| Message ID | 20200227134715.9715-1-desnesn@linux.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | fc37a1632d40c80c067eb1bc235139f5867a2667 |
| Headers | show |
| Series | [v2] powerpc: fix hardware PMU exception bug on PowerVM compatibility mode systems | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (e3a1ab299346a9a415f334e91a78da7ea84aa5a2) |
| snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
| snowpatch_ozlabs/checkpatch | warning | total: 0 errors, 1 warnings, 0 checks, 14 lines checked |
| snowpatch_ozlabs/needsstable | warning | Please consider tagging this patch for stable! |
On Thu, 2020-02-27 at 10:47 -0300, Desnes A. Nunes do Rosario wrote: > PowerVM systems running compatibility mode on a few Power8 revisions are > still vulnerable to the hardware defect that loses PMU exceptions arriving > prior to a context switch. > > The software fix for this issue is enabled through the CPU_FTR_PMAO_BUG > cpu_feature bit, nevertheless this bit also needs to be set for PowerVM > compatibility mode systems. > > Fixes: 68f2f0d431d9ea4 ("powerpc: Add a cpu feature CPU_FTR_PMAO_BUG") > Signed-off-by: Desnes A. Nunes do Rosario <desnesn@linux.ibm.com> > --- > arch/powerpc/kernel/cputable.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c > index e745abc5457a..245be4fafe13 100644 > --- a/arch/powerpc/kernel/cputable.c > +++ b/arch/powerpc/kernel/cputable.c > @@ -2193,11 +2193,13 @@ static struct cpu_spec * __init setup_cpu_spec(unsigned long offset, > * oprofile_cpu_type already has a value, then we are > * possibly overriding a real PVR with a logical one, > * and, in that case, keep the current value for > - * oprofile_cpu_type. > + * oprofile_cpu_type. Futhermore, let's ensure that the > + * fix for the PMAO bug is enabled on compatibility mode. > */ > if (old.oprofile_cpu_type != NULL) { > t->oprofile_cpu_type = old.oprofile_cpu_type; > t->oprofile_type = old.oprofile_type; > + t->cpu_features |= old.cpu_features & CPU_FTR_PMAO_BUG; > } > } > Looks good to me. Reviewed-by: Leonardo Bras <leonardo@linux.ibm.com>
On Thu, 2020-02-27 at 13:47:15 UTC, "Desnes A. Nunes do Rosario" wrote: > PowerVM systems running compatibility mode on a few Power8 revisions are > still vulnerable to the hardware defect that loses PMU exceptions arriving > prior to a context switch. > > The software fix for this issue is enabled through the CPU_FTR_PMAO_BUG > cpu_feature bit, nevertheless this bit also needs to be set for PowerVM > compatibility mode systems. > > Fixes: 68f2f0d431d9ea4 ("powerpc: Add a cpu feature CPU_FTR_PMAO_BUG") > Signed-off-by: Desnes A. Nunes do Rosario <desnesn@linux.ibm.com> Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/fc37a1632d40c80c067eb1bc235139f5867a2667 cheers
diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c index e745abc5457a..245be4fafe13 100644 --- a/arch/powerpc/kernel/cputable.c +++ b/arch/powerpc/kernel/cputable.c @@ -2193,11 +2193,13 @@ static struct cpu_spec * __init setup_cpu_spec(unsigned long offset, * oprofile_cpu_type already has a value, then we are * possibly overriding a real PVR with a logical one, * and, in that case, keep the current value for - * oprofile_cpu_type. + * oprofile_cpu_type. Futhermore, let's ensure that the + * fix for the PMAO bug is enabled on compatibility mode. */ if (old.oprofile_cpu_type != NULL) { t->oprofile_cpu_type = old.oprofile_cpu_type; t->oprofile_type = old.oprofile_type; + t->cpu_features |= old.cpu_features & CPU_FTR_PMAO_BUG; } }
PowerVM systems running compatibility mode on a few Power8 revisions are still vulnerable to the hardware defect that loses PMU exceptions arriving prior to a context switch. The software fix for this issue is enabled through the CPU_FTR_PMAO_BUG cpu_feature bit, nevertheless this bit also needs to be set for PowerVM compatibility mode systems. Fixes: 68f2f0d431d9ea4 ("powerpc: Add a cpu feature CPU_FTR_PMAO_BUG") Signed-off-by: Desnes A. Nunes do Rosario <desnesn@linux.ibm.com> --- arch/powerpc/kernel/cputable.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)