From 67d27727854def4a7e2b386429941f5c4741ccc4 Mon Sep 17 00:00:00 2001 From: Sandipan Das Date: Mon, 1 Jun 2026 17:43:05 +0530 Subject: [PATCH] perf/x86/amd/uncore: Use Node ID to identify DF and UMC domains For DF and UMC PMUs, a single context is shared across all CPUs that are connected to the same Data Fabric (DF) instance. Currently, the Package ID, which also happens to be the Socket ID, is used to identify DF instances. This approach works for configurations having a single IO Die (IOD) but fails in the following cases. * Older Zen 1 processors, where each chiplet has its own DF instance. * Any configurations with multiple DF instances or multiple IODs in the same package. The correct way to identify DF instances is through the Node ID (not to be confused with NUMA Node ID). This is available in ECX[7:0] of CPUID leaf 0x8000001e and returned via topology_amd_node_id(). Hence, replace usage of topology_logical_package_id() with topology_amd_node_id(). Fixes: 07888daa056e ("perf/x86/amd/uncore: Move discovery and registration") Signed-off-by: Sandipan Das Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/e7a71a727c6a7b118c23d3e469929c538c4665aa.1780315832.git.sandipan.das@amd.com --- arch/x86/events/amd/uncore.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/events/amd/uncore.c b/arch/x86/events/amd/uncore.c index dd956cfcadef..a0364ca2f917 100644 --- a/arch/x86/events/amd/uncore.c +++ b/arch/x86/events/amd/uncore.c @@ -700,7 +700,7 @@ void amd_uncore_df_ctx_scan(struct amd_uncore *uncore, unsigned int cpu) info.split.aux_data = 0; info.split.num_pmcs = NUM_COUNTERS_NB; info.split.gid = 0; - info.split.cid = topology_logical_package_id(cpu); + info.split.cid = topology_amd_node_id(cpu); if (pmu_version >= 2) { ebx.full = cpuid_ebx(EXT_PERFMON_DEBUG_FEATURES); @@ -999,8 +999,8 @@ void amd_uncore_umc_ctx_scan(struct amd_uncore *uncore, unsigned int cpu) cpuid(EXT_PERFMON_DEBUG_FEATURES, &eax, &ebx.full, &ecx, &edx); info.split.aux_data = ecx; /* stash active mask */ info.split.num_pmcs = ebx.split.num_umc_pmc; - info.split.gid = topology_logical_package_id(cpu); - info.split.cid = topology_logical_package_id(cpu); + info.split.gid = topology_amd_node_id(cpu); + info.split.cid = topology_amd_node_id(cpu); *per_cpu_ptr(uncore->info, cpu) = info; }