[PATCH v2 17/29] arm_mpam: Extend reset logic to allow devices to be reset any time

[Ben Horgan]

Hi James,

On 9/10/25 21:42, James Morse wrote:
> cpuhp callbacks aren't the only time the MSC configuration may need to
> be reset. Resctrl has an API call to reset a class.
> If an MPAM error interrupt arrives it indicates the driver has
> misprogrammed an MSC. The safest thing to do is reset all the MSCs
> and disable MPAM.
> 
> Add a helper to reset RIS via their class. Call this from mpam_disable(),
> which can be scheduled from the error interrupt handler.
> 
> Signed-off-by: James Morse <james.morse at arm.com>
> ---
> Changes since v1:
>  * more complete use of _srcu helpers.
>  * Use guard macro for srcu.
>  * Dropped a might_sleep() - something else will bark.
> ---
>  drivers/resctrl/mpam_devices.c | 56 ++++++++++++++++++++++++++++++++--
>  1 file changed, 54 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
> index e7faf453b5d7..a9d3c4b09976 100644
> --- a/drivers/resctrl/mpam_devices.c
> +++ b/drivers/resctrl/mpam_devices.c
> @@ -842,8 +842,6 @@ static int mpam_reset_ris(void *arg)
>  	u16 partid, partid_max;
>  	struct mpam_msc_ris *ris = arg;
>  
> -	mpam_assert_srcu_read_lock_held();
> -

Remove where it is introduced. There is already one in
mpam_reset_ris_partid() at that time.

>  	if (ris->in_reset_state)
>  		return 0;

Reviewed-by: Ben Horgan <ben.horgan at arm.com>

Thanks,

Ben