| Message ID | 1395955430-26050-4-git-send-email-ashwin.chaugule@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Thu, Mar 27, 2014 at 4:23 PM, Ashwin Chaugule <ashwin.chaugule@linaro.org> wrote: > PSCIv0.2 adds a new function called AFFINITY_INFO, which > can be used to query if a specified CPU has actually gone > offline. Calling this function via cpu_kill ensures that > a CPU has quiesced after a call to cpu_die. > > Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> One minor nit, but otherwise: Reviewed-by: Rob Herring <robh@kernel.org> > --- > arch/arm/kernel/psci_smp.c | 21 +++++++++++++++++++++ > include/uapi/linux/psci.h | 5 +++++ > 2 files changed, 26 insertions(+) > > diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c > index 570a48c..4c1adf9 100644 > --- a/arch/arm/kernel/psci_smp.c > +++ b/arch/arm/kernel/psci_smp.c > @@ -16,6 +16,7 @@ > #include <linux/init.h> > #include <linux/smp.h> > #include <linux/of.h> > +#include <uapi/linux/psci.h> > > #include <asm/psci.h> > #include <asm/smp_plat.h> > @@ -66,6 +67,25 @@ void __ref psci_cpu_die(unsigned int cpu) > /* We should never return */ > panic("psci: cpu %d failed to shutdown\n", cpu); > } > + > +int __ref psci_cpu_kill(unsigned int cpu) > +{ > + int err; > + > + if (!psci_ops.affinity_info) > + return 1; > + > + err = psci_ops.affinity_info(cpu_logical_map(cpu), 0); > + > + if (err != PSCI_AFFINITY_INFO_RET_OFF) { > + pr_err("psci: Cannot kill CPU:%d, psci ret val: %d\n", > + cpu, err); > + /* Make platform_cpu_kill() fail. */ > + return 0; > + } > + return err; I think this should just be "return 1;" PSCI_AFFINITY_INFO_RET_OFF happens to match, but it's really different meanings. > +} > + > #endif > > bool __init psci_smp_available(void) > @@ -78,5 +98,6 @@ struct smp_operations __initdata psci_smp_ops = { > .smp_boot_secondary = psci_boot_secondary, > #ifdef CONFIG_HOTPLUG_CPU > .cpu_die = psci_cpu_die, > + .cpu_kill = psci_cpu_kill, > #endif > }; > diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h > index c523051..2c177f5 100644 > --- a/include/uapi/linux/psci.h > +++ b/include/uapi/linux/psci.h > @@ -37,4 +37,9 @@ > #define PSCI_RET_EINVAL -2 > #define PSCI_RET_EPERM -3 > > +/* Return values from the PSCI_ID_AFFINITY_INFO Function. */ > +#define PSCI_AFFINITY_INFO_RET_ON 0 > +#define PSCI_AFFINITY_INFO_RET_OFF 1 > +#define PSCI_AFFINITY_INFO_RET_ON_PENDING 2 > + > #endif /* _UAPI_LINUX_PSCI_H */ > -- > 1.8.3.2 >
diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c index 570a48c..4c1adf9 100644 --- a/arch/arm/kernel/psci_smp.c +++ b/arch/arm/kernel/psci_smp.c @@ -16,6 +16,7 @@ #include <linux/init.h> #include <linux/smp.h> #include <linux/of.h> +#include <uapi/linux/psci.h> #include <asm/psci.h> #include <asm/smp_plat.h> @@ -66,6 +67,25 @@ void __ref psci_cpu_die(unsigned int cpu) /* We should never return */ panic("psci: cpu %d failed to shutdown\n", cpu); } + +int __ref psci_cpu_kill(unsigned int cpu) +{ + int err; + + if (!psci_ops.affinity_info) + return 1; + + err = psci_ops.affinity_info(cpu_logical_map(cpu), 0); + + if (err != PSCI_AFFINITY_INFO_RET_OFF) { + pr_err("psci: Cannot kill CPU:%d, psci ret val: %d\n", + cpu, err); + /* Make platform_cpu_kill() fail. */ + return 0; + } + return err; +} + #endif bool __init psci_smp_available(void) @@ -78,5 +98,6 @@ struct smp_operations __initdata psci_smp_ops = { .smp_boot_secondary = psci_boot_secondary, #ifdef CONFIG_HOTPLUG_CPU .cpu_die = psci_cpu_die, + .cpu_kill = psci_cpu_kill, #endif }; diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h index c523051..2c177f5 100644 --- a/include/uapi/linux/psci.h +++ b/include/uapi/linux/psci.h @@ -37,4 +37,9 @@ #define PSCI_RET_EINVAL -2 #define PSCI_RET_EPERM -3 +/* Return values from the PSCI_ID_AFFINITY_INFO Function. */ +#define PSCI_AFFINITY_INFO_RET_ON 0 +#define PSCI_AFFINITY_INFO_RET_OFF 1 +#define PSCI_AFFINITY_INFO_RET_ON_PENDING 2 + #endif /* _UAPI_LINUX_PSCI_H */
PSCIv0.2 adds a new function called AFFINITY_INFO, which can be used to query if a specified CPU has actually gone offline. Calling this function via cpu_kill ensures that a CPU has quiesced after a call to cpu_die. Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org> --- arch/arm/kernel/psci_smp.c | 21 +++++++++++++++++++++ include/uapi/linux/psci.h | 5 +++++ 2 files changed, 26 insertions(+)