Re: [PATCH 1/7] arm64: capabilities: Merge entries for ARM64_WORKAROUND_CLEAN_CACHE

From: Will Deacon
Date: Tue Nov 27 2018 - 14:31:09 EST


On Mon, Nov 26, 2018 at 03:09:56PM +0000, Suzuki K Poulose wrote:
> On Mon, Nov 26, 2018 at 02:06:04PM +0000, Will Deacon wrote:
> > On Mon, Nov 05, 2018 at 11:55:11AM +0000, Suzuki K Poulose wrote:
> > > We have two entries for ARM64_WORKAROUND_CLEAN_CACHE capability :
> > >
> > > 1) ARM Errata 826319, 827319, 824069, 819472 on A53 r0p[012]
> > > 2) ARM Errata 819472 on A53 r0p[01]
> > >
> > > Both have the same work around. Merge these entries to avoid
> > > duplicate entries for a single capability.
> > >
> > > Cc: Will Deacon <will.deacon@xxxxxxx>
> > > Cc: Andre Przywara <andre.przywara@xxxxxxx>
> > > Cc: Mark Rutland <mark.rutland@xxxxxxx>
> > > Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> > > ---
> > > arch/arm64/kernel/cpu_errata.c | 19 +++++++------------
> > > 1 file changed, 7 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
> > > index a509e351..c825bc0 100644
> > > --- a/arch/arm64/kernel/cpu_errata.c
> > > +++ b/arch/arm64/kernel/cpu_errata.c
> > > @@ -573,24 +573,19 @@ static const struct midr_range arm64_harden_el2_vectors[] = {
> > > const struct arm64_cpu_capabilities arm64_errata[] = {
> > > #if defined(CONFIG_ARM64_ERRATUM_826319) || \
> > > defined(CONFIG_ARM64_ERRATUM_827319) || \
> > > - defined(CONFIG_ARM64_ERRATUM_824069)
> > > + defined(CONFIG_ARM64_ERRATUM_824069) || \
> > > + defined(CONFIG_ARM64_ERRATUM_819472)
> > > {
> > > - /* Cortex-A53 r0p[012] */
> > > - .desc = "ARM errata 826319, 827319, 824069",
> > > + /*
> > > + * Cortex-A53 r0p[012]: ARM errata 826319, 827319, 824069
> > > + * Cortex-A53 r0p[01] : ARM errata 819472
> > > + */
> > > + .desc = "ARM errata 826319, 827319, 824069, 819472",
> > > .capability = ARM64_WORKAROUND_CLEAN_CACHE,
> > > ERRATA_MIDR_REV_RANGE(MIDR_CORTEX_A53, 0, 0, 2),
> > > .cpu_enable = cpu_enable_cache_maint_trap,
> >
> > Isn't this a semantic change wrt the Kconfig options? After this change,
> > if I /only/ set CONFIG_ARM64_ERRATUM_819472=y, then I still get the
> > workaround applied for CPUs > r0[p01] which isn't what I asked for.
>
> You're right. I could change this to :

Indeed, and you'll probably need something similar for the other entries
that you're merging.

Will