Messages in this thread | | | Date | Thu, 25 Jun 2015 12:01:36 -0400 | From | Vitaly Andrianov <> | Subject | Re: [PATCH] keystone: psci: adds cpu_die implementation |
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On 06/25/2015 10:59 AM, santosh shilimkar wrote: > On 6/25/2015 7:45 AM, Mark Rutland wrote: >> Hi, >> >> On Thu, Jun 25, 2015 at 03:02:50PM +0100, Vitaly Andrianov wrote: >>> This commit add cpu_die implementation using psci api >> >> I don't understand. If you have a PSCI implementation, it should be >> sufficient to have a PSCI node (and enable-method) in your DT, and the >> generic code will be used. Nothing should be required in your board >> code. >> >> You should also use CPU_ON to bring secondaries online rather than >> mixing up PSCI and platform-specific mechanisms. >> > Good point about CPU_ON. We need that as well. > Does it mean that keystone_defconfig must always have CONFIG_HOTPLUG_CPU and CONFIG_ARM_PSCI enabled?
What is if someone doesn't want to have HOTPLUG_CPU? How he can boot secondary CPU w/o platform-specific mechanizm?
>>> >>> Signed-off-by: Vitaly Andrianov <vitalya@ti.com> >>> --- >>> arch/arm/mach-keystone/platsmp.c | 32 ++++++++++++++++++++++++++++++++ >>> 1 file changed, 32 insertions(+) >>> >>> diff --git a/arch/arm/mach-keystone/platsmp.c >>> b/arch/arm/mach-keystone/platsmp.c >>> index 5f46a7c..2c40cc0 100644 >>> --- a/arch/arm/mach-keystone/platsmp.c >>> +++ b/arch/arm/mach-keystone/platsmp.c >>> @@ -20,6 +20,7 @@ >>> #include <asm/prom.h> >>> #include <asm/tlbflush.h> >>> #include <asm/pgtable.h> >>> +#include <asm/psci.h> >>> >>> #include "keystone.h" >>> >>> @@ -51,7 +52,38 @@ static inline void __cpuinit >>> keystone_smp_secondary_initmem(unsigned int cpu) >>> {} >>> #endif >>> >>> + >>> +#ifdef CONFIG_HOTPLUG_CPU >>> +static void keystone_cpu_die(unsigned int cpu) >>> +{ >>> +#ifdef CONFIG_ARM_PSCI >>> + struct psci_power_state pwr_state = {0, 0, 0}; >>> + >>> + pr_info("keystone_cpu_die(%d) from %d using PSCI\n", cpu, >>> + smp_processor_id()); >>> + >>> + if (psci_ops.cpu_off) >>> + psci_ops.cpu_off(pwr_state); >>> +#else >>> + /* >>> + * We may want to add here a direct smc call to monitor >>> + * if the kernel doesn't support PSCI API >>> + */ >>> +#endif >> >> You should determine this from your DT. Your FW/bootloader can patch in >> the relevant nodes and properties when support is present, so the >> presence of such nodes should guarantee that PSCI is available. >> > That will be a nice trick. FW already does some tweaks of dts for > LPAE/non_LPAE tweaks. > > Regards, > Santosh
Thanks, -Vitaly
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