numa: Move numa implementation to common code

ARM64 numa implementation is generic enough that RISC-V can reuse that
implementation with very minor cosmetic changes. This will help both
ARM64 and RISC-V in terms of maintanace and feature improvement

Move the numa implementation code to common directory so that both ISAs
can reuse this. This doesn't introduce any function changes for ARM64.

Signed-off-by: Atish Patra <[e-mail]>
Acked-by: Jonathan Cameron <[e-mail]>
Tested-by: Jonathan Cameron <[e-mail]>
Acked-by: Catalin Marinas <[e-mail]>
Signed-off-by: Palmer Dabbelt <[e-mail]>

arch/arm64/Kconfig

···
 # Common NUMA Features
 config NUMA
 	bool "NUMA Memory Allocation and Scheduler Support"
+	select GENERIC_ARCH_NUMA
 	select ACPI_NUMA if ACPI
 	select OF_NUMA
 	help

arch/arm64/include/asm/numa.h

···
 #define __ASM_NUMA_H
 
 #include <asm/topology.h>
-
-#ifdef CONFIG_NUMA
-
-#define NR_NODE_MEMBLKS		(MAX_NUMNODES * 2)
-
-int __node_distance(int from, int to);
-#define node_distance(a, b) __node_distance(a, b)
-
-extern nodemask_t numa_nodes_parsed __initdata;
-
-extern bool numa_off;
-
-/* Mappings between node number and cpus on that node. */
-extern cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
-void numa_clear_node(unsigned int cpu);
-
-#ifdef CONFIG_DEBUG_PER_CPU_MAPS
-const struct cpumask *cpumask_of_node(int node);
-#else
-/* Returns a pointer to the cpumask of CPUs on Node 'node'. */
-static inline const struct cpumask *cpumask_of_node(int node)
-{
-	if (node == NUMA_NO_NODE)
-		return cpu_all_mask;
-
-	return node_to_cpumask_map[node];
-}
-#endif
-
-void __init arch_numa_init(void);
-int __init numa_add_memblk(int nodeid, u64 start, u64 end);
-void __init numa_set_distance(int from, int to, int distance);
-void __init numa_free_distance(void);
-void __init early_map_cpu_to_node(unsigned int cpu, int nid);
-void numa_store_cpu_info(unsigned int cpu);
-void numa_add_cpu(unsigned int cpu);
-void numa_remove_cpu(unsigned int cpu);
-
-#else	/* CONFIG_NUMA */
-
-static inline void numa_store_cpu_info(unsigned int cpu) { }
-static inline void numa_add_cpu(unsigned int cpu) { }
-static inline void numa_remove_cpu(unsigned int cpu) { }
-static inline void arch_numa_init(void) { }
-static inline void early_map_cpu_to_node(unsigned int cpu, int nid) { }
-
-#endif	/* CONFIG_NUMA */
+#include <asm-generic/numa.h>
 
 #endif	/* __ASM_NUMA_H */

arch/arm64/mm/Makefile

···
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
 obj-$(CONFIG_PTDUMP_CORE)	+= ptdump.o
 obj-$(CONFIG_PTDUMP_DEBUGFS)	+= ptdump_debugfs.o
-obj-$(CONFIG_NUMA)		+= numa.o
 obj-$(CONFIG_DEBUG_VIRTUAL)	+= physaddr.o
 obj-$(CONFIG_ARM64_MTE)		+= mteswap.o
 KASAN_SANITIZE_physaddr.o	+= n

drivers/base/Kconfig

···
 	  appropriate scaling, sysfs interface for reading capacity values at
 	  runtime.
 
+config GENERIC_ARCH_NUMA
+	bool
+	help
+	  Enable support for generic NUMA implementation. Currently, RISC-V
+	  and ARM64 use it.
+
 endmenu

drivers/base/Makefile

···
 obj-$(CONFIG_DEV_COREDUMP) += devcoredump.o
 obj-$(CONFIG_GENERIC_MSI_IRQ_DOMAIN) += platform-msi.o
 obj-$(CONFIG_GENERIC_ARCH_TOPOLOGY) += arch_topology.o
+obj-$(CONFIG_GENERIC_ARCH_NUMA) += arch_numa.o
 
 obj-y			+= test/
 

include/asm-generic/numa.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_GENERIC_NUMA_H
+#define __ASM_GENERIC_NUMA_H
+
+#ifdef CONFIG_NUMA
+
+#define NR_NODE_MEMBLKS		(MAX_NUMNODES * 2)
+
+int __node_distance(int from, int to);
+#define node_distance(a, b) __node_distance(a, b)
+
+extern nodemask_t numa_nodes_parsed __initdata;
+
+extern bool numa_off;
+
+/* Mappings between node number and cpus on that node. */
+extern cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
+void numa_clear_node(unsigned int cpu);
+
+#ifdef CONFIG_DEBUG_PER_CPU_MAPS
+const struct cpumask *cpumask_of_node(int node);
+#else
+/* Returns a pointer to the cpumask of CPUs on Node 'node'. */
+static inline const struct cpumask *cpumask_of_node(int node)
+{
+	if (node == NUMA_NO_NODE)
+		return cpu_all_mask;
+
+	return node_to_cpumask_map[node];
+}
+#endif
+
+void __init arch_numa_init(void);
+int __init numa_add_memblk(int nodeid, u64 start, u64 end);
+void __init numa_set_distance(int from, int to, int distance);
+void __init numa_free_distance(void);
+void __init early_map_cpu_to_node(unsigned int cpu, int nid);
+void numa_store_cpu_info(unsigned int cpu);
+void numa_add_cpu(unsigned int cpu);
+void numa_remove_cpu(unsigned int cpu);
+
+#else	/* CONFIG_NUMA */
+
+static inline void numa_store_cpu_info(unsigned int cpu) { }
+static inline void numa_add_cpu(unsigned int cpu) { }
+static inline void numa_remove_cpu(unsigned int cpu) { }
+static inline void arch_numa_init(void) { }
+static inline void early_map_cpu_to_node(unsigned int cpu, int nid) { }
+
+#endif	/* CONFIG_NUMA */
+
+#endif	/* __ASM_GENERIC_NUMA_H */