Commit b7553676 authored by Zhang Rui's avatar Zhang Rui Committed by Rafael J. Wysocki
Browse files

thermal: intel: hfi: Give HFI instances package scope 



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: default avatarChen Yu <yu.c.chen@intel.com>
Signed-off-by: default avatarChen Yu <yu.c.chen@intel.com>
Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
Reviewed-by: default avatarRicardo 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: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 55397323

drivers/thermal/intel/intel_hfi.c

+17 −13
Original line number Diff line number Diff line
@@ -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