From: Saurabh Sengar <ssengar@linux.microsoft.com>
Date: Tue, 2 Apr 2024 14:40:29 +0000 (-0700)
Subject: x86/of: Map NUMA node to CPUs as per DeviceTree
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=85900d061884de85f557a06cf56ff69dfae07e26;p=linux.git

x86/of: Map NUMA node to CPUs as per DeviceTree

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

  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

Call the set_apicid_to_node() function in dtb_cpu_setup() for setting
the NUMA to CPU mapping for DeviceTree platforms.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/1712068830-4513-4-git-send-email-ssengar@linux.microsoft.com
---

diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index 0d3a50e8395dd..b93ce8a39ff7b 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));
 	}
 }