| Message ID | 20180123122809.16269-3-suzuki.poulose@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jan 23, 2018 at 12:27:55PM +0000, Suzuki K Poulose wrote: > We trigger CPU errata work around check on the boot CPU from > smp_prepare_boot_cpu() to make sure that we run the checks only > after the CPU feature infrastructure is initialised. On the surface of it, this sounds like a bug fix. Should there be a Fixes tag if so? If this reordering doesn't matter for upstream, it would be good to have a quick explanation here as to why not. Cheers ---Dave > > We can do this from init_cpu_features() which is called only > on the boot CPU and does the initilisation of the infrastructure. > As we are consolidating the cpu capability handling, let us > move this to where it should belong. No functional changes. > > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> > --- > arch/arm64/kernel/cpufeature.c | 6 ++++++ > arch/arm64/kernel/smp.c | 6 ------ > 2 files changed, 6 insertions(+), 6 deletions(-) > > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index 6a8dfdc532b1..ebb467340b9c 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -545,6 +545,12 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info) > init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr); > sve_init_vq_map(); > } > + > + /* > + * Run the errata work around checks on the boot CPU, once we have > + * initialised the cpu feature infrastructure. > + */ > + update_cpu_errata_workarounds(); > } > > static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new) > diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c > index 3b8ad7be9c33..5cef11450183 100644 > --- a/arch/arm64/kernel/smp.c > +++ b/arch/arm64/kernel/smp.c > @@ -448,12 +448,6 @@ void __init smp_prepare_boot_cpu(void) > jump_label_init(); > cpuinfo_store_boot_cpu(); > save_boot_cpu_run_el(); > - /* > - * Run the errata work around checks on the boot CPU, once we have > - * initialised the cpu feature infrastructure from > - * cpuinfo_store_boot_cpu() above. > - */ > - update_cpu_errata_workarounds(); > } > > static u64 __init of_get_cpu_mpidr(struct device_node *dn) > -- > 2.13.6 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On 23/01/18 14:59, Dave Martin wrote: > On Tue, Jan 23, 2018 at 12:27:55PM +0000, Suzuki K Poulose wrote: >> We trigger CPU errata work around check on the boot CPU from >> smp_prepare_boot_cpu() to make sure that we run the checks only >> after the CPU feature infrastructure is initialised. > > On the surface of it, this sounds like a bug fix. No, this is not. It is just moving the code to cpufeature.c Earlier it was : smp_prepare_boot_cpu() -> cpuinfo_store_boot_cpu() -> init_cpu_features() and then we did update_cpu_errata_workarounds() after we have done cpuinfo_store_boot_cpu(). With this change we do : smp_prepare_boot_cpu() -> cpuinfo_store_boot_cpu() -> init_cpu_features() -> update_cpu_errata_workarounds() > > Should there be a Fixes tag if so? > > If this reordering doesn't matter for upstream, it would be good to have > a quick explanation here as to why not. Sure, will make it clearer. Cheers Suzuki > > Cheers > ---Dave > >> >> We can do this from init_cpu_features() which is called only >> on the boot CPU and does the initilisation of the infrastructure. >> As we are consolidating the cpu capability handling, let us >> move this to where it should belong. No functional changes. >> >> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> >> --- >> arch/arm64/kernel/cpufeature.c | 6 ++++++ >> arch/arm64/kernel/smp.c | 6 ------ >> 2 files changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c >> index 6a8dfdc532b1..ebb467340b9c 100644 >> --- a/arch/arm64/kernel/cpufeature.c >> +++ b/arch/arm64/kernel/cpufeature.c >> @@ -545,6 +545,12 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info) >> init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr); >> sve_init_vq_map(); >> } >> + >> + /* >> + * Run the errata work around checks on the boot CPU, once we have >> + * initialised the cpu feature infrastructure. >> + */ >> + update_cpu_errata_workarounds(); >> } >> >> static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new) >> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c >> index 3b8ad7be9c33..5cef11450183 100644 >> --- a/arch/arm64/kernel/smp.c >> +++ b/arch/arm64/kernel/smp.c >> @@ -448,12 +448,6 @@ void __init smp_prepare_boot_cpu(void) >> jump_label_init(); >> cpuinfo_store_boot_cpu(); >> save_boot_cpu_run_el(); >> - /* >> - * Run the errata work around checks on the boot CPU, once we have >> - * initialised the cpu feature infrastructure from >> - * cpuinfo_store_boot_cpu() above. >> - */ >> - update_cpu_errata_workarounds(); >> } >> >> static u64 __init of_get_cpu_mpidr(struct device_node *dn) >> -- >> 2.13.6 >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Tue, Jan 23, 2018 at 03:07:18PM +0000, Suzuki K Poulose wrote: > On 23/01/18 14:59, Dave Martin wrote: > >On Tue, Jan 23, 2018 at 12:27:55PM +0000, Suzuki K Poulose wrote: > >>We trigger CPU errata work around check on the boot CPU from > >>smp_prepare_boot_cpu() to make sure that we run the checks only > >>after the CPU feature infrastructure is initialised. > > > >On the surface of it, this sounds like a bug fix. > > No, this is not. It is just moving the code to cpufeature.c > > Earlier it was : > > smp_prepare_boot_cpu() -> cpuinfo_store_boot_cpu() -> init_cpu_features() > > and then we did update_cpu_errata_workarounds() after we have done > cpuinfo_store_boot_cpu(). With this change we do : > > smp_prepare_boot_cpu() -> cpuinfo_store_boot_cpu() -> init_cpu_features() -> update_cpu_errata_workarounds() > > > > > >Should there be a Fixes tag if so? > > > >If this reordering doesn't matter for upstream, it would be good to have > >a quick explanation here as to why not. > > Sure, will make it clearer. Fair enough -- thanks. I was a bit sketchy on the exact code flow here. [...] Cheers ---Dave
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 6a8dfdc532b1..ebb467340b9c 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -545,6 +545,12 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info) init_cpu_ftr_reg(SYS_ZCR_EL1, info->reg_zcr); sve_init_vq_map(); } + + /* + * Run the errata work around checks on the boot CPU, once we have + * initialised the cpu feature infrastructure. + */ + update_cpu_errata_workarounds(); } static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new) diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 3b8ad7be9c33..5cef11450183 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -448,12 +448,6 @@ void __init smp_prepare_boot_cpu(void) jump_label_init(); cpuinfo_store_boot_cpu(); save_boot_cpu_run_el(); - /* - * Run the errata work around checks on the boot CPU, once we have - * initialised the cpu feature infrastructure from - * cpuinfo_store_boot_cpu() above. - */ - update_cpu_errata_workarounds(); } static u64 __init of_get_cpu_mpidr(struct device_node *dn)
We trigger CPU errata work around check on the boot CPU from smp_prepare_boot_cpu() to make sure that we run the checks only after the CPU feature infrastructure is initialised. We can do this from init_cpu_features() which is called only on the boot CPU and does the initilisation of the infrastructure. As we are consolidating the cpu capability handling, let us move this to where it should belong. No functional changes. Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> --- arch/arm64/kernel/cpufeature.c | 6 ++++++ arch/arm64/kernel/smp.c | 6 ------ 2 files changed, 6 insertions(+), 6 deletions(-)