linux-kernel - [patch 52/53] x86/cpu/topology: Provide __num_[cores|threads]_per

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Date:   Mon,  7 Aug 2023 15:53:55 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, Tom Lendacky <thomas.lendacky@....com>,
        Andrew Cooper <andrew.cooper3@...rix.com>,
        Arjan van de Ven <arjan@...ux.intel.com>,
        Huang Rui <ray.huang@....com>, Juergen Gross <jgross@...e.com>,
        Dimitri Sivanich <dimitri.sivanich@....com>,
        Michael Kelley <mikelley@...rosoft.com>,
        Sohil Mehta <sohil.mehta@...el.com>,
        K Prateek Nayak <kprateek.nayak@....com>,
        Kan Liang <kan.liang@...ux.intel.com>,
        Zhang Rui <rui.zhang@...el.com>,
        "Paul E. McKenney" <paulmck@...nel.org>,
        Feng Tang <feng.tang@...el.com>,
        Andy Shevchenko <andy@...radead.org>
Subject: [patch 52/53] x86/cpu/topology: Provide
 __num_[cores|threads]_per_package

Expose properly accounted information and accessors so the fiddling with
other topology variables can be replaced.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
 arch/x86/include/asm/topology.h |   12 ++++++++++++
 arch/x86/kernel/cpu/common.c    |    6 ++++++
 arch/x86/kernel/cpu/topology.c  |    8 +++++++-
 3 files changed, 25 insertions(+), 1 deletion(-)

--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -146,6 +146,8 @@ extern const struct cpumask *cpu_cluster
 extern unsigned int __max_dies_per_package;
 extern unsigned int __max_logical_packages;
 extern unsigned int __max_threads_per_core;
+extern unsigned int __num_threads_per_package;
+extern unsigned int __num_cores_per_package;
 
 static inline unsigned int topology_max_packages(void)
 {
@@ -157,6 +159,16 @@ static inline unsigned int topology_max_
 	return __max_dies_per_package;
 }
 
+static inline unsigned int topology_num_cores_per_package(void)
+{
+	return __num_cores_per_package;
+}
+
+static inline unsigned int topology_num_threads_per_package(void)
+{
+	return __num_threads_per_package;
+}
+
 int topology_get_logical_id(u32 apicid, enum x86_topology_domains at_level);
 
 static inline int topology_phys_to_logical_pkg(unsigned int pkg)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -81,6 +81,12 @@ EXPORT_SYMBOL(__max_dies_per_package);
 unsigned int __max_logical_packages __ro_after_init = 1;
 EXPORT_SYMBOL(__max_logical_packages);
 
+unsigned int __num_cores_per_package __ro_after_init = 1;
+EXPORT_SYMBOL(__num_cores_per_package);
+
+unsigned int __num_threads_per_package __ro_after_init = 1;
+EXPORT_SYMBOL(__num_threads_per_package);
+
 static struct ppin_info {
 	int	feature;
 	int	msr_ppin_ctl;
--- a/arch/x86/kernel/cpu/topology.c
+++ b/arch/x86/kernel/cpu/topology.c
@@ -391,7 +391,7 @@ void __init topology_init_possible_cpus(
 	unsigned int disabled = topo_info.nr_disabled_cpus;
 	unsigned int cnta, cntb, cpu, dom, allowed = 1;
 	unsigned int total = assigned + disabled;
-	u32 apicid;
+	u32 apicid, firstid;
 
 	if (!restrict_to_up()) {
 		if (total > 1)
@@ -430,6 +430,12 @@ void __init topology_init_possible_cpus(
 	__max_threads_per_core = 1U << (get_count_order(cntb) - get_count_order(cnta));
 	pr_info("Max. threads per core: %3u\n", __max_threads_per_core);
 
+	firstid = find_first_bit(apic_maps[TOPO_SMT_DOMAIN].map, MAX_LOCAL_APIC);
+	__num_cores_per_package = topology_unit_count(firstid, TOPO_CORE_DOMAIN, TOPO_PKG_DOMAIN);
+	pr_info("Num. cores per package:   %3u\n", __num_cores_per_package);
+	__num_threads_per_package = topology_unit_count(firstid, TOPO_SMT_DOMAIN, TOPO_PKG_DOMAIN);
+	pr_info("Num. threads per package: %3u\n", __num_threads_per_package);
+
 	pr_info("Allowing %u present CPUs plus %u hotplug CPUs\n", assigned, disabled);
 	if (topo_info.nr_rejected_cpus)
 		pr_info("Rejected CPUs %u\n", topo_info.nr_rejected_cpus);