Nathan Lynch via B4 Relay <devnull+nathanl.linux.ibm....@kernel.org>
writes:
> From: Nathan Lynch <nath...@linux.ibm.com>
>
> On RTAS platforms there is a general restriction that the OS must not
> enter RTAS on more than one CPU at a time. This low-level
> serialization requirement is satisfied by holding a spin
> lock (rtas_lock) across most RTAS function invocations.
...
> diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
> index 1fc0b3fffdd1..52f2242d0c28 100644
> --- a/arch/powerpc/kernel/rtas.c
> +++ b/arch/powerpc/kernel/rtas.c
> @@ -581,6 +652,28 @@ static const struct rtas_function
> *rtas_token_to_function(s32 token)
> return NULL;
> }
>
> +static void __rtas_function_lock(struct rtas_function *func)
> +{
> + if (func && func->lock)
> + mutex_lock(func->lock);
> +}
This is obviously going to defeat most static analysis tools. I assume
lockdep is OK with it though?
cheers
