x86/numa_emu: split __apicid_to_node update to a helper function

This is required to make numa emulation code architecture independent so
that it can be moved to generic code in following commits.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
Tested-by: Zi Yan <[email protected]> # for x86_64 and arm64
Tested-by: Jonathan Cameron <[email protected]> [arm64 + CXL via QEMU]
Acked-by: Dan Williams <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Andreas Larsson <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiaxun Yang <[email protected]>
Cc: John Paul Adrian Glaubitz <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Rob Herring (Arm) <[email protected]>
Cc: Samuel Holland <[email protected]>
Cc: Thomas Bogendoerfer <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

3 files changed, 25 insertions, 13 deletions

diff --git a/arch/x86/include/asm/numa.h b/arch/x86/include/asm/numa.h
index 2dab1ada96cf..7017d540894a 100644
--- a/arch/x86/include/asm/numa.h
+++ b/arch/x86/include/asm/numa.h
@@ -72,6 +72,8 @@ void debug_cpumask_set_cpu(int cpu, int node, bool enable);
 
 #ifdef CONFIG_NUMA_EMU
 int numa_emu_cmdline(char *str);
+void __init numa_emu_update_cpu_to_node(int *emu_nid_to_phys,
+					unsigned int nr_emu_nids);
 #else /* CONFIG_NUMA_EMU */
 static inline int numa_emu_cmdline(char *str)
 {
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 30b0ec801b02..ea3fc2d866e2 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -852,6 +852,28 @@ EXPORT_SYMBOL(cpumask_of_node);
 
 #endif	/* !CONFIG_DEBUG_PER_CPU_MAPS */
 
+#ifdef CONFIG_NUMA_EMU
+void __init numa_emu_update_cpu_to_node(int *emu_nid_to_phys,
+					unsigned int nr_emu_nids)
+{
+	int i, j;
+
+	/*
+	 * Transform __apicid_to_node table to use emulated nids by
+	 * reverse-mapping phys_nid.  The maps should always exist but fall
+	 * back to zero just in case.
+	 */
+	for (i = 0; i < ARRAY_SIZE(__apicid_to_node); i++) {
+		if (__apicid_to_node[i] == NUMA_NO_NODE)
+			continue;
+		for (j = 0; j < nr_emu_nids; j++)
+			if (__apicid_to_node[i] == emu_nid_to_phys[j])
+				break;
+		__apicid_to_node[i] = j < nr_emu_nids ? j : 0;
+	}
+}
+#endif /* CONFIG_NUMA_EMU */
+
 #ifdef CONFIG_NUMA_KEEP_MEMINFO
 static int meminfo_to_nid(struct numa_meminfo *mi, u64 start)
 {
diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c
index 439804e21962..f2746e52ab93 100644
--- a/arch/x86/mm/numa_emulation.c
+++ b/arch/x86/mm/numa_emulation.c
@@ -476,19 +476,7 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt)
 		    ei.blk[i].nid != NUMA_NO_NODE)
 			node_set(ei.blk[i].nid, numa_nodes_parsed);
 
-	/*
-	 * Transform __apicid_to_node table to use emulated nids by
-	 * reverse-mapping phys_nid.  The maps should always exist but fall
-	 * back to zero just in case.
-	 */
-	for (i = 0; i < ARRAY_SIZE(__apicid_to_node); i++) {
-		if (__apicid_to_node[i] == NUMA_NO_NODE)
-			continue;
-		for (j = 0; j < ARRAY_SIZE(emu_nid_to_phys); j++)
-			if (__apicid_to_node[i] == emu_nid_to_phys[j])
-				break;
-		__apicid_to_node[i] = j < ARRAY_SIZE(emu_nid_to_phys) ? j : 0;
-	}
+	numa_emu_update_cpu_to_node(emu_nid_to_phys, ARRAY_SIZE(emu_nid_to_phys));
 
 	/* make sure all emulated nodes are mapped to a physical node */
 	for (i = 0; i < ARRAY_SIZE(emu_nid_to_phys); i++)