diff mbox

ARM: xen: only set pm function ptrs for Xen guests

Message ID 1377706794-8481-1-git-send-email-robherring2@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Rob Herring Aug. 28, 2013, 4:19 p.m. UTC
From: Rob Herring <rob.herring@calxeda.com>

xen_pm_init was unconditionally setting pm_power_off and arm_pm_restart
function pointers. This breaks multi-platform kernels. Move this
initialization into xen_guest_init, so it is conditional on running as a
Xen guest.

Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
This breaks reset and poweroff for Midway when Xen is enabled. This 
should go into 3.11 or stable.

Rob

 arch/arm/xen/enlighten.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

Comments

Julien Grall Aug. 28, 2013, 4:32 p.m. UTC | #1
On 08/28/2013 05:19 PM, Rob Herring wrote:
> From: Rob Herring <rob.herring@calxeda.com>
> 
> xen_pm_init was unconditionally setting pm_power_off and arm_pm_restart
> function pointers. This breaks multi-platform kernels. Move this
> initialization into xen_guest_init, so it is conditional on running as a
> Xen guest.
> 
> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> Signed-off-by: Rob Herring <rob.herring@calxeda.com>
> ---
> This breaks reset and poweroff for Midway when Xen is enabled. This 
> should go into 3.11 or stable.
> Rob
> 
>  arch/arm/xen/enlighten.c | 12 +++---------
>  1 file changed, 3 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index 8a6295c..fa86452 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -263,6 +263,9 @@ static int __init xen_guest_init(void)
>  	if (xen_vcpu_info == NULL)
>  		return -ENOMEM;
>  
> +	pm_power_off = xen_power_off;
> +	arm_pm_restart = xen_restart;
> +

I think it's too early to set pm callbacks. If Linux is running as dom0,
xen needs to overwrite the power management callback. Otherwise, dom0
could shutdown/restart the whole platform, that is annoying.
For instance, on the versatile express, the power management callback
are set very late (ie during driver initialization).

pm callbacks should be updated by a late initcall and check if xen is
enabled.

>  	gnttab_init();
>  	if (!xen_initial_domain())
>  		xenbus_probe(NULL);
> @@ -271,15 +274,6 @@ static int __init xen_guest_init(void)
>  }
>  core_initcall(xen_guest_init);
>  
> -static int __init xen_pm_init(void)
> -{
> -	pm_power_off = xen_power_off;
> -	arm_pm_restart = xen_restart;
> -
> -	return 0;
> -}
> -subsys_initcall(xen_pm_init);
> -
>  static irqreturn_t xen_arm_callback(int irq, void *arg)
>  {
>  	xen_hvm_evtchn_do_upcall();
>
Rob Herring Aug. 28, 2013, 6:03 p.m. UTC | #2
On Wed, Aug 28, 2013 at 11:32 AM, Julien Grall <julien.grall@linaro.org> wrote:
> On 08/28/2013 05:19 PM, Rob Herring wrote:
>> From: Rob Herring <rob.herring@calxeda.com>
>>
>> xen_pm_init was unconditionally setting pm_power_off and arm_pm_restart
>> function pointers. This breaks multi-platform kernels. Move this
>> initialization into xen_guest_init, so it is conditional on running as a
>> Xen guest.
>>
>> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
>> Signed-off-by: Rob Herring <rob.herring@calxeda.com>
>> ---
>> This breaks reset and poweroff for Midway when Xen is enabled. This
>> should go into 3.11 or stable.
>> Rob
>>
>>  arch/arm/xen/enlighten.c | 12 +++---------
>>  1 file changed, 3 insertions(+), 9 deletions(-)
>>
>> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
>> index 8a6295c..fa86452 100644
>> --- a/arch/arm/xen/enlighten.c
>> +++ b/arch/arm/xen/enlighten.c
>> @@ -263,6 +263,9 @@ static int __init xen_guest_init(void)
>>       if (xen_vcpu_info == NULL)
>>               return -ENOMEM;
>>
>> +     pm_power_off = xen_power_off;
>> +     arm_pm_restart = xen_restart;
>> +
>
> I think it's too early to set pm callbacks. If Linux is running as dom0,
> xen needs to overwrite the power management callback. Otherwise, dom0
> could shutdown/restart the whole platform, that is annoying.
> For instance, on the versatile express, the power management callback
> are set very late (ie during driver initialization).
>
> pm callbacks should be updated by a late initcall and check if xen is
> enabled.
>
>>       gnttab_init();
>>       if (!xen_initial_domain())
>>               xenbus_probe(NULL);
>> @@ -271,15 +274,6 @@ static int __init xen_guest_init(void)
>>  }
>>  core_initcall(xen_guest_init);
>>
>> -static int __init xen_pm_init(void)
>> -{
>> -     pm_power_off = xen_power_off;
>> -     arm_pm_restart = xen_restart;
>> -
>> -     return 0;
>> -}
>> -subsys_initcall(xen_pm_init);
>> -
>>  static irqreturn_t xen_arm_callback(int irq, void *arg)
>>  {
>>       xen_hvm_evtchn_do_upcall();
>>
>
>
> --
> Julien Grall
diff mbox

Patch

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 8a6295c..fa86452 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -263,6 +263,9 @@  static int __init xen_guest_init(void)
 	if (xen_vcpu_info == NULL)
 		return -ENOMEM;
 
+	pm_power_off = xen_power_off;
+	arm_pm_restart = xen_restart;
+
 	gnttab_init();
 	if (!xen_initial_domain())
 		xenbus_probe(NULL);
@@ -271,15 +274,6 @@  static int __init xen_guest_init(void)
 }
 core_initcall(xen_guest_init);
 
-static int __init xen_pm_init(void)
-{
-	pm_power_off = xen_power_off;
-	arm_pm_restart = xen_restart;
-
-	return 0;
-}
-subsys_initcall(xen_pm_init);
-
 static irqreturn_t xen_arm_callback(int irq, void *arg)
 {
 	xen_hvm_evtchn_do_upcall();