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authorPeter Zijlstra <peterz@infradead.org>2026-03-03 11:55:40 +0100
committerPeter Zijlstra <peterz@infradead.org>2026-03-04 16:35:08 +0100
commit48084cc153a5b0fbf0aa98d47670d3be0b9f64d5 (patch)
tree53b2acb68b712aa3c003d40f93eea1f7b77bd0c4 /arch
parent3d1973a0c76a78a4728cff13648a188ed486cf44 (diff)
x86/numa: Store extra copy of numa_nodes_parsed
The topology setup code needs to know the total number of physical nodes enumerated in SRAT; however NUMA_EMU can cause the existing numa_nodes_parsed bitmap to be fictitious. Therefore, keep a copy of the bitmap specifically to retain the physical node count. Suggested-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ingo Molnar <mingo@kernel.org> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Tested-by: Zhang Rui <rui.zhang@intel.com> Tested-by: Chen Yu <yu.c.chen@intel.com> Tested-by: Kyle Meyer <kyle.meyer@hpe.com> Link: https://patch.msgid.link/20260303110059.889884023@infradead.org
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/numa.h6
-rw-r--r--arch/x86/mm/numa.c8
-rw-r--r--arch/x86/mm/srat.c2
3 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/include/asm/numa.h b/arch/x86/include/asm/numa.h
index 53ba39ce010c..a9063f332fa6 100644
--- a/arch/x86/include/asm/numa.h
+++ b/arch/x86/include/asm/numa.h
@@ -22,6 +22,7 @@ extern int numa_off;
*/
extern s16 __apicid_to_node[MAX_LOCAL_APIC];
extern nodemask_t numa_nodes_parsed __initdata;
+extern nodemask_t numa_phys_nodes_parsed __initdata;
static inline void set_apicid_to_node(int apicid, s16 node)
{
@@ -48,6 +49,7 @@ extern void __init init_cpu_to_node(void);
extern void numa_add_cpu(unsigned int cpu);
extern void numa_remove_cpu(unsigned int cpu);
extern void init_gi_nodes(void);
+extern int num_phys_nodes(void);
#else /* CONFIG_NUMA */
static inline void numa_set_node(int cpu, int node) { }
static inline void numa_clear_node(int cpu) { }
@@ -55,6 +57,10 @@ static inline void init_cpu_to_node(void) { }
static inline void numa_add_cpu(unsigned int cpu) { }
static inline void numa_remove_cpu(unsigned int cpu) { }
static inline void init_gi_nodes(void) { }
+static inline int num_phys_nodes(void)
+{
+ return 1;
+}
#endif /* CONFIG_NUMA */
#ifdef CONFIG_DEBUG_PER_CPU_MAPS
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 7a97327140df..99d0a9332c14 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -48,6 +48,8 @@ s16 __apicid_to_node[MAX_LOCAL_APIC] = {
[0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
};
+nodemask_t numa_phys_nodes_parsed __initdata;
+
int numa_cpu_node(int cpu)
{
u32 apicid = early_per_cpu(x86_cpu_to_apicid, cpu);
@@ -57,6 +59,11 @@ int numa_cpu_node(int cpu)
return NUMA_NO_NODE;
}
+int __init num_phys_nodes(void)
+{
+ return bitmap_weight(numa_phys_nodes_parsed.bits, MAX_NUMNODES);
+}
+
cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
EXPORT_SYMBOL(node_to_cpumask_map);
@@ -210,6 +217,7 @@ static int __init dummy_numa_init(void)
0LLU, PFN_PHYS(max_pfn) - 1);
node_set(0, numa_nodes_parsed);
+ node_set(0, numa_phys_nodes_parsed);
numa_add_memblk(0, 0, PFN_PHYS(max_pfn));
return 0;
diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c
index 6f8e0f21c710..44ca66651756 100644
--- a/arch/x86/mm/srat.c
+++ b/arch/x86/mm/srat.c
@@ -57,6 +57,7 @@ acpi_numa_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa)
}
set_apicid_to_node(apic_id, node);
node_set(node, numa_nodes_parsed);
+ node_set(node, numa_phys_nodes_parsed);
pr_debug("SRAT: PXM %u -> APIC 0x%04x -> Node %u\n", pxm, apic_id, node);
}
@@ -97,6 +98,7 @@ acpi_numa_processor_affinity_init(struct acpi_srat_cpu_affinity *pa)
set_apicid_to_node(apic_id, node);
node_set(node, numa_nodes_parsed);
+ node_set(node, numa_phys_nodes_parsed);
pr_debug("SRAT: PXM %u -> APIC 0x%02x -> Node %u\n", pxm, apic_id, node);
}