From: Zhang Rui rui.zhang@intel.com
[ Upstream commit b755367602d70deade956cbe0b8a3f5a12f569dc ]
The Intel Software Developer's Manual defines the scope of HFI (registers and memory buffer) as a package. Use package scope(*) in the software representation of an HFI instance.
Using die scope in HFI instances has the effect of creating multiple conflicting instances for the same package: each instance allocates its own memory buffer and configures the same package-level registers. Specifically, only one of the allocated memory buffers can be set in the MSR_IA32_HW_FEEDBACK_PTR register. CPUs get incorrect HFI data from the table.
The problem does not affect current HFI-capable platforms because they all have single-die processors.
(*) We used die scope for HFI instances because there had been processors with packages enumerated as dies. None of those systems supported HFI, though. If such a system emerged, it would need to be quirked.
Co-developed-by: Chen Yu yu.c.chen@intel.com Signed-off-by: Chen Yu yu.c.chen@intel.com Signed-off-by: Zhang Rui rui.zhang@intel.com Reviewed-by: Ricardo Neri ricardo.neri-calderon@linux.intel.com Link: https://patch.msgid.link/20240703055445.125362-1-rui.zhang@intel.com [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/thermal/intel/intel_hfi.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-)
diff --git a/drivers/thermal/intel/intel_hfi.c b/drivers/thermal/intel/intel_hfi.c index a180a98bb9f15..5b18a46a10b06 100644 --- a/drivers/thermal/intel/intel_hfi.c +++ b/drivers/thermal/intel/intel_hfi.c @@ -401,10 +401,10 @@ static void hfi_disable(void) * intel_hfi_online() - Enable HFI on @cpu * @cpu: CPU in which the HFI will be enabled * - * Enable the HFI to be used in @cpu. The HFI is enabled at the die/package - * level. The first CPU in the die/package to come online does the full HFI + * Enable the HFI to be used in @cpu. The HFI is enabled at the package + * level. The first CPU in the package to come online does the full HFI * initialization. Subsequent CPUs will just link themselves to the HFI - * instance of their die/package. + * instance of their package. * * This function is called before enabling the thermal vector in the local APIC * in order to ensure that @cpu has an associated HFI instance when it receives @@ -414,31 +414,31 @@ void intel_hfi_online(unsigned int cpu) { struct hfi_instance *hfi_instance; struct hfi_cpu_info *info; - u16 die_id; + u16 pkg_id;
/* Nothing to do if hfi_instances are missing. */ if (!hfi_instances) return;
/* - * Link @cpu to the HFI instance of its package/die. It does not + * Link @cpu to the HFI instance of its package. It does not * matter whether the instance has been initialized. */ info = &per_cpu(hfi_cpu_info, cpu); - die_id = topology_logical_die_id(cpu); + pkg_id = topology_logical_package_id(cpu); hfi_instance = info->hfi_instance; if (!hfi_instance) { - if (die_id >= max_hfi_instances) + if (pkg_id >= max_hfi_instances) return;
- hfi_instance = &hfi_instances[die_id]; + hfi_instance = &hfi_instances[pkg_id]; info->hfi_instance = hfi_instance; }
init_hfi_cpu_index(info);
/* - * Now check if the HFI instance of the package/die of @cpu has been + * Now check if the HFI instance of the package of @cpu has been * initialized (by checking its header). In such case, all we have to * do is to add @cpu to this instance's cpumask and enable the instance * if needed. @@ -504,7 +504,7 @@ void intel_hfi_online(unsigned int cpu) * * On some processors, hardware remembers previous programming settings even * after being reprogrammed. Thus, keep HFI enabled even if all CPUs in the - * die/package of @cpu are offline. See note in intel_hfi_online(). + * package of @cpu are offline. See note in intel_hfi_online(). */ void intel_hfi_offline(unsigned int cpu) { @@ -674,9 +674,13 @@ void __init intel_hfi_init(void) if (hfi_parse_features()) return;
- /* There is one HFI instance per die/package. */ - max_hfi_instances = topology_max_packages() * - topology_max_dies_per_package(); + /* + * Note: HFI resources are managed at the physical package scope. + * There could be platforms that enumerate packages as Linux dies. + * Special handling would be needed if this happens on an HFI-capable + * platform. + */ + max_hfi_instances = topology_max_packages();
/* * This allocation may fail. CPU hotplug callbacks must check