diff options
Diffstat (limited to 'drivers/misc/sgi-xp/xp_nofault.S')
| -rw-r--r-- | drivers/misc/sgi-xp/xp_nofault.S | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/misc/sgi-xp/xp_nofault.S b/drivers/misc/sgi-xp/xp_nofault.S new file mode 100644 index 000000000000..c13a709c4db5 --- /dev/null +++ b/drivers/misc/sgi-xp/xp_nofault.S @@ -0,0 +1,36 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (c) 2004-2008 Silicon Graphics, Inc. All Rights Reserved. + */ + + +/* + * The xp_nofault_PIOR function takes a pointer to a remote PIO register + * and attempts to load and consume a value from it. This function + * will be registered as a nofault code block. In the event that the + * PIO read fails, the MCA handler will force the error to look + * corrected and vector to the xp_error_PIOR which will return an error. + * + * The definition of "consumption" and the time it takes for an MCA + * to surface is processor implementation specific. This code + * is sufficient on Itanium through the Montvale processor family. + * It may need to be adjusted for future processor implementations. + * + * extern int xp_nofault_PIOR(void *remote_register); + */ + + .global xp_nofault_PIOR +xp_nofault_PIOR: + mov r8=r0 // Stage a success return value + ld8.acq r9=[r32];; // PIO Read the specified register + adds r9=1,r9;; // Add to force consumption + srlz.i;; // Allow time for MCA to surface + br.ret.sptk.many b0;; // Return success + + .global xp_error_PIOR +xp_error_PIOR: + mov r8=1 // Return value of 1 + br.ret.sptk.many b0;; // Return failure |