Hi Ben,
On 29/08/2025 13:41, Ben Horgan wrote:
> On 8/22/25 16:30, James Morse wrote:
>> An MSC is a container of resources, each identified by their RIS index.
>> Some RIS are described by firmware to provide their position in the system.
>> Others are discovered when the driver probes the hardware.
>>
>> To configure a resource it needs to be found by its class, e.g. 'L2'.
>> There are two kinds of grouping, a class is a set of components, which
>> are visible to user-space as there are likely to be multiple instances
>> of the L2 cache. (e.g. one per cluster or package)
>>
>> struct mpam_components are a set of struct mpam_vmsc. A vMSC groups the
>> RIS in an MSC that control the same logical piece of hardware. (e.g. L2).
>> This is to allow hardware implementations where two controls are presented
>> as different RIS. Re-combining these RIS allows their feature bits to
>> be or-ed. This structure is not visible outside mpam_devices.c
>>
>> struct mpam_vmsc are then a set of struct mpam_msc_ris, which are not
>> visible as each L2 cache may be composed of individual slices which need
>> to be configured the same as the hardware is not able to distribute the
>> configuration.
>>
>> Add support for creating and destroying these structures.
>>
>> A gfp is passed as the structures may need creating when a new RIS entry
>> is discovered when probing the MSC.
>> diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
>> index 71a1fb1a9c75..5baf2a8786fb 100644
>> --- a/drivers/resctrl/mpam_devices.c
>> +++ b/drivers/resctrl/mpam_devices.c
>> @@ -179,7 +650,10 @@ static int update_msc_accessibility(struct mpam_msc *msc)
>> cpumask_copy(&msc->accessibility, cpu_possible_mask);
>> err = 0;
>> } else {
>> - if (of_device_is_compatible(parent, "memory")) {
>> + if (of_device_is_compatible(parent, "cache")) {
>> + err = get_cpumask_from_cache(parent,
>> + &msc->accessibility);
>> + } else if (of_device_is_compatible(parent, "memory")) {
> The determination of the accessibility for the h/w msc doesn't fit with
> the subject of this patch. Could this hunk and the supporting functions
> be split into a precursor patch?
I've moved this bit into the previous patches.
Thanks,
James
