dtlb_prot.S 1.3 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455
  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. /*
  3. * dtlb_prot.S: DTLB protection trap strategy.
  4. * This is included directly into the trap table.
  5. *
  6. * Copyright (C) 1996,1998 David S. Miller ([email protected])
  7. * Copyright (C) 1997,1998 Jakub Jelinek ([email protected])
  8. */
  9. /* Ways we can get here:
  10. *
  11. * [TL == 0] 1) User stores to readonly pages.
  12. * [TL == 0] 2) Nucleus stores to user readonly pages.
  13. * [TL > 0] 3) Nucleus stores to user readonly stack frame.
  14. */
  15. /* PROT ** ICACHE line 1: User DTLB protection trap */
  16. mov TLB_SFSR, %g1
  17. stxa %g0, [%g1] ASI_DMMU ! Clear FaultValid bit
  18. membar #Sync ! Synchronize stores
  19. rdpr %pstate, %g5 ! Move into alt-globals
  20. wrpr %g5, PSTATE_AG|PSTATE_MG, %pstate
  21. rdpr %tl, %g1 ! Need a winfixup?
  22. cmp %g1, 1 ! Trap level >1?
  23. mov TLB_TAG_ACCESS, %g4 ! For reload of vaddr
  24. /* PROT ** ICACHE line 2: More real fault processing */
  25. ldxa [%g4] ASI_DMMU, %g5 ! Put tagaccess in %g5
  26. srlx %g5, PAGE_SHIFT, %g5
  27. sllx %g5, PAGE_SHIFT, %g5 ! Clear context ID bits
  28. bgu,pn %xcc, winfix_trampoline ! Yes, perform winfixup
  29. mov FAULT_CODE_DTLB | FAULT_CODE_WRITE, %g4
  30. ba,pt %xcc, sparc64_realfault_common ! Nope, normal fault
  31. nop
  32. nop
  33. /* PROT ** ICACHE line 3: Unused... */
  34. nop
  35. nop
  36. nop
  37. nop
  38. nop
  39. nop
  40. nop
  41. nop
  42. /* PROT ** ICACHE line 4: Unused... */
  43. nop
  44. nop
  45. nop
  46. nop
  47. nop
  48. nop
  49. nop
  50. nop