arch/m68k/kernel/sys_m68k.c

   1 /*
   2  * linux/arch/m68k/kernel/sys_m68k.c
   3  *
   4  * This file contains various random system calls that
   5  * have a non-standard calling sequence on the Linux/m68k
   6  * platform.
   7  */
   8
   9 #include <linux/capability.h>
  10 #include <linux/errno.h>
  11 #include <linux/sched.h>
  12 #include <linux/mm.h>
  13 #include <linux/fs.h>
  14 #include <linux/smp.h>
  15 #include <linux/smp_lock.h>
  16 #include <linux/sem.h>
  17 #include <linux/msg.h>
  18 #include <linux/shm.h>
  19 #include <linux/stat.h>
  20 #include <linux/syscalls.h>
  21 #include <linux/mman.h>
  22 #include <linux/file.h>
  23 #include <linux/ipc.h>
  24
  25 #include <asm/setup.h>
  26 #include <asm/uaccess.h>
  27 #include <asm/cachectl.h>
  28 #include <asm/traps.h>
  29 #include <asm/page.h>
  30 #include <asm/unistd.h>
  31 #include <linux/elf.h>
  32 #include <asm/tlb.h>
  33
  34 asmlinkage int do_page_fault(struct pt_regs *regs, unsigned long address,
  35                              unsigned long error_code);
  36
  37 asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
  38         unsigned long prot, unsigned long flags,
  39         unsigned long fd, unsigned long pgoff)
  40 {
  41         /*
  42          * This is wrong for sun3 - there PAGE_SIZE is 8Kb,
  43          * so we need to shift the argument down by 1; m68k mmap64(3)
  44          * (in libc) expects the last argument of mmap2 in 4Kb units.
  45          */
  46         return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff);
  47 }
  48
  49 /*
  50  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
  51  *
  52  * This is really horribly ugly.
  53  */
  54 asmlinkage int sys_ipc (uint call, int first, int second,
  55                         int third, void __user *ptr, long fifth)
  56 {
  57         int version, ret;
  58
  59         version = call >> 16; /* hack for backward compatibility */
  60         call &= 0xffff;
  61
  62         if (call <= SEMCTL)
  63                 switch (call) {
  64                 case SEMOP:
  65                         return sys_semop (first, ptr, second);
  66                 case SEMGET:
  67                         return sys_semget (first, second, third);
  68                 case SEMCTL: {
  69                         union semun fourth;
  70                         if (!ptr)
  71                                 return -EINVAL;
  72                         if (get_user(fourth.__pad, (void __user *__user *) ptr))
  73                                 return -EFAULT;
  74                         return sys_semctl (first, second, third, fourth);
  75                         }
  76                 default:
  77                         return -ENOSYS;
  78                 }
  79         if (call <= MSGCTL)
  80                 switch (call) {
  81                 case MSGSND:
  82                         return sys_msgsnd (first, ptr, second, third);
  83                 case MSGRCV:
  84                         switch (version) {
  85                         case 0: {
  86                                 struct ipc_kludge tmp;
  87                                 if (!ptr)
  88                                         return -EINVAL;
  89                                 if (copy_from_user (&tmp, ptr, sizeof (tmp)))
  90                                         return -EFAULT;
  91                                 return sys_msgrcv (first, tmp.msgp, second,
  92                                                    tmp.msgtyp, third);
  93                                 }
  94                         default:
  95                                 return sys_msgrcv (first, ptr,
  96                                                    second, fifth, third);
  97                         }
  98                 case MSGGET:
  99                         return sys_msgget ((key_t) first, second);
 100                 case MSGCTL:
 101                         return sys_msgctl (first, second, ptr);
 102                 default:
 103                         return -ENOSYS;
 104                 }
 105         if (call <= SHMCTL)
 106                 switch (call) {
 107                 case SHMAT:
 108                         switch (version) {
 109                         default: {
 110                                 ulong raddr;
 111                                 ret = do_shmat (first, ptr, second, &raddr);
 112                                 if (ret)
 113                                         return ret;
 114                                 return put_user (raddr, (ulong __user *) third);
 115                         }
 116                         }
 117                 case SHMDT:
 118                         return sys_shmdt (ptr);
 119                 case SHMGET:
 120                         return sys_shmget (first, second, third);
 121                 case SHMCTL:
 122                         return sys_shmctl (first, second, ptr);
 123                 default:
 124                         return -ENOSYS;
 125                 }
 126
 127         return -EINVAL;
 128 }
 129
 130 /* Convert virtual (user) address VADDR to physical address PADDR */
 131 #define virt_to_phys_040(vaddr)                                         \
 132 ({                                                                      \
 133   unsigned long _mmusr, _paddr;                                         \
 134                                                                         \
 135   __asm__ __volatile__ (".chip 68040\n\t"                               \
 136                         "ptestr (%1)\n\t"                               \
 137                         "movec %%mmusr,%0\n\t"                          \
 138                         ".chip 68k"                                     \
 139                         : "=r" (_mmusr)                                 \
 140                         : "a" (vaddr));                                 \
 141   _paddr = (_mmusr & MMU_R_040) ? (_mmusr & PAGE_MASK) : 0;             \
 142   _paddr;                                                               \
 143 })
 144
 145 static inline int
 146 cache_flush_040 (unsigned long addr, int scope, int cache, unsigned long len)
 147 {
 148   unsigned long paddr, i;
 149
 150   switch (scope)
 151     {
 152     case FLUSH_SCOPE_ALL:
 153       switch (cache)
 154         {
 155         case FLUSH_CACHE_DATA:
 156           /* This nop is needed for some broken versions of the 68040.  */
 157           __asm__ __volatile__ ("nop\n\t"
 158                                 ".chip 68040\n\t"
 159                                 "cpusha %dc\n\t"
 160                                 ".chip 68k");
 161           break;
 162         case FLUSH_CACHE_INSN:
 163           __asm__ __volatile__ ("nop\n\t"
 164                                 ".chip 68040\n\t"
 165                                 "cpusha %ic\n\t"
 166                                 ".chip 68k");
 167           break;
 168         default:
 169         case FLUSH_CACHE_BOTH:
 170           __asm__ __volatile__ ("nop\n\t"
 171                                 ".chip 68040\n\t"
 172                                 "cpusha %bc\n\t"
 173                                 ".chip 68k");
 174           break;
 175         }
 176       break;
 177
 178     case FLUSH_SCOPE_LINE:
 179       /* Find the physical address of the first mapped page in the
 180          address range.  */
 181       if ((paddr = virt_to_phys_040(addr))) {
 182         paddr += addr & ~(PAGE_MASK | 15);
 183         len = (len + (addr & 15) + 15) >> 4;
 184       } else {
 185         unsigned long tmp = PAGE_SIZE - (addr & ~PAGE_MASK);
 186
 187         if (len <= tmp)
 188           return 0;
 189         addr += tmp;
 190         len -= tmp;
 191         tmp = PAGE_SIZE;
 192         for (;;)
 193           {
 194             if ((paddr = virt_to_phys_040(addr)))
 195               break;
 196             if (len <= tmp)
 197               return 0;
 198             addr += tmp;
 199             len -= tmp;
 200           }
 201         len = (len + 15) >> 4;
 202       }
 203       i = (PAGE_SIZE - (paddr & ~PAGE_MASK)) >> 4;
 204       while (len--)
 205         {
 206           switch (cache)
 207             {
 208             case FLUSH_CACHE_DATA:
 209               __asm__ __volatile__ ("nop\n\t"
 210                                     ".chip 68040\n\t"
 211                                     "cpushl %%dc,(%0)\n\t"
 212                                     ".chip 68k"
 213                                     : : "a" (paddr));
 214               break;
 215             case FLUSH_CACHE_INSN:
 216               __asm__ __volatile__ ("nop\n\t"
 217                                     ".chip 68040\n\t"
 218                                     "cpushl %%ic,(%0)\n\t"
 219                                     ".chip 68k"
 220                                     : : "a" (paddr));
 221               break;
 222             default:
 223             case FLUSH_CACHE_BOTH:
 224               __asm__ __volatile__ ("nop\n\t"
 225                                     ".chip 68040\n\t"
 226                                     "cpushl %%bc,(%0)\n\t"
 227                                     ".chip 68k"
 228                                     : : "a" (paddr));
 229               break;
 230             }
 231           if (!--i && len)
 232             {
 233               /*
 234                * No need to page align here since it is done by
 235                * virt_to_phys_040().
 236                */
 237               addr += PAGE_SIZE;
 238               i = PAGE_SIZE / 16;
 239               /* Recompute physical address when crossing a page
 240                  boundary. */
 241               for (;;)
 242                 {
 243                   if ((paddr = virt_to_phys_040(addr)))
 244                     break;
 245                   if (len <= i)
 246                     return 0;
 247                   len -= i;
 248                   addr += PAGE_SIZE;
 249                 }
 250             }
 251           else
 252             paddr += 16;
 253         }
 254       break;
 255
 256     default:
 257     case FLUSH_SCOPE_PAGE:
 258       len += (addr & ~PAGE_MASK) + (PAGE_SIZE - 1);
 259       for (len >>= PAGE_SHIFT; len--; addr += PAGE_SIZE)
 260         {
 261           if (!(paddr = virt_to_phys_040(addr)))
 262             continue;
 263           switch (cache)
 264             {
 265             case FLUSH_CACHE_DATA:
 266               __asm__ __volatile__ ("nop\n\t"
 267                                     ".chip 68040\n\t"
 268                                     "cpushp %%dc,(%0)\n\t"
 269                                     ".chip 68k"
 270                                     : : "a" (paddr));
 271               break;
 272             case FLUSH_CACHE_INSN:
 273               __asm__ __volatile__ ("nop\n\t"
 274                                     ".chip 68040\n\t"
 275                                     "cpushp %%ic,(%0)\n\t"
 276                                     ".chip 68k"
 277                                     : : "a" (paddr));
 278               break;
 279             default:
 280             case FLUSH_CACHE_BOTH:
 281               __asm__ __volatile__ ("nop\n\t"
 282                                     ".chip 68040\n\t"
 283                                     "cpushp %%bc,(%0)\n\t"
 284                                     ".chip 68k"
 285                                     : : "a" (paddr));
 286               break;
 287             }
 288         }
 289       break;
 290     }
 291   return 0;
 292 }
 293
 294 #define virt_to_phys_060(vaddr)                         \
 295 ({                                                      \
 296   unsigned long paddr;                                  \
 297   __asm__ __volatile__ (".chip 68060\n\t"               \
 298                         "plpar (%0)\n\t"                \
 299                         ".chip 68k"                     \
 300                         : "=a" (paddr)                  \
 301                         : "0" (vaddr));                 \
 302   (paddr); /* XXX */                                    \
 303 })
 304
 305 static inline int
 306 cache_flush_060 (unsigned long addr, int scope, int cache, unsigned long len)
 307 {
 308   unsigned long paddr, i;
 309
 310   /*
 311    * 68060 manual says:
 312    *  cpush %dc : flush DC, remains valid (with our %cacr setup)
 313    *  cpush %ic : invalidate IC
 314    *  cpush %bc : flush DC + invalidate IC
 315    */
 316   switch (scope)
 317     {
 318     case FLUSH_SCOPE_ALL:
 319       switch (cache)
 320         {
 321         case FLUSH_CACHE_DATA:
 322           __asm__ __volatile__ (".chip 68060\n\t"
 323                                 "cpusha %dc\n\t"
 324                                 ".chip 68k");
 325           break;
 326         case FLUSH_CACHE_INSN:
 327           __asm__ __volatile__ (".chip 68060\n\t"
 328                                 "cpusha %ic\n\t"
 329                                 ".chip 68k");
 330           break;
 331         default:
 332         case FLUSH_CACHE_BOTH:
 333           __asm__ __volatile__ (".chip 68060\n\t"
 334                                 "cpusha %bc\n\t"
 335                                 ".chip 68k");
 336           break;
 337         }
 338       break;
 339
 340     case FLUSH_SCOPE_LINE:
 341       /* Find the physical address of the first mapped page in the
 342          address range.  */
 343       len += addr & 15;
 344       addr &= -16;
 345       if (!(paddr = virt_to_phys_060(addr))) {
 346         unsigned long tmp = PAGE_SIZE - (addr & ~PAGE_MASK);
 347
 348         if (len <= tmp)
 349           return 0;
 350         addr += tmp;
 351         len -= tmp;
 352         tmp = PAGE_SIZE;
 353         for (;;)
 354           {
 355             if ((paddr = virt_to_phys_060(addr)))
 356               break;
 357             if (len <= tmp)
 358               return 0;
 359             addr += tmp;
 360             len -= tmp;
 361           }
 362       }
 363       len = (len + 15) >> 4;
 364       i = (PAGE_SIZE - (paddr & ~PAGE_MASK)) >> 4;
 365       while (len--)
 366         {
 367           switch (cache)
 368             {
 369             case FLUSH_CACHE_DATA:
 370               __asm__ __volatile__ (".chip 68060\n\t"
 371                                     "cpushl %%dc,(%0)\n\t"
 372                                     ".chip 68k"
 373                                     : : "a" (paddr));
 374               break;
 375             case FLUSH_CACHE_INSN:
 376               __asm__ __volatile__ (".chip 68060\n\t"
 377                                     "cpushl %%ic,(%0)\n\t"
 378                                     ".chip 68k"
 379                                     : : "a" (paddr));
 380               break;
 381             default:
 382             case FLUSH_CACHE_BOTH:
 383               __asm__ __volatile__ (".chip 68060\n\t"
 384                                     "cpushl %%bc,(%0)\n\t"
 385                                     ".chip 68k"
 386                                     : : "a" (paddr));
 387               break;
 388             }
 389           if (!--i && len)
 390             {
 391
 392               /*
 393                * We just want to jump to the first cache line
 394                * in the next page.
 395                */
 396               addr += PAGE_SIZE;
 397               addr &= PAGE_MASK;
 398
 399               i = PAGE_SIZE / 16;
 400               /* Recompute physical address when crossing a page
 401                  boundary. */
 402               for (;;)
 403                 {
 404                   if ((paddr = virt_to_phys_060(addr)))
 405                     break;
 406                   if (len <= i)
 407                     return 0;
 408                   len -= i;
 409                   addr += PAGE_SIZE;
 410                 }
 411             }
 412           else
 413             paddr += 16;
 414         }
 415       break;
 416
 417     default:
 418     case FLUSH_SCOPE_PAGE:
 419       len += (addr & ~PAGE_MASK) + (PAGE_SIZE - 1);
 420       addr &= PAGE_MASK;        /* Workaround for bug in some
 421                                    revisions of the 68060 */
 422       for (len >>= PAGE_SHIFT; len--; addr += PAGE_SIZE)
 423         {
 424           if (!(paddr = virt_to_phys_060(addr)))
 425             continue;
 426           switch (cache)
 427             {
 428             case FLUSH_CACHE_DATA:
 429               __asm__ __volatile__ (".chip 68060\n\t"
 430                                     "cpushp %%dc,(%0)\n\t"
 431                                     ".chip 68k"
 432                                     : : "a" (paddr));
 433               break;
 434             case FLUSH_CACHE_INSN:
 435               __asm__ __volatile__ (".chip 68060\n\t"
 436                                     "cpushp %%ic,(%0)\n\t"
 437                                     ".chip 68k"
 438                                     : : "a" (paddr));
 439               break;
 440             default:
 441             case FLUSH_CACHE_BOTH:
 442               __asm__ __volatile__ (".chip 68060\n\t"
 443                                     "cpushp %%bc,(%0)\n\t"
 444                                     ".chip 68k"
 445                                     : : "a" (paddr));
 446               break;
 447             }
 448         }
 449       break;
 450     }
 451   return 0;
 452 }
 453
 454 /* sys_cacheflush -- flush (part of) the processor cache.  */
 455 asmlinkage int
 456 sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
 457 {
 458         struct vm_area_struct *vma;
 459         int ret = -EINVAL;
 460
 461         lock_kernel();
 462         if (scope < FLUSH_SCOPE_LINE || scope > FLUSH_SCOPE_ALL ||
 463             cache & ~FLUSH_CACHE_BOTH)
 464                 goto out;
 465
 466         if (scope == FLUSH_SCOPE_ALL) {
 467                 /* Only the superuser may explicitly flush the whole cache. */
 468                 ret = -EPERM;
 469                 if (!capable(CAP_SYS_ADMIN))
 470                         goto out;
 471         } else {
 472                 /*
 473                  * Verify that the specified address region actually belongs
 474                  * to this process.
 475                  */
 476                 vma = find_vma (current->mm, addr);
 477                 ret = -EINVAL;
 478                 /* Check for overflow.  */
 479                 if (addr + len < addr)
 480                         goto out;
 481                 if (vma == NULL || addr < vma->vm_start || addr + len > vma->vm_end)
 482                         goto out;
 483         }
 484
 485         if (CPU_IS_020_OR_030) {
 486                 if (scope == FLUSH_SCOPE_LINE && len < 256) {
 487                         unsigned long cacr;
 488                         __asm__ ("movec %%cacr, %0" : "=r" (cacr));
 489                         if (cache & FLUSH_CACHE_INSN)
 490                                 cacr |= 4;
 491                         if (cache & FLUSH_CACHE_DATA)
 492                                 cacr |= 0x400;
 493                         len >>= 2;
 494                         while (len--) {
 495                                 __asm__ __volatile__ ("movec %1, %%caar\n\t"
 496                                                       "movec %0, %%cacr"
 497                                                       : /* no outputs */
 498                                                       : "r" (cacr), "r" (addr));
 499                                 addr += 4;
 500                         }
 501                 } else {
 502                         /* Flush the whole cache, even if page granularity requested. */
 503                         unsigned long cacr;
 504                         __asm__ ("movec %%cacr, %0" : "=r" (cacr));
 505                         if (cache & FLUSH_CACHE_INSN)
 506                                 cacr |= 8;
 507                         if (cache & FLUSH_CACHE_DATA)
 508                                 cacr |= 0x800;
 509                         __asm__ __volatile__ ("movec %0, %%cacr" : : "r" (cacr));
 510                 }
 511                 ret = 0;
 512                 goto out;
 513         } else {
 514             /*
 515              * 040 or 060: don't blindly trust 'scope', someone could
 516              * try to flush a few megs of memory.
 517              */
 518
 519             if (len>=3*PAGE_SIZE && scope<FLUSH_SCOPE_PAGE)
 520                 scope=FLUSH_SCOPE_PAGE;
 521             if (len>=10*PAGE_SIZE && scope<FLUSH_SCOPE_ALL)
 522                 scope=FLUSH_SCOPE_ALL;
 523             if (CPU_IS_040) {
 524                 ret = cache_flush_040 (addr, scope, cache, len);
 525             } else if (CPU_IS_060) {
 526                 ret = cache_flush_060 (addr, scope, cache, len);
 527             }
 528         }
 529 out:
 530         unlock_kernel();
 531         return ret;
 532 }
 533
 534 asmlinkage int sys_getpagesize(void)
 535 {
 536         return PAGE_SIZE;
 537 }
 538
 539 /*
 540  * Do a system call from kernel instead of calling sys_execve so we
 541  * end up with proper pt_regs.
 542  */
 543 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 544 {
 545         register long __res asm ("%d0") = __NR_execve;
 546         register long __a asm ("%d1") = (long)(filename);
 547         register long __b asm ("%d2") = (long)(argv);
 548         register long __c asm ("%d3") = (long)(envp);
 549         asm volatile ("trap  #0" : "+d" (__res)
 550                         : "d" (__a), "d" (__b), "d" (__c));
 551         return __res;
 552 }
 553
 554 asmlinkage unsigned long sys_get_thread_area(void)
 555 {
 556         return current_thread_info()->tp_value;
 557 }
 558
 559 asmlinkage int sys_set_thread_area(unsigned long tp)
 560 {
 561         current_thread_info()->tp_value = tp;
 562         return 0;
 563 }
 564
 565 /* This syscall gets its arguments in A0 (mem), D2 (oldval) and
 566    D1 (newval).  */
 567 asmlinkage int
 568 sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
 569                       unsigned long __user * mem)
 570 {
 571         /* This was borrowed from ARM's implementation.  */
 572         for (;;) {
 573                 struct mm_struct *mm = current->mm;
 574                 pgd_t *pgd;
 575                 pmd_t *pmd;
 576                 pte_t *pte;
 577                 spinlock_t *ptl;
 578                 unsigned long mem_value;
 579
 580                 down_read(&mm->mmap_sem);
 581                 pgd = pgd_offset(mm, (unsigned long)mem);
 582                 if (!pgd_present(*pgd))
 583                         goto bad_access;
 584                 pmd = pmd_offset(pgd, (unsigned long)mem);
 585                 if (!pmd_present(*pmd))
 586                         goto bad_access;
 587                 pte = pte_offset_map_lock(mm, pmd, (unsigned long)mem, &ptl);
 588                 if (!pte_present(*pte) || !pte_dirty(*pte)
 589                     || !pte_write(*pte)) {
 590                         pte_unmap_unlock(pte, ptl);
 591                         goto bad_access;
 592                 }
 593
 594                 mem_value = *mem;
 595                 if (mem_value == oldval)
 596                         *mem = newval;
 597
 598                 pte_unmap_unlock(pte, ptl);
 599                 up_read(&mm->mmap_sem);
 600                 return mem_value;
 601
 602               bad_access:
 603                 up_read(&mm->mmap_sem);
 604                 /* This is not necessarily a bad access, we can get here if
 605                    a memory we're trying to write to should be copied-on-write.
 606                    Make the kernel do the necessary page stuff, then re-iterate.
 607                    Simulate a write access fault to do that.  */
 608                 {
 609                         /* The first argument of the function corresponds to
 610                            D1, which is the first field of struct pt_regs.  */
 611                         struct pt_regs *fp = (struct pt_regs *)&newval;
 612
 613                         /* '3' is an RMW flag.  */
 614                         if (do_page_fault(fp, (unsigned long)mem, 3))
 615                                 /* If the do_page_fault() failed, we don't
 616                                    have anything meaningful to return.
 617                                    There should be a SIGSEGV pending for
 618                                    the process.  */
 619                                 return 0xdeadbeef;
 620                 }
 621         }
 622 }
 623
 624 asmlinkage int sys_atomic_barrier(void)
 625 {
 626         /* no code needed for uniprocs */
 627         return 0;
 628 }