From: Mete Durlu <meted@linux.ibm.com>
Date: Wed, 8 Jan 2025 10:31:27 +0000 (+0100)
Subject: s390/topology: Improve topology detection
X-Git-Tag: v6.14-rc1~200^2~10
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9988df07dbe1ca8282f5ae95f1b534f91bab73fc;p=thirdparty%2Fkernel%2Flinux.git

s390/topology: Improve topology detection

Add early polarization detection instead of assuming horizontal
polarization.

Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
---

diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index 4f9c301a705b6..39f5ed21f31a6 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -556,6 +556,16 @@ static void __init alloc_masks(struct sysinfo_15_1_x *info,
 	}
 }
 
+static int __init detect_polarization(union topology_entry *tle)
+{
+	struct topology_core *tl_core;
+
+	while (tle->nl)
+		tle = next_tle(tle);
+	tl_core = (struct topology_core *)tle;
+	return tl_core->pp != POLARIZATION_HRZ;
+}
+
 void __init topology_init_early(void)
 {
 	struct sysinfo_15_1_x *info;
@@ -575,6 +585,7 @@ void __init topology_init_early(void)
 		      __func__, PAGE_SIZE, PAGE_SIZE);
 	info = tl_info;
 	store_topology(info);
+	cpu_management = detect_polarization(info->tle);
 	pr_info("The CPU configuration topology of the machine is: %d %d %d %d %d %d / %d\n",
 		info->mag[0], info->mag[1], info->mag[2], info->mag[3],
 		info->mag[4], info->mag[5], info->mnest);