dtlb_prot.S 1.3 KB

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  1. /*
  2. * dtlb_prot.S: DTLB protection trap strategy.
  3. * This is included directly into the trap table.
  4. *
  5. * Copyright (C) 1996,1998 David S. Miller (davem@redhat.com)
  6. * Copyright (C) 1997,1998 Jakub Jelinek (jj@ultra.linux.cz)
  7. */
  8. /* Ways we can get here:
  9. *
  10. * [TL == 0] 1) User stores to readonly pages.
  11. * [TL == 0] 2) Nucleus stores to user readonly pages.
  12. * [TL > 0] 3) Nucleus stores to user readonly stack frame.
  13. */
  14. /* PROT ** ICACHE line 1: User DTLB protection trap */
  15. mov TLB_SFSR, %g1
  16. stxa %g0, [%g1] ASI_DMMU ! Clear FaultValid bit
  17. membar #Sync ! Synchronize stores
  18. rdpr %pstate, %g5 ! Move into alt-globals
  19. wrpr %g5, PSTATE_AG|PSTATE_MG, %pstate
  20. rdpr %tl, %g1 ! Need a winfixup?
  21. cmp %g1, 1 ! Trap level >1?
  22. mov TLB_TAG_ACCESS, %g4 ! For reload of vaddr
  23. /* PROT ** ICACHE line 2: More real fault processing */
  24. ldxa [%g4] ASI_DMMU, %g5 ! Put tagaccess in %g5
  25. srlx %g5, PAGE_SHIFT, %g5
  26. sllx %g5, PAGE_SHIFT, %g5 ! Clear context ID bits
  27. bgu,pn %xcc, winfix_trampoline ! Yes, perform winfixup
  28. mov FAULT_CODE_DTLB | FAULT_CODE_WRITE, %g4
  29. ba,pt %xcc, sparc64_realfault_common ! Nope, normal fault
  30. nop
  31. nop
  32. /* PROT ** ICACHE line 3: Unused... */
  33. nop
  34. nop
  35. nop
  36. nop
  37. nop
  38. nop
  39. nop
  40. nop
  41. /* PROT ** ICACHE line 4: Unused... */
  42. nop
  43. nop
  44. nop
  45. nop
  46. nop
  47. nop
  48. nop
  49. nop