Re: [PATCH] xen:arm: use SMC64 version function id on ARM64

[Julien Grall <julien.grall@citrix.com>]

Hi,

FIY, the xen-arm mailing has been removed a year ago and was only 
targeting the Xen ARM PV port.

On 02/10/2015 22:36, Brijesh Singh wrote:
> On AMD Seattle, Xen failed to boot secondary CPU's. This patch fixes it.
>
> As per PSCI spec, If CPU_ON entry_point_address is 64-bit then function id parameter should be set to SMC64 version (0xC4000003).

The line in the commit message should never go above 72 characters. 
Please split it.

>
> Signed-off-by: Brijesh Singh <brijeshkumar.singh@amd.com>
> ---
>   xen/arch/arm/psci.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
> index 7ad6a43..117c6a9 100644
> --- a/xen/arch/arm/psci.c
> +++ b/xen/arch/arm/psci.c
> @@ -116,7 +116,11 @@ int __init psci_init_0_2(void)
>           return -EOPNOTSUPP;
>       }
>
> +#ifdef CONFIG_ARM_64
> +    psci_cpu_on_nr = PSCI_0_2_FN64_CPU_ON;
> +#else
>       psci_cpu_on_nr = PSCI_0_2_FN_CPU_ON;
> +#endif

Rather than open coding the function ID in the code, I would prefer to 
introduce a define/macro similar to the Linux one (see 
drivers/firmware/psci.c) which will return the 64-bit function ID for 
ARM64 and 32-bit one for ARM32:

#ifdef CONFIG_ARM_64
#define PSCI_0_2_FN_NATIVE(name)	PSCI_0_2_FN64_#name
#else
#define PSCI_0_2_FN_NATIVE(name)	PSCI_0_2_FN_#name
#endif

And then:

psci_cpu_on_nr = PSCI_0_2_FN_NATIVE(CPU_ON);

A comment on top for the macro would also be welcome for future 
reference explaining why.

Regards,

-- 
Julien Grall