Re: [PATCH v2 1/2] powerpc/powernv/cpuidle: Pass correct drv->cpumask for registration

2017-03-27 Thread Michael Ellerman 
"Rafael J. Wysocki"  writes:

> On Thu, Mar 23, 2017 at 4:22 PM, Vaidyanathan Srinivasan
>  wrote:
>> drv->cpumask defaults to cpu_possible_mask in __cpuidle_driver_init().
>> On PowerNV platform cpu_present could be less than cpu_possible in cases
>> where firmware detects the cpu, but it is not available to the OS.  When
>> CONFIG_HOTPLUG_CPU=n, such cpus are not hotplugable at runtime and hence
>> we skip creating cpu_device.
>>
>> This breaks cpuidle on powernv where register_cpu() is not called for
>> cpus in cpu_possible_mask that cannot be hot-added at runtime.
>>
>> Trying cpuidle_register_device() on cpu without cpu_device will cause
>> crash like this:
>>
>> cpu 0xf: Vector: 380 (Data SLB Access) at [c00ff1503490]
>> pc: c022c8bc: string+0x34/0x60
>> lr: c022ed78: vsnprintf+0x284/0x42c
>> sp: c00ff1503710
>>msr: 90009033
>>dar: 60006000
>>   current = 0xc00ff148
>>   paca= 0xcfe82d00   softe: 0irq_happened: 0x01
>> pid   = 1, comm = swapper/8
>> Linux version 4.11.0-rc2 (sv@sagarika) (gcc version 4.9.4
>> (Buildroot 2017.02-4-gc28573e) ) #15 SMP Fri Mar 17 19:32:02 IST 2017
>> enter ? for help
>> [link register   ] c022ed78 vsnprintf+0x284/0x42c
>> [c00ff1503710] c022ebb8 vsnprintf+0xc4/0x42c (unreliable)
>> [c00ff1503800] c022ef40 vscnprintf+0x20/0x44
>> [c00ff1503830] c00ab61c vprintk_emit+0x94/0x2cc
>> [c00ff15038a0] c00acc9c vprintk_func+0x60/0x74
>> [c00ff15038c0] c0619694 printk+0x38/0x4c
>> [c00ff15038e0] c0224950 kobject_get+0x40/0x60
>> [c00ff1503950] c022507c kobject_add_internal+0x60/0x2c4
>> [c00ff15039e0] c0225350 kobject_init_and_add+0x70/0x78
>> [c00ff1503a60] c053c288 cpuidle_add_sysfs+0x9c/0xe0
>> [c00ff1503ae0] c053aeac cpuidle_register_device+0xd4/0x12c
>> [c00ff1503b30] c053b108 cpuidle_register+0x98/0xcc
>> [c00ff1503bc0] c085eaf0 powernv_processor_idle_init+0x140/0x1e0
>> [c00ff1503c60] c000cd60 do_one_initcall+0xc0/0x15c
>> [c00ff1503d20] c0833e84 kernel_init_freeable+0x1a0/0x25c
>> [c00ff1503dc0] c000d478 kernel_init+0x24/0x12c
>> [c00ff1503e30] c000b564 ret_from_kernel_thread+0x5c/0x78
>>
>> This patch fixes the bug by passing correct cpumask from
>> powernv-cpuidle driver.
>>
>> Signed-off-by: Vaidyanathan Srinivasan 
>
> That needs to be ACKed by someone familiar with powernv.

Acked-by: Michael Ellerman 

cheers

Re: [PATCH v2 1/2] powerpc/powernv/cpuidle: Pass correct drv->cpumask for registration

2017-03-27 Thread Michael Ellerman 
"Rafael J. Wysocki"  writes:

> On Thu, Mar 23, 2017 at 4:22 PM, Vaidyanathan Srinivasan
>  wrote:
>> drv->cpumask defaults to cpu_possible_mask in __cpuidle_driver_init().
>> On PowerNV platform cpu_present could be less than cpu_possible in cases
>> where firmware detects the cpu, but it is not available to the OS.  When
>> CONFIG_HOTPLUG_CPU=n, such cpus are not hotplugable at runtime and hence
>> we skip creating cpu_device.
>>
>> This breaks cpuidle on powernv where register_cpu() is not called for
>> cpus in cpu_possible_mask that cannot be hot-added at runtime.
>>
>> Trying cpuidle_register_device() on cpu without cpu_device will cause
>> crash like this:
>>
>> cpu 0xf: Vector: 380 (Data SLB Access) at [c00ff1503490]
>> pc: c022c8bc: string+0x34/0x60
>> lr: c022ed78: vsnprintf+0x284/0x42c
>> sp: c00ff1503710
>>msr: 90009033
>>dar: 60006000
>>   current = 0xc00ff148
>>   paca= 0xcfe82d00   softe: 0irq_happened: 0x01
>> pid   = 1, comm = swapper/8
>> Linux version 4.11.0-rc2 (sv@sagarika) (gcc version 4.9.4
>> (Buildroot 2017.02-4-gc28573e) ) #15 SMP Fri Mar 17 19:32:02 IST 2017
>> enter ? for help
>> [link register   ] c022ed78 vsnprintf+0x284/0x42c
>> [c00ff1503710] c022ebb8 vsnprintf+0xc4/0x42c (unreliable)
>> [c00ff1503800] c022ef40 vscnprintf+0x20/0x44
>> [c00ff1503830] c00ab61c vprintk_emit+0x94/0x2cc
>> [c00ff15038a0] c00acc9c vprintk_func+0x60/0x74
>> [c00ff15038c0] c0619694 printk+0x38/0x4c
>> [c00ff15038e0] c0224950 kobject_get+0x40/0x60
>> [c00ff1503950] c022507c kobject_add_internal+0x60/0x2c4
>> [c00ff15039e0] c0225350 kobject_init_and_add+0x70/0x78
>> [c00ff1503a60] c053c288 cpuidle_add_sysfs+0x9c/0xe0
>> [c00ff1503ae0] c053aeac cpuidle_register_device+0xd4/0x12c
>> [c00ff1503b30] c053b108 cpuidle_register+0x98/0xcc
>> [c00ff1503bc0] c085eaf0 powernv_processor_idle_init+0x140/0x1e0
>> [c00ff1503c60] c000cd60 do_one_initcall+0xc0/0x15c
>> [c00ff1503d20] c0833e84 kernel_init_freeable+0x1a0/0x25c
>> [c00ff1503dc0] c000d478 kernel_init+0x24/0x12c
>> [c00ff1503e30] c000b564 ret_from_kernel_thread+0x5c/0x78
>>
>> This patch fixes the bug by passing correct cpumask from
>> powernv-cpuidle driver.
>>
>> Signed-off-by: Vaidyanathan Srinivasan 
>
> That needs to be ACKed by someone familiar with powernv.

Acked-by: Michael Ellerman 

cheers

Re: [PATCH v2 1/2] powerpc/powernv/cpuidle: Pass correct drv->cpumask for registration

2017-03-24 Thread Gautham R Shenoy 
On Thu, Mar 23, 2017 at 8:52 PM, Vaidyanathan Srinivasan
 wrote:
> drv->cpumask defaults to cpu_possible_mask in __cpuidle_driver_init().
> On PowerNV platform cpu_present could be less than cpu_possible in cases
> where firmware detects the cpu, but it is not available to the OS.  When
> CONFIG_HOTPLUG_CPU=n, such cpus are not hotplugable at runtime and hence
> we skip creating cpu_device.
>
> This breaks cpuidle on powernv where register_cpu() is not called for
> cpus in cpu_possible_mask that cannot be hot-added at runtime.
>
> Trying cpuidle_register_device() on cpu without cpu_device will cause
> crash like this:
>
> cpu 0xf: Vector: 380 (Data SLB Access) at [c00ff1503490]
> pc: c022c8bc: string+0x34/0x60
> lr: c022ed78: vsnprintf+0x284/0x42c
> sp: c00ff1503710
>msr: 90009033
>dar: 60006000
>   current = 0xc00ff148
>   paca= 0xcfe82d00   softe: 0irq_happened: 0x01
> pid   = 1, comm = swapper/8
> Linux version 4.11.0-rc2 (sv@sagarika) (gcc version 4.9.4
> (Buildroot 2017.02-4-gc28573e) ) #15 SMP Fri Mar 17 19:32:02 IST 2017
> enter ? for help
> [link register   ] c022ed78 vsnprintf+0x284/0x42c
> [c00ff1503710] c022ebb8 vsnprintf+0xc4/0x42c (unreliable)
> [c00ff1503800] c022ef40 vscnprintf+0x20/0x44
> [c00ff1503830] c00ab61c vprintk_emit+0x94/0x2cc
> [c00ff15038a0] c00acc9c vprintk_func+0x60/0x74
> [c00ff15038c0] c0619694 printk+0x38/0x4c
> [c00ff15038e0] c0224950 kobject_get+0x40/0x60
> [c00ff1503950] c022507c kobject_add_internal+0x60/0x2c4
> [c00ff15039e0] c0225350 kobject_init_and_add+0x70/0x78
> [c00ff1503a60] c053c288 cpuidle_add_sysfs+0x9c/0xe0
> [c00ff1503ae0] c053aeac cpuidle_register_device+0xd4/0x12c
> [c00ff1503b30] c053b108 cpuidle_register+0x98/0xcc
> [c00ff1503bc0] c085eaf0 powernv_processor_idle_init+0x140/0x1e0
> [c00ff1503c60] c000cd60 do_one_initcall+0xc0/0x15c
> [c00ff1503d20] c0833e84 kernel_init_freeable+0x1a0/0x25c
> [c00ff1503dc0] c000d478 kernel_init+0x24/0x12c
> [c00ff1503e30] c000b564 ret_from_kernel_thread+0x5c/0x78
>
> This patch fixes the bug by passing correct cpumask from
> powernv-cpuidle driver.
>
> Signed-off-by: Vaidyanathan Srinivasan 


Reviewed-by: Gautham R. Shenoy 

> ---
>  drivers/cpuidle/cpuidle-powernv.c | 18 ++
>  1 file changed, 18 insertions(+)
>
> diff --git a/drivers/cpuidle/cpuidle-powernv.c 
> b/drivers/cpuidle/cpuidle-powernv.c
> index a06df51..82f7b33 100644
> --- a/drivers/cpuidle/cpuidle-powernv.c
> +++ b/drivers/cpuidle/cpuidle-powernv.c
> @@ -175,6 +175,24 @@ static int powernv_cpuidle_driver_init(void)
> drv->state_count += 1;
> }
>
> +   /*
> +* On PowerNV platform cpu_present may be less that cpu_possible in
> +* cases where firmware detects the cpu, but it is not available to 
> the
> +* OS.  If CONFIG_HOTPLUG_CPU=n then such CPUs are not hotplugable at
> +* runtime and hence cpu_devices are not created for those cpus by
> +* generic topology_init().
> +*
> +* drv->cpumask defaults to cpu_possible_mask in
> +* __cpuidle_driver_init().  This breaks cpuidle on powernv where
> +* cpu_devices are not created for cpus in cpu_possible_mask that
> +* cannot be hot-added later at runtime.
> +*
> +* Trying cpuidle_register_device() on a cpu without cpu_devices is
> +* incorrect. Hence pass correct cpu mask to generic cpuidle driver.
> +*/
> +
> +   drv->cpumask = (struct cpumask *)cpu_present_mask;
> +
> return 0;
>  }
>
> --
> 2.9.3
>



-- 
Thanks and Regards
gautham.

Re: [PATCH v2 1/2] powerpc/powernv/cpuidle: Pass correct drv->cpumask for registration

2017-03-24 Thread Gautham R Shenoy 
On Thu, Mar 23, 2017 at 8:52 PM, Vaidyanathan Srinivasan
 wrote:
> drv->cpumask defaults to cpu_possible_mask in __cpuidle_driver_init().
> On PowerNV platform cpu_present could be less than cpu_possible in cases
> where firmware detects the cpu, but it is not available to the OS.  When
> CONFIG_HOTPLUG_CPU=n, such cpus are not hotplugable at runtime and hence
> we skip creating cpu_device.
>
> This breaks cpuidle on powernv where register_cpu() is not called for
> cpus in cpu_possible_mask that cannot be hot-added at runtime.
>
> Trying cpuidle_register_device() on cpu without cpu_device will cause
> crash like this:
>
> cpu 0xf: Vector: 380 (Data SLB Access) at [c00ff1503490]
> pc: c022c8bc: string+0x34/0x60
> lr: c022ed78: vsnprintf+0x284/0x42c
> sp: c00ff1503710
>msr: 90009033
>dar: 60006000
>   current = 0xc00ff148
>   paca= 0xcfe82d00   softe: 0irq_happened: 0x01
> pid   = 1, comm = swapper/8
> Linux version 4.11.0-rc2 (sv@sagarika) (gcc version 4.9.4
> (Buildroot 2017.02-4-gc28573e) ) #15 SMP Fri Mar 17 19:32:02 IST 2017
> enter ? for help
> [link register   ] c022ed78 vsnprintf+0x284/0x42c
> [c00ff1503710] c022ebb8 vsnprintf+0xc4/0x42c (unreliable)
> [c00ff1503800] c022ef40 vscnprintf+0x20/0x44
> [c00ff1503830] c00ab61c vprintk_emit+0x94/0x2cc
> [c00ff15038a0] c00acc9c vprintk_func+0x60/0x74
> [c00ff15038c0] c0619694 printk+0x38/0x4c
> [c00ff15038e0] c0224950 kobject_get+0x40/0x60
> [c00ff1503950] c022507c kobject_add_internal+0x60/0x2c4
> [c00ff15039e0] c0225350 kobject_init_and_add+0x70/0x78
> [c00ff1503a60] c053c288 cpuidle_add_sysfs+0x9c/0xe0
> [c00ff1503ae0] c053aeac cpuidle_register_device+0xd4/0x12c
> [c00ff1503b30] c053b108 cpuidle_register+0x98/0xcc
> [c00ff1503bc0] c085eaf0 powernv_processor_idle_init+0x140/0x1e0
> [c00ff1503c60] c000cd60 do_one_initcall+0xc0/0x15c
> [c00ff1503d20] c0833e84 kernel_init_freeable+0x1a0/0x25c
> [c00ff1503dc0] c000d478 kernel_init+0x24/0x12c
> [c00ff1503e30] c000b564 ret_from_kernel_thread+0x5c/0x78
>
> This patch fixes the bug by passing correct cpumask from
> powernv-cpuidle driver.
>
> Signed-off-by: Vaidyanathan Srinivasan 


Reviewed-by: Gautham R. Shenoy 

> ---
>  drivers/cpuidle/cpuidle-powernv.c | 18 ++
>  1 file changed, 18 insertions(+)
>
> diff --git a/drivers/cpuidle/cpuidle-powernv.c 
> b/drivers/cpuidle/cpuidle-powernv.c
> index a06df51..82f7b33 100644
> --- a/drivers/cpuidle/cpuidle-powernv.c
> +++ b/drivers/cpuidle/cpuidle-powernv.c
> @@ -175,6 +175,24 @@ static int powernv_cpuidle_driver_init(void)
> drv->state_count += 1;
> }
>
> +   /*
> +* On PowerNV platform cpu_present may be less that cpu_possible in
> +* cases where firmware detects the cpu, but it is not available to 
> the
> +* OS.  If CONFIG_HOTPLUG_CPU=n then such CPUs are not hotplugable at
> +* runtime and hence cpu_devices are not created for those cpus by
> +* generic topology_init().
> +*
> +* drv->cpumask defaults to cpu_possible_mask in
> +* __cpuidle_driver_init().  This breaks cpuidle on powernv where
> +* cpu_devices are not created for cpus in cpu_possible_mask that
> +* cannot be hot-added later at runtime.
> +*
> +* Trying cpuidle_register_device() on a cpu without cpu_devices is
> +* incorrect. Hence pass correct cpu mask to generic cpuidle driver.
> +*/
> +
> +   drv->cpumask = (struct cpumask *)cpu_present_mask;
> +
> return 0;
>  }
>
> --
> 2.9.3
>



-- 
Thanks and Regards
gautham.

Re: [PATCH v2 1/2] powerpc/powernv/cpuidle: Pass correct drv->cpumask for registration

2017-03-23 Thread Vaidyanathan Srinivasan 
* Rafael J. Wysocki  [2017-03-23 16:28:31]:

> On Thu, Mar 23, 2017 at 4:22 PM, Vaidyanathan Srinivasan
>  wrote:
> > drv->cpumask defaults to cpu_possible_mask in __cpuidle_driver_init().
> > On PowerNV platform cpu_present could be less than cpu_possible in cases
> > where firmware detects the cpu, but it is not available to the OS.  When
> > CONFIG_HOTPLUG_CPU=n, such cpus are not hotplugable at runtime and hence
> > we skip creating cpu_device.
> >
> > This breaks cpuidle on powernv where register_cpu() is not called for
> > cpus in cpu_possible_mask that cannot be hot-added at runtime.
> >
> > Trying cpuidle_register_device() on cpu without cpu_device will cause
> > crash like this:
> >
> > cpu 0xf: Vector: 380 (Data SLB Access) at [c00ff1503490]
> > pc: c022c8bc: string+0x34/0x60
> > lr: c022ed78: vsnprintf+0x284/0x42c
> > sp: c00ff1503710
> >msr: 90009033
> >dar: 60006000
> >   current = 0xc00ff148
> >   paca= 0xcfe82d00   softe: 0irq_happened: 0x01
> > pid   = 1, comm = swapper/8
> > Linux version 4.11.0-rc2 (sv@sagarika) (gcc version 4.9.4
> > (Buildroot 2017.02-4-gc28573e) ) #15 SMP Fri Mar 17 19:32:02 IST 2017
> > enter ? for help
> > [link register   ] c022ed78 vsnprintf+0x284/0x42c
> > [c00ff1503710] c022ebb8 vsnprintf+0xc4/0x42c (unreliable)
> > [c00ff1503800] c022ef40 vscnprintf+0x20/0x44
> > [c00ff1503830] c00ab61c vprintk_emit+0x94/0x2cc
> > [c00ff15038a0] c00acc9c vprintk_func+0x60/0x74
> > [c00ff15038c0] c0619694 printk+0x38/0x4c
> > [c00ff15038e0] c0224950 kobject_get+0x40/0x60
> > [c00ff1503950] c022507c kobject_add_internal+0x60/0x2c4
> > [c00ff15039e0] c0225350 kobject_init_and_add+0x70/0x78
> > [c00ff1503a60] c053c288 cpuidle_add_sysfs+0x9c/0xe0
> > [c00ff1503ae0] c053aeac cpuidle_register_device+0xd4/0x12c
> > [c00ff1503b30] c053b108 cpuidle_register+0x98/0xcc
> > [c00ff1503bc0] c085eaf0 powernv_processor_idle_init+0x140/0x1e0
> > [c00ff1503c60] c000cd60 do_one_initcall+0xc0/0x15c
> > [c00ff1503d20] c0833e84 kernel_init_freeable+0x1a0/0x25c
> > [c00ff1503dc0] c000d478 kernel_init+0x24/0x12c
> > [c00ff1503e30] c000b564 ret_from_kernel_thread+0x5c/0x78
> >
> > This patch fixes the bug by passing correct cpumask from
> > powernv-cpuidle driver.
> >
> > Signed-off-by: Vaidyanathan Srinivasan 
> 
> That needs to be ACKed by someone familiar with powernv.

Previous version at
https://lists.ozlabs.org/pipermail/linuxppc-dev/2017-March/155587.html

I had not CCed linux-pm in the first post.

Michael and Mikey have reviewed the previous version.  Let me get an
ack for you to proceed with the merge.

Thanks,
Vaidy

Re: [PATCH v2 1/2] powerpc/powernv/cpuidle: Pass correct drv->cpumask for registration

2017-03-23 Thread Vaidyanathan Srinivasan 
* Rafael J. Wysocki  [2017-03-23 16:28:31]:

> On Thu, Mar 23, 2017 at 4:22 PM, Vaidyanathan Srinivasan
>  wrote:
> > drv->cpumask defaults to cpu_possible_mask in __cpuidle_driver_init().
> > On PowerNV platform cpu_present could be less than cpu_possible in cases
> > where firmware detects the cpu, but it is not available to the OS.  When
> > CONFIG_HOTPLUG_CPU=n, such cpus are not hotplugable at runtime and hence
> > we skip creating cpu_device.
> >
> > This breaks cpuidle on powernv where register_cpu() is not called for
> > cpus in cpu_possible_mask that cannot be hot-added at runtime.
> >
> > Trying cpuidle_register_device() on cpu without cpu_device will cause
> > crash like this:
> >
> > cpu 0xf: Vector: 380 (Data SLB Access) at [c00ff1503490]
> > pc: c022c8bc: string+0x34/0x60
> > lr: c022ed78: vsnprintf+0x284/0x42c
> > sp: c00ff1503710
> >msr: 90009033
> >dar: 60006000
> >   current = 0xc00ff148
> >   paca= 0xcfe82d00   softe: 0irq_happened: 0x01
> > pid   = 1, comm = swapper/8
> > Linux version 4.11.0-rc2 (sv@sagarika) (gcc version 4.9.4
> > (Buildroot 2017.02-4-gc28573e) ) #15 SMP Fri Mar 17 19:32:02 IST 2017
> > enter ? for help
> > [link register   ] c022ed78 vsnprintf+0x284/0x42c
> > [c00ff1503710] c022ebb8 vsnprintf+0xc4/0x42c (unreliable)
> > [c00ff1503800] c022ef40 vscnprintf+0x20/0x44
> > [c00ff1503830] c00ab61c vprintk_emit+0x94/0x2cc
> > [c00ff15038a0] c00acc9c vprintk_func+0x60/0x74
> > [c00ff15038c0] c0619694 printk+0x38/0x4c
> > [c00ff15038e0] c0224950 kobject_get+0x40/0x60
> > [c00ff1503950] c022507c kobject_add_internal+0x60/0x2c4
> > [c00ff15039e0] c0225350 kobject_init_and_add+0x70/0x78
> > [c00ff1503a60] c053c288 cpuidle_add_sysfs+0x9c/0xe0
> > [c00ff1503ae0] c053aeac cpuidle_register_device+0xd4/0x12c
> > [c00ff1503b30] c053b108 cpuidle_register+0x98/0xcc
> > [c00ff1503bc0] c085eaf0 powernv_processor_idle_init+0x140/0x1e0
> > [c00ff1503c60] c000cd60 do_one_initcall+0xc0/0x15c
> > [c00ff1503d20] c0833e84 kernel_init_freeable+0x1a0/0x25c
> > [c00ff1503dc0] c000d478 kernel_init+0x24/0x12c
> > [c00ff1503e30] c000b564 ret_from_kernel_thread+0x5c/0x78
> >
> > This patch fixes the bug by passing correct cpumask from
> > powernv-cpuidle driver.
> >
> > Signed-off-by: Vaidyanathan Srinivasan 
> 
> That needs to be ACKed by someone familiar with powernv.

Previous version at
https://lists.ozlabs.org/pipermail/linuxppc-dev/2017-March/155587.html

I had not CCed linux-pm in the first post.

Michael and Mikey have reviewed the previous version.  Let me get an
ack for you to proceed with the merge.

Thanks,
Vaidy

Re: [PATCH v2 1/2] powerpc/powernv/cpuidle: Pass correct drv->cpumask for registration

2017-03-23 Thread Rafael J. Wysocki 
On Thu, Mar 23, 2017 at 4:22 PM, Vaidyanathan Srinivasan
 wrote:
> drv->cpumask defaults to cpu_possible_mask in __cpuidle_driver_init().
> On PowerNV platform cpu_present could be less than cpu_possible in cases
> where firmware detects the cpu, but it is not available to the OS.  When
> CONFIG_HOTPLUG_CPU=n, such cpus are not hotplugable at runtime and hence
> we skip creating cpu_device.
>
> This breaks cpuidle on powernv where register_cpu() is not called for
> cpus in cpu_possible_mask that cannot be hot-added at runtime.
>
> Trying cpuidle_register_device() on cpu without cpu_device will cause
> crash like this:
>
> cpu 0xf: Vector: 380 (Data SLB Access) at [c00ff1503490]
> pc: c022c8bc: string+0x34/0x60
> lr: c022ed78: vsnprintf+0x284/0x42c
> sp: c00ff1503710
>msr: 90009033
>dar: 60006000
>   current = 0xc00ff148
>   paca= 0xcfe82d00   softe: 0irq_happened: 0x01
> pid   = 1, comm = swapper/8
> Linux version 4.11.0-rc2 (sv@sagarika) (gcc version 4.9.4
> (Buildroot 2017.02-4-gc28573e) ) #15 SMP Fri Mar 17 19:32:02 IST 2017
> enter ? for help
> [link register   ] c022ed78 vsnprintf+0x284/0x42c
> [c00ff1503710] c022ebb8 vsnprintf+0xc4/0x42c (unreliable)
> [c00ff1503800] c022ef40 vscnprintf+0x20/0x44
> [c00ff1503830] c00ab61c vprintk_emit+0x94/0x2cc
> [c00ff15038a0] c00acc9c vprintk_func+0x60/0x74
> [c00ff15038c0] c0619694 printk+0x38/0x4c
> [c00ff15038e0] c0224950 kobject_get+0x40/0x60
> [c00ff1503950] c022507c kobject_add_internal+0x60/0x2c4
> [c00ff15039e0] c0225350 kobject_init_and_add+0x70/0x78
> [c00ff1503a60] c053c288 cpuidle_add_sysfs+0x9c/0xe0
> [c00ff1503ae0] c053aeac cpuidle_register_device+0xd4/0x12c
> [c00ff1503b30] c053b108 cpuidle_register+0x98/0xcc
> [c00ff1503bc0] c085eaf0 powernv_processor_idle_init+0x140/0x1e0
> [c00ff1503c60] c000cd60 do_one_initcall+0xc0/0x15c
> [c00ff1503d20] c0833e84 kernel_init_freeable+0x1a0/0x25c
> [c00ff1503dc0] c000d478 kernel_init+0x24/0x12c
> [c00ff1503e30] c000b564 ret_from_kernel_thread+0x5c/0x78
>
> This patch fixes the bug by passing correct cpumask from
> powernv-cpuidle driver.
>
> Signed-off-by: Vaidyanathan Srinivasan 

That needs to be ACKed by someone familiar with powernv.

> ---
>  drivers/cpuidle/cpuidle-powernv.c | 18 ++
>  1 file changed, 18 insertions(+)
>
> diff --git a/drivers/cpuidle/cpuidle-powernv.c 
> b/drivers/cpuidle/cpuidle-powernv.c
> index a06df51..82f7b33 100644
> --- a/drivers/cpuidle/cpuidle-powernv.c
> +++ b/drivers/cpuidle/cpuidle-powernv.c
> @@ -175,6 +175,24 @@ static int powernv_cpuidle_driver_init(void)
> drv->state_count += 1;
> }
>
> +   /*
> +* On PowerNV platform cpu_present may be less that cpu_possible in
> +* cases where firmware detects the cpu, but it is not available to 
> the
> +* OS.  If CONFIG_HOTPLUG_CPU=n then such CPUs are not hotplugable at
> +* runtime and hence cpu_devices are not created for those cpus by
> +* generic topology_init().
> +*
> +* drv->cpumask defaults to cpu_possible_mask in
> +* __cpuidle_driver_init().  This breaks cpuidle on powernv where
> +* cpu_devices are not created for cpus in cpu_possible_mask that
> +* cannot be hot-added later at runtime.
> +*
> +* Trying cpuidle_register_device() on a cpu without cpu_devices is
> +* incorrect. Hence pass correct cpu mask to generic cpuidle driver.
> +*/
> +
> +   drv->cpumask = (struct cpumask *)cpu_present_mask;
> +
> return 0;
>  }
>
> --
> 2.9.3
>

Re: [PATCH v2 1/2] powerpc/powernv/cpuidle: Pass correct drv->cpumask for registration

2017-03-23 Thread Rafael J. Wysocki 
On Thu, Mar 23, 2017 at 4:22 PM, Vaidyanathan Srinivasan
 wrote:
> drv->cpumask defaults to cpu_possible_mask in __cpuidle_driver_init().
> On PowerNV platform cpu_present could be less than cpu_possible in cases
> where firmware detects the cpu, but it is not available to the OS.  When
> CONFIG_HOTPLUG_CPU=n, such cpus are not hotplugable at runtime and hence
> we skip creating cpu_device.
>
> This breaks cpuidle on powernv where register_cpu() is not called for
> cpus in cpu_possible_mask that cannot be hot-added at runtime.
>
> Trying cpuidle_register_device() on cpu without cpu_device will cause
> crash like this:
>
> cpu 0xf: Vector: 380 (Data SLB Access) at [c00ff1503490]
> pc: c022c8bc: string+0x34/0x60
> lr: c022ed78: vsnprintf+0x284/0x42c
> sp: c00ff1503710
>msr: 90009033
>dar: 60006000
>   current = 0xc00ff148
>   paca= 0xcfe82d00   softe: 0irq_happened: 0x01
> pid   = 1, comm = swapper/8
> Linux version 4.11.0-rc2 (sv@sagarika) (gcc version 4.9.4
> (Buildroot 2017.02-4-gc28573e) ) #15 SMP Fri Mar 17 19:32:02 IST 2017
> enter ? for help
> [link register   ] c022ed78 vsnprintf+0x284/0x42c
> [c00ff1503710] c022ebb8 vsnprintf+0xc4/0x42c (unreliable)
> [c00ff1503800] c022ef40 vscnprintf+0x20/0x44
> [c00ff1503830] c00ab61c vprintk_emit+0x94/0x2cc
> [c00ff15038a0] c00acc9c vprintk_func+0x60/0x74
> [c00ff15038c0] c0619694 printk+0x38/0x4c
> [c00ff15038e0] c0224950 kobject_get+0x40/0x60
> [c00ff1503950] c022507c kobject_add_internal+0x60/0x2c4
> [c00ff15039e0] c0225350 kobject_init_and_add+0x70/0x78
> [c00ff1503a60] c053c288 cpuidle_add_sysfs+0x9c/0xe0
> [c00ff1503ae0] c053aeac cpuidle_register_device+0xd4/0x12c
> [c00ff1503b30] c053b108 cpuidle_register+0x98/0xcc
> [c00ff1503bc0] c085eaf0 powernv_processor_idle_init+0x140/0x1e0
> [c00ff1503c60] c000cd60 do_one_initcall+0xc0/0x15c
> [c00ff1503d20] c0833e84 kernel_init_freeable+0x1a0/0x25c
> [c00ff1503dc0] c000d478 kernel_init+0x24/0x12c
> [c00ff1503e30] c000b564 ret_from_kernel_thread+0x5c/0x78
>
> This patch fixes the bug by passing correct cpumask from
> powernv-cpuidle driver.
>
> Signed-off-by: Vaidyanathan Srinivasan 

That needs to be ACKed by someone familiar with powernv.

> ---
>  drivers/cpuidle/cpuidle-powernv.c | 18 ++
>  1 file changed, 18 insertions(+)
>
> diff --git a/drivers/cpuidle/cpuidle-powernv.c 
> b/drivers/cpuidle/cpuidle-powernv.c
> index a06df51..82f7b33 100644
> --- a/drivers/cpuidle/cpuidle-powernv.c
> +++ b/drivers/cpuidle/cpuidle-powernv.c
> @@ -175,6 +175,24 @@ static int powernv_cpuidle_driver_init(void)
> drv->state_count += 1;
> }
>
> +   /*
> +* On PowerNV platform cpu_present may be less that cpu_possible in
> +* cases where firmware detects the cpu, but it is not available to 
> the
> +* OS.  If CONFIG_HOTPLUG_CPU=n then such CPUs are not hotplugable at
> +* runtime and hence cpu_devices are not created for those cpus by
> +* generic topology_init().
> +*
> +* drv->cpumask defaults to cpu_possible_mask in
> +* __cpuidle_driver_init().  This breaks cpuidle on powernv where
> +* cpu_devices are not created for cpus in cpu_possible_mask that
> +* cannot be hot-added later at runtime.
> +*
> +* Trying cpuidle_register_device() on a cpu without cpu_devices is
> +* incorrect. Hence pass correct cpu mask to generic cpuidle driver.
> +*/
> +
> +   drv->cpumask = (struct cpumask *)cpu_present_mask;
> +
> return 0;
>  }
>
> --
> 2.9.3
>

[PATCH v2 1/2] powerpc/powernv/cpuidle: Pass correct drv->cpumask for registration

2017-03-23 Thread Vaidyanathan Srinivasan 
drv->cpumask defaults to cpu_possible_mask in __cpuidle_driver_init().
On PowerNV platform cpu_present could be less than cpu_possible in cases
where firmware detects the cpu, but it is not available to the OS.  When
CONFIG_HOTPLUG_CPU=n, such cpus are not hotplugable at runtime and hence
we skip creating cpu_device.

This breaks cpuidle on powernv where register_cpu() is not called for
cpus in cpu_possible_mask that cannot be hot-added at runtime.

Trying cpuidle_register_device() on cpu without cpu_device will cause
crash like this:

cpu 0xf: Vector: 380 (Data SLB Access) at [c00ff1503490]
pc: c022c8bc: string+0x34/0x60
lr: c022ed78: vsnprintf+0x284/0x42c
sp: c00ff1503710
   msr: 90009033
   dar: 60006000
  current = 0xc00ff148
  paca= 0xcfe82d00   softe: 0irq_happened: 0x01
pid   = 1, comm = swapper/8
Linux version 4.11.0-rc2 (sv@sagarika) (gcc version 4.9.4
(Buildroot 2017.02-4-gc28573e) ) #15 SMP Fri Mar 17 19:32:02 IST 2017
enter ? for help
[link register   ] c022ed78 vsnprintf+0x284/0x42c
[c00ff1503710] c022ebb8 vsnprintf+0xc4/0x42c (unreliable)
[c00ff1503800] c022ef40 vscnprintf+0x20/0x44
[c00ff1503830] c00ab61c vprintk_emit+0x94/0x2cc
[c00ff15038a0] c00acc9c vprintk_func+0x60/0x74
[c00ff15038c0] c0619694 printk+0x38/0x4c
[c00ff15038e0] c0224950 kobject_get+0x40/0x60
[c00ff1503950] c022507c kobject_add_internal+0x60/0x2c4
[c00ff15039e0] c0225350 kobject_init_and_add+0x70/0x78
[c00ff1503a60] c053c288 cpuidle_add_sysfs+0x9c/0xe0
[c00ff1503ae0] c053aeac cpuidle_register_device+0xd4/0x12c
[c00ff1503b30] c053b108 cpuidle_register+0x98/0xcc
[c00ff1503bc0] c085eaf0 powernv_processor_idle_init+0x140/0x1e0
[c00ff1503c60] c000cd60 do_one_initcall+0xc0/0x15c
[c00ff1503d20] c0833e84 kernel_init_freeable+0x1a0/0x25c
[c00ff1503dc0] c000d478 kernel_init+0x24/0x12c
[c00ff1503e30] c000b564 ret_from_kernel_thread+0x5c/0x78

This patch fixes the bug by passing correct cpumask from
powernv-cpuidle driver.

Signed-off-by: Vaidyanathan Srinivasan 
---
 drivers/cpuidle/cpuidle-powernv.c | 18 ++
 1 file changed, 18 insertions(+)

diff --git a/drivers/cpuidle/cpuidle-powernv.c 
b/drivers/cpuidle/cpuidle-powernv.c
index a06df51..82f7b33 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -175,6 +175,24 @@ static int powernv_cpuidle_driver_init(void)
drv->state_count += 1;
}
 
+   /*
+* On PowerNV platform cpu_present may be less that cpu_possible in
+* cases where firmware detects the cpu, but it is not available to the
+* OS.  If CONFIG_HOTPLUG_CPU=n then such CPUs are not hotplugable at
+* runtime and hence cpu_devices are not created for those cpus by
+* generic topology_init().
+*
+* drv->cpumask defaults to cpu_possible_mask in
+* __cpuidle_driver_init().  This breaks cpuidle on powernv where
+* cpu_devices are not created for cpus in cpu_possible_mask that
+* cannot be hot-added later at runtime.
+*
+* Trying cpuidle_register_device() on a cpu without cpu_devices is
+* incorrect. Hence pass correct cpu mask to generic cpuidle driver.
+*/
+
+   drv->cpumask = (struct cpumask *)cpu_present_mask;
+
return 0;
 }
 
-- 
2.9.3

[PATCH v2 1/2] powerpc/powernv/cpuidle: Pass correct drv->cpumask for registration

2017-03-23 Thread Vaidyanathan Srinivasan 
drv->cpumask defaults to cpu_possible_mask in __cpuidle_driver_init().
On PowerNV platform cpu_present could be less than cpu_possible in cases
where firmware detects the cpu, but it is not available to the OS.  When
CONFIG_HOTPLUG_CPU=n, such cpus are not hotplugable at runtime and hence
we skip creating cpu_device.

This breaks cpuidle on powernv where register_cpu() is not called for
cpus in cpu_possible_mask that cannot be hot-added at runtime.

Trying cpuidle_register_device() on cpu without cpu_device will cause
crash like this:

cpu 0xf: Vector: 380 (Data SLB Access) at [c00ff1503490]
pc: c022c8bc: string+0x34/0x60
lr: c022ed78: vsnprintf+0x284/0x42c
sp: c00ff1503710
   msr: 90009033
   dar: 60006000
  current = 0xc00ff148
  paca= 0xcfe82d00   softe: 0irq_happened: 0x01
pid   = 1, comm = swapper/8
Linux version 4.11.0-rc2 (sv@sagarika) (gcc version 4.9.4
(Buildroot 2017.02-4-gc28573e) ) #15 SMP Fri Mar 17 19:32:02 IST 2017
enter ? for help
[link register   ] c022ed78 vsnprintf+0x284/0x42c
[c00ff1503710] c022ebb8 vsnprintf+0xc4/0x42c (unreliable)
[c00ff1503800] c022ef40 vscnprintf+0x20/0x44
[c00ff1503830] c00ab61c vprintk_emit+0x94/0x2cc
[c00ff15038a0] c00acc9c vprintk_func+0x60/0x74
[c00ff15038c0] c0619694 printk+0x38/0x4c
[c00ff15038e0] c0224950 kobject_get+0x40/0x60
[c00ff1503950] c022507c kobject_add_internal+0x60/0x2c4
[c00ff15039e0] c0225350 kobject_init_and_add+0x70/0x78
[c00ff1503a60] c053c288 cpuidle_add_sysfs+0x9c/0xe0
[c00ff1503ae0] c053aeac cpuidle_register_device+0xd4/0x12c
[c00ff1503b30] c053b108 cpuidle_register+0x98/0xcc
[c00ff1503bc0] c085eaf0 powernv_processor_idle_init+0x140/0x1e0
[c00ff1503c60] c000cd60 do_one_initcall+0xc0/0x15c
[c00ff1503d20] c0833e84 kernel_init_freeable+0x1a0/0x25c
[c00ff1503dc0] c000d478 kernel_init+0x24/0x12c
[c00ff1503e30] c000b564 ret_from_kernel_thread+0x5c/0x78

This patch fixes the bug by passing correct cpumask from
powernv-cpuidle driver.

Signed-off-by: Vaidyanathan Srinivasan 
---
 drivers/cpuidle/cpuidle-powernv.c | 18 ++
 1 file changed, 18 insertions(+)

diff --git a/drivers/cpuidle/cpuidle-powernv.c 
b/drivers/cpuidle/cpuidle-powernv.c
index a06df51..82f7b33 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -175,6 +175,24 @@ static int powernv_cpuidle_driver_init(void)
drv->state_count += 1;
}
 
+   /*
+* On PowerNV platform cpu_present may be less that cpu_possible in
+* cases where firmware detects the cpu, but it is not available to the
+* OS.  If CONFIG_HOTPLUG_CPU=n then such CPUs are not hotplugable at
+* runtime and hence cpu_devices are not created for those cpus by
+* generic topology_init().
+*
+* drv->cpumask defaults to cpu_possible_mask in
+* __cpuidle_driver_init().  This breaks cpuidle on powernv where
+* cpu_devices are not created for cpus in cpu_possible_mask that
+* cannot be hot-added later at runtime.
+*
+* Trying cpuidle_register_device() on a cpu without cpu_devices is
+* incorrect. Hence pass correct cpu mask to generic cpuidle driver.
+*/
+
+   drv->cpumask = (struct cpumask *)cpu_present_mask;
+
return 0;
 }
 
-- 
2.9.3