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