PAGE_SIZE);
 581         r = minix_munmap((void *) a, size);
 582         if(r != OK) {
 583                 printf("memory: WARNING: munmap failed: %d\n", r);
 584         }
 585         m_vaddrs[minor] = (vir_bytes) NULL;
 586         dv->dv_size = 0;
 587   }
 588
 589 #if DEBUG
 590   printf("MEM:%d: allocating ramdisk of size 0x%x\n", minor, ramdev_size);
 591 #endif
 592
 593   mem = NULL;
 594
 595   /* Try to allocate a piece of memory for the RAM disk. */
 596   if(ramdev_size > 0 &&
 597         (mem = minix_mmap(NULL, ramdev_size, PROT_READ|PROT_WRITE,
 598                 MAP_PREALLOC|MAP_ANON, -1, 0)) == MAP_FAILED) {
 599         printf("MEM: failed to get memory for ramdisk\n");
 600         return(ENOMEM);
 601   }
 602
 603   m_vaddrs[minor] = (vir_bytes) mem;
 604
 605   dv->dv_size = cvul64(ramdev_size);
 606
 607   return(OK);
 608 }