This is a note to let you know that I've just added the patch titled
thermal: intel: hfi: Give HFI instances package scope
to the 6.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
thermal-intel-hfi-give-hfi-instances-package-scope.patch
and it can be found in the queue-6.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2ec2adabc97a9bdb14c023d44ce6706c8265be4e
Author: Zhang Rui <rui.zhang@xxxxxxxxx>
Date: Wed Jul 3 13:54:45 2024 +0800
thermal: intel: hfi: Give HFI instances package scope
[ 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@xxxxxxxxx>
Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
Reviewed-by: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx>
Link: https://patch.msgid.link/20240703055445.125362-1-rui.zhang@xxxxxxxxx
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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
