[PATCH] powerpc/iseries: Kexec is known not to work on iseries

[Nathan Lynch]

Hi,

Michael Ellerman wrote:
> The non-zero return from the prepare callback is returned by sys_kexec_load()
> to userspace, indicating that kexec is not supported on the machine.

...

> @@ -638,6 +639,13 @@ static int __init iseries_probe(void)
>  	return 1;
>  }
>  
> +#ifdef CONFIG_KEXEC
> +static int iseries_kexec_prepare(struct kimage *image)
> +{
> +	return -ENOSYS;
> +}
> +#endif
> +
>  define_machine(iseries) {
>  	.name			= "iSeries",
>  	.setup_arch		= iSeries_setup_arch,
> @@ -658,6 +666,9 @@ define_machine(iseries) {
>  	.probe			= iseries_probe,
>  	.ioremap		= iseries_ioremap,
>  	.iounmap		= iseries_iounmap,
> +#ifdef CONFIG_KEXEC
> +	.machine_kexec_prepare	= iseries_kexec_prepare,
> +#endif
>  	/* XXX Implement enable_pmcs for iSeries */
>  };

But machine_kexec_prepare() already returns -ENOSYS if the platform
doesn't have the hook in ppc_md.  I must be missing something; what is
this patch fixing?