[PATCH 1/6] powerpc/rtas: improve ppc_rtas_rmo_buf_show documentation

[Alexey Kardashevskiy]

On 15/01/2021 08:59, Nathan Lynch wrote:
> Add kerneldoc for ppc_rtas_rmo_buf_show(), the callback for
> /proc/powerpc/rtas/rmo_buffer, explaining its expected use.
> 
> Signed-off-by: Nathan Lynch <nathanl at linux.ibm.com>
> ---
>   arch/powerpc/kernel/rtas-proc.c | 11 ++++++++++-
>   1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/rtas-proc.c b/arch/powerpc/kernel/rtas-proc.c
> index 2d33f342a293..e0f8329966d6 100644
> --- a/arch/powerpc/kernel/rtas-proc.c
> +++ b/arch/powerpc/kernel/rtas-proc.c
> @@ -757,7 +757,16 @@ static int ppc_rtas_tone_volume_show(struct seq_file *m, void *v)
>   
>   #define RMO_READ_BUF_MAX 30
>   
> -/* RTAS Userspace access */
> +/**
> + * ppc_rtas_rmo_buf_show() - Describe RTAS-addressable region for user space.
> + *
> + * Base + size description of a range of RTAS-addressable memory set
> + * aside for user space to use as work area(s) for certain RTAS
> + * functions. User space accesses this region via /dev/mem.


mmm ufff wuuuuut argh^w^w^w^w Thanks for documenting it :)

Reviewed-by: Alexey Kardashevskiy <aik at ozlabs.ru>



> Apart from
> + * security policies, the kernel does not arbitrate or serialize
> + * access to this region, and user space must ensure that concurrent
> + * users do not interfere with each other.
> + */
>   static int ppc_rtas_rmo_buf_show(struct seq_file *m, void *v)
>   {
>   	seq_printf(m, "%016lx %x\n", rtas_rmo_buf, RTAS_RMOBUF_MAX);
> 

-- 
Alexey