| Message ID | 1395934715-31348-3-git-send-email-ashwin.chaugule@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Thu, Mar 27, 2014 at 10:38 AM, 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> > --- > arch/arm/kernel/psci_smp.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c > index 570a48c..2407843 100644 > --- a/arch/arm/kernel/psci_smp.c > +++ b/arch/arm/kernel/psci_smp.c > @@ -66,6 +66,24 @@ 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 = 0; > + > + if (psci_ops.affinity_info) { You can save a level of indentation with: if (!psci_ops.affinity_info) return 1; This fixes the return as no affinity_info call (i.e. 0.1 PSCI) should not fail. > + err = psci_ops.affinity_info(cpu, 0); You need to convert the logical cpu (0..N) to the mpidr value (cpu_logical_map). > + > + if (err != 1) { 1 should have a define (in the uapi header). Which reminds me, all the PSCI return code defines should also be in that header. > + 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 +96,6 @@ 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 > }; > -- > 1.8.3.2 >
On 27 March 2014 12:52, Rob Herring <rob.herring@linaro.org> wrote: > On Thu, Mar 27, 2014 at 10:38 AM, Ashwin Chaugule >> + >> +int __ref psci_cpu_kill(unsigned int cpu) >> +{ >> + int err = 0; >> + >> + if (psci_ops.affinity_info) { > > You can save a level of indentation with: > > if (!psci_ops.affinity_info) > return 1; > > This fixes the return as no affinity_info call (i.e. 0.1 PSCI) should not fail. > >> + err = psci_ops.affinity_info(cpu, 0); > > You need to convert the logical cpu (0..N) to the mpidr value (cpu_logical_map). Gah. Thanks. That "aff" stuff is confusing. > >> + >> + if (err != 1) { > > 1 should have a define (in the uapi header). > > Which reminds me, all the PSCI return code defines should also be in > that header. Makes sense. Thanks, Ashwin
diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c index 570a48c..2407843 100644 --- a/arch/arm/kernel/psci_smp.c +++ b/arch/arm/kernel/psci_smp.c @@ -66,6 +66,24 @@ 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 = 0; + + if (psci_ops.affinity_info) { + err = psci_ops.affinity_info(cpu, 0); + + if (err != 1) { + 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 +96,6 @@ 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 };
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 | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)