4.18-stable review patch. If anyone has any objections, please let me know.
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From: Jeffrey Hugo jhugo@codeaurora.org
[ Upstream commit 59bbff3775c0951300f7b41345a54b999438f8d0 ]
The type of a cache might not be specified by architectural mechanisms (ie system registers), but its type might be specified in the PPTT. In this case, we should populate the type of the cache, rather than leave it undefined.
This fixes the issue where the cacheinfo driver will not populate sysfs for such caches, resulting in the information missing from utilities like lstopo and lscpu, thus degrading the user experience.
Fixes: 2bd00bcd73e5 (ACPI/PPTT: Add Processor Properties Topology Table parsing) Reported-by: Vijaya Kumar K vkilari@codeaurora.org Signed-off-by: Jeffrey Hugo jhugo@codeaurora.org Reviewed-by: Sudeep Holla sudeep.holla@arm.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/acpi/pptt.c | 33 +++++++++++++-------------------- 1 file changed, 13 insertions(+), 20 deletions(-)
--- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -338,9 +338,6 @@ static struct acpi_pptt_cache *acpi_find return found; }
-/* total number of attributes checked by the properties code */ -#define PPTT_CHECKED_ATTRIBUTES 4 - /** * update_cache_properties() - Update cacheinfo for the given processor * @this_leaf: Kernel cache info structure being updated @@ -357,25 +354,15 @@ static void update_cache_properties(stru struct acpi_pptt_cache *found_cache, struct acpi_pptt_processor *cpu_node) { - int valid_flags = 0; - this_leaf->fw_token = cpu_node; - if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID) { + if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID) this_leaf->size = found_cache->size; - valid_flags++; - } - if (found_cache->flags & ACPI_PPTT_LINE_SIZE_VALID) { + if (found_cache->flags & ACPI_PPTT_LINE_SIZE_VALID) this_leaf->coherency_line_size = found_cache->line_size; - valid_flags++; - } - if (found_cache->flags & ACPI_PPTT_NUMBER_OF_SETS_VALID) { + if (found_cache->flags & ACPI_PPTT_NUMBER_OF_SETS_VALID) this_leaf->number_of_sets = found_cache->number_of_sets; - valid_flags++; - } - if (found_cache->flags & ACPI_PPTT_ASSOCIATIVITY_VALID) { + if (found_cache->flags & ACPI_PPTT_ASSOCIATIVITY_VALID) this_leaf->ways_of_associativity = found_cache->associativity; - valid_flags++; - } if (found_cache->flags & ACPI_PPTT_WRITE_POLICY_VALID) { switch (found_cache->attributes & ACPI_PPTT_MASK_WRITE_POLICY) { case ACPI_PPTT_CACHE_POLICY_WT: @@ -402,11 +389,17 @@ static void update_cache_properties(stru } } /* - * If the above flags are valid, and the cache type is NOCACHE - * update the cache type as well. + * If cache type is NOCACHE, then the cache hasn't been specified + * via other mechanisms. Update the type if a cache type has been + * provided. + * + * Note, we assume such caches are unified based on conventional system + * design and known examples. Significant work is required elsewhere to + * fully support data/instruction only type caches which are only + * specified in PPTT. */ if (this_leaf->type == CACHE_TYPE_NOCACHE && - valid_flags == PPTT_CHECKED_ATTRIBUTES) + found_cache->flags & ACPI_PPTT_CACHE_TYPE_VALID) this_leaf->type = CACHE_TYPE_UNIFIED; }