linux-kernel - [PATCH v5 2/4] arch_topology: Support SMT control for OF based system

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Message-ID: <20240806085320.63514-3-yangyicong@huawei.com>
Date: Tue, 6 Aug 2024 16:53:18 +0800
From: Yicong Yang <yangyicong@...wei.com>
To: <catalin.marinas@....com>, <will@...nel.org>, <sudeep.holla@....com>,
	<tglx@...utronix.de>, <peterz@...radead.org>, <mpe@...erman.id.au>,
	<linux-arm-kernel@...ts.infradead.org>, <mingo@...hat.com>, <bp@...en8.de>,
	<dave.hansen@...ux.intel.com>
CC: <linuxppc-dev@...ts.ozlabs.org>, <x86@...nel.org>,
	<linux-kernel@...r.kernel.org>, <dietmar.eggemann@....com>,
	<gregkh@...uxfoundation.org>, <rafael@...nel.org>,
	<jonathan.cameron@...wei.com>, <prime.zeng@...ilicon.com>,
	<linuxarm@...wei.com>, <yangyicong@...ilicon.com>, <xuwei5@...wei.com>,
	<guohanjun@...wei.com>
Subject: [PATCH v5 2/4] arch_topology: Support SMT control for OF based system

From: Yicong Yang <yangyicong@...ilicon.com>

On building the topology from the devicetree, we've already
gotten the SMT thread number of each core. Update the largest
SMT thread number to enable the SMT control.

Signed-off-by: Yicong Yang <yangyicong@...ilicon.com>
---
 drivers/base/arch_topology.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 75fcb75d5515..95513abd664f 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -11,6 +11,7 @@
 #include <linux/cleanup.h>
 #include <linux/cpu.h>
 #include <linux/cpufreq.h>
+#include <linux/cpu_smt.h>
 #include <linux/device.h>
 #include <linux/of.h>
 #include <linux/slab.h>
@@ -531,6 +532,16 @@ static int __init get_cpu_for_node(struct device_node *node)
 	return cpu;
 }
 
+static void __init update_smt_num_threads(unsigned int num_threads)
+{
+	static unsigned int max_smt_thread_num = 1;
+
+	if (num_threads > max_smt_thread_num) {
+		max_smt_thread_num = num_threads;
+		cpu_smt_set_num_threads(max_smt_thread_num, max_smt_thread_num);
+	}
+}
+
 static int __init parse_core(struct device_node *core, int package_id,
 			     int cluster_id, int core_id)
 {
@@ -561,6 +572,8 @@ static int __init parse_core(struct device_node *core, int package_id,
 		i++;
 	} while (1);
 
+	update_smt_num_threads(i);
+
 	cpu = get_cpu_for_node(core);
 	if (cpu >= 0) {
 		if (!leaf) {
-- 
2.24.0