There is need to use the cache sharing information quite early during the boot before the secondary cores are up and running. The permanent memory map for all the ACPI tables(via acpi_permanent_mmap) is turned on in acpi_early_init() which is quite late for the above requirement. As a result there is possibility that the ACPI PPTT gets mapped to different virtual addresses. In such scenarios, using virtual address as fw_token before the acpi_permanent_mmap is enabled results in different fw_token for the same cache entity and hence wrong cache sharing information will be deduced based on the same. Instead of using virtual address, just use the table offset as the unique firmware token for the caches. The same offset is used as ACPI identifiers if the firmware has not set a valid one for other entries in the ACPI PPTT. Link: https://lore.kernel.org/r/20220621192034.3332546-2-sudeep.holla@xxxxxxx Cc: linux-acpi@xxxxxxxxxxxxxxx Tested-by: Ionela Voinescu <ionela.voinescu@xxxxxxx> Acked-by: Rafael J. Wysocki <rafael@xxxxxxxxxx> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx> --- drivers/acpi/pptt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index 701f61c01359..763f021d45e6 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -437,7 +437,8 @@ static void cache_setup_acpi_cpu(struct acpi_table_header *table, pr_debug("found = %p %p\n", found_cache, cpu_node); if (found_cache) update_cache_properties(this_leaf, found_cache, - cpu_node, table->revision); + ACPI_TO_POINTER(ACPI_PTR_DIFF(cpu_node, table)), + table->revision); index++; } -- 2.36.1
