xp_nofault.S 1.3 KB

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  1. /*
  2. * This file is subject to the terms and conditions of the GNU General Public
  3. * License. See the file "COPYING" in the main directory of this archive
  4. * for more details.
  5. *
  6. * Copyright (c) 2004-2008 Silicon Graphics, Inc. All Rights Reserved.
  7. */
  8. /*
  9. * The xp_nofault_PIOR function takes a pointer to a remote PIO register
  10. * and attempts to load and consume a value from it. This function
  11. * will be registered as a nofault code block. In the event that the
  12. * PIO read fails, the MCA handler will force the error to look
  13. * corrected and vector to the xp_error_PIOR which will return an error.
  14. *
  15. * The definition of "consumption" and the time it takes for an MCA
  16. * to surface is processor implementation specific. This code
  17. * is sufficient on Itanium through the Montvale processor family.
  18. * It may need to be adjusted for future processor implementations.
  19. *
  20. * extern int xp_nofault_PIOR(void *remote_register);
  21. */
  22. .global xp_nofault_PIOR
  23. xp_nofault_PIOR:
  24. mov r8=r0 // Stage a success return value
  25. ld8.acq r9=[r32];; // PIO Read the specified register
  26. adds r9=1,r9;; // Add to force consumption
  27. srlz.i;; // Allow time for MCA to surface
  28. br.ret.sptk.many b0;; // Return success
  29. .global xp_error_PIOR
  30. xp_error_PIOR:
  31. mov r8=1 // Return value of 1
  32. br.ret.sptk.many b0;; // Return failure