Re: [PATCH V1 19/29] xen/arm: Create a fake PSCI node in dom0 device tree

[Julien Grall <julien.grall@linaro.org>]

On 09/09/2013 12:41 PM, Ian Campbell wrote:
> On Wed, 2013-08-28 at 15:47 +0100, Julien Grall wrote:
>> Xen uses PSCI to bring up secondary cpus for the guest.
>
> Does this account for/incorporate the changes in "dt: update PSCI
> binding documentation for v0.2" from Rob Herring? Msg-di
> <1377564633-31638-1-git-send-email-robherring2@gmail.com>
>
> That might require actual code changes in Xen too I suppose?

I don't think, the PSCI code in Xen is generic. We will only have to 
update the current patch.

Do you know if Linux supports PSCI 0.2?

>>
>> Signed-off-by: Julien Grall <julien.grall@linaro.org>
>>
>> ---
>>      Changes in v2:
>>          - Use fdt_property_cell
>> ---
>>   xen/arch/arm/domain_build.c |   38 ++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 38 insertions(+)
>>
>> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
>> index 11f247b..4c936c1 100644
>> --- a/xen/arch/arm/domain_build.c
>> +++ b/xen/arch/arm/domain_build.c
>> @@ -13,6 +13,7 @@
>>   #include <xen/guest_access.h>
>>   #include <asm/setup.h>
>>   #include <asm/platform.h>
>> +#include <asm/psci.h>
>>
>>   #include <asm/gic.h>
>>   #include <xen/irq.h>
>> @@ -306,6 +307,38 @@ static int make_hypervisor_node(void *fdt, const struct dt_device_node *parent)
>>       return res;
>>   }
>>
>> +static int make_psci_node(void *fdt, const struct dt_device_node *parent)
>> +{
>> +    int res;
>> +
>> +    DPRINT("Create PSCI node\n");
>> +
>> +    /* See linux Documentation/devicetree/bindings/arm/psci.txt */
>> +    res = fdt_begin_node(fdt, "psci");
>> +    if ( res )
>> +        return res;
>> +
>> +    res = fdt_property_string(fdt, "compatible", "arm,psci");
>> +    if ( res )
>> +        return res;
>> +
>> +    res = fdt_property_string(fdt, "method", "hvc");
>> +    if ( res )
>> +        return res;
>> +
>> +    res = fdt_property_cell(fdt, "cpu_off", __PSCI_cpu_off);
>> +    if ( res )
>> +        return res;
>> +
>> +    res = fdt_property_cell(fdt, "cpu_on", __PSCI_cpu_on);
>> +    if ( res )
>> +        return res;
>> +
>> +    res = fdt_end_node(fdt);
>> +
>> +    return res;
>> +}
>> +
>>   /* Map the device in the domain */
>>   static int map_device(struct domain *d, const struct dt_device_node *dev)
>>   {
>> @@ -393,6 +426,7 @@ static int handle_node(struct domain *d, struct kernel_info *kinfo,
>>       {
>>           DT_MATCH_COMPATIBLE("xen,xen"),
>>           DT_MATCH_COMPATIBLE("xen,multiboot-module"),
>> +        DT_MATCH_COMPATIBLE("arm,psci"),
>>           { /* sentinel */ },
>>       };
>>       const struct dt_device_node *child;
>> @@ -458,6 +492,10 @@ static int handle_node(struct domain *d, struct kernel_info *kinfo,
>>           res = make_hypervisor_node(kinfo->fdt, np);
>>           if ( res )
>>               return res;
>> +
>> +        res = make_psci_node(kinfo->fdt, np);
>> +        if ( res )
>> +            return res;
>>       }
>>
>>       res = fdt_end_node(kinfo->fdt);
>
>

-- 
Julien Grall