Hi James, On 8/22/25 16:29, James Morse wrote: > The bulk of the MPAM driver lives outside the arch code because it > largely manages MMIO devices that generate interrupts. The driver > needs a Kconfig symbol to enable it, as MPAM is only found on arm64 > platforms, that is where the Kconfig option makes the most sense. > > This Kconfig option will later be used by the arch code to enable > or disable the MPAM context-switch code, and registering the CPUs > properties with the MPAM driver. > > Signed-off-by: James Morse <james.morse@xxxxxxx> > Reviewed-by: Jonathan Cameron <jonathan.cameron@xxxxxxxxxx> > --- > arch/arm64/Kconfig | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index e9bbfacc35a6..658e47fc0c5a 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -2060,6 +2060,23 @@ config ARM64_TLB_RANGE > ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a > range of input addresses. > > +config ARM64_MPAM > + bool "Enable support for MPAM" > + help > + Memory Partitioning and Monitoring is an optional extension > + that allows the CPUs to mark load and store transactions with > + labels for partition-id and performance-monitoring-group. > + System components, such as the caches, can use the partition-id > + to apply a performance policy. MPAM monitors can use the > + partition-id and performance-monitoring-group to measure the > + cache occupancy or data throughput. > + > + Use of this extension requires CPU support, support in the > + memory system components (MSC), and a description from firmware > + of where the MSC are in the address space. > + > + MPAM is exposed to user-space via the resctrl pseudo filesystem. > + > endmenu # "ARMv8.4 architectural features" Should this be moved to "ARMv8.2 architectural features" rather than the 8.4 menu? In the arm reference manual, version L.b, I see FEAT_MPAM listed in the section A2.2.3.1 Features added to the Armv8.2 extension in later releases. > > menu "ARMv8.5 architectural features" Thanks, Ben
