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linux/debian/patches/patchset-pf/amd-pstate/0022-x86-amd-Use-heterogeneous-core-topology-for-identify.patch

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From ab9618cbe5e3d55b09b59f5e18e890be80ca1076 Mon Sep 17 00:00:00 2001
From: Mario Limonciello <mario.limonciello@amd.com>
Date: Fri, 25 Oct 2024 12:14:59 -0500
Subject: x86/amd: Use heterogeneous core topology for identifying boost
numerator
AMD heterogeneous designs include two types of cores:
* Performance
* Efficiency
Each core type has different highest performance values configured by the
platform. Drivers such as `amd_pstate` need to identify the type of
core to correctly set an appropriate boost numerator to calculate the
maximum frequency.
X86_FEATURE_AMD_HETEROGENEOUS_CORES is used to identify whether the SoC
supports heterogeneous core type by reading CPUID leaf Fn_0x80000026.
On performance cores the scaling factor of 196 is used. On efficiency
cores the scaling factor is the value reported as the highest perf.
Efficiency cores have the same preferred core rankings.
Tested-by: Eric Naim <dnaim@cachyos.org>
Tested-by: Peter Jung <ptr1337@cachyos.org>
Suggested-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
arch/x86/kernel/acpi/cppc.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
--- a/arch/x86/kernel/acpi/cppc.c
+++ b/arch/x86/kernel/acpi/cppc.c
@@ -239,8 +239,10 @@ EXPORT_SYMBOL_GPL(amd_detect_prefcore);
*/
int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator)
{
+ enum x86_topology_cpu_type core_type = get_topology_cpu_type(&cpu_data(cpu));
bool prefcore;
int ret;
+ u32 tmp;
ret = amd_detect_prefcore(&prefcore);
if (ret)
@@ -266,6 +268,27 @@ int amd_get_boost_ratio_numerator(unsign
break;
}
}
+
+ /* detect if running on heterogeneous design */
+ if (cpu_feature_enabled(X86_FEATURE_AMD_HETEROGENEOUS_CORES)) {
+ switch (core_type) {
+ case TOPO_CPU_TYPE_UNKNOWN:
+ pr_warn("Undefined core type found for cpu %d\n", cpu);
+ break;
+ case TOPO_CPU_TYPE_PERFORMANCE:
+ /* use the max scale for performance cores */
+ *numerator = CPPC_HIGHEST_PERF_PERFORMANCE;
+ return 0;
+ case TOPO_CPU_TYPE_EFFICIENCY:
+ /* use the highest perf value for efficiency cores */
+ ret = amd_get_highest_perf(cpu, &tmp);
+ if (ret)
+ return ret;
+ *numerator = tmp;
+ return 0;
+ }
+ }
+
*numerator = CPPC_HIGHEST_PERF_PREFCORE;
return 0;