Messages in this thread | | | Date | Mon, 29 Jun 2015 14:43:44 -0400 | From | Vitaly Andrianov <> | Subject | Re: [PATCH] keystone: adds cpu_die implementation |
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On 06/29/2015 01:52 PM, Mark Rutland wrote: > On Mon, Jun 29, 2015 at 06:52:32PM +0100, Vitaly Andrianov wrote: >> This commit add cpu_die implementation >> >> Signed-off-by: Vitaly Andrianov <vitalya@ti.com> >> --- >> >> The discussion of the "keystone: psci: adds cpu_die implementation" commit >> shows that if PCSI is enabled platform code doesn't need that implementation >> at all. Having PSCI commands in DTB should be sufficient. Unfortunately >> Keystone with LPAE enable requires some additional development. > > I don't follow. > > What do you need to implement for LPAE? Hi Mark,
The Keystone platform needs to set ttbr1 when it boots secondary core. It is done in the keystone_smp_secondary_initmem(), which is .smp_secondary_init member of the keystone_smp_ops. I couldn't find a way how I can add similar function to psci_smp_ops.
Do you have any idea?
> > Why not implement that rather than adding more platform code that you'll > likely want to remove later anyway?
If I can solve the above problem, I will not add this code.
Thanks, Vitaly
> > Thanks, > Mark. > >> To support HOTPLUG_CPU w/o PSCI we need platform implementation of >> the cpu_die(), which is added by this patch. >> >> arch/arm/mach-keystone/keystone.h | 1 + >> arch/arm/mach-keystone/platsmp.c | 24 ++++++++++++++++++++++++ >> 2 files changed, 25 insertions(+) >> >> diff --git a/arch/arm/mach-keystone/keystone.h b/arch/arm/mach-keystone/keystone.h >> index cd04a1c..93549cf 100644 >> --- a/arch/arm/mach-keystone/keystone.h >> +++ b/arch/arm/mach-keystone/keystone.h >> @@ -12,6 +12,7 @@ >> #define __KEYSTONE_H__ >> >> #define KEYSTONE_MON_CPU_UP_IDX 0x00 >> +#define KEYSTONE_MON_CPU_DIE_IDX 0x84000002 >> >> #ifndef __ASSEMBLER__ >> >> diff --git a/arch/arm/mach-keystone/platsmp.c b/arch/arm/mach-keystone/platsmp.c >> index 5f46a7c..4e5bdde 100644 >> --- a/arch/arm/mach-keystone/platsmp.c >> +++ b/arch/arm/mach-keystone/platsmp.c >> @@ -51,7 +51,31 @@ static inline void __cpuinit keystone_smp_secondary_initmem(unsigned int cpu) >> {} >> #endif >> >> + >> +#ifdef CONFIG_HOTPLUG_CPU >> +static void keystone_cpu_die(unsigned int cpu) >> +{ >> + int error; >> + >> + pr_debug("keystone-smp: cpu_die %d\n", cpu); >> + >> + error = keystone_cpu_smc(KEYSTONE_MON_CPU_DIE_IDX, cpu, 0); >> + if (error) >> + pr_err("CPU %d die failed with %d\n", cpu, error); >> + >> + /* >> + * we shouldn't come here. But in case something went >> + * wrong the code below prevents kernel from crush >> + */ >> + while (1) >> + cpu_do_idle(); >> +} >> +#endif >> + >> struct smp_operations keystone_smp_ops __initdata = { >> .smp_boot_secondary = keystone_smp_boot_secondary, >> .smp_secondary_init = keystone_smp_secondary_initmem, >> +#ifdef CONFIG_HOTPLUG_CPU >> + .cpu_die = keystone_cpu_die, >> +#endif >> }; >> -- >> 1.9.1 >>
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