[RFC PATCH 10/36] ACPI / MPAM: Parse the MPAM table

[James Morse]

Hi Ben,

On 24/07/2025 11:50, Ben Horgan wrote:
> On 11/07/2025 19:36, James Morse wrote:
>> Add code to parse the arm64 specific MPAM table, looking up the cache
>> level from the PPTT and feeding the end result into the MPAM driver.

>> diff --git a/drivers/acpi/arm64/mpam.c b/drivers/acpi/arm64/mpam.c
>> new file mode 100644
>> index 000000000000..f4791bac9a2a
>> --- /dev/null
>> +++ b/drivers/acpi/arm64/mpam.c
>> @@ -0,0 +1,365 @@

>> +static int acpi_mpam_parse_resource(struct mpam_msc *msc,
>> +                    struct acpi_mpam_resource_node *res)
>> +{
>> +    int level, nid;
>> +    u32 cache_id;
>> +
>> +    switch (res->locator_type) {
>> +    case ACPI_MPAM_LOCATION_TYPE_PROCESSOR_CACHE:
>> +        cache_id = res->locator.cache_locator.cache_reference;
>> +        level = find_acpi_cache_level_from_id(cache_id);
>> +        if (level < 0) {
>> +            pr_err_once("Bad level (%u) for cache with id %u\n", level, cache_id);
>> +            return -EINVAL;

> Nit: More robust to check for level <= 0.

Sure, that can probably happen!


Thanks,

James