From 5754ace3c3199c162dcee1f3f87a538c46d1c832 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 8 May 2024 21:53:47 +0200 Subject: [PATCH] x86/topology/amd: Ensure that LLC ID is initialized The original topology evaluation code initialized cpu_data::topo::llc_id with the die ID initialy and then eventually overwrite it with information gathered from a CPUID leaf. The conversion analysis failed to spot that particular detail and omitted this initial assignment under the assumption that each topology evaluation path will set it up. That assumption is mostly correct, but turns out to be wrong in case that the CPUID leaf 0x80000006 does not provide a LLC ID. In that case, LLC ID is invalid and as a consequence the setup of the scheduling domain CPU masks is incorrect which subsequently causes the scheduler core to complain about it during CPU hotplug: BUG: arch topology borken the CLS domain not a subset of the MC domain Cure it by reusing legacy_set_llc() and assigning the die ID if the LLC ID is invalid after all possible parsers have been tried. Fixes: f7fb3b2dd92c ("x86/cpu: Provide an AMD/HYGON specific topology parser") Reported-by: Yuezhang Mo Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov (AMD) Tested-by: Yuezhang Mo Link: https://lore.kernel.org/r/PUZPR04MB63168AC442C12627E827368581292@PUZPR04MB6316.apcprd04.prod.outlook.com --- arch/x86/kernel/cpu/topology_amd.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/cpu/topology_amd.c b/arch/x86/kernel/cpu/topology_amd.c index a7aa6eff4ae5..ce2d507c3b07 100644 --- a/arch/x86/kernel/cpu/topology_amd.c +++ b/arch/x86/kernel/cpu/topology_amd.c @@ -119,7 +119,7 @@ static bool parse_8000_001e(struct topo_scan *tscan, bool has_0xb) return true; } -static bool parse_fam10h_node_id(struct topo_scan *tscan) +static void parse_fam10h_node_id(struct topo_scan *tscan) { union { struct { @@ -131,20 +131,20 @@ static bool parse_fam10h_node_id(struct topo_scan *tscan) } nid; if (!boot_cpu_has(X86_FEATURE_NODEID_MSR)) - return false; + return; rdmsrl(MSR_FAM10H_NODE_ID, nid.msr); store_node(tscan, nid.nodes_per_pkg + 1, nid.node_id); tscan->c->topo.llc_id = nid.node_id; - return true; } static void legacy_set_llc(struct topo_scan *tscan) { unsigned int apicid = tscan->c->topo.initial_apicid; - /* parse_8000_0008() set everything up except llc_id */ - tscan->c->topo.llc_id = apicid >> tscan->dom_shifts[TOPO_CORE_DOMAIN]; + /* If none of the parsers set LLC ID then use the die ID for it. */ + if (tscan->c->topo.llc_id == BAD_APICID) + tscan->c->topo.llc_id = apicid >> tscan->dom_shifts[TOPO_CORE_DOMAIN]; } static void topoext_fixup(struct topo_scan *tscan) @@ -187,10 +187,7 @@ static void parse_topology_amd(struct topo_scan *tscan) return; /* Try the NODEID MSR */ - if (parse_fam10h_node_id(tscan)) - return; - - legacy_set_llc(tscan); + parse_fam10h_node_id(tscan); } void cpu_parse_topology_amd(struct topo_scan *tscan) @@ -198,6 +195,7 @@ void cpu_parse_topology_amd(struct topo_scan *tscan) tscan->amd_nodes_per_pkg = 1; topoext_fixup(tscan); parse_topology_amd(tscan); + legacy_set_llc(tscan); if (tscan->amd_nodes_per_pkg > 1) set_cpu_cap(tscan->c, X86_FEATURE_AMD_DCM);