diff options
Diffstat (limited to 'Documentation/powerpc')
| -rw-r--r-- | Documentation/powerpc/dawr-power9.rst | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/Documentation/powerpc/dawr-power9.rst b/Documentation/powerpc/dawr-power9.rst index e55ac6a24b97..310f2e0cea81 100644 --- a/Documentation/powerpc/dawr-power9.rst +++ b/Documentation/powerpc/dawr-power9.rst @@ -2,15 +2,23 @@ DAWR issues on POWER9 ===================== -On POWER9 the Data Address Watchpoint Register (DAWR) can cause a checkstop -if it points to cache inhibited (CI) memory. Currently Linux has no way to -distinguish CI memory when configuring the DAWR, so (for now) the DAWR is -disabled by this commit:: - - commit 9654153158d3e0684a1bdb76dbababdb7111d5a0 - Author: Michael Neuling <mikey@neuling.org> - Date: Tue Mar 27 15:37:24 2018 +1100 - powerpc: Disable DAWR in the base POWER9 CPU features +On older POWER9 processors, the Data Address Watchpoint Register (DAWR) can +cause a checkstop if it points to cache inhibited (CI) memory. Currently Linux +has no way to distinguish CI memory when configuring the DAWR, so on affected +systems, the DAWR is disabled. + +Affected processor revisions +============================ + +This issue is only present on processors prior to v2.3. The revision can be +found in /proc/cpuinfo:: + + processor : 0 + cpu : POWER9, altivec supported + clock : 3800.000000MHz + revision : 2.3 (pvr 004e 1203) + +On a system with the issue, the DAWR is disabled as detailed below. Technical Details: ================== |