Re: [PATCH v6 32/40] arm_mpam: resctrl: Add empty definitions for assorted resctrl functions
From: Gavin Shan
Date: Mon Mar 23 2026 - 23:44:20 EST
On 3/14/26 12:46 AM, Ben Horgan wrote:
From: James Morse <james.morse@xxxxxxx>Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
A few resctrl features and hooks need to be provided, but aren't needed or
supported on MPAM platforms.
resctrl has individual hooks to separately enable and disable the
closid/partid and rmid/pmg context switching code. For MPAM this is all the
same thing, as the value in struct task_struct is used to cache the value
that should be written to hardware. arm64's context switching code is
enabled once MPAM is usable, but doesn't touch the hardware unless the
value has changed.
For now event configuration is not supported, and can be turned off by
returning 'false' from resctrl_arch_is_evt_configurable().
The new io_alloc feature is not supported either, always return false from
the enable helper to indicate and fail the enable.
Add this, and empty definitions for the other hooks.
Tested-by: Gavin Shan <gshan@xxxxxxxxxx>
Tested-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
Tested-by: Peter Newman <peternewman@xxxxxxxxxx>
Tested-by: Zeng Heng <zengheng4@xxxxxxxxxx>
Tested-by: Punit Agrawal <punit.agrawal@xxxxxxxxxxxxxxxx>
Reviewed-by: Zeng Heng <zengheng4@xxxxxxxxxx>
Reviewed-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
Reviewed-by: Jonathan Cameron <jonathan.cameron@xxxxxxxxxx>
Signed-off-by: James Morse <james.morse@xxxxxxx>
Signed-off-by: Ben Horgan <ben.horgan@xxxxxxx>
---
Changes since v3:
Add resctrl_arch_pre_mount() {}
resctrl_arch_reset_rmid_all() signature update
add stubs for abmc
keep empty definitions together
Changes since v5:
Add resctrl_arch_reset_rmid() since mbwu will always use abmc
---
drivers/resctrl/mpam_resctrl.c | 65 ++++++++++++++++++++++++++++++++++
include/linux/arm_mpam.h | 9 +++++
2 files changed, 74 insertions(+)