linux_dsm_epyc7002/arch/ia64/sn/kernel/xp_nofault.S
Russ Anderson c034637967 [IA64] Force error to surface in nofault code
Montecito behaves slightly differently than previous processors,
resulting in the MCA due to a failed PIO read to sometimes surfacing
outside the nofault code.  Adding an additional or and stop bits
ensures the MCA surfaces in the nofault code.

Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2007-06-26 13:34:16 -07:00

33 lines
1.0 KiB
ArmAsm

/*
* 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) 2004-2005 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.
*
* 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
or r9=r9,r9;; // Or to force consumption
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