| Message ID | 1436433835-26030-1-git-send-email-lorenzo.pieralisi@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Jul 09, 2015 at 10:23:55AM +0100, Lorenzo Pieralisi wrote: > The boot_hyp_pgd is required to install HYP context through > cpu_init_hyp_mode, on cold-boot for primary and secondary cpus, but > also on the warm-boot path for secondaries (ie when a CPU is hotplugged > in). On platforms with power management capabilities (eg suspend to RAM > or idle-states that allow the core to enter deep idle where core is > shutdown on power down entry), the boot_hyp_pgd is required to restore > HYP context too upon CPU_PM notification, so the boot_hyp_pgd must not be > freed to guarantee a proper HYP context restore, which in turn ensures > proper core resume from low-power. > > This patch adds an additional guard to free_boot_hyp_pgd() to remove > its call from the kernel if CPU_PM is enabled, so that on platforms > where HOTPLUG_CPU is disabled (eg UP), CPU_PM operations (suspend and > CPUidle) are still guaranteed to function. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Cc: Christoffer Dall <christoffer.dall@linaro.org> > Cc: Marc Zyngier <marc.zyngier@arm.com> > Cc: Sudeep Holla <sudeep.holla@arm.com> > --- > arch/arm/kvm/arm.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c > index bc738d2..5e050c2 100644 > --- a/arch/arm/kvm/arm.c > +++ b/arch/arm/kvm/arm.c > @@ -1068,7 +1068,7 @@ static int init_hyp_mode(void) > if (err) > goto out_free_mappings; > > -#ifndef CONFIG_HOTPLUG_CPU > +#if !defined(CONFIG_HOTPLUG_CPU) && !defined(CONFIG_CPU_PM) > free_boot_hyp_pgd(); > #endif > > -- > 2.2.1 > Without knowing a lot about power management in Linux and exactly what these defines mean, I'm fine with this: Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index bc738d2..5e050c2 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -1068,7 +1068,7 @@ static int init_hyp_mode(void) if (err) goto out_free_mappings; -#ifndef CONFIG_HOTPLUG_CPU +#if !defined(CONFIG_HOTPLUG_CPU) && !defined(CONFIG_CPU_PM) free_boot_hyp_pgd(); #endif
The boot_hyp_pgd is required to install HYP context through cpu_init_hyp_mode, on cold-boot for primary and secondary cpus, but also on the warm-boot path for secondaries (ie when a CPU is hotplugged in). On platforms with power management capabilities (eg suspend to RAM or idle-states that allow the core to enter deep idle where core is shutdown on power down entry), the boot_hyp_pgd is required to restore HYP context too upon CPU_PM notification, so the boot_hyp_pgd must not be freed to guarantee a proper HYP context restore, which in turn ensures proper core resume from low-power. This patch adds an additional guard to free_boot_hyp_pgd() to remove its call from the kernel if CPU_PM is enabled, so that on platforms where HOTPLUG_CPU is disabled (eg UP), CPU_PM operations (suspend and CPUidle) are still guaranteed to function. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> --- arch/arm/kvm/arm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)