| Message ID | 1519051304-25141-1-git-send-email-will.deacon@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Feb 19, 2018 at 02:41:44PM +0000, Will Deacon wrote: > Our field definitions for CTR_EL0 suffer from a number of problems: > > - The IDC and DIC fields are missing, which causes us to enable CTR > trapping on CPUs with either of these returning non-zero values. > > - The ERG is FTR_LOWER_SAFE, whereas it should be treated like CWG as > FTR_HIGHER_SAFE so that applications can use it to avoid false sharing. > > - [nit] A RES1 field is described as "RAO" > > This patch updates the CTR_EL0 field definitions to fix these issues. > > Cc: <stable@vger.kernel.org> > Cc: Shanker Donthineni <shankerd@codeaurora.org> > Signed-off-by: Will Deacon <will.deacon@arm.com> Queued for -rc3.
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 29b1f873e337..2985a067fc13 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -199,9 +199,11 @@ static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = { }; static const struct arm64_ftr_bits ftr_ctr[] = { - ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RAO */ + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RES1 */ + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 29, 1, 1), /* DIC */ + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 28, 1, 1), /* IDC */ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_SAFE, 24, 4, 0), /* CWG */ - ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0), /* ERG */ + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_SAFE, 20, 4, 0), /* ERG */ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 1), /* DminLine */ /* * Linux can handle differing I-cache policies. Userspace JITs will
Our field definitions for CTR_EL0 suffer from a number of problems: - The IDC and DIC fields are missing, which causes us to enable CTR trapping on CPUs with either of these returning non-zero values. - The ERG is FTR_LOWER_SAFE, whereas it should be treated like CWG as FTR_HIGHER_SAFE so that applications can use it to avoid false sharing. - [nit] A RES1 field is described as "RAO" This patch updates the CTR_EL0 field definitions to fix these issues. Cc: <stable@vger.kernel.org> Cc: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> --- arch/arm64/kernel/cpufeature.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)