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| author | Patrick Williams <iawillia@us.ibm.com> | 2014-03-26 17:06:32 -0500 |
|---|---|---|
| committer | A. Patrick Williams III <iawillia@us.ibm.com> | 2014-04-03 20:28:20 -0500 |
| commit | 8c7a27be94470541d184cfec495b6cfe63953733 (patch) | |
| tree | 143c2fde82d3d5fc10396b8b14f8c5e503c93c14 /src/kernel/start.S | |
| parent | 9d4827735558fe03ee021afb7dacfa6ac76719bb (diff) | |
| download | talos-hostboot-8c7a27be94470541d184cfec495b6cfe63953733.tar.gz talos-hostboot-8c7a27be94470541d184cfec495b6cfe63953733.zip | |
Use per-core mutex for XSCOM for P8 errata.
See HW822317. The HMER register in P8 is not implemented to
handle multi-threaded XSCOM properly, so we need to move the
XSCOM mutex from per-thread to per-core. Also, there is an
issue where the 'done' bit can come on 1 cycle before the error
indicators, so need to potentially read the HMER a second time.
Change-Id: I495031a6e425fe7d5c6ffef8dda1e7a71caac9f2
CQ: SW250902
Backport: release-fips810
Reviewed-on: http://gfw160.aus.stglabs.ibm.com:8080/gerrit/9929
Reviewed-by: Michael Baiocchi <baiocchi@us.ibm.com>
Reviewed-by: A. Patrick Williams III <iawillia@us.ibm.com>
Tested-by: Jenkins Server
Diffstat (limited to 'src/kernel/start.S')
| -rw-r--r-- | src/kernel/start.S | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/kernel/start.S b/src/kernel/start.S index 790281305..b6f09d40e 100644 --- a/src/kernel/start.S +++ b/src/kernel/start.S @@ -707,6 +707,14 @@ system_call_fast_path: ;// Compare was already done in system call path. bne cr0, 2f mfspr r3, HMER + ;// Do XSCOM workaround for Errata HW822317. + ;// If the done bit (10) is on in HMER, it could take another cycle + ;// for any error status to show up. Perform another HMER read. + rldicr. r0, r3, 10, 0 + beq cr0, 1f ;// Done bit not set, jump to exit. + mfspr r0, HMER ;// Read HMER again and OR results. + or r3, r3, r0 + ;// --- end workaround HW822317 b 1f ;// Jump to exit point. ;// Check if this is HMER write (0x801). 2: |
