Nathan Lynch <nath...@linux.ibm.com> writes:
> sys_rtas() cannot call ibm,suspend-me directly in the same way it
> handles other inputs. Instead it must dispatch the request to code
> that can first perform the H_JOIN sequence before any call to
> ibm,suspend-me can succeed. Over time kernel/rtas.c has accreted a fair
> amount of platform-specific code to implement this.
>
> Since a different, more robust implementation of the suspend sequence
> is now in the pseries platform code, we want to dispatch the request
> there while minimizing additional dependence on pseries.
>
> Use a weak function that only pseries overrides.
Over the years weak functions have caused their fair share of problems.
There are cases where they are the cleanest option, but for intra-arch
code like this I think and ifdef is much simpler.
> diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
> index fdefe6a974eb..be0fc2536673 100644
> --- a/arch/powerpc/include/asm/rtas.h
> +++ b/arch/powerpc/include/asm/rtas.h
> @@ -260,6 +260,7 @@ extern int rtas_suspend_cpu(struct rtas_suspend_me_data
> *data);
> extern int rtas_suspend_last_cpu(struct rtas_suspend_me_data *data);
> int rtas_ibm_suspend_me_unsafe(u64 handle);
> int rtas_ibm_suspend_me(int *fw_status);
> +int rtas_syscall_dispatch_ibm_suspend_me(u64 handle);
ie. we'd just do:
#ifdef CONFIG_PPC_PSERIES
int rtas_syscall_dispatch_ibm_suspend_me(u64 handle);
#else
int rtas_syscall_dispatch_ibm_suspend_me(u64 handle)
{
return -EINVAL;
}
#endif
cheers
