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From: Saurabh Sengar <ssengar@linux.microsoft.com>
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Cc: ssengar@microsoft.com
Subject: [PATCH v2 3/4] x86/of: Map NUMA node to CPUs as per DeviceTree
Date: Tue,  2 Apr 2024 07:40:29 -0700
Message-Id: <1712068830-4513-4-git-send-email-ssengar@linux.microsoft.com>
In-Reply-To: <1712068830-4513-1-git-send-email-ssengar@linux.microsoft.com>
References: <1712068830-4513-1-git-send-email-ssengar@linux.microsoft.com>
Precedence: bulk

Currently for DeviceTree bootup, x86 code does the default mapping of
CPUs to NUMA, which is wrong. This can cause incorrect mapping and WARN
on a SMT enabled systems like below:

CPU #1's smt-sibling CPU #0 is not on the same node! [node: 1 != 0]. Ignoring dependency.
WARNING: CPU: 1 PID: 0 at topology_sane.isra.0+0x5c/0x6d
match_smt+0xf6/0xfc
set_cpu_sibling_map.cold+0x24f/0x512
start_secondary+0x5c/0x110

Add the set_apicid_to_node() function in dtb_cpu_setup() for allowing
the NUMA to CPU mapping for DeviceTree platforms.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
---
 arch/x86/kernel/devicetree.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index 0d3a50e8395d..b93ce8a39ff7 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -24,6 +24,7 @@
 #include <asm/pci_x86.h>
 #include <asm/setup.h>
 #include <asm/i8259.h>
+#include <asm/numa.h>
 #include <asm/prom.h>
 
 __initdata u64 initial_dtb;
@@ -137,6 +138,7 @@ static void __init dtb_cpu_setup(void)
 			continue;
 		}
 		topology_register_apic(apic_id, CPU_ACPIID_INVALID, true);
+		set_apicid_to_node(apic_id, of_node_to_nid(dn));
 	}
 }
 
-- 
2.34.1